Study Documents Obesity and its Association With Heart Risk

May 09, 2008

May 9, 2008 (Newswise) — Obesity rates appear high in most but not all ethnic groups in the United States, and extra weight is associated with cardiovascular risk factors and markers of sub-clinical heart disease, according to a report in the May 12 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

The United States, along with many other countries, is experiencing an epidemic of obesity, according to background information in the article. Between 1960 and 2000, rates of obesity increased from 11 percent to 28 percent in men and 16 percent to 34 percent in women. “The obesity epidemic has the potential to reduce further gains in the U.S. life expectancy, largely through an effect on cardiovascular disease mortality [death],” the authors write.

Gregory L. Burke, M.D., M.S., of Wake Forest University School of Medicine, Winston-Salem, N.C., and colleagues assessed data from the Multi-Ethnic Study of Atherosclerosis (MESA), which involved 6,814 individuals age 45 to 84 who did not have cardiovascular disease when the study began (2000 to 2002). Participants completed a standard questionnaire with information about demographics and health risk factors and also underwent testing for a variety of cardiovascular disease markers.

“A large proportion of white, African American and Hispanic participants were overweight (60 percent to 85 percent) and obese (30 percent to 50 percent), while fewer Chinese American participants were overweight (33 percent) or obese (5 percent),” the authors write. “A higher body mass index (BMI) was associated with more adverse levels of blood pressure, lipoproteins [cholesterol] and fasting glucose despite a higher prevalence of pharmacologic treatment.”

Obesity also was associated with the following risk factors for heart disease and stroke:
• A 17 percent greater risk of coronary artery calcium, which may be a marker of coronary artery disease
• A 45 percent greater risk of having artery walls thicker than the 80th percentile in the common carotid arteries, which is a marker for atherosclerosis
• A 2.7-fold greater risk of having a left ventricle (the lower chamber of the heart that pumps blood throughout the body) with a mass higher than the 80th percentile

“These data confirm the epidemic of obesity in most but not all racial and ethnic groups,” the authors conclude. “The observed low prevalence of obesity in Chinese American participants indicates that high rates of obesity should not be considered inevitable. These findings may be viewed as indicators of potential future increases in vascular disease burden and health care costs associated with the obesity epidemic.”
(Arch Intern Med. 2008;168[9]:928-935.

Posted by dlife at 09:20 AM | Comments (0)

How And Where Fat Is Stored Predicts Disease Risk Better Than Weight

April 16, 2008

April 16, 2008 (EurekAlert) - A new study in mice indicates that overeating, rather than the obesity it causes, is the trigger for developing metabolic syndrome, a collection of heath risk factors that increases an individual’s chances of developing insulin resistance, fatty liver, heart disease and type 2 diabetes.

How and where the body stores excess, unused calories appears to matter most when determining a person’s risk of developing metabolic syndrome, researchers at UT Southwestern Medical Center suggest.

“Most people today think that obesity itself causes metabolic syndrome,” said Dr. Roger Unger, professor of internal medicine at UT Southwestern and senior author of the study. “We’re ingrained to think obesity is the cause of all health problems, when in fact it is the spillover of fat into organs other than fat cells that damages these organs, such as the heart and the liver. Depositing fatty molecules in fat cells where they belong actually delays that harmful spillover.”

The study, available online, is to be published in a future issue of the Proceedings of the National Academy of Sciences. It is among the first to suggest that weight gain is an early symptom of pre-metabolic syndrome, rather than a direct cause.

“Obesity delays the onset of metabolic syndrome, but it doesn’t prevent it,” said Dr. Unger, who has investigated diabetes, obesity and insulin resistance for more than 50 years. “People who are obese or overweight are on the road to developing metabolic syndrome unless they stop overeating. Sooner or later, it will happen.”

Currently about 50 million Americans suffer from metabolic syndrome. The exact cause of metabolic syndrome is unknown, but obesity and lack of exercise have been considered to be the primary underlying contributors to its development. Several studies in Dallas have shown that overweight patients with metabolic syndrome have increased fat levels in their liver, heart and pancreas.

Individuals with congenital generalized lipodystrophy – a genetic condition in which people are born with no fat cells in which to store fat – develop metabolic syndrome at an earlier age than people who are obese. They also develop more severe cases of metabolic syndrome earlier than their obese counterparts.

The goal of this study was to determine whether an individual’s capacity to store fat in fat cells plays a role in whether they develop metabolic syndrome and type 2 diabetes and at what point that occurs.

For the study, the researchers compared mice genetically altered to prevent their fat cells from expanding when overfed to mice with no such protections against becoming obese. The normal mice got fat when overfed, but didn’t develop signs of metabolic syndrome until about 7 weeks into the experiment, at about 12 weeks of age.

The mice engineered to remain slim, however, enjoyed no such “pre-diabetic honeymoon period,” the study authors said. Some became seriously ill at 4 to 5 weeks of age and displayed evidence of severe heart problems and marked hyperglycemia by 10 weeks of age, a full 8 weeks before the normal mice displayed even minimal heart problems. The genetically altered mice also suffered devastating damage to heart cells and to the insulin-secreting cells in their pancreas.

“The genetically altered animals were perfectly normal as long as they were on a normal diet and not overfed. But as soon as we put them on a high-calorie diet, they got terribly sick very fast,” said Dr. May-yun Wang, assistant professor of internal medicine at and lead author of the study.

She said the mice engineered to stay slim got sick quicker because the extra calories were not stored in the fat cells, the one place in the body equipped to store fat. Instead, fat was stored in other tissues, mimicking what happens in people with congenital generalized lipodystrophy.

“Recognition of this should encourage physicians and obese patients to pursue more aggressive interventions before they develop metabolic syndrome, rather than after the onset of disease, as is customary,” Dr. Wang said.

The new results complement earlier findings by diabetes researchers at UT Southwestern who investigated why mice genetically engineered to be obese are at no more risk of developing metabolic syndrome than normal mice. The results of that study, which was led by Dr. Philipp Scherer, professor of internal medicine and director of the Touchstone Center for Diabetes Research, also suggested that it’s not the amount of body fat, but where it is stored in the body that appears to matter most to health.

Dr. Unger said the most recent findings, like Dr. Scherer’s, in no way condone obesity.

“It’s best to eat only what you need to replace the energy you burn,” he said. “But, if you eat more than you need, as most Americans do, it’s better to put the surplus calories in fat cells than in the rest of the body because fat cells are designed specifically for fat storage. You won’t be as trim, but you’ll be healthier,” Dr. Unger said.

The study results also imply that any gene that impairs the ability to store fat in the fat cells likely predisposes an individual to metabolic syndrome and type 2 diabetes, Dr. Unger said.

Posted by dlife at 11:37 AM | Comments (1)

Overweight Patients with Diabetes Appear More Likely to Achieve Remission with Weight-Loss Surgery

January 23, 2008

January 23, 2008 (EurekAlert) - Preliminary research indicates that obese patients with type 2 diabetes who had gastric banding surgery lost more weight and had a higher likelihood of diabetes remission compared to patients who used conventional methods for weight loss and diabetes control, according to a study in the January 23 issue of JAMA.

“Obesity and type 2 diabetes are likely to be the 2 greatest public health problems of the coming decades. The conditions are strongly linked, with the increased prevalence of diabetes correlating with the increased prevalence of obesity,” the authors write. Weight control is perhaps the most important aspect of type 2 diabetes management. Recent evidence indicates that improvement in blood glucose control is related to the degree of weight loss.

Currently available lifestyle and pharmacological strategies provide only small to modest levels of weight loss, a problem compounded by patients with diabetes experiencing greater difficulty in losing weight than those without diabetes. Significant sustained weight loss as a result of bariatric surgery has never been formally studied as a treatment for type 2 diabetes in obese participants, according to background information in the article.

John B. Dixon, M.B.B.S., Ph.D., of Monash University, Melbourne, Australia, and colleagues conducted a 2-year trial involving 60 obese participants (body mass index [BMI] greater than 30, less than 40) to compare surgically induced weight loss with conventional therapy for the management of type 2 diabetes. Patients were randomized to receive either conventional diabetes therapy with a focus on weight loss by lifestyle change or laparoscopic adjustable gastric banding with conventional diabetes care. Of the 60 patients enrolled, 55 (92 percent) completed the 2-year follow-up.

The researchers found that remission of type 2 diabetes was achieved by 26 study participants (43 percent) at two years, with 22/30 (73 percent) from the surgical program and 4/30 (13 percent) from the conventional-therapy program. This represented 76 percent and 15 percent remission rates for those in the surgery and conventional-therapy groups, respectively. Greater percentage of weight loss at two years and lower baseline HbA1c values (hemoglobin used primarily to identify the average plasma glucose concentration) were independently associated with remission, but percentage of weight loss alone explained most of the variance.

“After 2 years, the surgical group displayed a 5 times higher remission rate and 4 times greater reduction in HbA1C values than the conventional-therapy group,” the authors write.

The surgical group achieved an average 20.7 percent body weight loss at two years, compared with 1.7 percent among the conventional-therapy group, representing a loss of 62.5 percent of excess weight (using BMI of 25 as ideal weight) in the surgical group compared with 4.3 percent in the conventional-therapy group. There were no serious complications in either group.

“An important finding of this study is that degree of weight loss, not the method, appears to be the major driver of glycemic improvement and diabetes remission in obese participants. This has important implications, as it suggests that intensive weight-loss therapy may be a more effective first step in the management of diabetes than simple lifestyle change. This study shows that few participants achieved remission with a body weight loss of less than 10 percent, a level expected to produce important health benefits,” the researchers add.

“While caution is required in interpreting the longer-term benefits of surgery and weight loss, this study presents strong evidence to support the early consideration of surgically induced loss of weight in the treatment of obese patients with type 2 diabetes,” they conclude.

Posted by dlifenews at 10:15 AM | Comments (1)

Researchers Report Breakthrough in Lowering Cholesterol, Fatty Acids

January 14, 2008

January 14, 2008 (Newswise) — Researchers at the University of Alberta, in Edmonton, Canada, have found a way to reduce the amount of bad cholesterol and fatty acids that end up in the blood from food the body metabolizes, a key discovery that could lead to new drugs to treat and reverse the effects of Type 2 diabetes and heart disease related to obesity.

In a series of recently published articles,* Dr. Richard Lehner and his colleagues report they successfully decreased the level of LDL (low-density lipids) – the so-called bad cholesterol – and triglycerides in the blood of mice and hamsters by manipulating a particular enzyme.

It’s well-known that eating too much fat and sugar and too little exercise will make you fat, and that obesity often leads to diabetes and heart disease. Lehner’s group studied the mechanisms behind this.

“We established the proof of principle of how these metabolic pathways work,” he says. “We discovered the activity of an enzyme that releases fatty acids from fat cells and the liver into the blood and how to inhibit this from happening.”

Drugs called statins are used to lower LDL levels in patients, but do not treat obesity. What makes the U of A researchers’ findings noteworthy is their discovery of how to inhibit LDL and triglycerides, which are another form of fat in the blood and a leading risk in obesity-related Type 2 diabetes as well as heart disease.

Lehner is director of the Group on Molecular and Cell Biology of Lipids in the U of A’s Faculty of Medicine and Dentistry. The research is being supported by the Canadian Institutes of Health Research and the Heart and Stroke Foundation.

Lehner is also a senior scholar for the Alberta Heritage Foundation for Medical Research.

“There is a substantial pharmacological interest in the enzymes that control TG (triglycerides – fatty acids) and cholesterol metabolism in tissues,” he says.

This unique discovery is an important scientific breakthrough, but one that requires further testing, he notes.

He also notes that a pill would not be “a magic bullet.” People still need to make the right lifestyle choices by exercising and eating properly, he says.

*Journal of Lipid Research (December 2007); Journal of Biological Chemistry (November 2007, March 2007)

Posted by dlifenews at 10:18 AM | Comments (0)

Hormone Blocker Found to Help Prevent Obesity & Diabetes

January 03, 2008

January 3, 2008 (Newswise) — A new study finds that a chemical found in the body is capable of promoting weight loss, improving insulin resistance and reversing diabetes in an animal model. The hormone is gastric inhibitory polypeptide (GIP) receptor blockade.

Background

GIP is a peptide hormone that is secreted in response to food. It inhibits the secretion of acids stimulates the releases insulin as part of the digestive process in response to food. It is found in a variety of tissues, including the intestine, heart, stomach, brain and in adipose (fat).

While the significance of its action is largely unknown, its potent and prolonged stimulation after a high-fat diet has led researchers to speculate it may play a key role in metabolizing fat. Research has shown that high fat feeding results in elevated circulating GIP concentrations, traits often found in patients who are obese with diabetes. GIP also effects the growth of fat cells. Other studies have shown that mice injected with the GIP receptor antagonist – (Pro3)GIP – can reverse or prevent many of the metabolic abnormalities associated with obesity.

The Study

A new study examined whether prolonged GIP receptor antagonism using daily injections of (Pro3) GIP was able to reverse well established diet-induced obesity and related metabolic abnormalities.

The new study is entitled, “GIP Receptor Antagonism Reverses Obesity, Insulin Resistance, and Associated Metabolic Disturbances Induced in Mice by Prolonged Consumption of High-Fat Diet.” It was conducted by Paula L. McClean, Nigel Irwin, Roslyn S. Cassidy, Victor A. Gault and Peter R. Flatt, all of the School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, UK; and Jens J. Holst, Department of Medical Physiology, The Panum Institute, University of Copenhagen, Copenhagen, Denmark. It is entitled The findings appear in the American Journal of Physiology – Endocrinology and Metabolism (doi:10.1152/ajpendo.00460.2007), a publication of the American Physiological Society (APS; http://www.the-aps.org/).

Methodology

The researchers used a model for diet-induced obesity that has been used extensively alongside genetic models and has close parallels with obesity, increasingly found in humans who consume a high-fat, energy-rich diet. In this model, young (8-week old) male, age matched mice were age-divided into groups and housed individually in an air-conditioned room at 22±2°C with a 12 hour light: 12 hour dark cycle. Experimental animals had free access to drinking water and a high fat diet (45 percent fat, 20 percent protein and 35 percent carbohydrate; percent of total energy of 26.15kj/g). Age-matched control mice from the same colony had free access to a standard rodent maintenance diet (10 percent fat; 30 percent protein; 60 percent carbohydrate; percent of total energy of 12.99kj/g.). The two were used for comparison purposes.

Prior to the study, mice were maintained on a high fat diet for 160 days. In addition, a separate set of mice were maintained on a high fat diet for 112 days prior to measuring circulating GIP and GLP-1 levels. On both occasions, obesity and diabetes were clearly evident.

The mice which had previously been fed a high fat diet for 160 days received only daily injections of either saline or (Pro3)GIP over a 50-day period. Food intake and body weight were recorded daily while plasma glucose and insulin concentrations were monitored at 5-7 day intervals.

Blood was taken on day 50 to measure cholesterol, triglycerides, glucagon (the hormone involved in metabolizing carbohydrate), corticosterone (involved with carbohydrates in the liver) and circulating adipokines (which play a key role in obesity-related diseases). Glucose tolerance and insulin sensitivity tests were performed at the end of the study period. The metabolic response of both groups of mice was also analyzed.

Key Findings

Highlights of the research findings include the following:

* Compared with the standard rodent diet (control), the mice that were fed the high-fat diet for the previous 160 days exhibited increased body weight, energy intake, and circulating glucose concentrations. The levels remained elevated throughout the study. The cholesterol and triglycerides levels increased at day 50.

* consumption of the high fat diet resulted in progressive weight gain and elevations of plasma glucose and gyrated hemoglobin, leading to impaired insulin sensitivity and glucose intolerance by 10 days. Fat (adipose) tissue deposits were increased as were circulating cholesterol and triglyceride concentration levels.

* (Pro3)GIP was able to counter many of the detrimental effects of high fat diet on body weight and indices of glucose and lipid metabolism.

Conclusion

This study showed that blocking GIP activity using (Pro3)GIP in mice with established, high fat diet-induced obesity and diabetes results in significant weight loss, improvement of insulin resistance and amelioration of diabetes. These findings represent an interesting new approach to the treatment of obesity and metabolic disturbances.

According to the research team’s Nigel Irwin, Ph.D., “Interestingly, possible parallels exist with the benefits of Roux-en-Y surgery (gastric bypass surgery) in treating gross obesity and associated diabetes in people. In this procedure, nutrients surgically bypass the area of the small intestine, resulting in a deficiency of circulating GIP. We are looking to better understand how and why.”

Posted by dlifenews at 01:54 PM | Comments (0)

Abdominal Fat Distribution Predicts Heart Disease

December 10, 2007

American Heart Association rapid access journal report

December 10, 2007 (EurekAlert) - Abdominal obesity is a strong independent risk factor for heart disease, and using the waist-hip ratio rather than waist measurement alone is a better predictor of heart disease risk among men and women, researchers reported in a study published in Circulation: Journal of the American Heart Association.

In the study, researchers also looked at whether the association between fat distribution and heart disease risk was independent of body mass index (BMI), which assesses body weight relative to height, as well as other heart disease risk factors, such as high blood pressure and high cholesterol.

“The size of the hips seems to predict a protective effect,” said Dexter Canoy, M.Phil., M.D., Ph.D., lead author of the study and a research fellow in epidemiology and public health at the University of Manchester in the United Kingdom. “In other words, a big waist with comparably big hips does not appear to be as worrisome as a big waist with small hips.”

The research was based on 24,508 men and women ages 45 to 79 in the United Kingdom who participated in the European Prospective Investigation into Cancer cohort study (EPIC-Norfolk) which is based at the University of Cambridge in the UK. Researchers measured participants’ weight, height, waist circumference, hip circumference and other heart disease risk factors from 1993 to 1997. They then followed up with participants for an average 9.1 years.

During the follow-up, 1,708 men and 892 women developed coronary heart disease. When they divided the men and women into five groups, according to waist-hip ratio, researchers found that those with the highest waist-to-hip ratio had the highest heart disease risk. Among the findings:

• Men in the top one-fifth of the distribution (those with the biggest waists in relation to their hips) had a 55 percent higher risk of developing coronary heart disease compared to men in the bottom one-fifth of the distribution (those with the smallest waists in relation to their hips).
• Women in the top one-fifth, or the highest waist-to-hip ratio group, were 91 percent more likely to develop heart disease than women with the smallest waists in relation to their hips.
• Waist-only measurements underestimated heart disease risk by 10 percent to 18 percent when compared to risk estimates for waist measurements when hip is considered (waist-to-hip ratio).
• When waist-only, body mass index and coronary heart disease risk factors are considered, for every 6.4 centimeter (cm) increase in hip circumference in men and for every 9.2 cm hip circumference increase in women, there is a 20 percent lower risk for developing heart disease.

The study’s results are definitive for predicting risk in relatively healthy men and women in the general population, Canoy said. More research is needed on whether abdominal fat distribution is an independent risk factor for heart disease among people who have chronic and other diseases at baseline.

“People whose abdominal fat puts them at higher risk for heart disease do not always appear overweight or obese,” Canoy said. “However, the overriding message from this and other studies about heart disease risk is that, despite the different measures and risk estimates, the bottom line is that many of us need to lose excess weight. Doctors should start looking beyond weight, height, simple waist circumference and BMI to assess heart disease. A simple waist-hip ratio measurement is a strong predictor of heart disease.”

Posted by dlifenews at 12:17 PM | Comments (0)

Doubled Calorie Intake From Beverages Likely Contributes to Adult Obesity

November 19, 2007

November 19, 2007 (EurekAlert) - It’s not just sugary sodas that are adding to the obesity crisis – it’s fruit drinks, alcohol and a combination of other high-calorie beverages, say University of North Carolina at Chapel Hill School of Public Health researchers. And during the holidays, when eggnog, cocktails and spiced cider are abundant, the problem can be even more apparent.

Over the past 37 years, the number of calories adults get through beverages has nearly doubled, according to a UNC study published in the November issue of Obesity Research by Kiyah J. Duffey, a doctoral candidate in the department of nutrition, and Barry M. Popkin, Ph.D., professor of nutrition and a fellow at the Carolina Population Center.

The study used nationally representative data to quantify both trends and patterns in beverage consumption among 46,576 American adults aged 19 and older. Patterns and trends of all beverages adults consumed were examined between 1965 and 2002. Researchers found that, over these 37 years, total daily intake of calories from beverages increased by 94 percent, providing an average 21 percent of daily energy intake among U.S. adults. That amounts to an additional 222 calories from all beverages daily.

Water intake was measured from 1989 to 2002, and during that time, the amount of water consumed stayed roughly the same, but the average adult consumed an additional 21 ounces per day of other beverages, Popkin said.

“This has considerable implications for numerous health outcomes, including obesity and diabetes as this is just adding several hundred calories daily to our overall caloric intake,” Popkin said.
Most researchers agree that beverages do not fill you up, Popkin said. “Regardless of beverage type – water, sodas, milk, orange juice or beer – those extra calories are not compensated for by a reduction in food intake.”

Data analyzed for this study came from the federally funded Nationwide Food Consumption Surveys of 1965 and 1977-1978 and the National Health and Nutrition Examination Surveys of 1989-1994 and 1999-2002.

“For each exam year, we calculated total energy intake, percent consuming and calories per consumer for 16 different beverages, and determined total beverage intake (fluid ounces) for each beverage,” Duffey said. “Then, using a method that finds patterns within data, we generated 5 different groups of individuals who had similar patterns of beverage consumption and compared the beverages that comprised these groups in 1977 and 2002 to determine if the combinations of beverages were different.”

As it turns out, they were different.

“The biggest difference we observed was that the 2002 beverage patterns were more complex than they were in 1977,” she said. “For example, just five beverages dominated the patterns in 1977, but in 2002 there were eight beverages consumed in significant quantities – and new beverages appeared in these 2002 patterns. Fruit and vegetable juices and diet beverages were not important in 1977 patterns, but were in 2002.”

Equally important, Popkin noted, are the overall trends in total calories from beverages. In 1965, beverages accounted for just 12 percent of daily energy intake. That number jumped to 21 percent by 2002.

As noted in previous studies, 23 percent more adults reported drinking soda between 1965 and 2002 (accounting for an additional 108 calories per day) while calories from whole-fat milk declined nearly 45 percent (from 119 calories per day in 1965 to 69 calories per day in 2002). Alcohol (up 73 calories per day) and fruit juice (up 20 calories per day) had considerable increases in their contribution to daily energy intake as well.

“One of the strengths of this study,” Popkin said, “is that we examined the full range of beverages consumed, providing a broad understanding of the role of beverages, and patterns of beverages, to overall dietary intake.”

Because data are not collected on the same individuals over time, conclusions cannot be made about the influence of the observed trends or patterns on changes in individual health outcomes over time, but they can provide a starting point for future analyses to examine this issue.

Posted by dlifenews at 12:12 PM | Comments (0)

Obese Children Show Early Signs of Heart Disease

October 30, 2007

October 30, 2007 (EurekAlert) - Children who are obese or who are at risk for obesity show early signs of heart disease similar to obese adults with heart disease, a study by researchers at Washington University School of Medicine in St. Louis has found.

“Based on this study, these subtle markers can help us predict who could be at risk for heart disease and heart attacks,” said Angela Sharkey, M.D., associate professor of pediatrics at Washington University School of Medicine and a pediatric cardiologist at St. Louis Children’s Hospital.

The study was published in the Winter 2007 issue of the Journal of Cardiometabolic Syndrome.

Childhood obesity in the United States is an epidemic -- nationwide, 19 percent of children ages 6 to 11 and 17 percent of those 12 to 19 are overweight, according to the Centers for Disease Control and Prevention (CDC). Those who are overweight during childhood also have an increased risk of obesity in adulthood and are at greater risk for complications such as diabetes, high blood pressure and heart disease, because obesity increases total blood volume, which leads to extra stress on the heart.

Sharkey and Steven M. Lorch, M.D., a former fellow at the School of Medicine now at University of Texas Health Science Center at Houston, analyzed data from 168 children ages 10 to 18 who had been referred to them for cardiac ultrasound with symptoms including heart murmur, chest pain, acid reflux or high blood cholesterol. Based on CDC guidelines for body mass index for age (BMIA), 33 patients were found to have a BMIA as obese, or the 95th percentile or above for their age; 20 had a BMIA that classified them as at risk for obesity, or between the 85th and 94th percentile; and 115 were considered normal, or below the 85th percentile.

To analyze the hearts of the obese children and those at risk, Sharkey and Lorch used a new tissue Doppler imaging technique called vector velocity imaging which tracks the movement of the heart’s muscular wall. Any changes in the rate of motion of heart muscle were averaged within each group and compared to the normal rate of motion.

“In the patients who are obese, the rate of motion of heart muscle changed,” Sharkey said. “As a child’s BMIA increases, we see alterations in both the relaxation and contraction phase of the heartbeat. Many of these changes that have been seen in adults were assumed to be from long-standing obesity, but it may be that these changes start much earlier in life than we thought.”

As vector velocity imaging becomes more broadly available, Sharkey said, it could potentially help pediatric cardiologists follow these children more closely over time to see if changes in the heart progress.

“We may be able to determine whether we could intervene in the process, such as focusing the families on understanding the importance of regular exercise and dietary modifications for weight loss and prescribing statin drugs for high-blood cholesterol,” she said.

Sharkey said the results of the study give more ammunition to physicians to use in counseling pediatric patients and their parents about the risks of obesity and the need to attain a healthy weight.
“Even in teenagers, obesity leads to decreased myocardial performance and abnormal diastolic function,” she said.

Further study is needed to determine how soon the changes in the heart set in after a child becomes obese and whether those changes are reversible with weight loss.

Posted by dlifenews at 10:20 AM | Comments (0)

Exercise Improves Thinking, Reduces Diabetes Risk in Overweight Children

October 23, 2007

October 23, 2007 (EurekAlert) - Just three months of daily, vigorous physical activity in overweight children improves their thinking and reduces their diabetes risk, researchers say.

Studies of about 200 overweight, inactive children ages 7-11 also showed that a regular exercise program reduces body fat and improves bone density.

“Is exercise a magic wand that turns them into lean, healthy kids? No. They are still overweight but less so, with less fat, a healthier metabolism and an improved ability to handle life,” says Dr. Catherine Davis, clinical health psychologist at the Medical College of Georgia and lead investigator.

All study participants learned about healthy nutrition and the benefits of physical activity; one-third also exercised 20 minutes after school and another third exercised for 40 minutes. Children played hard, with running games, hula hoops and jump ropes, raising their heart rates to 79 percent of maximum, which is considered vigorous.

“Aerobic exercise training showed dose-response benefits on executive function (decision-making) and possibly math achievement, in overweight children,” researchers write in an abstract being presented during The Obesity Society’s Annual Scientific Meeting Oct. 20-24 in New Orleans. “Regular exercise may be a simple, important method of enhancing children’s cognitive and academic development. These results may persuade educators to implement vigorous physical activity curricula during a childhood obesity epidemic.”

Functional magnetic resonance imaging studies, which show the brain at work, were performed on a percentage of children in each group and found those who exercised had different patterns of brain activity during an executive function task.

“Look what good it does when they exercise,” says Dr. Davis. “This is an important public health issue we need to look at as a nation to help our children learn and keep them well.”

Unprecedented obesity and inactivity rates in America’s children are impacting health, including dramatic increases in the incidence of type 2 diabetes, a disease formerly known as adult-onset diabetes.

Overweight children also have slightly lower school achievement, on average.

“We hope these findings will help persuade policymakers, schools and communities that time spent being physically active enhances, rather than detracts, from learning,” says Dr. Davis.

“There have been several studies that have shown that exercise produces kind of a selective effect, particularly with older adults, in cognitive tasks that require regulation of behaviors,” says Dr. Phillip D. Tomporowski, experimental psychologist at the University of Georgia and a key collaborator.

For this study, researchers gave the children tests that look at their decision-making processes. In the first such studies in children, the researchers found small to moderate improvements in children who exercised as well as a hint of increased math achievement.

“We have a number of studies conducted with animals that examined what influence physical activity has on blood flow, metabolic activity, brain function, glucose regulation, and they all demonstrate the same theme: that physical activity done on a regular basis has a protective effect,” says Dr. Tomporowski. “It doesn’t take too much to make the leap that it might influence developing children as well.”

Looking at the children’s insulin resistance, a precursor of type 2 diabetes in which it takes more insulin to convert glucose into energy, researchers found levels dropped 15 percent in the 20-minute exercise group and 21 percent in the 40-minute group. The control group stayed about the same.

“Increasing volume of regular aerobic exercise shows increased benefits on insulin resistance in overweight children, indicating reduced risk of type 2 diabetes, regardless of sex or race,” they write.
“We also know that if you stop exercising, you lose all the benefits,” adds Dr. Davis. “Exercise works if you do it.”

Adult studies have yielded comparable findings regarding exercise’s impact on insulin resistance and cognition.

The researchers tested oral glucose tolerance, measuring insulin response after children drank a small amount of glucose, before and after the studies. “Once your glucose levels start to rise, it’s called impaired glucose tolerance and that is a precursor of diabetes. It’s called pre-diabetes now,” says Dr. Davis, noting that overweight children typically have higher insulin resistance than their leaner peers. Insulin resistance is an early sign of diabetes risk that appears before glucose levels start to rise. Growth associated with puberty can temporarily increase insulin resistance, Dr. Davis notes, so because some of the children were beginning puberty, they made adjustments for the level of sex hormones.

DEXA scanning, which uses a small amount of radiation to quantify bone, tissue and fat, was used to accurately assess body composition. Executive function was measured using the Cognitive Assessment System and math skills using the Woodcock Johnson Test of Achievement III.

“If physical education were ideal, which it’s not – it’s not daily and it’s not active – then children could achieve this within the school day,” Dr. Davis says, pointing to benefits derived by children exercising just 20 minutes a day. “We are not there. To achieve maximum benefit, we were able to show it will take more than PE.”

Posted by dlifenews at 03:54 PM | Comments (0)

'Skinny Gene' Exists

September 05, 2007

September 5, 2007 (Science Daily) — Researchers at UT Southwestern Medical Center have found that a single gene might control whether or not individuals tend to pile on fat, a discovery that may point to new ways to fight obesity and diabetes.

"From worms to mammals, this gene controls fat formation," said Dr. Jonathan Graff, associate professor of developmental biology and internal medicine at UT Southwestern and senior author of a study appearing in the Sept. 5 issue of Cell Metabolism. "It could explain why so many people struggle to lose weight and suggests an entirely new direction for developing medical treatments that address the current epidemic of diabetes and obesity.

"People who want to fit in their jeans might someday be able to overcome their genes."

The gene, called adipose, was discovered in fat fruit flies more than 50 years ago by a graduate student at Yale University, but few people knew about it. Its mechanism was unknown, and whether it's important in other genes was a mystery.

In the current study, the UT Southwestern researchers examined how adipose works by analyzing fruit flies, tiny worms called C. elegans, cultured cells, and genetically engineered mice, as well as by exploiting sophisticated molecular techniques. Using several methods, they manipulated adipose in the various animals, turning the gene on and off at different stages in the animals' lives and in various parts of their bodies.

It was discovered that the gene, which is also present in humans, is likely to be a high-level master switch that tells the body whether to accumulate or burn fat.

In the mice, the researchers found that increasing adipose activity improved the animals' health in many ways. Mice with experimentally increased adipose activity ate as much or more than normal mice; however, they were leaner, had diabetes-resistant fat cells, and were better able to control insulin and blood-sugar metabolism.

In contrast, animals with reduced adipose activity were fatter, less healthy and had diabetes.

The researchers' work on flies showed that the gene is "dose-sensitive" -- that is, the various combinations of the gene's variants lead to a range of body types from slim to medium to obese.

"This is good news for potential obesity treatments, because it's like a volume control instead of a light switch; it can be turned up or down, not just on or off," Dr. Graff said. "Eventually, of course, the idea is to develop drugs to target this system, but that's in the years to come."

This genetic mechanism makes survival sense, he said, because if a population has many versions of the gene scattered among many different individuals, at least some will survive in different conditions. For instance, a fat fruit fly may be able to survive famine, but a sleeker model might be better at evading predators.

Dr. Graff said the next step is to understand better the exact mechanisms by which adipose exerts its control.

Although the current study finally identifies the adipose gene's function, the gene was discovered more than 50 years ago when Winifred Doane, now a professor emeritus at Arizona State University, was studying fruit flies and noticed that some contained more fat than others. She linked this trait to a gene she named adipose and hypothesized that this natural variation gave the chubbier flies an evolutionary advantage; they could hoard more fat on the same amount of food as their skinnier counterparts, allowing them to survive times of famine.

But for people in developed countries, this trait has backfired. It's all feast and no famine, so the fat builds and builds.

"Even a pound a year adds up over a lifetime," Dr. Graff said.

Other UT Southwestern researchers involved in the study were Dr. Jae Myoung Suh, postdoctoral researcher in developmental biology; Daniel Zeve, Robert Li and Michael Wang, students in the Medical Scientist Training Program; Dr. Renee McKay, instructor of developmental biology; Dr. Jin Seo, postdoctoral researcher in developmental biology; and Zack Salo, undergraduate at UT Arlington.

The work was supported by the National Institutes of Health.

Note: This story has been adapted from a news release issued by UT Southwestern Medical Center.

Posted by dlifenews at 11:13 AM | Comments (0)

Treating Diabetes During Pregnancy can Break Link to Childhood Obesity

August 28, 2007

New study shows higher maternal sugar levels increases risk of childhood obesity

August 28, 2007 (EurekAlert) -- Treating diabetes during pregnancy can break the link between gestational diabetes and childhood obesity, according to a Kaiser Permanente study featured in the September issue of Diabetes Care.

The largest study of its kind, this research shows that the risk of childhood obesity rises in tandem with a pregnant woman’s blood sugar level and that untreated gestational diabetes nearly doubles a child's risk of becoming obese by age 5 to 7. The study also shows for the first time that by treating women with gestational diabetes, the child’s risk of becoming obese is significantly reduced. In fact, children whose moms were treated for gestational diabetes had the same risk for becoming obese as children whose mothers had normal blood sugar levels.

Researchers at Kaiser Permanente’s Center for Health Research (CHR) in Portland and Hawaii used the organization’s integrated databases to analyze medical records of 9,439 mother-child pairs. The subjects were members of the health plan in Oregon, Washington and Hawaii and gave birth between 1995 and 2000. The authors found that treating gestational diabetes lowers the child's risk of becoming obese during childhood to the same levels of those pregnant mothers with normal blood sugar levels.

Gestational diabetes, the condition in which pregnancy triggers insulin resistance and raises the woman’s blood glucose level (hyperglycemia), affects up to 8 percent of pregnant women each year in the United States. The rate of childhood obesity in this country more than doubled in the last two decades, so much so that it is now one the nation’s fastest growing health conditions. Nearly 7 million overweight and obese children in the United States today will grow up to become overweight or obese adults.

"Hyperglycemia during pregnancy is clearly playing a role in America's epidemic of childhood obesity," said Teresa Hillier, MD, MS, an endocrinologist and senior investigator at CHR Northwest and Hawaii, and the lead author of the study. "The key finding here is that the risk of overweight and obese children rises in step with higher levels of blood sugar during pregnancy. The good news for pregnant women is that by treating gestational diabetes, your children's risk of becoming overweight or obese drops considerably."

"My advice to pregnant women is three-fold: Discuss gestational diabetes screening with your doctor, usually between weeks 24 and 28 of pregnancy; if you have gestational diabetes, work with your physician to treat it, and stick with the treatment during your pregnancy. It's the best thing you can do to reduce your child's risk of obesity," said Dr. Hillier.

Funded by a grant from the American Diabetes Association, the study was made possible by Kaiser Permanente's interlinked, computerized databases. As the nation's largest and oldest integrated care delivery system, Kaiser Permanente researchers can anonymously review patient records dating back many years and look for connections with the patient's family members and other aspects of the members’ health.

The women in the study were screened during pregnancy for blood sugar level and gestational diabetes. The women's children were measured for weight between the ages of 5 and 7 – the so-called "adiposity rebound" period, a strong predictor of adult obesity. The relationship between maternal blood sugar and childhood obesity was then analyzed.

Children of mothers with high levels of blood sugar who were untreated were 89 percent more likely to be overweight and 82 percent more likely to be obese by the time they were 5 to 7 years of age, compared to children whose mothers had normal blood sugar levels during pregnancy.

“The obesity risk of children whose mothers had the highest blood sugar levels—and were treated for gestational diabetes—was not statistically different than children of mothers with normal blood sugar levels. This suggests that the 'metabolic imprinting' for childhood obesity that results from gestational diabetes in pregnant women may be reversible," Hillier said.

Posted by dlifenews at 11:50 AM | Comments (0)

New Report Finds U.S. Obesity Epidemic Continues to Grow; Mississippi Tops List for Adults, D.C. for Youths

August 27, 2007

August 27, 2007 (Healthy Americans) – Adult obesity rates rose in 31 states last year, according to the fourth annual F as in Fat: How Obesity Policies are Failing in America, 2007 report from the Trust for America’s Health (TFAH). Twenty-two states experienced an increase for the second year in a row; no states decreased. A new public opinion survey featured in the report finds 85 percent of Americans believe that obesity is an epidemic.

Mississippi topped the list with the highest rate of adult obesity in the country for the third year in a row, and is the first state to reach a rate of over 30 percent (at 30.6 percent). Colorado was the leanest state again this year, however, its adult obesity rate increased over the past year (from 16.9 to 17.6 percent). Ten of the 15 states with the highest rates of adult obesity are located in the South. Rates of adult obesity now exceed 25 percent in 19 states, an increase from 14 states last year and 9 in 2005. In 1991, none of the states exceeded 20 percent.

The report also finds that rates of overweight children (ages 10 to 17) ranged from a high of 22.8 percent in Washington, D.C. to a low of 8.5 percent in Utah. Eight of the ten states with the highest rates of overweight children were in the South.

“There has been a breakthrough in terms of drawing attention to the obesity epidemic. Now, we need a breakthrough in terms of policies and results,” said Jeff Levi, PhD, Executive Director of TFAH. “Poor nutrition and physical inactivity are robbing America of our health and productivity.”
The F as in Fat report contains rankings of state obesity rates and a review of federal and state government policies aimed at reducing or preventing obesity.

Other Key Findings from F as in Fat 2007

• Twenty-two percent of American adults report that they do not engage in any physical activity. Mississippi has the highest rate of inactivity at 31.6 percent and Minnesota had the lowest rate of inactivity at 15.4 percent.

• Seventeen states require their school lunches, breakfasts and snacks to meet higher nutritional standards than the U.S. Department of Agriculture (USDA) requires (6 states enacted new laws in 2006-07).

• Twenty-two states have set nutritional standards for foods sold in vending machines, à la carte, in school stores, or in bake sales in schools (9 states enacted new laws in 2006-07), and 26 states limit when and where these foods may be sold on school property beyond federal requirements (6 states enacted new laws in 2006-07).

• While every state has school physical education requirements, many are limited in scope or are not enforced.

• Sixteen states screen students’ body mass index (BMI) or fitness status and confidentially provide information to parents or guardians (8 states enacted new laws in 2006-07).

Public Opinion Survey on Obesity

The report also contains a national opinion survey conducted for TFAH by Greenberg Quinlan Rosner Research, Inc. from July 12-16, 2007 (with a +/-3.1 percent margin of error). Key findings about government’s role, school lunches, physical education and body measurement include:

• Eighty-one percent of Americans believe that the government should have a role in
addressing the obesity crisis. Majorities strongly support government working on proposals to expand education programs about healthy living, provide low-cost access to exercise programs, and reduce the marketing of unhealthy foods.

• Fifty-five percent of parents with children under 18 believe lunches provided in schools are not nutritious enough. Sixty-six percent of Americans rated proposals to establish higher nutrition in school lunches as very useful.

• More than two-thirds of Americans believe children do not participate in adequate amounts of physical activity during the school day or engage in enough physical activity outside of school. More than 70 percent of Americans rated proposals to increase physical education in schools as very useful.

• Sixty percent of Americans favor a proposal to measure students’ BMI annually and confidentially provide this information to parents or guardians.

Recommendations for Combating Obesity

TFAH recommends a comprehensive approach for helping individuals make healthy choices including support from families, communities, schools, employers, the food and beverage industries, health professionals, and government at all levels. Some key recommendations include:

• Think big. The federal government should develop and implement a National Strategy to Combat Obesity. This plan should involve every federal government agency, define clear roles and responsibilities for states and localities, and engage private industry and community groups.

• Make healthy choices easy choices. Federal, state , and local governments should develop and implement policies that give Americans the tools they need to make it easier to engage in the recommended levels of physical activity and choose healthy foods, ranging from improving food served and increasing opportunities for physical activity in schools to requiring restaurants and food companies to provide better and more readily accessible information about the nutritional content of their products to securing more safe, affordable recreation places for all Americans.

• Improve your bottom line. Federal, state, and local governments should work with private employers and insurers to ensure that every working American has access to a workplace wellness program.

• Escalate research on how to promote healthy choices. Public health officials have identified a number of strategies to help encourage people to make healthier decisions about nutrition and activity, however, much more research needs to be done about how to effectively promote healthier habits.

The full report with complete state rankings in all categories is available on TFAH’s Web site at www.healthyamericans.org. The report was supported by a grant from the Robert Wood Johnson Foundation.

STATE-BY-STATE ADULT OBESITY RANKINGS

Note: 1 = Highest rate of adult obesity, 51 = lowest. Rankings are based on combining three years of data (2004-2006) from the U.S. Centers for Disease Control and Prevention’s Behavioral Risk Surveillance System to “stabilize” data for comparison purposes. States with statistically significant (p<0.05) increases for one year are noted with an asterisk (*), states with statistically significant increases for two years in a row are noted with two asterisks (**).

Additional information about methodologies and confidence intervals are available in the report.

Individuals with a body mass index (BMI) (a calculation based on weight and height ratios) of 30 or higher are considered obese.

1: Mississippi**; 2: West Virginia*; 3: Alabama; 4: Louisiana; 5 (tie): South Carolina**,
Tennessee*; 7: Kentucky**; 8: Arkansas; 9 (tie): Indiana, Michigan*, Oklahoma**; 12 (tie): Missouri**, Texas; 14: Georgia; 15: Ohio**; 16: Alaska; 17: North Carolina**; 18: Nebraska**; 19: North Dakota; 20 (tie): Iowa, South Dakota**; 22: Wisconsin**; 23 (tie): Pennsylvania, Virginia*; 25 (tie): Illinois, Maryland**; 27: Kansas*; 28: Minnesota; 29: Delaware**; 30: Oregon**; 31 (tie): Idaho, Washington**; 33: Maine*; 34: Florida**; 35: Wyoming**; 36: California; 37: Nevada*; 38 (tie): New Hampshire**, New York; 40 (tie): D.C., New Jersey**; 42: New Mexico**; 43: Arizona; 44: Utah; 45: Montana; 46: Rhode Island**; 47 (tie): Connecticut**, Hawaii*; 49: Vermont; 50: Massachusetts**; 51: Colorado*.

STATE-BY-STATE OVERWEIGHT CHILDREN AGES 10-17 RANKINGS

Note: 1 = Highest rate of childhood overweight, 51 = lowest. Rankings are based on the National Survey of Children’s Health, a phone survey of parents with children ages 10-17 conducted in 2003-04 by the U.S. Department of Health and Human Services. Additional information about methodologies and confidence intervals are available in the report. Children with a body mass index (BMI) (a calculation based on weight and height ratios) at or above the 95th percentile for their age are considered overweight.

1: D.C.; 2: West Virginia; 3: Kentucky; 4: Tennessee; 5: North Carolina; 6: Texas; 7: South Carolina; 8: Mississippi; 9: Louisiana; 10: New Mexico; 11: Alabama; 12 (tie): Arkansas, Georgia; 14: Illinois; 15 (tie) Indiana, Missouri; 17: Oklahoma; 18: New York; 19: Delaware; 20: Michigan; 21: Florida; 22: Ohio; 23: Oregon; 24: Kansas; 25: Virginia; 26: New Jersey; 27: Massachusetts; 28: Wisconsin; 29 (tie) Hawaii, Maryland, Pennsylvania; 32: California; 33: New Hampshire; 34: Maine; 35: Iowa; 36: Nevada; 37: Connecticut; 38: Arizona; 39 (tie): North Dakota, South Dakota; 41 (tie): Nebraska, Rhode Island; 43: Vermont; 44 (tie) Alaska, Montana; 46: Washington; 47 (tie): Idaho, Minnesota; 49: Colorado; 50: Wyoming; 51: Utah.

Trust for America’s Health is a non-profit, non-partisan organization dedicated to saving lives by protecting the health of every community and working to make disease prevention a national priority. www.healthyamericans.org

The Robert Wood Johnson Foundation, which supported this report, focuses on the pressing health and health care issues facing our country. As the nation’s largest philanthropy devoted exclusively to improving the health and health care of all Americans, the Foundation works with a diverse group of organizations and individuals to identify solutions and achieve comprehensive, meaningful and timely change. For more than 35 years the Foundation has brought experience, commitment, and a rigorous, balanced approach to the problems that affect the health and health care of those it serves. Helping Americans lead healthier lives and get the care they need—the Foundation expects to make a difference in our lifetime. For more information, visit www.rwjf.org.

Posted by dlifenews at 11:44 AM | Comments (0)

Despite Overeating, Morbidly Obese Mice Gain Protection Against Diabetes

August 23, 2007

August 23, 2007 (EurekAlert) – The “world’s fattest mice” can overeat without developing insulin resistance or diabetes thanks to a glut of a key hormone, a dichotomy that helps explain why not all obese people are diabetic, a UT Southwestern Medical Center researcher has found.

Consuming excess calories usually spurs insulin resistance and diabetes. But in a multicenter study appearing online today in the Journal of Clinical Investigation, scientists show how an abundance of adiponectin, a hormone that controls sensitivity to insulin, and a lack of leptin, a hormone that curbs appetite, enables mice to store excess calories in fat tissue instead of in liver, heart or muscle tissue – places where excess fat can lead to inflammation, diabetes and heart disease.

The mice get morbidly obese, but are insulin-sensitive with normal blood-glucose levels.

“The message isn’t that it’s good to be obese, but that expanded fat mass, when stored in the right places, can help prevent diabetes and reduce the risk of heart disease,” said Dr. Philipp Scherer, professor of internal medicine and the study’s senior author. “In fact, these are the first mice to directly show that fat-mass expansion has antidiabetic effects.” Dr. Scherer directs the Touchstone Center for Diabetes Research at UT Southwestern.

Fat tissue, which was largely perceived as a useless storage bin until the early 1990s, has been found to release hormones, including adiponectin, that play integral roles in metabolism and obesity. Adiponectin levels decline as a person accumulates more fat, making the levels a good predictor of future risk of developing diabetes, heart disease and cancer, said Dr. Scherer, who discovered the hormone in 1994.
But what would happen if, despite overeating, adiponection levels increased"

To find out, Dr. Scherer and other researchers in this study genetically engineered mice to produce an overabundance of adiponectin while lacking leptin. Without leptin’s signals to stop eating or burn energy, the mice continually consumed food and their weight ballooned.

The high levels of adiponectin, however, made the mice physiologically skinny, Dr. Scherer said.

“The continual firing of adiponectin generated a ‘starvation signal’ from fat that says it is ready to store more energy,” he said. “The mice became what may be the world’s fattest mice, but they have normal fasting glucose levels and glucose tolerance.

“This indicates that the inability to appropriately expand fat mass in times of overeating may be an underlying cause of insulin resistance, diabetes and cardiovascular disease.”

This discovery also suggests that in people who have low adiponectin levels fat cells don’t send the signal that they’re ready to accept fat, Dr. Scherer said. Instead, the fat is stored in dangerous places – liver, heart and muscle tissues – where it can cause inflammation and pave the way for disease.

“More than 66 percent of American adults are overweight or obese, so most people have excess caloric intake. We need to find ways to deposit these calories in the least harmful places, because the fat has to go somewhere,” he said. “For instance, people with excess weight around their abdomen run a higher risk of heart disease and diabetes than those who have excess weight in the thighs.”

Dr. Scherer’s next goal is to investigate how to manipulate individual areas of fat to find ways to maximize the “good” fat areas and shrink the “bad” areas. Researchers also could try to develop new disease treatments that don’t require shedding fat.

“Until then, exercise and reduction of food intake are the best ways to stay healthy,” Dr. Scherer said.

Posted by dlifenews at 01:35 PM | Comments (0)

Common Virus May Contribute to Obesity in Some People, New Study Shows

August 20, 2007

August 20, 2007 (EurekAlert) — Scientists today reported new evidence that infection with a common virus may be a contributing factor to the obesity epidemic sweeping through the United States and other countries. In laboratory experiments they showed that infection with human adenovirus-36 (Ad-36), long recognized as a cause of respiratory and eye infections in humans, transforms adult stem cells obtained from fat tissue into fat cells. Stem cells not exposed to the virus, in contrast, were unchanged.

In addition, the study reported identification of a specific gene in the virus that appears to be involved in this obesity-promoting effect. The findings, which could lead to a vaccine or antiviral medication to help fight viral obesity in the future, were presented at the 234th national meeting of the American Chemical Society.

“We’re not saying that a virus is the only cause of obesity, but this study provides stronger evidence that some obesity cases may involve viral infections,” says study presenter Magdalena Pasarica, M.D., Ph.D., of the Pennington Biomedical Research Center, a campus of the Louisiana State University system.

“Not all infected people will develop obesity,” she notes. “We would ultimately like to identify the underlying factors that predispose some obese people to develop this virus and eventually find a way to treat it.”

Pasarica was part of the original research group which demonstrated that the Ad-36 virus was capable of causing animals infected with the virus to accumulate fat. Led by Nikhil Dhurandhar, Ph.D., now an associate professor at Pennington Biomedical Research Center, the group also conducted a noted epidemiologic study — the first to associate a virus with human obesity — showing 30 percent of obese people were infected with the Ad-36 virus in comparison to 11 percent of lean individuals. But evidence that the virus could actually cause fat levels to increase in human cells was lacking until now, Pasarica says.

In the current study, Pasarica and her associates obtained adult stem cells from fatty tissue from a broad cross-section of patients who had undergone liposuction. Half of the stem cells were exposed to Ad-36 and the other half were not exposed to the virus.

After about a week of growth in tissue culture, most of the virus-infected adult stem cells developed into fat cells, whereas the non-infected stem cells did not, the researchers say.

Funded by the National Institutes of Health (NIH), Dr. Dhurandhar’s group recently identified a gene in the Ad-36 virus that appears to be involved in causing fat accumulation observed in infected animals. That gene, called E4Orfl, is now emerging as a promising target for future human therapies, such as vaccines and anti-viral medicines, aimed at preventing or inhibiting the obesity virus, she says.

The exact mechanism by which the virus might cause obesity in people is currently unknown, says Pasarica, who does not rule out the possibility that other human viruses may also contribute to obesity.

Researchers also do not know how long the virus remains in the body of obese individuals nor how long its fat-enhancing effect lasts once the virus is gone. However, Pasarica notes a recent study demonstrated that animals that developed the virus remained obese up to six months after their infection was gone. More studies are needed, especially in humans, she adds.

Pasarica and her associates are now in the process of trying to identify the factors that predispose some people with the virus to develop obesity while others do not, but results of this investigation are not yet available, they say.

About 97 million adults in the United States are overweight or obese, according to NIH, and face an increased risk of Type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, and other health disorders. Obesity has many established causes that include over-eating, eating high-fat foods, lack of exercise, a genetic predisposition and certain medications.

Posted by dlifenews at 03:30 PM | Comments (1)

Fat on Chest and Upper Back Increases Risk of Insulin Resistance

August 17, 2007

August 17, 2007 (EurekAlert) - Upper trunk fat –– deposits of fat on the chest and back –– is associated with an increased risk of insulin resistance, a condition that is a precursor of type 2 diabetes, according to a study led by researchers at the San Francisco VA Medical Center (SFVAMC).

It is the first time such an association has been demonstrated, say the researchers.

The association was equally strong in both HIV infected subjects and HIV negative control subjects in the Study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM), a national long-term longitudinal study of HIV infected people taking modern antiretroviral therapy and HIV negative controls.
The presence of visceral fat, which is located between and around the internal organs, was also associated with an increased risk of insulin resistance in both populations. The researchers found that each type of fat contributes independently to insulin resistance whether or not the other type is present.
The study appears in online Publish Ahead of Print section (http://www.jaids.com/pt/re/jaids/paptoc.htm) of the Journal of Acquired Immune Deficiency Syndromes.

“We knew about the insulin resistance risk associated with visceral fat, which has been shown in previous studies, but no one had ever looked at the contribution of upper trunk fat,” says lead author and FRAM principal investigator Carl Grunfeld, MD, PhD, chief of the metabolism and endocrine sections at SFVAMC. “Strikingly, there was very little difference between HIV infected people and controls. If you have fat up top, it’s bad for you.”

In insulin resistance, cells in the body become increasingly resistant to the action of insulin, a hormone that regulates blood glucose levels. The result is chronically high blood glucose, which has many adverse health effects.

The researchers measured visceral and subcutaneous fat deposits in the legs, arms, upper trunk, and lower trunk of 926 HIV infected subjects and 258 HIV negative controls. They divided each population into tertiles, or thirds, based on the amount of fat in each location. Among the HIV infected subjects in the highest tertile of upper trunk fat, 57 percent showed insulin resistance; of those, half lacked high visceral fat. Among the highest tertile of controls with upper trunk fat, 61 percent were insulin resistant. A third of that group did not have high visceral fat.

“So, basically, there are people who have a lot of fat in their upper trunk and not so much inside their belly, yet they are at risk for insulin resistance,” observes Grunfeld, who is also a professor of medicine at the University of California, San Francisco (UCSF). “And there are people with a lot of visceral fat but not upper trunk fat who are in the same boat. But if you’ve got both, it’s a double whammy. Your risk of insulin resistance is quite high.”

Grunfeld says that the researchers looked at all regions of the body where fat is usually deposited in order to investigate abnormalities in fat distribution that have been reported in HIV infection, particularly the presence of so-called “buffalo hump,” a prominent fat deposit in the middle of the upper back. “But we found that fat in that area was present, and associated with the same risk for insulin resistance, in both HIV infected and control subjects,” he says.

Grunfeld explains the lack of difference in risk between HIV infected and HIV negative subjects by noting that two thirds of all Americans are overweight and one third are obese. “With the new, highly effective antiretroviral medications, Americans with HIV now have the same weight problems as everybody else,” he says. “No matter who you are, if you eat too much and you don’t exercise, you’re going to be at risk for insulin resistance, cardiovascular disease, and every other problem associated with being overweight.”

Posted by dlifenews at 11:42 AM | Comments (0)

Cases of Diabetes in Cats Give Cause for Concern

August 07, 2007

August 7, 2007 (University of Edinburgh) Increasing numbers of pet cats are being diagnosed with diabetes, with those that are overweight being over three times more likely to suffer from the condition.

A study by the University of Edinburgh has shown that one in 230 pet cats in the UK is now diabetic, with being male, neutered, overweight, and having reduced exercise among the main risk factors.

The number of diabetic cats in the UK is now nearly five times higher than that recorded in a study carried out in the 1970s in the United States.

Professor Danielle Gunn-Moore, from the Royal (Dick) School of Veterinary Studies at the University, said: “The lifestyle of cats, just like their owners, is changing. They are tending to eat too much, gain weight, and take less exercise. Unfortunately, just like people, cats will overeat if they are offered too much tasty food, particularly if they are bored and have little else to do. While cats would naturally exercise outside, many cats are now housebound - perhaps because they live in a flat or because their owners feel that it is too dangerous to let them out - so they have little to do all day but eat, sleep, and gain weight.”

Whereas previously the most common hormone problem in cats was overactive thyroid disease, this has now been overtaken by diabetes. Between 85-95 per cent of diabetic cats suffer from Type 2 diabetes, which is often referred to in humans as maturity onset diabetes and is most commonly seen in older overweight people.

Diabetes in cats is a very serious and often fatal condition. Affected cats need daily insulin injections and a special diet, and have an increased risk of developing pancreatic disease, urinary tract infections and many other health problems.

The research, published in the Journal of Feline Medicine and Surgery, was based on an analysis of more than 14,000 cats, whose owners had taken out private pet insurance. The researchers also sent out questionnaires to members of the Feline Advisory Bureau, which included questions about their cat's weight and diet.

The completed questionnaires covered details of more than 760 pet cats, with diabetes being found to be more likely among male, neutered, overweight and inactive cats. In addition, Burmese cats were found to be three times more likely to develop diabetes than any other pedigree breed and, unlike non-pedigree cats, both sexes were found to be equally likely to develop this serious illness.

Professor Gunn-Moore, who is Professor of Feline Medicine, said: “This is the first study of its kind to try to quantify diabetes among cats in the UK and the results show extremely worrying levels. To reduce your cat's risk of developing this often fatal disease you need to keep them active, and not allow them to gain too much weight.”

Posted by dlifenews at 05:00 PM | Comments (1)

New Role for Protein in Fat Cells May Improve Understanding of Obesity and Diabetes

July 20, 2007

July 20, 2007 (EurekAlert) -- Scientists have shown for the first time that a protein involved in the transfer of fat in the blood may also influence how fat cells store fat. Richard E. Morton and Lahoucine Izem, research scientists at the Cleveland Clinic Foundation, have shown that the protein, called cholesteryl ester transfer protein (CETP), is involved in the cellular storage and regulation of cholesterol and other fats and, as a result, probably has unexpected contributions to obesity and diabetes.

“CETP is known to shuttle different types of fat between lipoproteins – combinations of fat and protein that transport fats in the blood,” Morton says. “In this study, we show that CETP also shuttles fats inside fat cells between two separate areas and that fat cells with reduced levels of CETP are unable to process fats normally.”

The new study, to be published in the July 27 issue of the Journal of Biological Chemistry, was selected as a “Paper of the Week” by the journal’s editors, meaning that it belongs to the top one percent of papers reviewed in significance and overall importance.

Research performed during the past decade has shown that CETP affects how a type of fat called cholesteryl ester is moved from the blood plasma into cells. Since fat cells make abundant CETP, Morton and Izem decided to examine what CETP does inside a fat cell and what would happen to fat cells that are deficient in CETP.

The scientists noticed that fat cells lacking CETP could not make and store cholesterol, cholesteryl ester, and another fat called triglyceride like normal fat cells do. In CETP-deficient cells, cholesteryl ester and triglyceride accumulated in a cellular compartment called the endoplasmic reticulum (ER), while an abnormally low amount of these fats was seen in “lipid droplets” – local accumulations of fat in fat cells.

Morton and Izem suggest that, in normal cells, CETP transfers cholesteryl ester and triglyceride from the ER, where they are made, to the lipid droplets, where they are stored. In cells lacking CETP, only a fraction of both fats is carried from the ER to the lipid droplets. Also, since cholesterol is produced by breaking down cholesteryl ester in lipid droplets, lower levels of cholesteryl ester lead to smaller amounts of cholesterol in the droplets.

“CETP-deficient cells have unbalanced amounts of cholesterol and fats,” Morton says. “They have too much cholesteryl ester and triglycerides in the ER and not enough of them in the lipid droplets. Also, these cells sense that they have too much cholesterol, although they actually have low amounts of cholesterol. Overall, the cells don’t correctly control the amount of fats they make and store anymore.”

A consequence of the abnormal distribution of fats between cell compartments is that cholesteryl ester and triglycerides cannot be used easily. In normal cells, when these two fats accumulate in the droplets, they can be removed from the droplets and then used by the cell after the fats are broken down by enzymes called hydrolases. But since hydrolases are in the droplets and not in the ER, cells low in CETP cannot break down the fats they store as effectively, Morton and Izem say.

The scientists conclude that CETP is probably essential for lipid metabolism and storage in fat cells and that fat tissue is not only an energy storage tissue but also a major endocrine organ.

“CETP deficiency disrupts storage of important fats in fat cells, which can lead to insulin resistance – a major contributor to diabetes – and the abnormal release of cytokines, proteins that stimulate the immune system,” Morton says. “This unexpected contribution of CETP provides a new understanding of how our body stores and regulates fats and of conditions such as obesity and diabetes.”

Posted by dlifenews at 02:31 PM | Comments (0)

Weight Management Program Cuts Diabetes Risk, Improves BMI in Overweight Children

June 26, 2007

June 26, 2007 (EurekAlert) - A family-based weight management program developed by researchers at Yale School of Medicine was more effective at reducing weight, body fat, body mass index (BMI) and insulin sensitivity than traditional clinic-based weight counseling.

Mary Savoye-Desanti, research associate in Yale’s Department of Pediatrics, will present the findings at a JAMA media briefing in New York on June 26 at 10 a.m. The study will be published in JAMA’s June 27 theme issue on chronic diseases of children.

Savoye-Desanti, a registered dietician and certified diabetes educator, and her team conducted the one-year clinical trial of 209 overweight children between the ages of 8 and16 to address the increasing prevalence of childhood obesity, especially in the African American and Hispanic population. The childhood obesity epidemic has also sparked an increase of type 2 diabetes among adolescents.

Savoye-Desanti and colleagues measured the effectiveness of the weight management program Bright Bodies, in comparison to care provided at a pediatric obesity clinic. Bright Bodies was created 10 years ago by Savoye-Desanti and combines nutrition education, behavior modification and exercise tailored to the needs of inner-city children. The study sought to compare changes in BMI, body composition, insulin sensitivity, blood pressure and lipid profiles.

The 105 children randomly assigned to the Bright Bodies program participated in 50 minutes of exercise for two nights per week. The eight to 10-year-old group participated in several games such as relay races, obstacle courses and several other games including “Swim Fish Swim.” The older group (11- to 16-year-olds) played flag football, basketball and other activities. Both groups played “Dance, Dance Revolution” by Konami.

The study revealed great differences in BMI, body weight, body fat and percent body fat between the control group and the weight management group. While the average body weight was essentially unchanged among the weight management group, BMI was reduced by 1.7 units and there was an improvement in overall cholesterol. The control group gained an average of 17 pounds and increased their BMI by 1.6 units. Percent and total body fat was reduced in the weight management group and increased in the control group.

Insulin sensitivity, which measures the risk of developing type 2 diabetes, was increased in the weight management group and decreased in the control group. Increased insulin sensitivity is linked to a reduced risk of developing type 2 diabetes.
“We have shown that a family-based program that uses nutrition education, behavior modification and supervised exercise can lower BMI, improve body composition and increase insulin sensitivity,” said Savoye-Desanti, who stresses that the success of the Bright Bodies program relates to frequent contact between the families and staff members. “This is a family problem. The child can’t do it alone.”

Savoye-Desanti said that while the program was very successful in treating overweight children, the expense incurred in operating such a program is substantial. “We will focus future studies on cost-benefit analyses, as this would be helpful for pediatric clinicians or health management organizations that are considering offering similar services to overweight children and adolescents,” said Savoye-Desanti.

Posted by dlifenews at 04:15 PM | Comments (0)

Portion-Control Dishes May Help Obese Diabetics Lose Weight

June 26, 2007 (EurekAlert) - A plate and cereal bowl with markers for proper portion sizes appear to help obese patients with diabetes lose weight and decrease their use of glucose-controlling medications, according to a report in the June 25 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Between 1960 and 2000, the proportion of U.S. adults who were obese increased from 13.4 percent to 30.9 percent, according to background information in the article. Most cases of type 2 diabetes can be attributed directly to obesity. Restricting calories has been shown to improve blood sugar control in diabetics, partially by contributing to weight loss. “The increasing prevalence of obesity is paralleled by increasing portion sizes in the marketplace,” the authors write. “Portion sizes are an important determinant of energy intake; the number of calories ingested by subjects at a meal has been directly correlated with the serving size offered.”

Sue D. Pedersen, M.D., F.R.C.P.C., and colleagues at the University of Calgary, Alberta, Canada, conducted a six-month controlled trial of commercially available portion control plates and bowls in 2004. The plates were divided into sections for carbohydrates, proteins, cheese and sauce, with the rest left open for vegetables. The sections approximately totaled an 800-calorie meal for men and a 650-calorie meal for women. The cereal bowl is designed to allow a 200-calorie meal of cereal and milk. Half of 130 obese patients with diabetes (average age 56) were randomly assigned to use the plate for their largest meal and the bowl when they ate cereal for breakfast. The other half of the participants received usual care, which consisted of dietary assessment and teaching by dieticians.

At the end of the six-month follow-up, 122 patients remained in the study. Individuals using the portion-control dishes lost an average of 1.8 percent of their body weight, while those receiving usual care lost an average of 0.1 percent. A significantly larger proportion of those using the dishes—16.9 percent vs. 4.6 percent—lost at least 5 percent of their body weight. “This is important, as a 5 percent weight loss has been shown to be clinically significant in terms of decreasing morbidity and mortality associated with obesity-linked disorders such as cancer and myocardial infarction [heart attack],” the authors write.

In addition, more of those in the intervention group vs. the regular care group experienced a decrease in their use of diabetes medications after six months (26.2 percent vs. 10.8 percent).

“In conclusion, the portion control tool studied in this trial was effective in inducing weight loss in obese persons with type 2 diabetes mellitus comparable to that seen in investigations of weight loss pharmacotherapy,” the authors write. “This simple, inexpensive tool also enabled obese patients with diabetes mellitus to decrease their hypoglycemic medication requirements. This intervention holds promise for use in overweight populations with and without diabetes mellitus.”

Posted by dlifenews at 09:45 AM | Comments (2)

Heart Disease Deaths Fall, as Obesity and Diabetes Increase, Experts Find

June 07, 2007

June 7, 2007 (EurekAlert) - Epidemiologists at the University of Liverpool and the Heart of Mersey have found that approximately half the recent fall in coronary heart disease deaths in the US is due to positive life style changes and a further half to medical therapies.

The team found that a decrease in smoking, cholesterol, blood pressure and physical inactivity contributed to the fall in deaths from coronary heart disease, yet this decrease could have been substantially more had it not been for the increases in obesity and diabetes cases.

Coronary heart disease (CHD) death rates in the US almost halved between 1980 and 2000. To understand how this fall occurred scientists combined information on medical treatments with national changes in the levels of major risk factors, such as smoking and high cholesterol. The UK has seen similar falls in heart disease, but this fall is mainly attributed to healthier diets rather than medication.
From 1980 to 2000, the US death rates for CHD fell from 543 to 267 per 100,000 population among men and from 263 to 134 per 100,000 population among women. Overall there were 341, 745 fewer CHD deaths in 2000 than in 1980.

The team found that this decrease was attributed to reductions in risk factors such as total cholesterol, systolic blood pressure, smoking and physical inactivity. However, they found that this reduction could have been 15% more had it not been for an increase in obesity and diabetes. Approximately half the fall in CHD deaths was also attributed to medical treatments, including medications for heart failure and emergency treatments for heart attacks and angina.

Professor Simon Capewell, from the University of Liverpool’s Division of Public Health and Trustee at CHD prevention charity, Heart of Mersey, said: “Using a sophisticated computer model called IMPACT we were able to combine and analyse data on the uptake and effectiveness of specific cardiac treatments and changes in risk factors among adults aged 25 to 84 years in the US. Data included results from trials, official statistics and national surveys.

"We found that CHD death rates halved, and 47% of the fall was attributed to medical treatments and approximately 44% to changes in risk factors. Prevalence of smoking, for example had fallen by 12%. Decreases in physical inactivity however, were offset by increases in body mass index and diabetes.”

Robin Ireland, Chief Executive at Heart of Mersey, added: “We have recently seen similar falls in heart disease here in the UK. These changes mainly reflect healthier diets, not tablets. However the increase in obesity and diabetes are a wakeup call. They reflect the increasing consumption of large helpings of junk food. We need legislation to encourage food manufacturers and supermarkets to provide healthier food options.”

Posted by dlifenews at 03:36 PM | Comments (0)

Lean for Life: Baby Formula That Fights Fat

April 23, 2007

April 23, 2007 (EurekAlert) - Infant formula and other baby foods that provide permanent protection from obesity and diabetes into adulthood could be on shop shelves soon, reports Lisa Melton in Chemistry & Industry, the magazine of the SCI.

The foods, under development at the Clore Laboratory at the University of Buckingham, will be supplemented with leptin, the hunger hormone. Those who take the foods early in life should remain permanently slim. 'Like those people who are lean by nature even though they overeat ? like we all do – they will tend to be inefficient in terms of using energy,' says Mike Cawthorne, who heads the Metabolic Research group at Clore.

Cawthorne's group has already demonstrated that supplementing infant rats' diets with leptin means that they never get fat or develop diabetes (AM J Physiol Regul Integr Comp Physiol, doi: 10.1152/ajpregu.00676.2006). Even animals fed a high-fat diet remained slim.

Leptin, the fat hormone that turns off hunger in the brain, is produced in the body throughout life. Its discovery was heralded as a major breakthrough, but research in adults proved disappointing because individuals soon seemed to resist its hunger-quenching effect.

But Cawthorne says this time things are different. Providing leptin earlier enough effectively hard-wires the body's energy balance. In fact, whether one is fat or thin may be determined before birth. Feeding the hormone to pregnant rats has been found to have a lifelong impact on their offspring's predisposition to obesity. Animals born of leptin-treated mothers remain lean even when fed a fat-laden diet, while those from untreated dams gained weight and developed diabetes.

The difference boils down to energy expenditure. The offspring of leptin-treated mothers burn up more energy. 'The infants are permanently inefficient in terms of using energy,' says Cawthorne.

Leptin-based products may also find their way into the pet obesity market.

Edinburgh researcher Jonathan Seckl says. 'We need to know whether leptin is acting pre- and post-natally, figure out how it works, and dissect the possible side-effects before this becomes a potential approach for humans. Nonetheless, this is good science,' he says.

Posted by dlifenews at 02:14 PM | Comments (0)

Weight-Loss Surgery Reduces Insulin Resistance, Improves Beta Cell

March 28, 2007

March 28, 2007 (PR Newswire) - Bariatric surgery -- any of several procedures designed to reduce how much a person eats or how many calories their bodies absorb -- can reduce insulin resistance and improve beta cell function in severely obese people, regardless of whether they lose any weight, according to a study by researchers in Italy.

With the number of obese people rising rapidly in the U.S. and around the world, bariatric surgery has been growing in popularity. Previous research has shown this surgery can restore glucose tolerance in the majority of severely obese people. But this study found it could also improve beta cell function, regardless of how much weight a person does or doesn't lose after surgery.

Obesity greatly increases a person's risk of developing type 2 diabetes, which is characterized by insulin resistance and impaired beta cell function.

"Why these surgeries would improve beta cell function and glucose tolerance, independent of weight loss, remains unclear," said lead researcher Dr. Ele Ferrannini, Department of Internal Medicine and CNR Institute of Clinical Physiology, University of Pisa School of Medicine, Italy. "But obviously the fact that it does improve beta-cell function could make bariatric surgery a useful tool in the prevention of diabetes in the severely obese patient."

Posted by dlife at 09:24 AM | Comments (2)

Belly Fat May Drive Inflammatory Processes Associated with Disease

March 14, 2007

March 14, 2007 (Eurekalert) - As scientists learn more about the key role of inflammation in diabetes, heart disease and other disorders, new research from Washington University School of Medicine in St. Louis suggests that fat in the belly may be an important promoter of that inflammation.

Excess fat is known to be associated with disease, but now the researchers have confirmed that fat cells inside the abdomen are secreting molecules that increase inflammation. It's the first evidence of a potential mechanistic link between abdominal fat and systemic inflammation.

For years, scientists have been aware of a relationship between disease risk and excess belly fat. "Apple-shaped" people, who carry fat in the abdomen, have a higher risk of heart disease, diabetes and other problems than "pear-shaped" people, who tend to store fat in the hips and thighs. Too much abdominal fat is associated with a defect in the body's response to insulin. During medical exams, some physicians measure waist circumference to identify patients at increased risk for these problems.

Not just any belly fat will cause inflammation, however. Back in 2004, Washington University investigators found that removing abdominal fat with liposuction did not provide the metabolic benefits normally associated with similar amounts of fat loss induced by dieting or exercising.

"Despite removing large amounts of subcutaneous fat from beneath the skin — about 20 percent of a person's total body fat mass — there were no beneficial medical effects," says Samuel Klein, M.D., the Danforth Professor of Medicine and Nutritional Science and the senior investigator on both studies.

"These results demonstrated that decreasing fat mass by surgery, which removes billions of fat cells, does not provide the metabolic benefits seen when fat mass is reduced by lowering calorie intake, which shrinks the size of fat cells and decreases the amount of fat inside the abdomen and other tissues."

In this new study, researchers looked instead at visceral fat — the fat that surrounds the organs in the gut. Unlike subcutaneous fat, visceral fat is not easy to remove surgically because it is very close to the intestines and other internal organs. Since they couldn't just take out the fat, the research team decided to analyze the blood that ran through it to determine whether visceral fat was involved in inflammation or whether, like subcutaneous fat, it was merely a marker of potential problems.

Reporting in the journal Diabetes, the research team says visceral fat likely contributes to increases in systemic inflammation and insulin resistance. They sampled blood from the portal vein in obese patients undergoing gastric bypass surgery and found that visceral fat in the abdomen was secreting high levels of an important inflammatory molecule called interleukin-6 (IL-6) into portal vein blood.

"The portal vein is filled with blood that drains visceral fat," says first author Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University in St. Louis and an investigator at the Istituto Superiore di Sanita, Rome, Italy. "Portal vein blood had levels of IL-6 that were 50 percent higher than blood from the periphery."

Increased IL-6 levels in the portal vein correlated with concentrations of an inflammatory substance called C-reactive protein (CRP) in the body. High CRP levels are related to inflammation, and chronic inflammation is associated with insulin resistance, hypertension, type 2 diabetes and atherosclerosis, among other things.

"These data support the notion that visceral fat produces inflammatory cytokines that contribute to insulin resistance and cardiovascular disease," says Klein.

Klein, Fontana and J. Christopher Eagon, M.D., assistant professor of surgery, looked at blood samples from 25 patients. All were extremely obese, and all were undergoing gastric bypass surgery. They took blood from the portal vein and from the radial artery in the arm and found differences in levels of IL-6 between the samples.

Fontana believes the findings help explain how visceral fat can lead to inflammation, insulin resistance and other metabolic problems. And he says by contributing to inflammation, visceral fat cells in the abdomen may be doing even more than that.

"Many years ago, atherosclerosis was thought to be related to lipids and to the excessive deposit of cholesterol in the arteries," Fontana says. "Nowadays, it's clear that atherosclerosis is an inflammatory disease. There also is evidence that inflammation plays a role in cancer, and there is even evidence that it plays a role in aging. Someday we may learn that visceral fat is involved in those things, too."

Posted by dlife at 10:45 AM | Comments (3)

Strong Evidence Links Soft Drink Consumption to Obesity, Diabetes

March 08, 2007

March 8, 2007 (Newswise) — The case against swigging soda just got stronger. A large systematic review reveals clear associations between consumption of nondiet soft drinks and increased calorie intake and body weight.

Full-calorie soft drinks are also linked with reduced intake of milk and fruit and increased risk of type 2 diabetes. “Recommendations to reduce population soft drink consumption are strongly supported by the available science,” concludes the review of 88 studies.

The American Beverage Association, however, presents a different view on its Web site. “It is not feasible to blame any one food product or beverage as being a sole contributor to obesity …. No science supports such a claim.”
Carbonated soft drinks are the single largest source of calories in the American diet, according to a 2005 report called “Liquid Candy,” produced by the nonprofit Center for Science in the Public Interest (CSPI). Companies annually manufacture enough soda pop to provide more than 52 gallons to every man, woman and child in the United States.

“Nobody claims there is a single cause to the obesity problem, but the existing science certainly puts soft drinks in the list of leading contributors,” said review co-author Kelly Brownell, Ph.D. He is director of the Rudd Center for Food Policy and Obesity at Yale University.

The systematic review appears in the April issue of the American Journal of Public Health. The work was supported in part by the Rudd Foundation, a private philanthropic organization focusing on obesity and education.
The authors say that a “true test” of links between a consumer product such as soft drinks and health outcomes requires a critical mass of large studies employing strong methods.

“These conditions now exist, and several clear conclusions are apparent,” they say. One of the most “powerful” findings is the link between soft drink intake and increased calorie consumption.

Of 21 studies, 19 showed that as people drink more soda pop, the number of calories they consume rises. Moreover, the studies using the most reliable statistical methods showed the largest effects.

Instead of satisfying a sweet tooth, soft drinks may do just the opposite. Several studies found that the caloric increase is actually greater than that contained in the soda, raising “the possibility that soft drinks increase hunger, decrease satiety or simply calibrate people to a high level of sweetness that generalizes to preferences in other foods,” the authors say.

“These results, taken together, provide clear and consistent evidence that people do not compensate for the added calories they consume in soft drinks by reducing their intake of other foods,” the reviewers say.

The authors anticipated a weaker relationship between soft drink consumption and body weight, because there are many other calorie sources in the diet. Yet in the highest-quality studies, which controlled for a number of unrelated variables, a moderate relationship existed. The review also showed a slight correlation between soft drink consumption and lower intakes of milk, calcium, fruit and fiber.

The “most striking link” was between soft drink consumption and the incidence of type 2 diabetes, according to the reviewers. In a study of 91,249 women followed for eight years, those who consumed one or more soft drinks per day were twice as likely as those who consumed less than one per month to develop diabetes

“This result alone warrants serious concern about soft drink intake, particularly in light of the unprecedented rise in type 2 diabetes among children,” the review says.

The authors acknowledge that there is a great deal of variability among the studies included in this review, which incorporate differing methods, populations, beverage types and measurements of key factors such as body weight. Future research with more uniform approaches “would help clarify the impact of soft drink consumption on nutrition and health outcomes,” they say.

CSPI, on the other hand, is satisfied with the research to date. “There’s so much damning evidence,” says Michael F. Jacobson, Ph.D., executive director. “This is just sugar water. The real need is for laws and regulations that would help rein in soft drink consumption.”

The consumer advocacy group calls for clearly presented calorie information at vending machines, convenience stores and restaurants. The group urges schools to stop selling full-calorie soft drinks. CSPI has also petitioned the federal government to require health notices on all nondiet sodas warning that they may promote obesity, diabetes, tooth decay, osteoporosis and other health problems.

The soft drink industry, for its part, has developed voluntary school beverage guidelines designed to limit the availability of sugary sodas and offer more water, milk, juice, energy drinks and diet soft drinks to students.

“All foods and beverages can play an important role in a healthy diet if they’re consumed in moderation and also with regular exercise,” said Tracey Halliday, a spokesperson for the American Beverage Association.

Posted by dlife at 10:12 AM | Comments (0)

New Joslin Study Reveals How a Specific Fat Type Can Protect Against Weight Gain and Diabetes

March 01, 2007

March 1, 2007 (Joslin) - A new study from Joslin Diabetes Center may shed light on why some people can eat excessive amounts of food and not gain weight or develop type 2 diabetes, while others are more likely to develop obesity and this most common form of diabetes on any diet. The study, which used two strains of mice with differing tendencies to gain weight and develop diabetes on a high-fat diet, identified genetic and cellular mechanisms that may prevent certain mice on a calorie-dense diet from gaining weight and developing metabolic syndrome.

"Although this study was done with mice, it points out new mechanisms that may underlie the ability of genetically different mice