October 9, 2009 (Newswise) - According to a recent study of clinical characteristics of teens who underwent laparoscopic Roux-en-Y gastric bypass surgery from 2002 until 2007, doctors may have a much narrower window of opportunity to reverse morbid obesity in teens than previously thought.The study, conducted at Cincinnati Children's Hospital Medical Center, appears in the current online edition of the Journal of Pediatrics.

The study focused on 61 teens who underwent laparoscopic Roux-en-Y gastric bypass at Cincinnati Children's. The results of the study showed that one year after the study, BMI in the overall group of teens pre-surgery decreased by 37 percent, however because of their starting weights, the teens were still considered to be morbidly obese. This means that doctors can predict what a patient's weight will be one-year post weight loss surgery.

Lead author of the study, Thomas Inge, MD, PhD, Associate Professor of Surgery and Pediatrics, explains that "Current guidelines for adolescent weight loss surgery suggest that we begin to consider surgery only after a teen is 80-100 percent overweight. Our new data show that when we intervene when a patient is between 100 and 150 percent over ideal weight, we can expect successfully resolution of obesity. But by the time the teen is 200 percent over their ideal weight for age, the surgery will reduce their weight substantially, but many of the patients will still remain morbidly obese.

This is the first study in adolescents to specifically show that the postoperative weight is strongly influenced by the patient's starting weight. This finding raises a concern that waiting until children are super obese to begin to think of surgery may result in major weight loss, but not resolution of obesity and certain medical problems than intervening at an early stage of the disease. For instance, in those who remain significantly obese following surgery, this excess weight can have negative effects on joints and mobility; the long-term risks of remaining seriously overweight are unknown.

Co-author Dr. Stavra Xanthakos, Assistant Professor of Pediatrics and pediatric gastroenterologist feels that, "We [doctors] have to do a better job of identifying teens who are gaining enormous amounts of weight quickly and get help for them earlier." Dr. Xanthakos says that when doctors or parents notice that a teen is beginning to gain weight rapidly, there should be a staged approach to managing the weight problem. "If the weight gain is not effectively stopped with initial nutritional or exercise measures, then even more intensive treatments or programs are indicated, and ultimately some very serious thought has to be given to surgery," said Dr. Xanthakos.

Prior to weight loss surgery, teens with extreme obesity present with the most significant and global impairments in quality of life relative to other pediatric chronic illness populations and rates of depressive symptoms that are 3-4 times higher than national rates, says pediatric psychologist and co-author Dr. Meg Zeller, Associate Professor of Pediatrics. "We cannot underestimate the psychological impact on the adolescent when obesity progresses to such extreme levels and is not durably treated." In fact, Zeller's recent data (published in the journal Obesity) from the same group of teens demonstrated significant psychosocial improvements following surgery at one-year. "As we learn more about the benefits of surgery in this age group, it pushes the medical community to ask when is the optimal time to intervene surgically and potentially change a young person's developmental course in a more positive direction?"

Mary L. Brandt, MD, Professor and Vice Chair of the Michael E. DeBakey Department of Surgery and a pediatric surgeon at Texas Children's Hospital worries about these results as well. "We are trying to help teenagers who are at high risk for preventable but life-threatening diseases such as diabetes or obesity induced liver disease. Bariatric surgery will improve the medical condition of obese teenagers regardless of the starting weight of the patient. But our ability to help these children prevent or reverse their life-threatening diseases will be even greater if our patients are able to approach a normal weight."

According to Brandt, "The other major implication of this new data is that many insurance companies will delay surgery for years, usually by requiring documentation of multiple attempts at weight loss. Severely obese teenagers only rarely respond to these kinds of treatments and, despite intense efforts to lose weight, often will gain weight during these efforts. Although it is ethically important for these children to have a least one well supervised attempt to lose weight without surgery, this report shows us that delaying the surgery while trying multiple times may not be in their best interest."

This study, like others, found that after surgery, patients generally show significant improvement or resolution of cardiovascular risk factors such as blood pressure, cholesterol, and triglyceride levels.
Dr. Inge said that the study indicates that families and communities need to take childhood weight problems seriously and aggressively pursue the best treatment options available for them before the weight problem gets out of hand. "As doctors who take care of kids, we have an obligation to identify those patients who are at highest risk and start explaining treatment options to families earlier before the child or teen gets to be two or three times his or her ideal weight, " said Dr. Inge.

October 7, 2009 (Newswise) - Doctors should pay more attention to the link between common mental illness and obesity in patients because the two health problems are closely linked, according to researchers at the University of Adelaide.In an editorial published today in the British Medical Journal (BMJ), the Adelaide researchers add support to claims of a two-way risk between obesity and common mental disorders.

The editorial makes comments on a new research paper on this topic published in the same issue of the BMJ by Professor Mika Kivimäki from University College London.

"A better understanding of the mechanisms for the apparent bi-directional risk between obesity and common mental disorders is needed for effective treatment and prevention," says the lead author of the editorial, Dr Evan Atlantis from the University of Adelaide's School of Medicine.

"Although the topic is largely unexplored, several psychosocial, lifestyle and physiological factors may be involved in the complex inter-relationship between obesity and mental illness," he says.

"Obese people - especially those who perceive themselves as being overweight - often experience weight-related stigma and discrimination, and consequently present with symptoms of low self esteem, low self worth, and guilt. Obesity is associated with socioeconomic disadvantage and low levels of physical activity, both of which are strong predictors of depression.

"Obesity may constitute a chronic stressful state, which in turn can cause significant physiological dysfunction. Such dysfunction would then predispose individuals to depressed mood and associated symptoms," he says.

Dr Atlantis says reduced physical activity and overeating - "particularly comfort foods rich in fats and sugars to improve mood" - are common among depressed and anxious patients.

"Activation of the endocannabinoid system, which increases appetite and may simultaneously alleviate depression, is likely to reinforce this eating behavior. Socioeconomic disadvantage may further exacerbate the over-consumption of comfort foods because of their low cost," he says.

Dr Atlantis says patients presenting to their doctor with symptoms of common mental disorder should be assessed for obesity and related chronic diseases, and vice versa.

"A multidisciplinary approach that focuses on promoting a healthy lifestyle is important. Further research on how best to deliver lifestyle interventions is needed, along with government action on taxes, tariffs, and trade laws to encourage the supply and consumption of healthy food and physical activity choices," he says.

October 6, 2009 (EurekAlert) - Restrictions on fast-food chain restaurants in South Los Angeles are not addressing the main differences between neighborhood food environments and are unlikely to improve the diet of residents or reduce obesity, according to a new RAND Corporation study.
Researchers from RAND Health found that the South Los Angeles region has no more fast-food chain establishments on a per capita basis than other parts of the city, but rather many more small food stores and other food outlets.

Those outlets are more likely to be the source of high-calorie snacks and soda consumed substantially more often by residents of South Los Angeles as compared to other parts of the city, according to the study published online by the journal Health Affairs.

"The Los Angeles ordinance may have been an important first by being concerned with health outcomes, but it is not the most promising approach to lowering the high rate of obesity in South Los Angeles," said Roland Sturm, the study's lead author and a senior economist at RAND, a nonprofit research organization. "It does not address the main differences we see in the food environment between Los Angeles neighborhoods nor in the diet of residents."

The Los Angeles City Council in August 2008 approved a ban on opening or expanding fast-food restaurants in an area of the city known as South Los Angeles. The ordinance focused on fast food restaurants characterized by "excessive signage, little or no landscaping, large expanses of surface parking, drive-through windows, multiple driveways, parking lots fronting the street" and argued that the low-income region had a higher concentration of fast-food establishments than more-affluent sections of the city.

But an analysis by Sturm and study co-author Dr. Deborah Cohen found that South Los Angeles actually has a lower concentration of fast-food chain restaurants than other parts of the city.

Researchers found there were about 19 fast-food chain restaurants per 100,000 residents in South Los Angeles, while there were 29 per 100,000 people in affluent West Los Angeles and 30 per 100,000 residents for all of Los Angeles County. There are significantly fewer restaurants of any type per person in South Los Angeles compared to Los Angeles County overall, according to the study.

In contrast, the density of small food stores was about double that of the county average and more than three times the number in West Los Angeles. This was partially offset by a lower density of large supermarkets in South Los Angeles.

Researchers also analyzed information from a survey of 1,480 adults from across Los Angeles County that asked residents about their food purchases and habits of eating out. The results showed that adults in South Los Angeles consumed significantly more "discretionary" calories from sugary or salty snacks and soft drinks compared with residents of wealthier neighborhoods.

Residents of South Los Angeles and residents of more-affluent areas reported eating similar amounts of fruits and vegetables each day and had fairly similar levels of physical activity, although residents of South Los Angeles did report watching more television.

Researchers say their work suggests that focusing on the sources of snack calories would address the differences between South Los Angeles and other parts of Los Angeles better than the current ban on new fast-food establishments.

"The ubiquitous availability of food can be overwhelming and stimulate hunger and cravings for food, regardless of whether an individual has a physiological need for nutrition," Cohen said. "Research has made it clear that frequency and saliency of food cues in the environment, the type of foods available, and the portion sizes served, are key issues that effective policies need to address."

One of the goals of the Los Angeles regulation is the creation of more sit-down restaurants, but in terms of diet, this is not necessarily an improvement, according to researchers.

"There is a misconception that sit-down restaurants provide 'healthier' food and are less likely to lead to obesity," Sturm says. "However, when we looked at some common offerings, an average lunch sandwich in a sit-down restaurant had more than the combined calories of three Big Mac hamburgers; many dinner choices have over 2,000 calories and cover the energy needs for a full day. And that does not even include possible appetizers or desserts."

The study also found that residents of South Los Angeles and those from wealthier areas reported eating out in restaurants at about the same frequency, although South Los Angeles residents are more likely to purchase items from a food cart or mobile vender and less likely to eat in a sit-down restaurant.

While residents of South Los Angeles and those from more-affluent areas seem to shop at similar types of stores, there was one dramatic difference -- many South Los Angeles residents walk or take public transit to the market, something seldom done in higher-income areas.

October 5, 2009 (EurekAlert) - Skeletal muscle plays a critical role in regulating blood sugar levels in the body. But few studies have comprehensively examined how obesity caused by a high-fat diet affects the health of muscle in adolescents who are pre-diabetic.In a paper published tomorrow in the scientific journal PLoS One, a team of McMaster University researchers report that the health of young adult muscle declines during the pre-diabetic state, which is when blood sugar levels are higher than normal but lower than during Type 2 diabetes. The researchers found that during this period significant impairments occur in the muscle, even though it appears to be functioning normally.

"Based on the way the muscles performed, you would think that they're still healthy," said Thomas Hawke, an associate professor of pathology and molecular medicine of the Michael G. DeGroote School of Medicine at McMaster University. "But the fact is the muscle is not healthy. It's undergone a lot of pathological changes."

Hawke led a team of researchers at McMaster and York universities in using mice to examine how a high-fat diet, leading to obesity, affected the form and function of skeletal muscle. The researchers found the high-fat diet resulted in insulin resistance, large increases in fat mass and weight gain. But it also led to initial adaptations in the muscle.

"What our results tell us is that, initially, skeletal muscle appears to respond positively to the high-fat diet. By changing the size or type of its muscle fibres, the muscle adapts to the high-fat diet by saying 'Let's burn more of this fuel,' " Hawke said.

"But with continued high-fat feeding, we're giving the muscle more fuel than it can handle. So, even though it has made these initial, positive changes, continued high-fat feeding is more than the muscle can cope with. That's when a downward spiral starts."

The researchers also discovered that not all muscles responded in the same way to obesity. Some adapted by changing their fibre type, while others altered the size of their fibres. But, in all cases analyzed, a high-fat diet decreased the ability of skeletal muscle to use fat or glucose as fuel.

When the researchers looked at function, and examined the maximum effort the muscles could generate, they discovered no difference between the high-fat diet group and the control group which was eating a diet significantly lower in fat. However, if the muscles were fatigued and then were required to work, the high-fat diet group didn't recover as quickly as the control group.

"What this suggests is that the muscle is trying to maintain function despite all the negative changes that have resulted," Hawke said. "When we stress the muscle a bit though, such as fatiguing it, there are some hints toward functional impairment, but overall the muscle has coped well, functionally anyways."

The authors concluded that early therapeutic interventions in obese, pre-diabetic youth are needed prior to significant long-term effects on the growth and function of their muscles.

October 5, 2009 (EurekAlert) - A recent study by researchers from the University of Colorado looked at post-transplant care to determine whether primary care physicians (PCPs) or hepatologists are better suited to manage the overall health care of patients who received a liver transplant (LT). Researchers learned that hepatologists believe metabolic complications to be common in LT patients, but not well controlled. The hepatologists surveyed also felt that PCPs should be responsible for managing these conditions, but that this group was not taking an active role. Full details of this study appear in the October issue of Liver Transplantation, a journal published by Wiley-Blackwell on behalf of the American Association for the Study of Liver Diseases.In the U.S. approximately 6,000 liver transplants are performed annually. Since liver transplantation began in 1963, survival rates have increased dramatically with overall 1-year and 5-year patient survival rates at 86.9% and 73.6%, respectively. As long-term survival rates increase, metabolic complications such as cardiovascular diseases, diabetes, chronic renal insufficiency and bone disease become a concern to the welfare of LT patients.

Lisa Forman, M.D. and colleagues surveyed 280 hepatologists in programs that transplanted at least 8 adult livers during the 2004 study year. Of the 191 respondents, 86% were male with a mean age of 50 years and had been in practice for an average of 13 years. Close to half of the hepatologists who replied noted that they cared for 21-50 liver transplant patients each month, while only 2.1% stated that a PCP was a working member of the practice group's post-transplant team.

Researchers found that more than 70% of hepatologists surveyed noted hypertension, chronic renal insufficiency, diabetes, and osteoporosis were present in at least 25% of patients 1 year post-transplant. The majority of respondents felt that these metabolic complications significantly contributed to morbidity and mortality 10 years after liver transplantation. Based on survey responses, the most commonly cited barriers to control post-transplant complications were dietary non-adherence, adverse effects of immunosuppressive agents, and inadequate primary care.

Approximately 75% of respondents felt that metabolic complications should be managed by PCPs, but believe that PCPs are adequately managing these health issues in only 38%-51% of LT recipients. "While there are many factors which influence the management of metabolic health concerns, the transplant community needs to be aggressive in influencing aspects that are modifiable such as PCP involvement," stated Dr. Forman. "If PCPs are reluctant to treat LT patients, and hepatologists assume their overall care, perhaps transplant hepatology fellowships should include rotations in cardiology, endocrinology, rheumatology and nephrology to give fellows more exposure to the management of metabolic complications," she suggested.

"Despite the fact that this study was based on perception rather than hard data, it does serve as a basis for future studies," stated Bashar Aqel, M.D., from the Mayo Clinic in his editorial also published in the October issue of Liver Transplantation. The authors acknowledged this study was based on the perception of hepatologists without hard data collected on the prevalence of metabolic complications and noted that PCPs were not surveyed likely leading to a bias toward the hepatologist. "More research is needed to address the real prevalence of metabolic complications, adequacy of treatment and to identify the barriers to care in the treatment of metabolic complications after liver transplantation," added Dr. Aqel.

October 2, 2009 (Newswise) - Obesity and type 2 diabetes are inextricably linked, but Cornell biochemist and geneticist Ling Qi is working to break that connection. Finding just the right gene could do it, says Qi, an assistant professor of nutritional sciences in Cornell's College of Human Ecology.In his Cornell laboratory, Qi is looking at two mechanisms that could potentially impact obesity and diabetes: the endoplasmic-reticulum (ER) stress response, which affects the expression of proteins, and the inflammation status of fat tissues. As a postdoctoral fellow at the Salk Institute for Biological Studies in La Jolla, Calif., before he joined the Cornell faculty last summer, Qi found that some of the mice in his lab became obese on a Western-diet regimen while others did not. In other cases, some developed diabetes after gaining weight on a Western diet but some didn't. The question is: Why?

Qi is trying to find out. In his Cornell laboratory, he is looking at two mechanisms that could potentially impact obesity and diabetes: the endoplasmic-reticulum (ER) stress response, which affects the expression of proteins, and the inflammation status of fat tissues.

Diabetes occurs when certain molecules malfunction in the signaling pathway, an event Qi finds fascinating.

"In the case of ER stress response, there's a DNA-binding protein that drives gene expression in cells; it's a key element for cells to respond to environmental cues -- in this case to glucose changes," explains Qi, who just won the 2008 Rosalinde and Arthur Gilbert Foundation/American Federation for Aging Research (AFAR) New Investigator Awards in Alzheimer's Disease as well as a Junior Faculty Award from the American Diabetes Association..

Little is known about this protein, so Qi and his research associate, postdoctoral fellow, graduate student, technician and an undergraduate student in his lab are seeking to learn more. Their studies in inflammation status also are proving to be promising, because it is now recognized that fat is a lot more than a storage depot for energy; it is an active organ that secretes hormones, many of which affect obesity and insulin sensitivity.

In a 2006 Science paper he published and in a manuscript he recently submitted, Qi describes how he demonstrated that altering fat-cell function changes obesity and insulin.

"Fat tissue has become the center of the metabolic control. If you change the fat mass, you will likely see the changes in insulin sensitivity of the whole system," says Qi, who has also published in the journal Nature.

When fat cells become bigger, immune cells infiltrate into the fat tissues. Qi wants to know what the functions of these macrophages are and what signals the recruitment of these macrophages. Such studies are so fundamental that they could one day reveal the origins of obesity and diabetes.

"It is crucial to understand the mechanism underlying the etiology of obesity and diabetes to develop well-targeted, efficient pharmacological interventions," Qi explains. "Working on genetic control of obesity and diabetes is very challenging but quite rewarding."

September 29, 2009 (Newswise) - A simple, non-invasive test appears to be an effective screening tool for identifying patients with silent heart disease who are at risk for a heart attack or sudden death. Coronary artery calcium scans can be done without triggering excessive additional testing and costs, according to the multi-center EISNER (Early Identification of Subclinical Atherosclerosis by Noninvasive Imaging Research) study, led by investigators at the Cedars-Sinai Heart Institute. The findings appear in today's issue of the Journal of the American College of Cardiology.Coronary artery calcium scans that detect plaque in the coronary arteries have been shown to be more effective than standard cholesterol and blood pressure measurements in identifying patients who are most vulnerable to heart disease. Currently, these scans are not covered by private insurance carriers, in part because of concerns that detection of low levels of cardiovascular disease will result in unnecessary and expensive further testing, including exercise imaging and invasive cardiac catheterization procedures. "Over half of patients who suffer heart attacks have no warning that they have heart disease until the heart attack occurs. If we knew the patients were at risk, current treatments could prevent the majority of these unnecessary events. We had to address the concerns about unnecessary testing and costs related to this potentially lifesaving procedure," said Daniel S. Berman, M.D., the study's principal investigator and chief of Cardiac Imaging at Cedars-Sinai's S. Mark Taper Foundation Imaging Center in Los Angeles.

In the EISNER study, supported by The Eisner Foundation, researchers performed coronary calcium scans on 1,361 volunteers at intermediate risk for coronary artery disease, and followed them over a four-year period, from May 2001 to June 2005. The objective was to determine the relationship between coronary artery calcium scores and subsequent cardiac events and to evaluate the performance of additional cardiac diagnostic testing. Coronary artery calcium scores of 0 indicate no plaque, 1-9 minimal, 10-99 mild, 100-399 moderate, 400-999 extensive, and 1,000 or more very extensive plaque.

Coronary artery calcium scores varied widely but the vast majority of the patients had low scores. More than half - 56.7 percent of subjects -- had scores of less than 10, and only 8.2 percent had scores higher than 400. There was a strong relationship between the coronary calcium scores and subsequent cardiac events. The unique finding of the EISNER study was that there was a marked difference in the number, type and frequency of medical tests and costs given a subject's coronary artery calcium score. Additional stress testing was infrequent and related costs were low among subjects with low coronary artery calcium scores. Both rose progressively as the coronary artery calcium score increased, particularly in the patients at highest risk-those with scores of greater than 1,000-found in only 2.2 percent of subjects (31). Importantly, catheter-based invasive coronary angiography was performed exclusively among subjects with high coronary artery calcium scores. And even then, only 19.4 percent of participants who were in the highest risk category underwent this expensive procedure associated with a small but definite risk.

Recent evidence has demonstrated that screening with coronary artery calcium is a better prognosticator of risk than the Framingham Risk Score-the traditional way of assessing risk based on blood testing and blood pressure--in middle aged and elderly patients. Yet controversy surrounds expansion of cardiac screening to include coronary calcium scanning imaging because of concerns that the extra costs may not outweigh the benefits. The findings of the EISNER study, the researchers note, is the first direct evidence that coronary artery calcium scanning could be an acceptable cost-effective screening test for coronary artery disease, since it is able to identify high risk subgroups in need of aggressive medical treatment, and patients who undergo additional testing constitute only a small fraction of the screened population.

September 29, 2009 (EurekAlert) - The more weight women gain from the age of 18 until middle age, the less likely they are to enjoy a long and healthy life, according to new research published on bmj.com today.Compared with lean women, the results show that being obese in middle age reduces those odds by 79%, underscoring the importance of maintaining a healthy weight from early adulthood, say the authors.

Despite the evidence that overweight and obesity can significantly increase the risk of early death, little is known about how adiposity affects overall health and wellbeing among those who survive to older ages.

To address this issue, researchers in the United States investigated the theory that being overweight in mid life is associated with a reduced probability of maintaining optimal health among those who survive to older ages.

Their findings are based on comprehensive two yearly monitoring of more than 17,000 middle-aged women in the United States as part of the Nurses Health Study.

Healthy survival referred to participants who survived to age 70 years or older, were free of major chronic diseases, and had good cognitive, physical and mental health. Usual survival referred to participants who survived to age 70 years or older but did not meet these criteria.

After adjusting for several factors, increased body mass index at the start of the study was significantly associated with reduced odds of healthy survival. Every one unit increase of body mass index was associated with a 12% reduction in the odds of healthy survival.

Similarly, in comparison to women of stable weight, weight gain since the age of 18 was significantly associated with reduced odds of healthy survival. For every one kilogram increase of weight gain since age 18 years, the odds of healthy survival decreased by 5%.

The worst odds of healthy survival were found among women who were overweight at 18 and gained 10kg or more by middle age.

But even among women who were lean at 18, relative to those who kept a stable weight, women who gained more than 10kg by middle age were 59% less likely to achieve healthy survival.

These data provide evidence that adiposity in mid life is strongly related to a reduced probability of healthy survival among women who live to older ages, and stress the importance of maintaining a healthy weight from early adulthood, say the authors.

"Given that more and more Americans are surviving to older ages and, at the same time, gaining weight, our results may be particularly important with respect to clinical or public health policies and deserve further investigation and confirmation in additional studies," they conclude.

September 11, 2009 (EurekAlert) - Have you ever noticed that people have thinner arms and legs as they get older? As we age it becomes harder to keep our muscles healthy. They get smaller, which decreases strength and increases the likelihood of falls and fractures. New research is showing how this happens - and what to do about it.A team of Nottingham researchers has already shown that when older people eat, they cannot make muscle as fast as the young. Now they've found that the suppression of muscle breakdown, which also happens during feeding, is blunted with age.

The scientists and doctors at The University of Nottingham Schools of Graduate Entry Medicine and Biomedical Sciences believe that a 'double whammy' affects people aged over 65. However the team think that weight training may "rejuvenate" muscle blood flow and help retain muscle for older people.

These results may explain the ongoing loss of muscle in older people: when they eat they don't build enough muscle with the protein in food; also, the insulin (a hormone released during a meal) fails to shut down the muscle breakdown that rises between meals and overnight. Normally, in young people, insulin acts to slow muscle breakdown. Common to these problems may be a failure to deliver nutrients and hormones to muscle because of a poorer blood supply.

The work has been done by Michael Rennie, Professor of Clinical Physiology, and Dr Emilie Wilkes, and their colleagues at The University of Nottingham. The research was funded by the UK's Biotechnology and Biological Sciences Research Council (BBSRC) as part of ongoing work on age-related muscle wasting and how to lessen that effect.

Research just published in the American Journal of Clinical Nutrition compared one group of people in their late 60s to a group of 25-year-olds, with equal numbers of men and women. Professor Rennie said "We studied our subjects first - before breakfast - and then after giving them a small amount of insulin to raise the hormone to what they would be if they had eaten breakfast, of a bowl of cornflakes or a croissant."

"We tagged one of the amino acids (from which proteins are made) so that we could discover how much protein in leg muscle was being broken down. We then compared how much amino acid was delivered to the leg and how much was leaving it, by analysing blood in the two situations.

"The results were clear. The younger people's muscles were able to use insulin we gave to stop the muscle breakdown, which had increased during the night. The muscles in the older people could not."

"In the course of our tests, we also noticed that the blood flow in the leg was greater in the younger people than the older ones," added Professor Rennie. "This set us thinking: maybe the rate of supply of nutrients and hormones is lower in the older people? This could explain the wasting we see."

Following this up led Beth Phillips, a PhD student working with Professor Rennie, to win the Blue Riband Award for work she presented at the summer meeting of The Physiological Society in Dublin. In her research Beth confirmed the blunting effect of age on leg blood flow after feeding, with and without exercise. The team predicted that weight training would reduce this blunting. "Indeed, she found that three sessions a week over 20 weeks 'rejuvenated' the leg blood flow responses of the older people. They became identical to those in the young," said Professor Rennie.

"I am extremely pleased with progress," he said. "Our team is making good headway in finding more and more out about what causes the loss of muscle with age. It looks like we have good clues about how to lessen it with weight training and possibly other ways to increase blood flow."

September 11, 2009 (EurekAlert) - A team of scientists led by researcher Brenda Hernandez, Ph.D., M.P.H. - an assistant professor at the University of Hawai'i at Mānoa's Cancer Research Center of Hawai'i - has reported that body mass in younger and older adulthood, and weight gain between these life periods, may influence a man's risk for prostate cancer. This risk varies among different ethnic groups, according to findings reported in a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.Dr. Hernandez and colleagues studied the relationship in a multiethnic population consisting of blacks, Japanese, Hispanics, Native Hawaiians and whites, and compared differences among age groups using the Multiethnic Cohort, a longitudinal study of men 45-75 years of age established in Hawai'i and California from 1993-1996. Of the 83,879 men who participated in the study, 5,554 developed prostate cancer. Overall, men who were overweight or obese by age 21 had a decreased risk of localized and low-grade prostate cancer, according to Dr. Hernandez.

Their results suggested that being overweight in older adulthood was associated with increased prostate cancer risk among white and Native Hawaiian men, but a decreased risk among Japanese men. While excessive weight gain between younger and older adulthood was observed to increase the risk of advanced and high-grade prostate cancers in white men and increase the risk of localized and low-grade disease in black men, it appeared to decrease the risk of localized prostate cancer in Japanese men.

Dr. Hernandez said, "The relationship of certain characteristics, such as body size, with cancer risk may vary across ethnic groups due to the combined influence of both genes and lifestyle."

Obesity is a known risk factor in other common cancers, including colorectal cancer and breast cancer in post-menopausal women. However, the relationship between body size and prostate cancer risk is not entirely understood.

Excess fat is associated with a number of conditions that contribute to cancer development including low-grade chronic inflammation, insulin resistance, metabolic abnormalities, and hormone imbalances. These conditions may in turn contribute to more aggressive prostate malignancies.

Ethnic differences in cancer risk may be explained by differences in the distribution of stored body fat that could have a differential effect on the development of prostate cancer. For example, in comparison to whites, Asian men and women tend to accumulate more fat in their upper bodies and less fat in their lower bodies (including legs and buttocks). These differences in the distribution of body fat may influence the specific way that excess fat influences cancer risk.

Elizabeth A. Platz, Sc.D., M.P.H., associated professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health, Baltimore, and an editorial board member for Cancer Epidemiology, Biomarkers & Prevention, emphasized as a strength of this study, in spite of its inconsistency across racial/ethnic groups, that it was conducted prospectively and consisted of large numbers of men in most of the ethnic groups studied. An estimated 30 percent of prostate cancer cases occurred among Japanese men, 25 percent among white men, 27 percent among Hispanic men, 13 percent among black men, and seven percent among Native Hawaiian men. According to Dr. Hernandez, their findings do not warrant a change in public health messages about obesity that all men of normal weight should be encouraged to avoid weight gain and those who are overweight or obese should be encouraged to lose weight to achieve good health.