Even when pressure is high, uncertainty stems from ambiguous standards, competing demands and overlapping health problems, U-M/VA study finds

May 19, 2008 (UMHS Newsroom) - For people with diabetes, high blood pressure poses a special threat, multiplying their risk of heart attacks, strokes and kidney problems.But a new study finds that even when people with diabetes show up in their doctor's office with a high blood pressure reading, there's only a 50-50 chance that each of them will get some sort of attention for it. That might mean a change to their medications, or a plan to follow up a few weeks later to see if the reading is still high.

What happens the other 50 percent of the time? Something that others have termed "clinical inertia" takes over, say the University of Michigan Health System and VA Ann Arbor Healthcare System researchers who conducted the study, which is appearing in the May 20 issue of the Annals of Internal Medicine.

The fear is that this lack of response to high blood pressure readings at clinic visits could mean that patients' pressures will keep getting worse.

The study takes a look at possible causes of clinical inertia and finds little evidence supporting the idea that providers are just "ignoring" blood pressure problems.

What really seems to have an impact on treatment decisions is plain old uncertainty about whether the blood pressure is really elevated, or providers being occupied with other medical issues. Providers might need to spend the visit addressing more pressing problems, some of which, like pain, may be contributing to elevated blood pressures. Or, they might take another reading and conclude there's no need for action. Or, patients may report that their pressure readings at home have been fine.

More systematic guidelines for monitoring blood pressure in people with diabetes, and better guidance for when to change treatment when pressures get too high, are needed, say the researchers. They're led by Eve Kerr, M.D., MPH, and Timothy Hofer, M.D., M.S., of the Center for Clinical Management Research at the VA Ann Arbor Healthcare System and U-M Medical School's Division of General Medicine.

In the meantime, says Kerr, "While there are many guidelines about treating hypertension, there is an amazing lack of clarity and guidance about how many blood pressures should be taken at a clinic visit, whether those blood pressures should be averaged or whether just the lowest should be used, and how to incorporate home blood pressure readings in decisions to intensify medications. As long as this confusion exists, we may not make progress in treating hypertension."

The study was performed among 1,169 people with diabetes who were seen in VA primary care clinics over a one-year period, at nine different sites in three states.

All the patients had a blood pressure reading over 140/90 mm Hg at the start of their clinic visits. The national goal for people with diabetes is less than 130/80 mm Hg. (For people without diabetes or kidney problems, the goal is less than 140/90, which is considered the cutoff for Stage I hypertension.)

Of these patients, 573, or 49 percent, received a change in their blood pressure treatment at the same clinic visit - either a new prescription for a medication, a change in the dosage of an existing medication or medications, or a documented plan to follow up within four weeks. While this rate is higher than has been reported in other settings, there still appears to be room for improvement.

As part of the study, the researchers asked both patients and providers to complete brief questionnaires before the end of the day of the clinic visit. Most of the 92 providers who saw the patients were physicians, but they also included nurse practitioners and physician assistants. This prospective design allowed the researchers to look at all the different variables associated with providers' tendency to adjust blood pressure treatment in reaction to the high initial reading.

Their analysis revealed findings that have implications for how patients, and clinicians, measure and react to blood pressure in clinics. For instance, there was wide variation among clinics in the likelihood that providers would order a treatment change in patients with a reading over 140/90 mm Hg.

Uncertainty about what the patient's blood pressure was one of the largest factors. Providers variably repeated the blood pressure check once the patient was in the exam room, and not surprisingly were much less likely to change treatment if the new reading was lower than 140/90 mm Hg. Only 13 percent of such patients had a treatment change, compared with 61 percent of those with a high second reading, or who didn't get one.

"Providers clearly 'trust' their own reading more than they do the reading taken at the clinic intake point," suggests Hofer. "But there is no evidence that supports that approach. In fact, the literature suggests that provider measurements are less reliable and subject to large biases relative to independent measures by nurses using electronic blood pressure cuffs."

Additionally providers responded to their patient's own report about what kind of readings he or she was getting using a home blood pressure monitor. Only 18 percent of patients who told their providers their home measurements had been below 140/90 mm Hg received a treatment change, compared with 52 percent who said their pressures at home had been high, or who didn't report at-home monitoring.

While at-home monitoring can be important, Kerr says, the fact of the matter is that there is no standard for how often to monitor and how to record home pressure readings over time. Further, patients might preferentially report only the "normal" blood pressures and ignore the out-of-range values.

Patients should talk to their doctors about how often to monitor and record their blood pressure and look at averages over time, she says. If their average is above the target, it might be time to change treatment.

Finally, another major factor interfering with a patient's chances of getting a treatment adjustment turned out to be somewhat predictable: attention to other issues. If a patient's chief reason for coming to the clinic was unrelated to their diabetes or their blood pressure - for instance, if they were seeking treatment for pain - they were much less likely to receive attention for their blood pressure. The same was true for clinic visits where a patient's medications weren't discussed.

The team is continuing its study to see how long it takes for patients to get a treatment change. They hope their work will help guide further hypertension guidelines, and standardization of clinic practices. And that, they hope, will help millions of diabetes patients protect their long-term health.

In addition to Kerr and Hofer, the researchers include Brian Zikmund-Fisher, Ph.D., Mandi Klamerus, MPH, Usha Subramanian, M.D., M.S., and Mary M. Hogan, Ph.D., RN. Funding for the study came from the VA, and from the Michigan Diabetes Research and Training Center.

Reference: Annals of Internal Medicine, May 20, 2008, Vol. 148, No. 10.

ED not only interferes with romance, it warns of future heart disease

May 19, 2008 (Eurekalert) -- Erectile dysfunction is always a matter of the heart, but new research shows that more than romance is at stake. Two new studies of men with type 2 diabetes found that erectile dysfunction (ED) was a powerful early warning sign for serious heart disease, including heart attack and death. One of the studies also showed that cholesterol-lowering medications could cut the risk of heart problems by about one-third-and suggested that Viagra and other compounds in the same drug family might offer similar protection.

The research, which was published in the May 27, 2008, issue of the Journal of the American College of Cardiology (JACC), underscores the importance of encouraging men to report ED to their physicians, and of focusing treatment not only on overcoming sexual dysfunction but also on improving overall cardiovascular health.

"The development of erectile dysfunction should alert both patients and healthcare providers to the future risk of coronary heart disease," said Peter Chun-Yip Tong, Ph.D., an associate professor in the Department of Medicine & Therapeutics at The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong. "Other risk factors such as poor blood glucose control, high blood pressure, high cholesterol levels, smoking and obesity should be reviewed and addressed aggressively."

Diabetes, erectile dysfunction and heart disease share an ominous link: damage to the blood vessels by high blood sugar levels. The same process that hinders the extra blood flow needed to maintain an erection can have even more serious consequences in the heart. "The first event is probably endothelial dysfunction-when the smoothness and reactivity of the blood vessel are damaged," said Dr. Tong. "This process encourages local inflammation on the inner surface of the blood vessels and the deposition of cholesterol, resulting in formation of clots and atherosclerosis. Therefore, there is a high risk of blockage of blood vessels in the heart, which can lead to a heart attack."

Men typically show signs of ED more than three years before the onset of symptoms of coronary heart disease. In one study of diabetic men, symptoms of ED always preceded coronary symptoms.

In the Hong Kong-based study, Dr. Tong and his colleagues set out to determine whether ED could be used as an early warning sign of poor cardiovascular health. Researchers recruited 2,306 men with type 2 diabetes, performing a thorough medical evaluation of diabetic control and complications, including damage to the kidneys, eyes and cardiovascular system. At the beginning of the study, just over one-quarter of the study participants had ED. None of the participants had any signs or history of heart disease, vascular disease or stroke.

The researchers followed-up the patients for an average of four years. During that time, 123 men either suffered a heart attack, died from heart disease, developed chest pain caused by clogged arteries, or needed bypass surgery or a catheter procedure to restore blood flow to the heart. Men who had ED at the beginning of the study were far more likely to develop one of these signs of coronary heart disease-or a "CHD event"-than were men who initially did not have ED. Statistical analysis showed that out of every 1,000 diabetic men with ED, 19.7 could be expected to experience a CHD event each year, as compared to only 9.5 of 1,000 diabetic men without ED.

The research team then performed an analysis that included many different characteristics that, like erectile dysfunction, were associated with the development of CHD, including age, high blood pressure, the need for cholesterol- or blood-pressure-lowering medications, the duration of diabetes, and damage to the kidneys or the eyes as a result of diabetes. Even when these characteristics were taken into account, ED was found to be an independent early warning sign of coronary heart disease. In fact, ED signaled a 58 percent increase in the risk of CHD. Only spillage of large amounts of protein in the urine-a sign of extensive kidney damage-was a stronger warning sign, doubling the risk of heart disease.

The second study, conducted by researchers from four medical centers in Italy, focused on 291 men who not only had type 2 diabetes but also silent CHD discovered by stress testing and confirmed by x-ray angiography. Of these, 118 had ED at the beginning of the study. Lead investigator Carmine Gazzaruso, M.D., Ph.D., and his colleagues followed-up patients for an average of nearly four years, documenting major adverse cardiac events (MACE), which they defined as not only CHD events but also stroke, mini-stroke (transient ischemic attacks) and arterial disease in the legs. They found that patients who had ED at the beginning of the study were twice as likely to suffer a major adverse cardiac event when compared to those without ED.

The study also showed that among patients who were taking cholesterol-lowering statins, the risk of MACE was reduced by one third (hazard ratio, 0.66, p = 0.036). Viagra and other medications in a family known as 5-phosphodiesterase (5PDE) inhibitors also appeared to reduce the MACE risk (hazard ratio, 0.68); however this finding was just beyond the cusp of being statically significant (p = 0.056).

"These are important studies," said Robert A. Kloner, M.D., Ph.D., F.A.C.C., a professor of medicine at the Keck School of Medicine at the University of Southern California, and director of research for the Heart Institute at Good Samaritan Hospital in Los Angeles. "While we have known that ED shares many common risk factors with CHD, such as hypertension, smoking, dyslipidemia and diabetes, what is new here is that ED remained a significant risk factor for developing heart disease after controlling for other cardiovascular risk factors.

"Men should know that ED is a true harbinger of atherosclerotic coronary heart disease," he said.

Dr. Kloner, who wrote an editorial about the new studies in the same issue of JACC, also noted that not only have statins been shown to reduce the risk of cardiovascular illness in diabetic patients, controlling blood pressure and other risk factors is also critical.

"In diabetic patients, it is important to not only control the blood sugar level, but also to keep blood pressure below 130/80 mmHg and reduce 'bad' (low-density-lipoprotein, or LDL) cholesterol to less than 100 mg/dL. If a patient smokes, a smoking cessation program is crucial," Dr. Kloner said.

Dr. Tong said that he and his colleagues are continuing to analyze a database of nearly 10,000 patients with diabetes in an attempt to answer several remaining questions about the link between ED, diabetes and heart disease. For example, will improvements in the control of blood sugar and other cardiovascular risk factors reduce the likelihood of developing erectile dysfunction or suffering a heart attack or other serious heart disease" Are patients who have ED in addition to diabetes-related eye problems and kidney problems at higher risk for death or cardiovascular disease" And if so, how great is the increased risk"

"All of these questions are relevant to those who suffer from diabetes," Dr. Tong said. "The information we find will help patients to focus on improving their own health."