Highlights from the American Diabetes Association's 66th Annual Scientific Sessions

Cardiology Review® Online, July 2006, Volume 23, Issue 7

Washington, DC-Primary care physicians and cardiologists fail to intensify antihypertensive drug therapy in the vast majority of patients with type 2 diabetes, leading to suboptimal control of blood pressure, found Shari Bolen, MD, MPH.

Physicians failing to intensify blood pressure management in patients with diabetes

“There is complacency in intensifying treatment, especially with milder elevations in blood pressure,” she said at the 66th Scientific Sessions of the American Diabetes Association. “Providers were more likely to intensify treatment at higher blood pressure levels and at routine office visits with their regular patients.” Variability in blood pressure readings may partly explain the reluctance to intensify therapy when blood pressure is mildly elevated, she said.

A lack of communication between the primary provider and the cardiologist may also contribute to the lack of intensifying treatment, she added.

She studied a random sample of 411 patients with type 2 diabetes who were enrolled in a managed care program. Over 2 years of follow-up, 1374 visits in which blood pressure was suboptimally controlled (systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg) in 254 unique patients were identified through a review of medical records.

Intensification was determined using the electronic pharmacy database, and was defined as adding a new antihypertensive prescription or uptitrating the dose of an old prescription. Blood pressure readings were abstracted from medical records.

Primary care physicians intensified therapy at only 13% of the 1374 visits in which blood pressure was suboptimally controlled. Cardiologists intensified therapy at 24% of the visits with these same patients.

The likelihood of intensification increased 2-fold for every 20-mm Hg increase in systolic blood pressure. Primary providers that intensified treatment were more likely to order a fingerstick glucose, urine dipstick, and refer the patient to specialists during their office visits.

However, if the fingerstick glucose reading was high, the physician was less likely to pay attention to blood pressure, said Dr Bolen, instructor in general internal medicine at Johns Hopkins University in Baltimore.

Surprisingly, physicians were even less likely to intensify treatment when seeing patients with a history of heart disease. Primary physicians were 50% less likely to intensify when the cardiologist did not intensify, perhaps because the primary physician deferred to the cardiologist for treatment of cardiovascular disease. “It may be that each assumes that the other is intensifying treatment,” she said.

A systems approach may be required to ensure optimal care to patients with diabetes. “We may need a care coordinator who recognizes all the issues related to diabetes and can deliver patient education and monitor patient adherence,” she said.

These findings were confirmed in a review of 11,000 outpatient records of 1244 hypertensive patients with diabetes who were followed by 166 physicians from 2000 to 2004. The antihypertensive regimen was intensified in only 26% of the visits in which elevated blood pressure was documented, said lead investigator Alexander Turchin, MD, MS, associate physician, division of endocrinology, Brigham and Women’s Hospital, Boston.

Similar to Dr Bolen’s study, the blood pressure level affected the likelihood that treatment would be intensified. For every 10-mm Hg of systolic blood pressure, the probability of intensification increased 40%; for every 10-mm Hg increase in diastolic blood pressure, the probability increased 20%. Younger physicians were more likely than older physicians to intensify treatment.

Washington, DC-Identifying persons with impaired fasting glucose (IFG) is also likely to identify a group with a high prevalence of modifiable risk factors for cardiovascular disease, according to Farah M. Chowdhury, MBBS, MPH.

Impaired fasting glucose associated with multiple cardiovascular risk factors

According to data she presented at the ADA’s Scientific Sessions, persons with IFG were more likely than those with normal fasting glucose to have hypertension, an enlarged waist circumference, obesity, and dyslipidemias.

“We found higher values for every cardiovascular variable we looked at in persons with IFG compared with normal fasting glucose, defined as less than 100 mg/dL,” said Dr Chowdhury, research fellow, division of diabetes translation, National Center for Chronic Disease Prevention and Health Promotion, Cen­ters for Disease Control and Prevention, Atlanta. “Persons with IFG need more attention to cardiovascular risk screening. We should target this group for intervention because we’ve known that they’re more likely to develop diabetes and intervention can prevent diabetes, and intervention may prevent cardiovascular disease as well.”

Her findings were based on an analysis of a sample of 3030 persons aged 20 to 75 years without self-reported diabetes who participated in the Na­tional Health and Nutrition Examination Surveys 1999 to 2002. IFG was defined as fasting plasma glucose (FPG) of 100 to 125 mg/dL.

Modifiable risk factors assessed were hypertension (≥130/85 mm Hg, or on an antihypertensive medication), enlarged waist circumference (men > 102 cm, women >88 cm), obesity (body mass index ≥30 kg/m2), elevated total cholesterol (≥200 mg/dL), a low level of high-density lipoprotein (HDL) cholesterol (< 40 mg/dL in men, < 50 mg/dL in women), a high level of low-density lipoprotein (LDL) cholesterol (≥130 mg/dL), high triglyceride (≥ 150 mg/dL), and current smoking.

Some 27.9% of the study sample had IFG. This percentage represents 46 million people in the United States

The prevalence of cardiovascular risk factors in the persons with IFG compared with those with normal fasting glucose:

• Hypertension: 48.3% versus 31%

• Enlarged waist circumference: 56% versus 37.3%

• Obesity: 38% versus 23.4%

• Elevated total cholesterol: 57.2% versus 44.8%

• Low HDL cholesterol: 4.2% versus 32.7%

• Elevated LDL cholesterol: 47.5% versus 37.1%

• Elevated triglycerides: 44.1% versus 26.2%

The proportion of current smokers was similar in both groups (24.5% in IFG vs 26.3% in normal fasting glucose).

In patients with IFG, each mg/dL of fasting glucose increases the risk of diabetes by 7% to 8%, which suggests a constant linear relationship between FPG and diabetes risk, reported Gregory A. Nichols, PhD, at the Center for Health Research, Kaiser Permanente Northwest, Portland, Ore.

This determination was made from studying 5480 normoglycemic patients with at least 1 measured FPG < 100 mg/dL who had 2 or more subsequent test results ≥100 mg/dL.

Overall, 8.1% of patients with baseline FPG from 100 to 109 mg/dL (stage 1 subjects) and 24.3% of those with baseline FPG of 110 to 125 mg/dL (stage 2 subjects) ultimately developed diabetes.

Stage-1 subjects who progressed to diabetes did so in a mean of 41.4 months, converting at a rate of 1.34% per year. Stage-2 subjects converted to diabetes at a rate of 5.56% per year after an average of 29.0 months. “Subjects at greatest risk of diabetes had steeper trajectories of glucose increase, allowing less time for time-sensitive interventions that prevent or delay diabetes,” according to Dr Nichols.

Screening to detect pre-diabetes or diabetes in high-risk individuals, particularly those with a high body-mass index, should be conducted at yearly intervals rather than the 3-year interval recommended by the American Diabetes Association, he concluded.

Washington, DC-New findings indicate that patients with coronary heart disease (CHD) who have metabolic syndrome (Met-S) have a significantly higher cardiovascular risk than those with CHD only.

Aggressive statin therapy cuts increased risk in CHD patients with metabolic syndrome

This increased risk in patients with Met-S was significantly reduced with intensive lipid-lowering therapy with 80 mg/day of atorvastatin, according to a sub-analysis of the Treating to New Targets (TNT) trial.

“Our results support the classification of patients with CHD and Met-S as very high risk, which makes them excellent candidates for more intensive lipid-lowering therapy,” Prakash Deedwania, MD, chief, division of cardiology, University of California at San Francisco’s Fresno program, said. “In fact, reducing low-density lipoprotein (LDL) cholesterol levels to less than 70 mg/dL may be particularly warranted.”

In this sub-analysis, the researchers examined the effect of atorvastatin, 80 mg/day, versus 10 mg/day on Met-S and its components in patients with CHD. Overall, 5584 patients enrolled in TNT had Met-S.

Metabolic syndrome is closely linked to the development of diabetes and cardiovascular disease, Dr Deedwania said. In 2001, the third report of the National Cholesterol Education Panel (NCEP) recognized the importance of treating metabolic risk factors as a secondary target of cardiovascular risk reduction, after reduction of LDL cholesterol.

In 2004, the NCEP Adult Treatment Panel III (ATP III) affirmed its LDL cholesterol goal of less than 100 mg/dL in patients with cardiovascular disease or risk equivalents, with an optional LDL cholesterol goal of less than 70 mg/dL in very high-risk patients. Very-high risk patients are patients with established CHD plus other high-risk conditions including Met-S.

More recently, on the basis of the TNT and the Incremental Decrease in End Points Through Aggressive Lipid Low&shy;ering (IDEAL) trials, the American Heart Association, the American College of Cardiology, and the National Heart, Lung, and Blood Institute confirmed the ATP III LDL cholesterol goal of less than 100 mg/dL in CHD patients and indicated that further reduction to less than 70 mg/dL is reasonable for all CHD patients.

Dr Deedwania reported that after a median follow-up of 4.9 years, 629 (11.3%) patients with Met-S experienced a major cardiovascular event irrespective of treatment assignment versus 353 (8.0%) patients without Met-S (hazard ratio [HR]: 1.44; P <.001).

A major cardiovascular event was defined as death from CHD, nonfatal non-procedure related myocardial in&shy;farction, resuscitated cardiac arrest, or fatal or nonfatal stroke.

In all TNT patients randomized to atorvastatin, 10 mg/day, the risk of major cardiovascular events increased as the number of Met-S components increased (ATP III listed 5 possible Met-S components). This risk was reduced in the high-dose atorvastatin group, with increasing significance for each additional Met-S component. “Thus, the absolute risk reduction for patients with 0 to 2 components was 0.6% (HR = 0.92) versus 5.2% (HR = 0.68) for patients with 5 components,” said Dr Deedwania.

Patients with Met-S and diabetes were at highest risk of cardiovascular events. Atorvastatin, 80 mg/day, reduced the risk of cardiovascular events in the 1231 patients with Met-S and diabetes by 24% and diabetes, and by 30% in the 4353 patients without diabetes.

“Our results show that patients with CHD and Met-S have an elevated cardiovascular risk irrespective of the presence of diabetes and that these patients may benefit from aggressive lipid-lowering strategy aimed at reducing their LDL cholesterol to below 70 mg/dL,” he said.