Diabetes Dateline

NIH Studies CVD in People With Diabetes

Trials Examine Lifestyle Interventions and Surgical Options

The National Institutes of Health is studying the best strategies to prevent and treat cardiovascular disease (CVD) in people with diabetes in three trials: Look AHEAD, ACCORD, and BARI 2D. These studies are all joint efforts of the National Institute of Diabetes and Digestive and Kidney Diseases and the National Heart, Lung, and Blood Institute.

CVD is the leading cause of diabetes-related deaths. About 65 percent of those with diabetes die from heart disease or stroke, a rate about 2 to 4 times higher than in adults without diabetes. The increased risk can be attributed in large part to the high rate of concomitant CVD risk factors such as hypertension, dyslipidemia, and obesity in people with diabetes. However, diabetes is an independent risk factor. When people with diabetes and other risk factors are compared with people who have the same risk factors but not diabetes, people with diabetes still have higher rates of death and disability from CVD. Even though death rates from cardiovascular causes have declined for the population as a whole over the past 30 years, the decline has been much smaller in people with diabetes. In fact, the death rate from CVD in adult women with diabetes has increased over that period.

Look AHEAD: Action for Health in Diabetes

We now know that weight loss can dramatically reduce the development of type 2 diabetes in those at high risk, but we don't know whether weight loss can prevent complications in people with diabetes, or even if it is beneficial over the long term. Because support from health care providers for achievement of weight loss is costly, it is important to establish the benefits and the cost-effectiveness of weight loss in people with type 2 diabetes. To address this issue, the NIH is conducting the largest clinical trial to date to examine the long-term health effects of voluntary weight loss. This multi-center, randomized clinical trial will examine the consequences of a lifestyle intervention designed to achieve and maintain weight loss over the long term through decreased caloric intake and increased exercise. Look AHEAD will focus on the disease most associated with overweight and obesity, type 2 diabetes, and on the outcome that causes the greatest morbidity and mortality, cardiovascular disease.

In June 2001, 16 Look AHEAD Clinical Centers and a Data Coordinating Center began the 2-1/2-year process of enrolling 5,000 obese patients with type 2 diabetes. Trial participants, who will be followed for up to 11.5 years, are randomly assigned to one of two protocols, the Lifestyle Intervention, which is designed to help participants achieve and maintain weight loss over the long term, or less intensive Diabetes Support and Education. Look AHEAD will primarily study the impact of these two interventions on major cardiovascular events: heart attack, stroke, and cardiovascular death. The trial also will investigate the effect of the interventions on other cardiovascular disease-related outcomes, cardiovascular risk factors, and all-cause mortality. Additional outcomes include diabetes control and complications, fitness, general health, health-related quality of life, and psychological outcomes. The cost and cost-effectiveness will be assessed for each of the two interventions.

For more information on the Look AHEAD trial or to find a site near you enrolling volunteers, call 1–866–55AHEAD (1–866–552–4323) or visit the website at www.lookAHEADstudy.org.

Action to Control Cardiovascular Risk in Diabetes (ACCORD)

This randomized, multi-center trial is being undertaken by the NIH to study three key approaches to preventing major cardiovascular events in individuals with type 2 diabetes. The risk factors to be targeted in the ACCORD interventions are control of blood glucose, blood pressure, and lipid levels. Despite the two- to four-fold elevation of cardiovascular disease in the American population with type 2 diabetes, there is a lack of definitive data on the effects of intensive control of blood glucose on cardiovascular disease event rates in diabetic patients. ACCORD is designed to compare current practice guidelines with more intensive glycemic control in 10,000 individuals with type 2 diabetes, including those at especially high risk for cardiovascular disease events because of age, evidence of subclinical atherosclerosis, or existing clinical cardiovascular disease. More intensive control of blood pressure than is called for in current guidelines and a medication to reduce triglyceride levels and raise HDL (good) cholesterol levels will also be studied in subgroups of these 10,000 volunteers. Each treatment strategy will be accompanied by standard advice regarding lifestyle, including diet, physical activity, and smoking cessation, appropriate for diabetic individuals.

The primary outcome that ACCORD will measure is the first occurrence of a major cardiovascular disease event, specifically heart attack, stroke, or cardiovascular death. In addition, the study will investigate the impact of the treatment strategies on other cardiovascular outcomes; total mortality; limb amputation; eye, kidney, or nerve disease; health-related quality of life; and cost-effectiveness. Volunteers will be treated and followed for 4 to 8 years at approximately 70 clinical sites associated with seven clinical center networks in the United States and Canada.

For more information on the ACCORD trial, visit the website at www.accordtrial.org.

Bypass Angioplasty Revascularization Investigation in Type 2 Diabetics Trial (BARI 2D)

This 5-year, multi-center clinical trial compares medical versus early surgical management of patients with type 2 diabetes who also have coronary artery disease and stable angina or ischemia. At the same time, BARI 2D is studying the effect of two different strategies to control blood glucose—providing insulin versus increasing the sensitivity of the body to insulin—on risk of cardiovascular mortality and morbidity.

A total of 2,800 patients, both men and women, are being entered into BARI 2D at 40 clinical centers. Upon enrollment, study volunteers are randomized to receive medical therapy or either angioplasty or bypass surgery and, simultaneously, are randomly assigned to an insulin-providing or insulin-sensitizing strategy of blood glucose control.

Patients in both groups will be followed for 5 years with state-of-the-art management of risk factors, including hyperlipidemia, hypertension, and lifestyle. In addition, hyperglycemia will be aggressively treated to a hemoglobin A1C goal of 7 percent, as recommended by the American Diabetes Association. The primary trial outcome to be measured is total mortality. Secondary outcomes will also be examined, such as cardiac mortality, heart attack, angina, and quality of life.

For more information on the BARI 2D trial, visit the website at www.bari2d.org or call the nearest research site (listed on the website).

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