DALLAS (AHA) - Controlling blood pressure may be the key factor in preventing cardiovascular disease in people who have diabetes, and ACE inhibitors appear the best means to that end. This conclusion comes from a "state of the science" report on diabetic hypertension that appears in this month's Hypertension: Journal of the American Heart Association.

Cardiovascular disease (CVD) is the major cause of death in diabetics. It accounts for up to 80 percent of deaths in people with type II diabetes. CVD is 7.5 times more likely among type II diabetics without a previous heart attack than in people without diabetes. In addition, hypertension is twice as frequent in diabetics, and up to 75 percent of CVD cases in people with diabetes may be attributable to hypertension. Recent data also suggest that hypertensive patients are more likely to develop diabetes than are patients with normal blood pressure.

James Sowers, M.D., professor of medicine and cell biology at the State University of New York, Brooklyn, led a team that reviewed the latest clinical trial results on diabetes, hypertension and cardiovascular disease into a single update.

"The results of these studies point toward possible direct effects of ACE inhibitors on the heart and blood vessels in addition to their effect on blood pressure," says Sowers. "The lessons learned from these studies suggest that ACE inhibitor therapy may improve insulin sensitivity and also delay the development of diabetes in patients at high risk."

Rigorous control of blood pressure to less than 130 millimeters of mercury (mmHg) systolic and 85 mmHg diastolic strikingly decreases heart attacks, strokes and end-stage renal disease in diabetic patients. Data from the Hypertension Optimal Treatment trial suggests that reduction in diastolic pressures from less than 90 to less than 85 lowers the risk of CVD even further. Systolic pressure is the top number in a blood pressure reading; diastolic is the bottom number.

ACE inhibitors have been shown to reduce the progression of renal disease and CVD in diabetic people with normal blood pressure. They may also help prevent diabetes. Sowers says the discovery that interruption of the renin-angiotensin system reduces the onset of diabetes ? as shown by the Heart Outcomes Prevention Evaluation (HOPE) and Captopril Prevention Project (CAPP) trials ? is particularly important. "ACE inhibitor therapy should be an integral component of any antihypertensive therapy in patients with diabetes."

CAPP enrolled 10,985 patients ages 25-66 with diastolic pressures of at least 100 mmHg. Patients received either captopril or conventional therapy (diuretics and/or beta-blocker), and results were tracked for six years. The diabetic group showed better outcomes across the board for individuals who received captopril. The captopril group also had an 11 percent lower risk of developing diabetes than the conventional therapy group.

In HOPE, 3,577 individuals with diabetes and documented vascular disease showed a 25 percent reduction in heart attack, stroke or death from CVD when treated with the ACE inhibitor ramipril. The group showed other improvements such as a trend toward less end-stage renal disease and eye disease. Perhaps most striking is the fact that relatively large risk reductions were achieved with comparatively small reductions in blood pressure. At the beginning of the study, patients? average blood pressure was 139/79 mmHg. While the average blood pressure reduction was only 3 mmHg systolic and 2 mmHg diastolic, study results showed a 34 percent reduction in the development of diabetes in patients without the disease at the time of their enrollment. Sowers notes that diabetic patients derived an even greater reduction in CVD than did the rest of the participants.

Co-authors include Murray Epstein, M.D., and Edward D. Frohlich, M.D.

This research was funded in part by the National Institutes of Health, the Veterans Affairs Medical Center and the American Diabetes Association.

Copyright 2001 The American Heart Association. All rights reserved.