Baseline characteristics of the diabetic participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

Objective - Hypertension (HTN) is a major risk factor for cardiovascular disease (CVD) in the setting of diabetes. There is no consensus on how best to treat hypertension among those with diabetes. Here we describe the characteristics of a cohort of hypertensive adults with diabetes who are part of a large prospective blood pressure study. This study will help clarify the treatment of HTN in the setting of diabetes. Research design and methods - The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (AI.I.HAT) is a double-blind randomized trial of 42,448 high-risk hypertensive participants, ages greater than or equal to 55 years, designed to determine whether the incidence of fatal and nonfatal coronary heart disease (CHD) and combined cardiovascular events (fatal and nonfatal CHD, revascularization surgery, angina pectoris, congestive heart failure, and stroke) differs between diuretic (chlorthahdone) treatment and three alternative antihypertensive therapies: a calcium channel blocker (amlodipine), an ACE inhibitor (lisinopril), and an alpha-adrenergic blocker (doxazosin). The planned follow-up is an average of 6 years, to be completed in March 2002. Results - There are 15,297 diabetic individuals in the ALLHAT study (36.0% of the entire cohort). Of these individuals, 50.2% are male, 39.4% are African-American, and 17.7% are Hispanic. Demographic and laboratory characteristics of the cohort are similar to those of other studies of the U.S. elderly population with HTN. The sample size has 42 and 93% confidence respectively, for detecting a 16% difference between the diuretic and each of the nondiuretic treatments for the two study outcomes. Conclusions - The diabetic cohort in ALLHAT will be able to provide valuable information about the treatment of hypertension in older diabetic patients at risk for incident CVD.