Objective: Epidemiologically, there is a strong relationship between BMI and blood pressure (BP) levels. We prospectively examined randomization to first-step chlorthalidone, a thiazide-type diuretic; amlodipine, a calcium-channel blocker; and lisinopril, an angiotensin-converting enzyme inhibitor, on BP control and cardiovascular outcomes in a hypertensive cohort stratified by baseline BMI [kg/m(2); normal weight (BMI <25), overweight (BMI = 25-29.9), and obese (BMI >30)].
Methods: In a randomized, double-blind, practice-based Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, 33,357 hypertensive participants, aged at least 55 years, were followed for an average of 4.9 years, for a primary outcome of fatal coronary heart disease or nonfatal myocardial infarction, and secondary outcomes of stroke, heart failure, combined cardiovascular disease, mortality, and renal failure.
Results: Of participants, 37.9% were overweight and 42.1% were obese at randomization. For each medication, BP control (<140/90 mmHg) was equivalent in each BMI stratum. At the fifth year, 66.1, 66.5, and 65.1% of normal-weight, overweight, and obese participants, respectively, were controlled. Those randomized to chlorthalidone had highest BP control (67.2, 68.3, and 68.4%, respectively) and to lisinopril the lowest (60.4, 63.2, and 59.6%, respectively) in each BMI stratum. A significant interaction (P = 0.004) suggests a lower coronary heart disease risk in the obese for lisinopril versus chlorthalidone (hazard ratio 0.85, 95% confidence interval 0.74-0.98) and a significant interaction (P = 0.011) suggests a higher risk of end-stage renal disease for amlodipine versus chlorthalidone in obese participants (hazard ratio 1.49, 95% confidence interval 1.06-2.08). However, these results were not consistent among other outcomes.
Conclusion: BMI status does not modify the effects of antihypertensive medications on BP control or cardiovascular disease outcomes.
Trial registration: ClinicalTrials.gov NCT00000542.