Effects of antihypertensive therapy on glucose, insulin metabolism, left ventricular diastolic dysfunction and renin system in overweight and obese hypertensives

Abstract

We attempted to test the hypothesis that the direct renin inhibitor aliskiren can improve diastolic dysfunction, glucose, and insulin metabolism (GIM) in overweight and obese hypertensive patients. Seventy-eight hypertensive patients were divided into two groups: 38 treated with aliskiren for six months, and 40 treated without aliskiren but with only traditional anti-hypertensive therapy, as controls. Doppler mitral flow velocity patterns were assessed before and after aliskiren during a six-month period. GIM (three-hour intravenous glucose tolerance test) was measured after four to six weeks of washout and six months of treatment. The mitral E/A ratio increased from 0.65 ± 0.11 to 0.75 ± 0.19. None of the indexes changed in the control group. In the control group, GIM parameters, fasting glucose levels (5.3 ± 0.9 to 6.0 ± 1.5 mmol/l; p = 0.003), fasting insulin levels (121 ± 121 to 189 ± 228 pmol/l; p = 0.03), and most other relevant metabolic measures (p < 0.05 for all) significantly worsened. Aliskiren did not affect GIM. In the control group LVM/height was not affected (119 ± 12 to 120 ± 17 g/m; p = 0.8), whereas aliskiren significantly reduced LVM/height (120 ± 13 to 111 ± 19 g/m; p = 0.04). Optimal target BP was achieved in the group as a whole and in both obese patient groups, while benefits to cardiac structure were of a smaller magnitude. In high-risk, overweight/obese patients with hypertension, traditional therapy provides significantly greater BP- versus aliskiren-lowering throughout the 24-hour dosing interval. Therefore in obese, hypertensive individuals, adequate and similar blood pressure control was achieved with aliskiren; however, the aliskiren group and not the control group was associated with a more favorable GIM profile and led to a significant regression of LVM; overall aliskiren-based treatment offers sustained control of PRA.