Abstract 14264: Weight Loss-Induced Blood Pressure Reduction: Different Mechanisms Between a Calorie Restricted Diet and Exercise
Objective: The present study compared the effectiveness of a mild calorie restricted diet (D) alone, exercise (EX) alone and a combination of D+EX on weight loss-induced blood pressure (BP) reduction over 24 weeks. We focussed especially on the relationship between sympathetic nervous activity, as indicated from measures of plasma norepinephrine (NE), and insulin resistance (homeostasis model of insulin resistance, HOMA-IR).
Methods: The three groups each comprised 30 obese, hypertensive men. Body mass index (BMI), fat-mass, waist-to-hip ratio (W/H), BP, plasma NE, and HOMA-IR were measured every 2 weeks during the first 4 weeks and subsequently every 4 weeks for the next 20 weeks.
Results: All basal parameters were similar among the 3 groups. At 24 weeks, the combination group with D+EX comprised a significantly higher prevalence of normotensive subjects than the D alone or EX alone group (NT/HT at 24 weeks, D+EX 24/6, D alone 14/16, EX alone 9/21; χ2=13.92, P<0.05). In the D alone group, plasma NE was decreased significantly at 2 weeks, reductions in BMI, fat-mass and BP were observed at 8 weeks, and W/H and HOMA-IR were decreased at 12 weeks. In comparison, in the EX alone group, significant reductions of fat-mass and HOMA-IR were observed at 4 weeks. Plasma NE and HOMA-IR were significantly reduced at 8 weeks whilst decreases in BP were detected at 12 weeks. In the D+EX group, significant reductions in plasma NE were observed at 2 weeks followed by significant decreases in BMI, fat-mass, W/H, BP levels and HOMA-IR at 4 weeks. The magnitudes of reductions of all parameters were greatest in the D+EX group. In multiple regression analyses, decreases in plasma NE, HOMA-IR and leptin over 24 weeks were significant determinant variables for WL over 24 weeks, but only decreases in plasma NE was a significant determinant for BP reduction. Similarly, reductions in plasma NE, not HOMA-IR or leptin, over the first 4 weeks was a significant determinant variable for WL and BP reductions over 24 weeks.
Conclusions: A calorie restricted diet and exercise might, perhaps, exert different mechanisms on weight loss and WL-induced BP reduction, however a combination of caloric restriction and exercise is preferred to control BP levels in obese hypertensive patients.
- © 2011 by American Heart Association, Inc.