Effect of diet and exercise intervention on blood pressure, insulin, oxidative stress, and nitric oxide availability.

Abstract

Diet and exercise can affect blood pressure and atherosclerotic risk. The present study was designed to examine the effects of a short-term, rigorous diet and exercise intervention on blood pressure, hyperinsulinemia, and nitric oxide (NO) availability. Men (n=11) were placed on a low-fat, high-fiber diet combined with daily exercise for 45 to 60 minutes for 3 weeks. Pre- and post fasting blood was drawn for serum lipid, insulin, 8-isoprostaglandin F(2alpha) (8-iso-PGF(2alpha)), and glucose measurements. Anthropometric parameters, blood pressure (BP), and 24-hour urinary NO metabolite excretion (NO(X)), a marker of NO bioavailability, were measured. Systolic (P<0.01) and diastolic BP (P<0.01) and 8-iso-PGF(2alpha) decreased (P<0.05), whereas urinary NO(X) increased (P<0.05). There was a significant reduction in fasting insulin (P<0.01) and a significant correlation between the decrease in serum insulin and the increase in urinary NO(X) (r2=0.68, P<0.05). All fasting lipids decreased significantly, and the total cholesterol to high-density lipoprotein cholesterol ratio improved. Although body weight and body mass index (P<0.01) decreased, obesity was still present and there were no correlations between the change in body mass index and the change in insulin, BP, or urinary NO(X). This intervention resulted in dramatic improvements in BP, oxidative stress, NO availability, and the metabolic profile within 3 weeks, mitigating the risk for atherosclerosis progression and its clinical sequelae.