Effect of Diet and Exercise Intervention on Blood Pressure, Insulin, Oxidative Stress, and Nitric Oxide Availability

BACKGROUND: Diet and exercise can affect blood pressure and atherosclerotic risk. METHODS AND RESULTS: 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). CONCLUSIONS: 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.