P-472: Fat impairs stress-induced pressure natriuresis in African-American boys

We hypothesize that impaired stress-induced pressure natriuresis is a pathophysiologic mechanism underlying obesity-associated hypertension in African-Americans. In this study 55 African-American boys and 71 girls aged 15–18 years underwent a 5-hour stress protocol (2 hour baseline, 1 hour stress, 2 hour recovery) after being brought into similar levels of sodium balance. Dual-energy x-ray absorptiometry was performed to determine total percent body fat. Both girls and boys showed significant increases from baseline to stress and significant decreases from stress to recovery for blood pressure and sodium excretion (P