Acute hyperlipidemia increases oxidative stress more in African Americans than in white Americans

Oxidative stress emerges as a potential factor in the pathogenesis of hypertension and a common signal transduction mechanism by which various risk factors mediate cardiovascular and renal disease. A greater level of oxidative stress could contribute to higher rates of hypertension and related cardiovascular and renal complications in African Americans than in white Americans. The objective of this study was to compare oxidative stress induced by a standardized episode of acute hyperlipidemia in the two groups. Fifteen African Americans (37 +/- 1 years, 9 women/6 men, body mass index 30 +/- 2 kg/m(2)) and 15 whites (38 +/- 2 years, 9 women/6 men, body mass index 27 +/- 1 kg/m(2)) were evaluated. Acute hyperlipidemia was induced by a 4-h long infusion of Intralipid and heparin. Blood samples were drawn at baseline and after 2 and 4 h of acute hyperlipidemia for nonesterified fatty acids, triglycerides, and F2-isoprostanes, a biomarker of oxidative stress. Plasma nonesterified fatty acids and triglycerides increased significantly and similarly in African Americans and whites after 2 and 4 h of the Intralipid and heparin infusion. Although baseline plasma F2-isoprostanes did not differ between groups, F2-isoprostanes increased more in African Americans than in whites at 2 h (12.2 +/- 2.6 v 5.0 +/- 2.9 pg/mL, P < .05) and 4 h (13.9 +/- 3.1 v 3.0 +/- 3.0 pg/mL, P < .05) of acute hyperlipidemia. The results indicate that acute hyperlipidemia increases F2-isoprostanes more in African Americans than in whites. The findings may have important implications for ethnic differences in the prevalence of hypertension and cardiovascular and renal disease. (C) 2003 American Journal of Hypertension, Ltd.