Clinical risk factors demonstrate an age-dependent relationship with oxidative stress biomarkers in African Americans.

OBJECTIVE To examine the interaction of oxidative stress biomarkers with age, and also factors that influence oxidative stress such as body mass index (BMI) and fitness in a population of individuals with established higher risk of cardiovascular disease, African Americans. METHODS Blood samples were obtained from healthy college-age and middle-age to older African Americans. Participants underwent a graded exercise test. Superoxide dismutase (SOD) activity, total antioxidant capacity and thiobarbituric acid reactive substances (TBARS) levels were measured. RESULTS TBARS levels were significantly (P = .001) lower in young participants relative to middle-age to older participants. SOD activity was significantly (P = .001) lower in middle-age to older participants with low fitness relative to participants with normal fitness, and lower (P = .04) in middle-age to older participants that were overweight relative to normal weight participants. DISCUSSION In a healthy middle-age to older population of African Americans, BMI and fitness are crucial for maintaining a healthy endothelium.