Background: African Americans have a higher prevalence of and mortality rates from cardiovascular disease than Caucasians. One important risk factor for cardiovascular disease is poor cardiovascular fitness. We quantified associations between fitness and related primary risk factors for cardiovascular disease in healthy African Americans and Caucasians.
Methods and results: Participants included African American (n = 91) and Caucasian (n = 51) men and women aged 18 to 45 years with a body mass index less than 38 kg/m2, fasting blood glucose less than 126 mg/dL, and blood pressure less than 140/90 mm Hg. Fitness, waist and hip circumference, percent body fat, fasting blood glucose, insulin, lipid profiles, and C-reactive protein (CRP) were measured. The majority of African Americans (57.1%) were low-fair fitness (Caucasians, 31.4%), and only 20.8% were good/high fitness (Caucasians, 39.2%). The number of cardiovascular disease risk factors increased with decreasing fitness, and CRP was negatively associated with fitness in both groups.
Conclusions: Low fitness may characterize apparently healthy African Americans as at risk for cardiovascular disease. Including fitness as a risk factor may improve early identification of at-risk African Americans. Importantly, prescribing exercise as medicine and promoting regular physical activity to improve fitness is essential among African Americans.