Risk factors associated with urinary albumin excretion in African Americans

Microalbuminuria is considered a marker of heightened risk for cardiovascular events. We examined cardiovascular risk factors, including inflammatory cytokines, which contribute to urinary albumin excretion (UAE) in a cross-sectional study of African Americans aged 18-49 years. Measurements included a timed overnight urine collection for UAE, blood pressure (BP), body mass index, glucose, lipids, insulin and inflammatory cytokines. Non-normally distributed variables were log transformed for analysis using multiple linear regressions. Data were obtained from 488 participants with mean age 37.8 years; 50% were obese, 42% had hypertension. Log UAE correlated significantly with systolic BP (SBP) (geometric mean ratio=1.011; 95% confidence interval 1.003-1.019). When subjects were stratified into four UAE groups, the only variables significantly different between groups were SBP (P=0.013) and diastolic BP (P=0.036). There were no statistically significant associations with obesity, metabolic parameters, insulin resistance or any inflammatory cytokines identified. In young, relatively healthy, African Americans, BP level is significantly associated with levels of UAE even below the threshold for microalbuminuria. The presence of diabetes and insulin resistance in the absence of high BP did not seem to contribute significantly to UAE in this cohort.