Racial and ethnic variations in albuminuria in the US Third National Health and Nutrition Examination Survey (NHANES III) population: associations with diabetes and level of CKD.

BACKGROUND: Racial and ethnic differences in prevalence of albuminuria in a nationally representative population with and without diabetes were assessed.

METHODS: We analyzed cross-sectional data collected for the 20,050 participants of the Third National Health and Nutrition Examination Survey (NHANES III) to determine factors that contributed to racial/ethnic differences in microalbuminuria and macroalbuminuria prevalence.

RESULTS: For the 15,522 NHANES III participants for whom relevant data were available, racial/ethnic minorities tended to be younger, be less well educated, have lower income, and be less likely to have insurance than non-Hispanic whites, findings that were similar for those with and without diabetes. After adjusting for baseline covariates and medication use, racial and ethnic minorities with and without diabetes had greater odds of albuminuria compared with whites without diabetes (blacks with diabetes, adjusted odds ratio [aOR], 2.77; 95% confidence interval [CI], 1.46 to 2.72), Mexican Americans with diabetes (aOR, 2.43; 95% CI, 1.07 to 2.11), and those of other ethnicity with diabetes (aOR, 2.93; 95% CI, 1.28 to 6.75). Of those without diabetes, blacks had 2.18-fold (95% CI, 1.44 to 3.30) and Mexican Americans had 1.81-fold (95% CI, 1.08 to 3.02) greater odds of microalbuminuria or macroalbuminuria than whites after adjustment for potential confounding factors. Stratifying by estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m(2) (<1.00 mL/s) showed similar results for racial/ethnic minorities and those with diabetes, whereas results were significant only for blacks with and without diabetes for those with an eGFR of 60 mL/min/1.73 m(2) or greater. Level of metabolic control (hemoglobin A(1c) level), systolic blood pressure, income, diuretic use, and hypertensive treatment status remained independent factors associated with albuminuria.

CONCLUSION: Racial and ethnic minorities have greater odds of albuminuria than whites with and without diabetes, which persists primarily for those with an eGFR less than 60 mL/min/1.73 m(2).