The association of poverty with the prevalence of albuminuria: Data from the Third National Health and Nutrition Examination Survey (NHANES III)

Background Albuminuria is a major risk factor for the development and progression of chronic kidney disease (CKD) and cardiovascular disease. Socioeconomic factors also have been reported to modify CKD and cardiovascular risk factors and clinical outcomes. The extent to which poverty influences the prevalence of albuminuria, particularly among racial/ethnic minority populations, is not well established. The influence of poverty on the prevalence of albuminuria and the implication of this relationship for the racial and/or ethnic differences in the prevalence of albuminuria were examined. Methods: We examined data from 6,850 male and 7,634 female adults from a national probability survey conducted between 1988 and 1994. Results: In univariate analysis, poverty, defined as less than 200% federal poverty level (FPL), was associated with the presence of both microalbuminuria (odds ratio [OR], 1.35; 95% confidence interval, 1.22 to 1.49) and macroalbuminuria (OR, 1.78; 95% confidence interval, 1.40 to 2.26). The association of less than 200% FPL with microalbuminuria persisted in a multivariate model controlling for age, sex, race, education, obesity, hypertension, diabetes, reduced glomerular filtration rate, and medication use (OR, 1.18; 95% confidence interval, 1.05 to 1.33). FPL less than 200% was not associated with macroalbuminuria in the multivarlate model. When multivariate analysis is stratified by FPL (<200% and >= 200%), differences in ORs for microalbuminuria and macroalbuminuria among racial/ethnic minority participants compared with whites were more apparent among the less affluent participants in the FPL-less-than-200% stratum. Conclusion: FPL less than 200% is associated with microalbuminuria, and differences in FPL levels may account for some of the observed differences in prevalence of albuminuria between racial/ethnic minority participants and their white counterparts.