Association of Socioeconomic Status and CKD Among African Americans: The Jackson Heart Study

Background: Socioeconomic status (SES) is recognized as a key social environmental factor because it has implications for access to resources that help individuals care for themselves and others. Few studies have examined the association of SES with chronic kidney disease (CKD) in high-risk populations. Study Design: Single-site longitudinal population-based cohort. Setting & Participants: Data for this study were drawn from the baseline examination of the Jackson Heart Study. The analytic cohort consisted of 3,430 African American men and women living in the tricounty region of the Jackson, MS, metropolitan area with complete data to determine CKD status. Predictor: High SES (defined as having a family income at least 3.5 times the poverty level or having at least 1 undergraduate degree). Outcomes & Measurements: CKD (defined as the presence of albuminuria or decreased estimated glomerular filtration rate [<60 mL/min/1.73 m(2)]). Associations were explored using bivariable analyses and multivariable logistic regression analyses adjusting for CKD and cardiovascular disease risk factors, as well as demographic factors. Results: The prevalence of CKD in the Jackson Heart Study was 20% (865 of 3,430 participants). Proportions of the Jackson Heart Study cohort with albuminuria and decreased estimated glomerular filtration rate were 12.5% (429 of 3,430 participants) and 10.1% (347 of 3,430 participants), respectively. High SES was associated inversely with CKD. The odds of having CKD were 41% lower for affluent participants than their less affluent counterparts. There were no statistically significant interactions between sex and education or income, although subgroup analysis showed that high income was associated with CKD in men (OR, 0.47; 95% CI, 0.23-0.97), but not women (OR, 0.64; 95% CI, 0.40-1.03). Limitations: Models were estimated using cross-sectional data. Conclusion: CKD is associated with SES. Additional research is needed to elucidate the impact of wealth and social contexts in which individuals are embedded and the mediating effects of sociocultural factors. Am J Kidney Dis 55: 1001-1008. (C) 2010 by the National Kidney Foundation, Inc.