Socioeconomic status and risk of kidney dysfunction: the Atherosclerosis Risk in Communities study

Abstract

Abstract Background There is strong evidence of an association between socioeconomic status (SES) and end-stage renal disease (ESRD). However, the association of SES with the risk of chronic kidney disease (CKD) and the rate of change in kidney function is unclear. Methods A cohort of 14 086 participants with an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 at baseline in the Atherosclerosis Risk in Communities study (1987–89) were studied. The association of annual household income, educational attainment and neighborhood deprivation with incident ESRD, incident CKD and change in eGFR using four measurements over ∼23 years was assessed. Results A total of 432 participants developed ESRD and 3510 developed CKD over a median follow-up time of ∼23 years. After adjustment for demographics and baseline eGFR, the hazard ratio (HR) for incident ESRD compared with the high-income group was 1.56 [95% confidence interval (CI) 1.22–1.99 in the medium-income group and 2.30 (95% CI 1.75–3.02) in the low-income group (P-trend < 0.001), and for CKD was 1.10 (95% CI 1.01–1.20) in the medium-income group and 1.30 (95% CI 1.17–1.44) in the low-income group (P-trend < 0.001). After full adjustments, the HR for ESRD was 1.33 (95% CI 1.03–1.70) in the medium-income group and 1.50 (95% CI 1.14–1.98) in the low-income group (P-trend = 0.003) and for CKD was 1.01 (95% CI 0.92–1.10) in the medium-income group and 1.04 (95% CI 0.93–1.16) in the low-income group (P-trend = 0.50). The eGFR decline was 5% and 15% steeper in the medium- and low-income groups, respectively, after full adjustment (P-trend < 0.001). Results were similar, with lower educational attainment and higher neighborhood deprivation being associated with adverse outcomes. Conclusions SES (annual household income, educational attainment or neighborhood deprivation) was associated not only with ESRD risk but also with eGFR decline, although the association with CKD appeared weaker.