Life Course Socioeconomic Status, Allostatic Load, and Kidney Health in Black Americans

Background and objectives Low socioeconomic status confers unfavorable health, but the degree and mechanisms by which life course socioeconomic status affects kidney health is unclear. Design, setting, participants, 63% female), cumulative lifetime socioeconomic status ranged from −3.3 to 2.3, and 673 (20%) had prevalent CKD. After multivariable adjustment, lower cumulative lifetime socioeconomic status was associated with greater prevalence of CKD both directly (odds ratio OR, 1.18; 95% confidence interval 95% CI, 1.04 to 1.33 per 1 SD and OR, 1.45; 95% CI, 1.15 to 1.83 in lowest versus highest tertile) and via higher allostatic load (OR, 1.09; 95% CI, 1.06 to 1.12 per 1 SD and OR, 1.17; 95% CI, 1.11 to 1.24 in lowest versus highest tertile). After a median follow-up of 8 years (interquartile range, 7–8 years), mean annual eGFR decline was 1 ml/min per 1.73 m 2 (SD 2), and 254 out of 2043 (12%) participants developed incident CKD. Lower cumulative lifetime socioeconomic status was only indirectly associated with greater CKD incidence (OR, 1.04; 95% CI, 1.01 to 1.07 per 1 SD and OR, 1.08; 95% CI, 1.02 to 1.14 in lowest versus highest tertile) and modestly faster annual eGFR decline, in milliliters per minute (OR, 0.01; 95% CI, 0.00 to 0.02 per 1 SD and OR, 0.02; 95% CI, 0.00 to 0.04 in lowest versus highest tertile), via higher baseline allostatic load. Conclusions Lower cumulative lifetime socioeconomic status was substantially associated with CKD prevalence but modestly with CKD incidence and eGFR decline via baseline allostatic load.