Race, APOL1 risk, and EGFR decline in the general population

The APOL1 high-risk genotype, present in approximately 13%of blacks in the United States, is a risk factor for kidney function decline in populations with CKD. It is unknown whether genetic screening is indicated in the general population. We evaluated the prognosis of APOL1 high-risk status in participants in the population-based Atherosclerosis Risk in Communities (ARIC) study, including associations with EGFR decline, variability in EGFR decline, and related adverse health events (AKI, ESRD, hypertension, diabetes, cardiovascular disease, pre-ESRD and total hospitalization rate, and mortality). Among 15,140 ARIC participants followed from 1987-1989 (baseline) to 2011-2013, 75.3% were white, 21.5% were black/APOL1 low-risk, and 3.2% were black/APOL1 high-risk. In a demographic-adjusted analysis, blacks had a higher risk for all assessed adverse health events; however, in analyses adjusted for comorbid conditions and socioeconomic status, blacks had a higher risk for hypertension, diabetes, and ESRD only. Among blacks, the APOL1 high-risk genotype associated only with higher risk of ESRD in a fully adjusted analysis. Black race and APOL1 high-risk status were associated with faster EGFR decline (P,0.001 for each). However, we detected substantial overlap among the groups: median (10th-90th percentile) unadjusted EGFR decline was 1.5 (1.0-2.2) ml/min per 1.73 m² per year for whites, 2.1 (1.4-3.1) ml/min per 1.73 m² per year for blacks with APOL1 low-risk status, and 2.3 (1.5-3.5) ml/min per 1.73 m² per year for blacks with APOL1 high-risk status. The high variability in EGFR decline among blacks with and without the APOL1 high-risk genotype suggests that population-based screening is not yet justified.