Crews DC, et al. - Among US adults with chronic kidney disease, the relation of dietary acid load (DAL) to racial/ethnic differences in the risk of end-stage renal disease (ESRD) was assessed. As per findings, DAL had a stronger association with progression to ESRD among non-Hispanic black (NHB) than non-Hispanic white (NHW).

Methods

• Researchers estimated DAL among 1,123 NHB and NHW National Health and Nutrition Examination Survey III participants with estimated glomerular filtration rate 15–59 mL/min/1.73 m².
• They used the Remer and Manz net acid excretion (NAEes) formula and 24-h dietary recall to estimate DAL.
• Via linkage with Medicare, they ascertained ESRD events.
• They used a competing risk model (accounting for death) to determine the hazard ratio (HR) for treated ESRD, comparing NHBs with NHWs, adjusting for demographic, clinical and nutritional factors (body surface area, total caloric intake, serum bicarbonate, protein intake), and NAEes.
• Furthermore, they tested if the relation of NAEes with ESRD risk varied by race/ethnicity.

Results

• NHBs showed greater NAEes (50.9 vs 44.2 mEq/day) at baseline, than NHWs.
• Over a median of 7.5 years, 22% developed ESRD.
• Comparing NHBs to NHWs, the unadjusted HR was 3.35 (95% CI 2.51–4.48) and adjusted HR (for factors above) was 1.68 (95% CI 1.18–2.38).
• NHBs showed a stronger association of NAE with risk of ESRD (adjusted HR per mEq/day increase in NAE 1.21, 95% CI 1.12–1.31) than NHWs (HR 1.08, 95% CI 0.96–1.20), p interaction for race/ethnicity × NAEes = 0.004.