Association Between Potential Renal Acid Load and 10-Year Mortality in Patients on Hemodialysis

Higher dietary acid load (DAL) has been linked to elevated incidence and progression of chronic kidney disease. However, the association between DAL and mortality in patients on maintenance hemodialysis (MHD) has not been evaluated.

We retrospectively analyzed baseline laboratory data, self-administered diet history questionnaire results, and 10-year mortality rates in 44 patients (26 men, 67.9 ± 10.4 years) on MHD who participated in a randomized, double-blind, crossover pilot trial of rice endosperm protein supplementation, which was conducted in 2013. DAL was estimated from nutrition intake using potential renal acid load (PRAL), and patients were divided into tertiles using this score.

During the 10-year observation period, 19 patients (43%) died. A higher PRAL score was significantly associated with higher all-cause mortality. The multivariable-adjusted hazard ratio for all-cause mortality in the highest tertile of PRAL versus the lowest tertile was 3.88 (95% confidence interval [CI], 1.10-13.61). Multiple logistic regression analysis showed a significant association between higher PRAL and lower intake of green and yellow vegetables (odds ratio, 5.40; 95% CI, 1.37-21.26) and fruits (odds ratio, 4.76; 95% CI, 1.30-16.76).

Higher PRAL is positively associated with all-cause mortality, and these associations might be affected by a lower intake of fruits and vegetables in Japanese patients on MHD.