THE INFLUENCE OF BICARBONATE SUPPLEMENTATION ON PLASMA-LEVELS OF BRANCHED-CHAIN AMINO-ACIDS IN HEMODIALYSIS-PATIENTS WITH METABOLIC-ACIDOSIS

Background. It has been hypothesized that correction of metabolic acid osis might improve the nutritional state of acidotic haemodialysis (HD ) patients partly because of a reduced oxidation of branched-chain ami no acids (BCAA). Aim. We investigated whether bicarbonate (Bic) supple mentation in acidotic HD patients results in increased plasma levels o f BCAA. Methods. In a longitudinal study (run-in period, 2 months; stu dy period, 6 months), the effect of Bic supplementation on plasma leve ls of BCAA was studied in 12 acidotic HD patients (7 men, 5 women, mea n age 54+/-18 years) with a predialysis bicarbonate (Bic) concentratio n smaller or equal to 22 mmol/l. Bic was supplemented by increasing Bi c concentration of the dialysate and by oral Bic supplementation. Resu lts. Predialysis Bic increased significantly during the study period ( 18.7+/-2.7 vs 23.1+/-11.5 mmol/l). There was no change in nutritional parameters. However, plasma levels of the BCAA valine, leucine, and is oleucine increased significantly. Conclusions. In haemodialysis patien ts with metabolic acidosis, Bic supplementation over a 6-months period resulted in an increase in plasma levels of BCAA. Further study is ne eded to elucidate the mechanisms behind, and the clinical importance o f the observed changes in plasma BCAA levels.