CORRECTION OF METABOLIC-ACIDOSIS AND ITS EFFECT ON ALBUMIN IN CHRONIC-HEMODIALYSIS PATIENTS

Serum albumin concentration has been strongly associated with risk of death in hemodialysis patients, with mortality increasing as albumin d ecreases. Metabolic acidosis stimulates protein catabolism and decreas es protein synthesis. A study was undertaken to investigate the effect of increasing predialysis serum bicarbonate (HCO3) concentrations on the nutrition of hemodialysis patients as measured by albumin and tota l lymphocyte count (TLC). Metabolic acidosis was defined as a predialy sis serum bicarbonate concentration of less than or equal to 18 mEq/L. Thirty-six hemodialysis patients were enrolled in the study. Each had been stable on hemodialysis for greater than or equal to 3 months and each had a mean serum bicarbonate concentration of less than or equal to 18 mEq/L on predialysis monthly laboratory values during the prece ding 3 months. The subjects were randomized into 2 groups. The first g roup consisted of 18 control subjects who were dialyzed on a standard bicarbonate bath of 35 mEq/L. The second group consisted of 18 experim ental patients who were dialyzed on a bicarbonate bath of 40 mEq/L, Su bjects in the experimental group who had predialysis serum bicarbonate concentrations less than 22 mEq/L after 2 weeks on the higher bicarbo nate bath were additionally supplemented with oral sodium bicarbonate at a dosage of 1 mEq/kg dry weight/d. Monthly predialysis laboratory v alues were checked for all subjects and included serum electrolytes, b lood urea nitrogen, calcium, and albumin. TLCs were obtained at the in itiation and at the conclusion of the study. Intact parathyroid hormon e, blood pressures, and interdialytic weight gains were also followed. The study lasted 16 weeks; 32 subjects completed the study (16 in eac h group). There were no statistically significant differences between the two groups at the initiation of the study. The serum bicarbonate c oncentrations were significantly different between the two groups at t he end of the study (control HCO3 17.3 +/- 3.2 mEq/L v experimental HC O3 20.2 +/- 2.9 mEq/L; P = 0.01). Serum albumin concentrations and TLC s were not statistically different (P > 0.05) between the two groups a t the end of the study (control albumin 3.88 +/- 0.28 g/dL v experimen tal albumin 3.76 +/- 0.26 g/dL and control TLC 1,780.0 +/- 779.4/mm(3) v experimental TLC 2,020.1 +/- 888.0/mm(3)). Potassium, intact parath yroid hormone, interdialytic weight gain, blood pressures, Kt/Vs, and protein catabolic rates did not differ. We found that the change in se rum bicarbonate concentration was well-tolerated and was without any d emonstrable side effects. We conclude that increasing the serum bicarb onate concentration by 3 mEq/L for 16 weeks has no effect on the indic ators of nutrition that we measured (serum albumin and TLC). (C) 1998 by the National Kidney Foundation, Inc.