Long-term oral sodium bicarbonate supplementation does not improve serum albumin levels in hemodialysis patients

Abstract

Metabolic acidosis, a frequent event in hemodialysis patients, has been implicated as a potential cause of protein-energy malnutrition. Unfortunately, correction of metabolic acidosis by means of high bicarbonate concentration in the dialysate does not seem to lead to significant changes in nutritional parameters. The project was a single-arm, open-label, 12-month pilot study at a university-based tertiary care center aimed at evaluating whether correction of metabolic acidosis through long-term oral sodium bicarbonate supplementation improves serum albumin levels and other nutritional parameters in patients undergoing maintenance hemodialysis. Twenty highly acidotic hemodialysis patients patients were invited to consume an oral supplementation of sodium bicarbonate (1 g, thrice daily), for 12 months. Patients were followed at baseline and every month, until month 12. At each follow-up visit, dry body weight, BMI, blood pressure, presence of edema, venous bicarbonate, and serum albumin were measured. Total lymphocyte count, fasting total cholesterol and C-reactive protein were assessed every 2 months. At baseline and at 12 months, the subjective global assessment of nutritional status and the protein equivalent of nitrogen appearance normalized to actual body weight were determined. Plasma bicarbonate level rose from 18.1 +/- 2.7 to 22.1 +/- 4.5 mmol/l after 10 months (p = 0.001). Mean serum albumin levels were 3.8 +/- 0.2 mg/dl at baseline and 3.9 +/- 0.2 at the end of the study. Repeated measure ANOVA showed that there was no significant effect of bicarbonate treatment on serum albumin levels (p = 0.29), dry weight (p = 0.1), serum total cholesterol (p = 0.97), total lymphocyte count (p = 0.69), or C-reactive protein (p = 0.85). Mean subjective global assessment score was 4.53 +/- 0.37 at baseline and 4.58 +/- 0.54 at 12 months (p = 0.1). Mean nPNA (g/kg/day) was 0.86 +/- 0.05 at baseline and 0.85 +/- 0.08 at month 12. The present study demonstrates that long-term oral sodium bicarbonate at the dose of 1 gram thrice daily has no significant effect on nutritional status of HD patients.