Correction of metabolic acidosis on serum albumin and protein catabolism in hemodialysis patients.

BACKGROUND: The effect of the correction of metabolic acidosis (MA) on serum albumin concentrations (sAlbs) in hemodialysis (HD) patients is controversial. This study evaluated the role of the correction of MA on sAlb concentrations, normalized protein catabolic rate (nPCR), and the effect of the concomitant inflammatory status, in a group of acidotic HD patients.

METHODS: The correction of MA by oral supplementation with sodium bicarbonate, and the evaluation of its effect on sAlb, nPCR, and high-sensitivity C-reactive protein (hsCRP), were performed in 29 patients on bicarbonate dialysis for a median of 30 months. Other variables included pre-HD arterial pH, serum bicarbonate, serum creatinine, serum Na, body weight, interdialytic weight gain, pre-HD systolic and diastolic blood pressure, and Kt/V.

RESULTS: Serum bicarbonate and pH increased significantly (P < .0001), from 19.1 +/- 0.7 mmol/L to 24.6 +/- 1.1 mmol/L and from 7.33 +/- 0.03 to 7.39 +/- 0.02, respectively (all values with +/- are SD). The nPCR decreased from 1.13 +/- 0.14 g/kg/day to 1.05 +/- 0.14 g/kg/day (P < .0001). The other variables did not change significantly. In 17 patients with high-sensitivity C-reactive protein <10 mg/L, sAlb increased from 3.7 +/- 0.3 g/dL to 4.0 +/- 0.3 g/dL (P < .01), whereas in 12 with high-sensitivity C-reactive protein >or=10 mg/L, sAlb did not change (3.5 +/- 0.17 g/dL vs. 3.4 +/- 0.13 g/dL; P = NS).

CONCLUSIONS: Oral sodium bicarbonate supplementation is effective in correcting MA in HD patients and does not affect interdialytic weight gain, plasma Na, and blood pressure. The correction of MA is effective in reducing protein catabolism (nPCR) in both inflamed and less inflamed HD patients, but increases sAlb only in patients without inflammation. In inflamed patients, the correction of MA is not sufficient per se to improve sAlb concentrations.