Effect of the correction of metabolic acidosis on nutritional status in elderly patients with chronic renal failure.

BACKGROUND: Metabolic acidosis (MA) is a frequent complication in advanced chronic renal failure (CRF). Currently, there is good evidence that MA contributes to malnutrition in CRF patients. METHODS: We evaluated the effect of correcting MA on nutritional status after 6 months of oral sodium bicarbonate supplementation in 18 patients aged 73 +/- 6 years with CRF to maintain serum bicarbonate levels at 24 +/- 2 mmol/L. The following parameters were measured: dietary record, energy intake, dietary protein intake (DPI), mini-nutritional assessment (MNA), serum albumin level, prealbumin level, prognosis inflammatory and nutritional index (PINI), and protein catabolic rate (nPCR). RESULTS: No significant changes in body weight or systolic and diastolic blood pressure were observed. Serum albumin and prealbumin levels showed a significant increase. nPCR decreased significantly. DPI, energy intake, PINI, and MNA score did not change significantly. No patient reported side effects or fluid retention during the study. CONCLUSION: Correction of MA improves serum albumin and prealbumin concentration, and it is not associated with any significant change in DPI, but induces a decrease in nPCR values. Whereas nPCR may provide an index of protein catabolism, it does not differentiate between dietary sources of protein or net catabolism of endogenous proteins. In the absence of dietary changes, the decrease in nPCR values may be attributed to a decrease in whole body protein degradation.