Moderate metabolic acidosis and its effects on nutritional parameters in hemodialysis patients.

We screened the laboratory data of all of our chronic hemodialysis patients to identify 2 groups: 1) those with a pre-dialysis total CO2 concentration equal or less than 21 mEq/l (group A) and 2) those with a pre-dialysis total CO2 concentration equal or greater than 25 mEq/l (group B) and then both groups were compared for the following parameters: protein catabolic rate, dietary protein intake by dietary history, Kt/V, serum albumin, weight, pre-dialysis serum creatinine and pre-dialysis BUN. Patients from group A had a significantly lower age, a significantly higher protein catabolic rate and significantly higher values for pre-dialysis serum creatinine and BUN. The values for body weight, dietary protein intake and serum albumin were also higher in group A than in group B but the differences did not reach statistical significance. There was a good correlation between protein catabolic rate and pre-dialysis total CO2 and between the latter and serum albumin. These results suggest that moderately low pre-dialysis serum bicarbonate concentration is usually the result of high protein intake and should be of no concern in well-dialyzed patients with a protein catabolic rate greater than 1 g/kg/day. However, further studies are needed to confirm this conclusion.