Abstract: 【Abstract】 Objective To evaluate the role of dialysis dose and metabolic acidosis on nutrition status. Methods We measured serum HCO3, pH, serum albumin, normalized protein catabolic rate (PCRn), Kt/V and body mass index (BMI) before dialysis in 42 uremic patients on maintenance bicarbonate hemodialysis (HD) for 100±37 months. Patients with chronic liver diseases, malignancies, and cachexia were excluded. Results Their mean age was 61±13 years, Kt/V 1.34±0.15, PCRn 1.09±0.06 g/kg/day, serum albumin 39.3±3.3 g/L, BMI 20±2.3 kg/m2, HCO3 21.0±2.4 mmol/l, and pH 7.36±0.06. Serum albumin correlated positively with PCRn (P<0.05), HCO3- (P<0.05) and pH (P<0.05), but not with Kt/V and BMI. Serum HCO3- inversely correlated with PCRn (P<0.05). Linear regression analysis confirmed the significant role of serum bicarbonate, age and PCRn on serum albumin concentration, and the insignificant role of Kt/V on serum albumin. We then divided the patients into two groups. Serum albumin was 36.9±2.3 g/L in the group with HCO3-< 20 mmol/l, and was 41.1±2.8 g/L in the group with serum HCO3 > 20 mmol/L (P<0.05). PCRn was 1.08±0.07 g/kg/day in the former group and was 1.09±0.06 g/kg/day in the latter group. Serum albumin did not affected by dialysis dose (Kt/V ranging from 0.95 to 1.82). Conclusions In HD patients with adequate Kt/V, metabolic acidosis is a detrimental effect on serum albumin concentration, and is unrelated to protein intake as evaluated by PCRn. In patients with moderate to severe metabolic acidosis, PCRn can not appropriately reflect the dietary protein intake of the patients, probably due to the increased catabolism of endogenous proteins.

Key words: Haemodialysis, Nutrition, PCRn, Kt/V