Patient-related factors influencing the plasma acetate concentration during haemodialysis

In 44 adult patients, 16 men and 28 women, with chronic renal failure who were dialysed under uniform conditions (Dialyser area 1.2 m2, blood flow 200 ml/min, dialysate flow 500 ml/min, dialysis fluid acetate concentration 35 mmol/l) we determined the plasma acetate concentration after 1 h of haemodialysis (1H-Ac) and 3 h of dialysis (3H-Ac). 1H-Ac was significantly lower than 3H-Ac in both male and female patients, and both mean values were significantly greater in males than in females. 3H-Ac showed a negative correlation with body surface area, serum creatinine before dialysis, and serum albumin, respectively. Using multivariate analysis, body surface area and serum creatinine showed the strongest significant combination of independent variables (R = 0.66), and accounted for 43% of the total variance in 3H-Ac. Sex, age, serum albumin and haematocrit did not further contribute to explaining the variance in 3H-Ac independently of body surface area and serum creatinine. Assuming that serum creatinine to some extent reflects the generation rate of creatinine and thus the muscle mass of the patients, our findings suggest that the rate of metabolism of acetate is proportional to the body size and that acetate is metabolised to a large extent in skeletal muscle. Accordingly, malnutrition with muscle-wasting may lead to slow metabolism of acetate and possibly to exaggerated acetate-related side-effects.