The effect of dialysis dose and membrane flux on nutritional parameters in hemodialysis patients: Results of the HEMO Study

Background. The effect of standard or high dialysis dose and low or high dialysis flux on nutritional status was ascertained in 1846 maintenance hemodialysis patients enrolled in the HEMO Study. Methods. Serum albumin levels, equilibrated protein catabolic rate, and postdialysis weight were obtained monthly, while adjusted protein and energy intake, self-reported appetite assessment, upper arm circumference, and calf circumference were obtained yearly. To account for patient attrition due to death or transfer, three statistical models were used to test the effects of the study interventions on longitudinal changes in nutritional parameters. Results. During the first 3 years of follow-up, neither mean serum albumin levels, which declined by 0.21 g/dL, nor mean postdialysis weight, which declined by 2.7 kg, were significantly affected by either study intervention. Mean levels of all anthropometric measures declined during follow-up. For years 1, 2, and 3, the mean SE declines in upper arm and calf circumferences were 0.35 0.16 cm (P=0.031) and 0.31+/-0.13 (P=0.015) cm less, respectively, in the high flux compared to the low flux group. Appetite scores and mean equilibrated protein catabolic rate also declined in all randomized groups; however, the average decline in equilibrated protein catabolic rate during years 1, 2, and 3 was 0.019+/-0.007 g/kg/day less in the high dose than the standard dose group (P=0.007). There was no significant change in either mean energy or protein intake from diet records over time, and neither parameter was affected by the study interventions. Conclusion. Although the dose and flux interventions may subtly influence certain nutritional parameters, neither intervention prevented deterioration in nutritional status over time.