Supplementary Material for: Effect of Nocturnal Haemodialysis on Body Composition

Background: Haemodialysis patients have a high risk of
malnutrition which is associated with increased mortality. Nocturnal
haemodialysis (NHD) is associated with a significant increase in protein
intake compared with conventional haemodialysis (CHD). It is unclear
whether this leads to improved nutritional status. Therefore, we studied
whether 1 year of NHD is associated with a change in body composition. Methods:
Whole-body composition using dual-energy X-ray absorptiometry (DEXA)
and normalised protein catabolic rate (nPCR) were measured in 11 adult
patients before and 1 year after the transition from CHD (12 h
dialysis/week) to NHD (28-48 h dialysis/week). Similar measurements were
performed in a matched control group of 13 patients who stayed on CHD.
Differences between groups were analysed with linear mixed models. Results:
At baseline, nPCR, total mass, fat-free mass, and fat mass did not
differ significantly between the CHD and NHD groups. nPCR increased in
the NHD group (from 0.96 ± 0.23 to 1.12 ± 0.20 g/kg/day; p = 0.027)
whereas it was stable in the CHD group (0.93 ± 0.21 at baseline and 0.87
± 0.09 g/kg/day at 1 year, n.s.). The change in nPCR differed
significantly between the two groups (p = 0.027). We observed no
significant differences in the course of total mass, fat-free mass, and
fat mass during the 1-year observation period between the NHD and CHD
groups. Conclusions: One year of NHD had no significant
effect on body composition in comparison with CHD, despite a
significantly higher protein intake in patients on NHD.