The effect of extended hemodialysis on nutritional parameters: a systematic review

Objective This systematic review provides an up-to-date synthesis on the effects of extended hemodialysis on nutritional outcomes. Design and Methods Ten databases were searched. Inclusion criteria were: randomised and non-randomised studies of extended hemodialysis (defined by > 15 h/week) with a comparator group which received conventional in-centre hemodialysis (usually ≤ 12 h per week). Outcomes of interest included lean body mass, protein and carbohydrate intake, body mass index, dry lean mass, water-soluble vitamin levels, serum levels of appetite hormones, and nutritional status as assessed by the PEW and SGA scoring tools. Results Five studies were eligible. All investigated extended nocturnal hemodialysis (one with the addition of short daily), three were in-centre and two were at home. Range of duration for the included studies was 2–18 months. These studies reported data on lean body mass, protein and carbohydrate intake, body mass index, dry lean mass and water-soluble vitamin levels. There was insufficient homogeneity between the studies to meta-analyse the data. Extended hemodialysis had no significant effects on any of the reported outcomes except for lean body mass, where a significant increase was found, and water-soluble vitamin levels, where deficiency was identified in one of the included studies. Conclusion There is currently no evidence to suggest that extended hemodialysis modalities impact nutritional parameters, although the quality of the available evidence is low. Graphical abstract