Extended Treatment Time on Hemodialysis: Effect on Hydration and Nutritional Status

Background: The association of nutritional status on mortality is established. However the effect on nutritional status by extending Treatment time (TT) on in-centre day HD is unknown. Methods: Randomised cross-over study of 29 in-centre HD patients with extended TT of 6 hr or standard TT of 4 hr for a period of 24 wks with a 4wk washout period between the two arms (NCT01721421). Nutritional status was measured using hand grip strength (HGS), bioimpedance spectroscopy (BIA) and Malnutrition infl ammation score (MIS). Results:29 HD patients (27 male, mean age 65.2 ± 15.2 years, pre study TT 4.6 ±0.4hrs) were assessed.There was a significant increase in extracellular water (ECW) on the 4 hr arm which may have masked a decline in fl esh weight. On the 6 hr arm, there was no change in hydration status, but there was a trend towards improved nutritional status with a lower MIS (p=0.06). There was also a signifi cant reduction (p<0.0001) in serum phosphate levels without increased phosphate binder use, despite matching blood volume processed to that of the 4 hr arm. Conclusions: This randomised crossover study shows increased ECW during 4 hr TT and some improvement in nutritional markers during 6 hr TT. Further studies are needed to more robustly investigate the presence of a nutritional effect.