Long-term weight loss as a predictor of mortality in haemodialysis patients.

Abstract

Serial weight decrease can be a prognostic predictor in chronic haemodialysis (HD) patients. We investigated the impact of long-term post-HD body weight (BW) changes on all-cause mortality among HD patients. This longitudinal cohort study and post-hoc analysis evaluated participants of a previous randomised controlled trial conducted between 2006 and 2011 who were followed up until 2018. Weight change slopes were generated with repeated measurements every 6 months during the trial for patients having ≥5 BW measurements. Participants were categorised into four groups based on quartiles of weight change slopes; the median weight changes per 6 months were -1.02 kg, -0.25 kg, +0.26 kg, and +0.86 kg. Cox proportional hazard regression was used to evaluate differences in subsequent survival among the four groups. BW trajectories were plotted with a backward time-scale and multilevel regression analysis to visualise the difference in BW trajectories between survivors and non-survivors. Among the 461 patients, 404 were evaluated, and 168 (41.6%) died within a median follow-up period of 10.2 years. The Cox proportional hazard regression adjusted for covariates and baseline BW showed that a higher rate of weight loss was associated with higher mortality. The hazard ratios were 2.02 (1.28-3.20), 1.77 (1.10-2.85), 1.00 (reference), and 1.11 (0.67-1.83) for the first, second, third (reference), and fourth quartiles, respectively. BW trajectories revealed a significant decrease in BW in non-survivors. Weight loss elucidated by serial BW measurements every 6 months is significantly associated with higher mortality among HD patients.