Dietary Plant Protein and Mortality Among Patients Receiving Maintenance Hemodialysis: A Cohort Study.

Abstract

RATIONALE & OBJECTIVE\nAlthough greater dietary intake of protein has been associated with beneficial health effects among patients receiving maintenance hemodialysis (MHD), the effects of plant protein intake are less certain. We studied the association of the proportion of protein intake derived from plant sources with the risk of mortality among patients receiving MHD and explored factors that may modify these associations.\n\n\nSTUDY DESIGN\nProspective observational cohort study.\n\n\nSETTING & PARTICIPANTS\n1119 Chinese hemodialysis patients aged over 18 years receiving MHD in the interval 2014 to 2015.\n\n\nPREDICTORS\nThe proportion of plant protein intake to total protein intake.\n\n\nOUTCOMES\nAll-cause mortality and cardiovascular diseases (CVD) mortality.\n\n\nANALYTIC APPROACH\nSegmented regression models were fit to examine the association of plant protein intake proportion on the risk of all-cause mortality and CVD mortality. Multivariable-adjusted Cox proportional and cause-specific hazards models were used to estimate the HRs and 95%CI for these outcomes.\n\n\nRESULTS\nThe means (standard deviation, SD) of plant protein intake normalized to ideal body weight and plant protein intake proportion were 0.6 (0.2) g/Kg/d and 0.538 (0.134), respectively. During a median follow up of 28.0 months, 249 deaths occurred with 146 of these deaths resulting from CVD. Overall, there was a U-shaped association between plant protein intake proportion and the risk of all-cause mortality, with an inflection point at 45%. Among patients with plant protein intake proportion <45%, there was a 17% lower rate of mortality with each 5% greater intake of plant protein proportion (HR, 0.83; 95%CI: 0.73-0.96). Among patients with plant protein intake proportion >45%, there was a 9% greater rate of mortality with each 5% greater intake of plant protein proportion. Similar U-shaped associations were observed for CVD mortality with an inflection point at 44%.\n\n\nLIMITATIONS\nObservational study, potential unmeasured confounding.\n\n\nCONCLUSIONS\nThere was a U-shaped association between plant protein intake proportion and the risk of all-cause and cardiovascular mortality in MHD patients. If confirmed, these findings suggest a potential avenue to improve outcomes in this patient population.