The association between dietary energy intake and the risk of mortality in maintenance hemodialysis patients: a multicenter prospective cohort study.

Maintenance hemodialysis (MHD) is the use of a machine to filter wastes, salts and fluid from blood for at least 3 months to prolong the life of patients with advanced kidney failure. Although low dietary energy intake (DEI) has been observed in MHD patients, few studies have related DEI to the risk of mortality. To explore this relationship, a study included 1039 MHD patients from 8 centers was conducted. DEI was assessed by three 24-hour diet recalls including one dialysis day and two non-dialysis days, and was normalized to ideal body weight (IBW). All-cause mortality and CVD mortality were the primary and secondary outcomes, respectively. During a median follow-up of 28 months, all-cause and CVD mortality occurred in 230 (22.1%) and 140 (13.5%) participants. Overall, a U-shaped relationship was observed between DEI and all-cause or CVD mortality. The risk of all-cause mortality decreased significantly with the increase of DEI in participants with DEI <40kcal/kg IBW/d (HR, 0.98; 95% CI: 0.96-1.00) and increased significantly with the increase of DEI in those with DEI ≥40kcal/kg IBW/d (HR, 1.12; 95%CI: 1.04-1.20). Similarly, the risk of CVD mortality decreased with the increase of DEI in participants with DEI <36.5kcal/kg IBW/d (HR, 0.96; 95%CI: 0.93-0.99) and increased with the increase of DEI in participants with DEI ≥36.5kcal/kg IBW/d (HR, 1.11; 95%CI: 1.04-1.18). In summary, there was a U-shaped association between DEI and all-cause or CVD mortality, with a turning point at about 40 and 36.5 kcal/kg IBW/d, respectively, in MHD patients.