The association between dietary energy intake and the risk of mortality in maintenance haemodialysis patients: a multi-centre prospective cohort study

Maintenance haemodialysis (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 eight centres was conducted. DEI was assessed by three 24-h diet recalls and was normalised 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, 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 <167 center dot 4 kJ/kg IBW per d (hazard ratio (HR) 0 center dot 98; 95 % CI 0 center dot 96, 1 center dot 00) and increased significantly with the increase of DEI in those with DEI >= 167 center dot 4 kJ/kg IBW per d (HR 1 center dot 12; 95 % CI 1 center dot 04, 1 center dot 20). Similarly, the risk of CVD mortality decreased with the increase of DEI in participants with DEI <152 center dot 7 kJ/kg IBW per d (HR 0 center dot 96; 95 % CI 0 center dot 93, 0 center dot 99) and increased with the increase of DEI in participants with DEI >= 152 center dot 7 kJ/kg IBW per d (HR 1 center dot 11; 95 % CI 1 center dot 04, 1 center dot 18). In summary, there was a U-shaped association between DEI and all-cause or CVD mortality, with a turning point at about 167 center dot 4 and 152 center dot 7 kJ/kg IBW per d, respectively, in MHD patients.