POS-599 EXTENDED-HOURS HEMODIALYSIS WITH LIBERALIZED DIET IS ASSOCIATED WITH REDUCED RISK OF NON-CARDIOVASCULAR MORTALITY IN ELDERLY DIALYSIS PATIENTS

Abstract

As the world’s population ages, it is becoming more difficult to improve a prognosis of dialysis patients. Moreover, there are growing concerns about strict dietary restrictions on elderly hemodialysis (HD) patients and consequently the deterioration of nutritional status. Extended-hours HD (≥6 hours per session) is able to offer a liberalized dietary intake strategy as well as better metabolic status and hemodynamic stability. Our hypothesis is that extended-hours HD without dietary restrictions improves survival especially in non-cardiovascular mortality in elderly dialysis patients who are prone to malnutrition. The aim of the present study was to clarify the association between extended-hours HD and non-cardiovascular mortality comparing to conventional HD. A retrospective cohort study including 198 consecutive patients who started in-center daytime extended-hours HD (Extended-HD) and 1407 consecutive patients who initiated conventional HD of less than 6 hours per session (Conventional HD) was performed. The main outcome was non-cardiovascular death. The baseline was defined as the time to start outpatient maintenance dialysis. Patients were followed from baseline up to the first 5 years. Kaplan-Meier analysis was used for the survival analysis. The association between treatment groups and non-cardiovascular mortalitywere analyzed using Cox proportional hazard model with multivariable adjustments and propensity-score based method. We also examined competing risk analysis setting the competing event as cardiovascular death. Multivariable adjustment was performed using age, sex, body mass index, serum albumin, hemoglobin, diabetes, cardiovascular disease, malignancy, and vascular accesses. The median age was 67.1 [54.7-75.5] years in the Extended-HD and 70.7 [62.1-78.0] years in the Conventional HD group. Extended-HD group had a higher prevalence of diabetes (63% vs. 55%) compared to the Conventional HD group. During a median follow-up period of 3.6 years, 225 non-cardiovascular deaths were observed. Extended-HD group showed better event-free survival on non-cardiovascular mortality than Conventional HD overall and for the subgroup >70 years of age on Kaplan-Meier analysis (log-rank P < 0.001, P = 0.002, respectively). In the fully adjusted Cox proportional hazard model, Extended-HD was associated with a reduced risk of non-cardiovascular mortality in overall patients and the subgroup >70 years (adjusted hazard ratios of 0.39 [95% CI, 0.17-0.88] and 0.20 [95% CI, 0.05-0.81], respectively). The competing risk regression model with fully adjustment also suggested the lower risk of non-cardiovascular mortality in the Extended-HD than the Conventional HD (subdistribution hazard ratio of 0.46 [95% CI, 0.23-0.93]). In-center daytime extended-hours HD with liberalized dietary approach was associated with a lower risk of non-cardiovascular mortality than conventional HD. This relationship was also evident in subgroup of elderly patients aged over 70 years.