Relationship of body mass index（BMI） to 5-year survival prognosis in maintenance hemodialysis patients

Abstract

【Objectives】　The significance of the body mass index（BMI） in hemodialysis patients in Japan is not sufficiently clear. The relationship between the 5-year survival prognosis and BMI in maintenance hemodialysis patients at our facility was investigated. 【Methods】　The 5-year survival of 988 patients undergoing maintenance hemodialysis at our institution was studied. The cumulative survival rate was calculated for each BMI stratum among the overall population, group <70 years old and group ≥70 years old. And each group was also divided with or without diabetes status. 【Results】5-year outcomes were 573 alive, 236 dead, and 179 moved out. Multivariate analysis showed that the death group had a higher proportion of males, higher prevalence of diabetes, higher age, lower serum albumin levels and lower BMI than the survival group. These results were statistically significant. There was no significant difference in cumulative survival by BMI class in the non-diabetic group aged <70 years, whereas in the diabetic group lower BMI was associated with lower cumulative survival. In the age group of ≥ 70 years, the cumulative survival rate was lower with lower BMI in both the non-diabetic group and the diabetic group, and the cumulative survival rate was lower in the diabetic group than in the non-diabetic group. The BMI cutoff for 5-year mortality in hemodialysis patients ≥70 years old was 19.7 kg/m2, with an odds ratio of 2.2278. Lower BMI tended to be associated with higher mortality from infections and lower mortality from malignancies. 【Conclusion】 5-year cumulative survival rates for hemodialysis patients tended to be lower with lower BMI, except for the non-diabetic group aged <70 years. Especially in the elderly≥70 years old, it seems important to manage nutrition so that BMI does not fall below 20kg/m2.