SAT-268 IN PATIENTS WITH DIABETES AND END STAGE RENAL DISEASE, ASSOCIATION BETWEEN BODY MASS INDEX AND RISK OF MORTALITY IS DIFFERENT IN HEMODIALYSIS AND PERITONEAL DIALYSIS

Abstract

The association between body mass index (BMI) and risk of mortality has been very variable in previous studies of patients with end stage renal disease (ESRD) and dialysis treatment. Aim: To study the association between BMI and risk of all-cause mortality in patients with diabetes and ESRD on peritoneal (PD) or hemodialysis (HD) treatment. Diabetic patients (n=3235) with ESRD (mean age 65±14 years, 67% men) on dialysis treatment (HD, n=2452 and PD, n=783) were followed for 2.0±2.2 years. The data were extracted from the Swedish Renal Register (SNR). BMI was calculated as weight (kg) / [height (m)]2 and defined as the mean BMI value during the study period. The relationships between BMI and mortality were examined by calculating hazard ratios (HR) and 95% confidence intervals (CI) using univariate and multivariate time-dependent Cox models, which adjusted for demographics, laboratory findings and comorbidity. BMI between 18.5-25 kg/m2 was used as a reference group During the study, 1688 (52%) of the patients died. 1. In the HD group: 1275 (51%) of the patients died. In group classification, in patients with normal BMI (18.5-24.9 kg/m2) 54% of patients died. Highest incidence of mortality was observed with BMI <18.5 kg/m2 and 64% of patients died. BMI>30 kg/m2 related to lowest incidence of mortality with 44%. In the multivariate analyses: BMI<18.5 kg/m2 was associated with increased risk of all-cause mortality (HR 1.57, 95% CI 1.21- 2.04; p<0.001). BMI between 30-34.9 and 35-40 kg/m2 were associated with decreased risk of mortality (HR 0.66, 95% CI 0.56- 0.78; p<0.001 and HR 0.60, 95% CI 0.46- 0.78; p<0.001, respectively). BMI>40 kg/m2 associated non significantly with the risk of mortality (p=0.52). 2. In the PD group: 413(53%) of patients died. In group classification the incidence of mortality was almost similar between 52-54 % in all groups except in group with BMI>40 kg/m2 and all patients (100%) died during the follow up time. In the multivariate analyses: BMI<18.5 and BMI= 30-34.9 or 35-40 kg/m2 did not significantly associate with the risk of all-cause mortality (p=0.31, p=0.63 and p=0.60, respectively). The BMI> 40 kg/m2 associated with increase the risk of mortality (HR 2.39, 95% CI 1.12- 5.10; p<0.001). In this study, in diabetic patients with ESRD receiving HD treatment, underweight (BMI<18.5 kg/m2) was associated with increased risk of mortality. Overweight (BMI =25-29.9 kg/m2) and class 1 obesity (BMI=30-34.9 kg/m2) were associated with improved survival.