Pretransplantation and Posttransplantation Body Mass Indices and Prognosis in Renal Transplant Recipients: Low Versus Normal

Abstract

Body mass index (BMI) is strongly associated with outcomes in renal transplantation, independent of other risk factors. The aim of this study was to evaluate the impact of low BMI on graft survival in renal transplant recipients. The demographic and laboratory data as well as presence of acute or chronic rejection were retrospectively obtained for 115 recipients (80 men, 35 women) of mean age 34.56 ± 11.14 years with posttransplantation follow-up duration of 5 years. Pretransplantation and one year posttransplantation BMIs were calculated. Patients were stratified to 2 groups according to their posttransplantation BMIs: group 1 had BMIs <19 kg/m 2 (17.8 ± 1.0; n = 23), and group 2 had BMIs ≥19 kg/m 2 (23.7 ± 1.8; n = 92). Twenty (87.0%) of 23 patients had low pretransplantation BMIs ( P < .0001). Although mean serum creatinine levels at discharge after transplantation were lower among the low-BMI group ( P < .03), the fifth-year levels were significantly higher in this group than in the normal-BMI group ( P = .01). Follow-up serum albumin, triglyceride, and cholesterol levels were lower in group 1. According to the 5-year data, the percentages of recipients who suffered from chronic rejection (73.9% vs 20.7%; P < .001) and graft loss (73.9% vs 31.5%; P < .001) were significantly higher among group 1 than group 2. Multivariate backward analysis disclosed that BMI was closely associated with chronic rejection ( P < 0.0001; odds ratio = 14.5; 95% confidence interval 4.3–49.6). In conclusion, a low BMI is an adverse prognostic factor after transplantation. To improve graft outcome, we recommend pretransplantation evaluation of recipient metabolic status, as well as early intensive dietary advice and follow-up for normalization of BMI.