Morbid Obesity Is Not an Independent Predictor of Graft Failure or Patient Mortality After Kidney Transplantation

Objective Obesity is often an absolute contraindication to kidney transplant, but an internal analysis of our center's recipients suggests that not all obese populations exhibit poor outcomes. We used national data to compare outcomes in select groups of morbidly obese and normal-weight recipients after kidney transplant. Design This study was a retrospective analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing database. Subjects The study sample consisted of 30,132 morbidly obese (body mass index [BMI] 35-40 kg/m2 ) and normal-weight (BMI 18.5-24.9 kg/m2 ) patients who underwent primary kidney-only transplantation between 2001 and 2006. Main Outcome Measure Crude 3-year graft and patient survival rates of morbidly obese and normal-weight subgroups were evaluated. Logistic regression modeling compared 3-year graft failure and patient mortality in morbidly obese and normal-weight subgroups with opposite characteristics. Kaplan-Meier survival curves were created for 3-year graft and patient survival. Cox proportional hazard regression modeling was used to determine hazards for patient and graft mortality. Results No differences in crude graft and patient survival rates were seen between normal weight and morbidly obese recipients who were African American, diabetic, and 50 to 80 years of age. Morbidly obese recipients who were nondialysis dependent, nondiabetic, had good functional status, and received living-donor transplants had significantly lower 3-year graft failure and patient mortality risk compared with normal-weight recipients who were dialysis dependent, diabetic, had poor functional status, and received a deceased-donor transplant, respectively ( P < .01). Morbidly obese recipients have significantly lower graft and patient survival curves compared with normal-weight recipients; however, multivariate regression analysis reveals that morbid obesity is not an independent predictor of graft failure or patient mortality. Conclusions Morbid obesity is not independently associated with graft failure or patient mortality; therefore, it should not be used as a contraindication to kidney transplantation.