The effect of body mass index on long-term renal allograft survival

Background A number of factors have been implicated in decreasing long-term renal graft survival. Factors such as living versus cadaveric donor status, acute rejection, and HLA matching have been studied in detail. Mild obesity defined as a body mass index (BMI) of >25 has been found to have a deleterious effect on a number of physiologic processes. We studied the effect of a BMI >25 on long-term renal transplantation outcome. Methods. A total of 405 patients who underwent transplantation at Saint Barnabas Medical Center from 1990 to 1997 were evaluated. All known variables impacting on long-term graft function were collected. Multivariate analysis utilizing the Cox-proportional hazard model and Kaplan-Meier actuarial survival were applied to these risk factors. Results. BMI >25 was isolated as an independent risk factor for both decreased graft survival and patient survival (relative risk 2.0 for each). Cadaveric donor status, acute rejection, and use of azathioprine versus mycophenolate mofetil were the only other significant risk factors. Conclusions. Mild obesity before transplantation has a negative impact on long-term renal graft and patient survival.