Kidney transplantation is the treatment of choice for end stage renal disease. Improvement of transplant technology has lowered the rate of acute rejection, but until now there has not been an appreciable change in long term- results. Chronic renal allograft dysfunction is the most common cause of graft loss; multiple risk factors have been introduced for this phenomenon; including obesity before transplantation, which is thought to lower long-term renal allograft survival.
182 patients undergone kidney transplantation in Southern Iran Organ Transplant Center were studied. Body mass index (BMI) at date of transplant was calculated for patients by standard formula [weight (kg)/height _(m)]. BMI values were categorized into four categories: 1) patients with BMI less than 20, 2) 20> BMI <25, 3) 25> BMI <30, and 4) BMI> 30. The mean follow up period in this study was 3 years after transplantation. Renal allograft dysfunction was described with serum creatinine more than 1.8 mg/dl, admission in hospital due to allograft dysfunction, kidney biopsy and pathologic diagnosis of graft rejection, and receiving steroid pulse therapy. The link between categorized BMI and the presence of renal allograft dysfunction and mortality within 3 years post transplant was investigated using independent sample t-test by SPSS software version 11.5. BMI at date of transplantation showed statistically significant association with presence of renal allograft dysfunction and mortality within 3 years post transplantation (p= 0.008, p=0.01), in a way that development of renal allograft dysfunction and mortality rate in underweight category (BMI <20) was more than in normal BMI group (20> BMI <25); and there was a significant increase in development of graft dysfunction and mortality rate with increase in BMI in patients with BMI above 25 kg/m2. BMI at date of transplantation has a strong association with outcomes after renal transplantation. The extremes of very high and very low BMI are important risk factors for chronic renal allograft dysfunction; therefore, weight adjustment before kidney transplantation can be useful in improving the function of transplanted kidney and increasing patients’ survival.