Body mass index before kidney transplantation — principal risk factor for NODAT

Abstract

Purpose. Pretransplant obesity is a well-known risk factor for post-transplant outcomes such as patient and graft survival, delayed graft function, rejection, and wound complications. According to the recommendations of the European Renal Best Practice, patients who have body mass index (BMI) value of more than 30 kg/m2 before kidney transplantation should reduce their weight. Materials and methods. In the group of 297 patients who had undergone primary kidney transplantation from post-mortem donors, we found that assessed the impact of BMI on the development of new onset diabetes after transplantation (NODAT). Additionally, relationships between immunosuppression, weight gain and BMI in patients after kidney transplantation were also analysed. We measured the value of the patients’ BMI and weight before kidney transplantation, 12 months after kidney transplantation, and 5 years after kidney transplantation. The group contained only those patients who, at the time of the kidney transplantation, did not suffer from diabetes mellitus. According to the development of NODAT in the monitored period, the group of patients was divided into the control group and NODAT group. We detected analysed the data on the type of immunosuppression (tacrolimus, cyclosporine A, mTOR inhibitor) and the average levels in the monitored period and identified whether BMI or increased weight 12 months and 5 years after kidney transplantation is related to the level (or dose) of the used immunosuppression. Results. In our group, the patients who developed NODAT in the post-transplant period were significantly older in the 12-month analysis (p < 0.0001) and also in the 5-year analysis (p = 0.0001); had higher BMI at the time of transplantation (p = 0.0003) and higher BMI 12 months after kidney transplantation (p = 0.0004) and a significantly higher weight gain 12 months after kidney transplantation (p = 0.0469). We discovered that neither the level of immunosuppression nor the dose of prednisone had any effect on the increase in BMI or weight gain during the monitored period. Conclusion. The patients in the waiting list, who have any risk factors for the development of diabetes mellitus, should be informed how to eliminate these risk factors (weight control, diet, physical exercises, etc.). In addition to the above, all candidates for kidney transplantation are recommended to stop smoking, to control blood pressure, and perform a lipidogram.