Impact of different immunosuppressive protocols on clinical outcomes in obese kidney transplant recipients: A propensity score matched analysis

Abstract Background Although obesity has become a significant problem in transplantation medicine, the impact of different immunosuppressive protocols on clinical outcomes in obese transplant recipients remains unclear. Methods We performed an analysis of the Scientific Registry of Transplant Recipients (SRTR) database. Kidney transplant recipients were categorized according to BMI categories and immunosuppressive protocols: I) Tacrolimus/Mycophenolat-Mofetil (Tac-MMF), II) mTOR-Inhibitor/Tac (mTORi-Tac), III) mTORi/Cyclosporin (mTORi-Cyc) and IV) mTORi/MMF. Results Graft recipients with advanced obesity (BMI ≥ 35 kg/m2) exhibited significantly lower rates of acute rejection (AR) during the first year after transplantation in the mTORi-Tac (6.4%) group compared to Tac-MMF (11.2%). Obesity class I (30 < BMI < 35 kg/m2) was associated with a significant risk of graft loss for the mTORi-Tac group (Obese 1 HR: 1.79, 95% CI 1.21–2.62, p value = 0.003). Similar trend was observed in the mTORi-Tac group for advanced obesity HR: 1.29, 95% CI 0.96–1.73 p = 0.087). For the Tac-MMF group, recipients with both overweight and obesity had significantly impaired survival due to cardiovascular events and also increased mortality due to infection in advanced obesity. Combination of mTORi and CNI was associated with lower rejection rates and stable long-term kidney function while reducing cardiovascular side effects linked to CNIs in obese kidney graft recipients. Conclusion These results are critical for the growing number of obese graft recipients and warrant prospective evaluation.