Successful Kidney Transplantation Is Associated With Weight Gain From Truncal Obesity and Insulin Resistance.

OBJECTIVE: The objective of this study is to compare changes in body composition, lifestyle factors, and metabolic responses occurring in living kidney transplant recipient patients after transplantation. DESIGN AND METHODS: The study was a single-site, prospective, observational study. To identify metabolic responses during the initial years after transplantation, we obtained state-of-the-art, high-resolution measurements of body composition from a 4-compartment model using dual-energy X-ray absorptiometry, air displacement plethysmography, and total body potassium and nitrogen counters. We also assessed dietary recalls and actigraphy before transplantation and 3- and 12-month after transplantation. The study was conducted at a quaternary care hospital outpatient transplant center and a United States Department of Agriculture Agricultural Research Service center. Thirty-one adults receiving a living donor kidney allograft were studied. The main outcome measures were change in body composition at 3 months and 1 year after transplantation, and this was correlated with the occurrence of insulin resistance. RESULTS: In patients receiving a successful kidney transplant from living donors treated with standard immunosuppression, significant increases in body weight were detected at 3 and 12 months after transplantation (2.2 kg, P = .03 and 6.6 kg, P < .0001, respectively). Weight gain was principally due to adipose tissue accumulation in the truncal region. There was no increase in muscle mass or fluid accumulation. Weight gain was not associated with changes in resting energy expenditure or physical activity. Notably, increases in visceral and subcutaneous adipose tissue were positively correlated with insulin resistance. CONCLUSION: Successful transplantation was associated with increased insulin resistance and weight gain without increases in muscle or fluid. This metabolic pattern suggests potential interventions that could prevent or mitigate the consequences of adipose tissue accumulation in transplant recipients.