Weight gain, and especially visceral fat gain early after kidney transplantation has a worse outcome for metabolic disorder, graft function, and cardiovascular disease. The mammalian target of rapamycin (mTOR) is a regulator of metabolism and associated with obesity. The aim of this study is to investigate the role of mTOR inhibition in post-transplant obesity and body composition change.
Method: This is single-center cohort study. We analyzed 96 healthy adult kidney transplant patients and they were divided 2 groups; (1) Everolimus (EVR: introduced 3-months after transplantation), mPSL, MMF and reduced tacrolimus (TAC) (n=48) (2) mPSL, MMF and normal tacrolimus (n=48. These patients were transplanted before EVR was approved in Japan). In this analysis, change of body weight and visceral fat area at 3-12 months were compared between two groups by using logistic regression adjusted propensity score analysis. Vital signs, lipid and glucose profile, such as parameters of metabolic syndrome were also analyzed.
Results: Mean increase in body weight from 3 to 12 months after transplantation ware 2.45±7.98 kg (EVR group) and 2.35±5.42 kg (control group), and there was no significant difference. Visceral fat area was significantly increased in control group (13.34±28.51 cm2, EVR group: 8.34±16.93 cm2). EVR and reduced TAC significantly reduced the risk of abdominal obesity (visceral fat area≧100cm2) at 12-months after transplantation (Odds ratio; EVR: 0.14 95% confidence interval (CI), 0.03-0.67, Age: 1.06 95% CI, 1.01-1.02, pre-transplant abdominal obesity: 16.50 95% CI, 3.88-70.27). There were no significant differences about kidney function, glucose metabolism and occurrence of metabolic syndrome between two groups. Dyslipidemia was highly occurred in EVR group.
Conclusion: EVR with reduced TAC regimen had a possibility to attenuate visceral fat gain early after kidney transplantation without graft dysfunction. There was no significant effect for metabolic syndrome and impaired glucose metabolism. Further analysis is required.