Diabetes mellitus, and not obesity, is associated with lower survival following liver transplantation.

BACKGROUND AND AIMS: The impact of obesity on survival following liver transplantation is unclear, and existing studies report conflicting results. Our current study aims to further delineate the impact of obesity using population-based registry data from the USA.

METHODS: All US adult liver transplant recipients from 2003 to 2012 were evaluated using the United Network for Organ Sharing registry. The impact of obesity on survival following liver transplantation was further stratified into class I obesity [body mass index (BMI) 30.0-34.9 kg/m(2)], class II obesity (BMI 35.0-39.9 kg/m(2)), and class III obesity (BMI ≥ 40 kg/m(2)) and evaluated using Kaplan-Meier methods and multivariate Cox proportional hazards models.

RESULTS: Overall, 57,255 patients with chronic liver disease underwent liver transplantation, among which 32.9 % had BMI ≥ 30 kg/m(2). While patients in all obesity classes had similar survival to patients with BMI 18.0-24.9 kg/m(2), the presence of concurrent diabetes mellitus resulted in significantly lower post-transplant survival. After multivariate regression, post-transplant survival in patients with class II obesity (HR 0.97; 95 % CI 0.89-1.05) or class III obesity (HR 0.99; 95 % CI 0.90-1.09) was not significantly lower than patients with BMI 18.0-24.9 kg/m(2), but diabetes mellitus was independently associated with lower post-transplant survival (HR 1.29; 95 % CI 1.21-1.36).

CONCLUSION: In conclusion, obesity alone was not associated with lower post-transplant survival. However, DM, either alone or comorbid with obesity, is associated with significantly greater post-transplant mortality.