Higher Mortality and Survival Benefit in Obese Patients Awaiting Liver Transplantation

Over 85% of US centers adhere to practice guidelines that consider morbid obesity to be a contraindication to liver transplantation (LT). The relationship of morbid obesity with LT outcomes and survival benefit in the current era is unknown.

We investigated the association of body mass index with waitlist and post-LT outcomes, and survival benefit, using the United Network for Organ Sharing registry. We categorized body mass index as follows: 18.5 to 29.9 kg/m, normal/overweight; 30 to 34.9 kg/m, obese; 35 to 39.9 kg/m, severely obese; and ≥40 kg/m, morbidly obese, and evaluated waitlist outcomes using competing risk regression and post-LT outcomes and survival benefit using Cox regression.

3.9% of 80 221 waitlisted and 3.5% of 38 177 transplanted patients were morbidly obese. Waitlist mortality was higher for morbidly obese than normal/overweight patients (subdistribution hazard ratio, 1.16; 95% confidence interval [CI]:1.08-1.26), but post-LT mortality and graft failure were comparable (hazard ratio [HR], 1.01; 95% CI, 0.86-1.19; and HR, 1.15; 95% CI, 0.95-1.40). Morbidly obese patients also benefited more from LT (88% mortality reduction vs 80% for normal/overweight). Morbid obesity predicted higher post-LT mortality before 2007 (HR, 1.18; 95% CI, 1.04-1.34), but not afterward (HR, 0.98; 95% CI, 0.81-1.18).

Morbid obesity is associated with higher mortality on the LT waitlist, but no longer predicts inferior outcomes after LT. Morbidly obese patients should be considered potential candidates for LT.