The impact of obesity on patient survival in liver transplant recipients: a meta-analysis

Background & AimsIt is controversial if obesity has an impact on overall survival after liver transplantation (LT). The goal of this study was to determine if obesity impacts liver transplant recipient survival. Through subgroup analysis, we also evaluated different body mass index (BMI) thresholds and the confounding effect of ascites on survival. MethodsA systematic literature search from 1990 until July 2013. The main outcome was to evaluate the impact of obesity on survival in adult LT recipients. Dochotomous outcomes were reported as relative risk (RR) with 95% confidence intervals (CI). ResultsThirteen studies with a total 2275 obese and 72212 non obese patients were included in the analysis. The combined analysis showed no difference in mortality between control and increased weight patients (RR=0.97, 95% CI [0.82, 1.13], P=0.66) at last follow-up. Moreover, no differences in mortality were noted in subgroup analysis comparing different BMI thresholds. There was also no differences in survival when BMI was adjusted for ascites or in studies where the liver disease severity was similar. Obese patients had worse survival than nonobese patients in pooled analysis of studies which had similar causes of liver disease (RR=0.69, 95% CI [0.52, 0.92], P=0.01). ConclusionThe results of our pools analysis suggest that BMI does not specifically impact patient survival. However, obese patients have worse survival when analysis was performed in studies whose cohorts of obese and nonobese patients had similar causes of liver disease.