Background: Weight gain is frequently observed after lung transplantation, but the magnitude, predictors and implications of weight gain after lung transplant are unknown.
Methods: This retrospective cohort study included 826 lung transplant recipients randomly selected from 12 international transplant centers. We included adult patients with available weight data at baseline and 1 year post-transplant. We examined demographic and clinical predictors of first year weight gain using a multiple linear regression model (n = 579) with percent weight change as the dependent variable. To study the association between first year weight gain and subsequent survival, we performed a Cox proportional hazards analysis. p < 0.05 was considered statistically significant.
Results: The median weight change was 10% (range -32% to 84%). On multi-variate analysis, increasing age and prolonged mechanical ventilation were inversely associated with weight gain; obstructive disease, interstitial disease and increasing ischemic time were positively associated with weight gain. Increasing baseline weight was negatively associated with weight gain in patients with obstructive and interstitial disease. The model accounted for 14% of the variance in weight gain. Patients with weight gain above the median had better subsequent survival (adjusted hazard ratio 0.61, 95% confidence interval 0.41 to 0.90). Infection was a more common cause of death in these patients, whereas malignant deaths were more frequent in patients with below-median weight gain.
Conclusions: Substantial weight gain occurs in the first year after lung transplantation. The predictors of weight gain may be used to target high-risk patients for early intervention. Higher weight gain is associated with better subsequent survival.