Trends, Determinants, and Impact on Survival of Post-Lung Transplant Weight Changes: A Single-center Longitudinal Retrospective Study.

Background: Weight gain is commonly seen in lung transplant (LTx) recipients. Although previous studies have focused on weight changes at fixed time periods and relatively early after transplant, trends over time and long-term weight evolution have not been described in this population. The study objectives were to document weight changes up to 15 years post-LTx and assess the predictors of post-LTx weight changes and their associations with mortality.

Methods: Retrospective cohort study of LTx recipients between January 1, 2000, and November 30, 2016 (n = 502). Absolute weight changes from transplant were calculated at fixed time periods (6 mo, 1, 2, 5, 10, and 15 y), and continuous trends over time were generated. Predictors of weight changes and their association with mortality were assessed using linear and Cox regression analysis.

Results: LTx recipients experienced a gradual increase in weight, resulting from the combination of multiple weight trajectories. Interstitial lung disease diagnosis negatively predicted post-LTx weight changes at all time points, whereas transplant body mass index categories were significant predictors at earlier time points. Patients with a weight gain of >10% at 5 years had a better survival (hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.20-0.66), whereas a 10% weight loss at earlier time points was associated with worse survival (1 y: HR, 2.04; 95% CI, 1.22-3.41 and 2 y: HR, 2.37; 95% CI, 1.22-4.58).

Conclusions: Post-LTx weight changes display various trajectories, are predicted to some extent by individual and LTx-related factors, and have a negative or positive impact on survival depending on the time post-LTx. These results may lead to a better individualization of weight management after transplant.