Survival Outcomes of Lung Transplant Recipients from Donors with High Body Mass Index

Abstract

Aim of this study is to assess lung utilization from donors with high Body Mass Index (BMI) and outcomes of lung transplant recipients from these donors. We reviewed United Network for Organ Sharing (UNOS) registry for first-time adult lung transplant recipients and donors from 06/2005 to 03/2017. Donors were stratified into 4 groups according to their BMI: normal 18.5-29.9, underweight <18.5, obese 30-34.9 and moderately/severely obese >35 kg/m2. Percentage lung utilization for each group was compared using Chi square test. Recipient survival was estimated with Kaplan-Meier curves and compared using multivariate Cox regression model. Of 20380 donors, 15765 (77.3%) donors had normal BMI, 916 (4.5%) were underweight, 2406 (11.8%) were obese and 1262 (6%) were moderately/severely obese. No significant difference was seen among 4 groups in terms of lung transplant survival (adjusted p=0.59, multivariate cox regression model, Figure 1). The 1, 3 and 5 year recipient survival rates were: 85.8 %, 68.9% and 55.1% in normal donor BMI group, 85.4%, 68.8% and 57.1% in underweight donor group, 86.3%, 67.6% and 56.0 % in the obese donor group and 86.7%, 67.1%, and 54.2 %in moderately/severely obese donor group, respectively. When donors with normal BMI were used as reference, the hazard ratio (95% confidence interval) for donors with obesity was 0.97 (0.88-1.07), donors with moderate/severe obesity was 1.03 (0.96-1.10) and for underweight donors was 1.05 (0.95-1.17). The lung utilization from donors with normal BMI was 31.1% and from donors with BMI >30 was 17% (p<0.0001). There is no significant difference in lung transplant recipient survival among the 4 donor BMI groups but there is lower organ utilization in the obese groups. Lungs from donors with high BMI should be considered more carefully before turning them down.