Body mass index extremes 5 years post-lung transplant were associated with poorer physical quality of life (-4.93 for BMI 18.5) and increased depression (+2.40 for BMI 34) versus a BMI of 24.
Are extremes of BMI associated with poorer physical health and increased depression in lung transplant recipients 5 years post-transplant?
In lung transplant recipients 5 years post-transplant, both low and high BMI are associated with poorer self-perceived physical quality of life and greater depression.
Abstract Rationale Obesity is associated with worse patient-centered outcomes (PCOs) in chronic respiratory disease; whether this is also true in lung transplant recipients is unknown. A better understanding of how obesity is associated with PCOs could elucidate roles for anti-obesity treatments to improve mental and physical quality of life (QoL) as well as reduce depression, disability, or frailty after lung transplant. Methods We performed a cross-sectional analysis of adult lung transplant recipients enrolled in the Lung Transplant Outcomes Group cohort at 7 US centers. Subjects were included if they completed the Short Physical Performance Battery (SPPB) or at least one questionnaire: Short Form-12 (SF-12), Lung Transplant Valued Life Activities (LT-VLA), Patient Health Questionnaire-8 (PHQ-8) 5 +/- 1 years post-transplant. We used mixed effects linear regression with linear splines to evaluate the association between body mass index (BMI) as a continuous variable and physical health-related QoL (HRQoL, SF-12 PCS), mental HRQoL (SF-12 MCS), disability (LT-VLA), depression (PHQ-8), and frailty (SPPB) adjusted for age, sex, transplant diagnosis, time from transplant, and highest education level based on a directed acyclic graph. Results One hundred sixty-seven subjects had available, concurrent PCO and BMI data 5 +/- 1 years post-transplant. PCOs were completed a median (interquartile range, IQR) of 5.0 (4.5-5.5) years post-transplant. Subjects were 59% male, 57 (45-64) years of age at transplant, with median BMI 26.3 (22.9-30.7) kg/m2 at PCO completion. Transplant diagnoses were 53% ILD, 28% COPD, 13% CF, and 6% PVD. Both high and low BMI seemed to be associated with poorer physical health and increased depression. Relative to a subject with a BMI of 24 kg/m2, a subject with a BMI of 18.5 kg/m2 had significantly lower SF-12 PCS (-4.93, 95% CI -9.73 to -0.14) indicating poorer physical QoL and higher PHQ-8 (1.75, 95% CI -0.25 to 3.75) indicating more depressive symptoms. Relative to a subject with a BMI of 24 kg/m2, a subject with a BMI of 34 kg/m2 had lower SF-12 PCS (-1.28, 95% CI -4.56 to 2.01) and significantly higher PHQ-8 (2.40, 95% CI 1.05 to 3.74). BMI was not associated with disability, frailty, or mental HRQoL. Conclusion In a multi-center cohort of lung transplant recipients alive 5 years after transplant, both low and high BMI seem to be associated with poorer self-perceived physical QoL and greater depression. Further work is required to understand whether treating obesity can improve these patient-centered outcomes. This abstract is funded by: K23 HL150280, T32 HL007891
Fishman et al. (2026) studied this question. Body mass index extremes 5 years post-lung transplant were associated with poorer physical quality of life (-4.93 for BMI 18.5) and increased depression (+2.40 for BMI 34) versus a BMI of 24.