Background
Lung transplant recipients are at an increased risk of osteoporosis due to prolonged steroid regimens, and risk factors including smoking, sarcopenia, and chronic inflammation(1,2,3). The poor correlation between fracture risk and bone mineral density (BMD) is particularly evident in steroid associated osteoporosis(4). Trabecular bone score (TBS) is a validated measure of bone microarchitecture that enhances fracture risk prediction when combined with BMD(5,6). TBS was introduced in June 2021 to Alfred Health, the state-wide lung transplant service in Victoria.
Aims
To evaluate the utility of TBS in lung transplant recipients by examining its correlation with BMD, its association with post-transplant fracture incidence, and its impact on fracture risk prediction through TBS-adjusted Fracture Risk Assessment (FRAX).
Methods
This was a retrospective study of patients aged >50 years who underwent lung transplantation from June 2021 to June 2024 at Alfred Health. Data collected from medical records included BMD, TBS, cumulative steroid use, lung function, and osteoporotic fractures.
Results
In our pilot study (n = 54), spine BMD and corresponding T-score improved following transplantation, with the T-score increasing from –1.2 ± 1.7 to –0.95 ± 1.5—shifting from the osteopaenic to the normal bone density range. However, the TBS was unchanged post-transplant, varying only slightly from 1.27 ± 0.1 to 1.24 ± 0.1, remaining within the partially degraded bone category (TBS 1.2–1.35). We aim to further investigate this observed divergence between BMD and TBS in our ongoing expanded study of 104 participants (64 ± 6 years, 67% male). We will present these findings including correlation of baseline TBS and post lung transplant fractures, and correlation between FRAX, TBS-adjusted FRAX and post lung transplant fractures.
Conclusion
This study will provide insights into the utility of TBS and its clinical implications for managing osteoporosis in the lung transplant population.