OR01-6 Bone Health Outcomes Post-Lung Transplantation in Cystic Fibrosis Patients

BACKGROUND: Osteoporosis is a common comorbidity in patients with cystic fibrosis (CF); malabsorption, chronic glucocorticoid use, and chronic inflammation all contribute to increased bone resorption and decreased bone formation. Although lung transplantation (LTx) improves quality of life and short- and long-term outcomes of CF patients, there is little research examining long-term bone health outcomes following LTx in these patients. METHODS: We collected demographic and clinical data on patients who underwent LTx at a single institution between 2006-2019 and had bone mineral density (BMD) measured pre- and post-transplantation. We compared baseline characteristics, long-term BMD trends, and fracture incidence between the two patient populations. We also examined factors associated with post-LTx fractures in CF patients. RESULTS: Charts of 59 LTx recipients were reviewed including 30 with CF and 29 without CF. Compared with non-CF patients, patients with CF were significantly younger (32.8±10.0 vs. 56.7±10.7 years), had lower body mass index (19.7±3.0 vs. 26.7±4.4 kg/m(2)), and significantly lower baseline BMD Z-scores at the lumbar spine (-2.0±1.1 vs. -0.3±1.6), femoral neck (-1.6±0.8 vs. -0.7±1.0), and total hip (-1.6±0.8 vs. -0.7±1.0) (all p<0.001). BMD at all three sites declined significantly in both groups in the first year post-LTx. In subsequent years, and compared with non-CF patients, CF patients exhibited better BMD recovery relative to pre-transplantation, but continued to have lower BMD post-LTx. Post-transplant fractures were relatively common, occurring in 30% and 34% of CF and non-CF patients, respectively. Within the CF group, those who developed fractures after LTx were more likely to have lower baseline BMD T-scores at the femoral neck (p=0.017) and total hip (p=0.050), and lower pre-transplantation percent predicted forced expiratory volume in 1 second (FEV1%) (p=0.042). CONCLUSIONS: Compared with their non-CF counterparts, CF patients undergoing lung transplantation start with significantly lower BMD pre-LTx but exhibit better BMD recovery post-LTx. Despite their younger age at transplantation, CF patients experience a similarly high rate of post-LTx fractures. In CF patients, lower BMD and worse FEV1% pre-LTx are associated with development of post-LTx fractures. These findings highlight the unique contribution of the CF disease process to bone health, as well as a clear need for better prevention and treatment of osteoporosis in CF patients before and after LTx. Presentation: Saturday, June 11, 2022 12:45 p.m. - 1:00 p.m.