9313 Prevalence And Incidence Of Fragility Fractures In Patients With Nonfunctioning Adrenal Incidentalomas

Disclosure: V. Favero: None. E. Cairoli: None. C. Eller-Vainicher: None. V. Morelli: None. A.S. Salcuni: None. S. Della Casa: None. G. Muscogiuri: None. C. Columbu: None. F. Pugliese: None. S. Corbetta: None. L. Persani: None. A. Scillitani: None. I. Chiodini: None. Context: The risk of vertebral fractures (VFx) in patients with non-functioning adrenal incidentalomas (NFAI) is unknown. Objective: To evaluate the VFx prevalence and incidence in NFAI patients. Design. Cross-sectional and longitudinal study on retrospective data. Setting. Four Italian endocrinology units. Patients. 306 NFAI patients (cross-sectional arm) and 213 matched control subjects to evaluate VFx prevalence; 85 NFAI patients (longitudinal arm, follow-up 30.3±17.5 months) to evaluate VFx incidence. Main outcome measures: serum cortisol after 1 mg-dexamethasone test (F-1mgDST), bone mineral density (BMD) at spine (LS) and femur (FN), and VFx presence by x-ray. Cross-sectional arm: prevalent VFx was associated with F-1mgDST with the cut-off set at 1.2 µg/dL (33 nmol/L, area under the curve 0.620±0.39, p=0.002). As compared with controls and with NFAI patients with F-1mgDST <1.2 µg/dL (33 nmol/L, Group NFAI-A), NFAI patients with F-1mgDST ≥1.2 µg/dL (33 nmol/L, Group NFAI-B) showed higher VFx prevalence (10.8%, 12.6% and 29.5%, respectively, p<0.001 for all comparisons), which was independently associated with F-1mgDST ≥1.2 µg/dL (33 nmol/L, odds ratio 3.02, 95% confidence interval 1.63-5.58, p<0.001) regardless for influencing factors including BMD. Longitudinal arm: the VFx incidence was higher in Group NFAI-B than in Group NFAI-A (19.3% vs 3.6%, p=0.05). In NFAI-B group, all incident VFx occurred in patients without low BMD. The F-1mgDST cut-off for predicting an incident VFx was 1.2 µg/dL (33 nmol/L), but the incident VFx was not independently predicted by F-1mgDST ≥1.2 µg/dL (33 nmol/L) after adjusting for possible influencing factors, including BMD and presence of prevalent VFx. Conclusions: In NFAI patients, F-1mgDST levels ≥1.2 µg/L (33 nmol/L) are associated with prevalent VFx and may identify NFAI patients at higher risk of incident VFx Presentation: 6/3/2024