7281 Increased Incidence Of Fracture And Predicted Fracture Risk In Patients With Mild Autonomous Cortisol Secretion

Abstract Disclosure: R. Sagar: None. A. Saadulla: None. A. Abbas: None. Background: Mild autonomous cortisol secretion (MACS) is common in patients presenting with adrenal incidentalomas (AI) and has been associated with cardiovascular and metabolic co-morbidities. Whilst there is growing evidence to support the increased risk of cardiometabolic co-morbidity in this cohort, the bone health effects are less well characterised. Our study evaluated the prevalence of fragility fracture and fracture risk in patients with AI and MACS compared with a cohort of patients with benign, non-functional AI. Methods: Retrospective observational data were collected on 391 patients with MACS and an AI along with 626 patients with a benign, non-functional AI. Demographic, biochemical, radiological and bone health data were recorded. FRAX, a validated fracture risk stratifying tool, was used to calculated risk scores for all patients aged between 40 and 90 and risk category according to national guidance were also recorded. Results: MACS cohort (mean age 69±10 and 53% female) had a mean cortisol on overnight dexamethasone suppression test of 76.6±21nmol/l. Benign, non-functional patients had a mean age 61.4±12 and 57% female. Both cohorts had predominantly unilateral lesions (76% in MACS versus 84%). Patients with MACS had a significantly higher prevalence of all fragility fractures, 15.9% compared with 6.7% in the benign, non-functional group, p<0.0001. Patients with MACS had a significantly higher 10-year risk of major osteoporotic fracture (10.6±3.8% versus 7.1±5.4%, p<0.0001) and also hip fracture (7.2±4.1% versus 1.9±2.7%, p<0.0001). 17% of MACS cohort were classed as either high or very high fracture risk, with a further 28% classed as intermediate risk requiring further assessment of bone health compared with 3% high/very high risk in the non-functional group. Despite this only 31% of the MACS group had undergone DEXA scan to assess bone mineral density compared to 13% of the non-MACS group. Only 5% of MACS patients were on osteoporosis treatment (3% in non-MACS cohort). Conclusions: Patients with MACS make up a large proportion of those presenting with adrenal incidentaloma. Our study suggests an increased prevalence of fragility fractures along with increased fracture risk in patients with MACS compared to those with non-functional AI. However, we also demonstrate an unmet need, with less than 1/3 of patients with MACS undergoing formal bone health assessment and just 5% of the total cohort on treatment for osteoporosis despite a significant proportion meeting intervention thresholds. Presentation: 6/1/2024