Mild Autonomous Cortisol Secretion (MACS) - Related Osteoporosis

: Mild autonomous cortisol secretion (MACS) has thus far been associated with several comorbidities, among which osteoporosis and fractures appear to be highly prevalent. Recent guidelines for adrenal incidentalomas have updated the definition of MACS, currently formulated on serum cortisol after a 1-mg dexamethasone test above 1.8 µg/dL or 50 nmol/L. Previous studies on bone health in adrenal incidentalomas had adopted different definitions of MACS, which produced heterogenous results in terms of fracture prevalence. This review aims to summarize the clinical impact of MACS in relation to fractures, bone quantity and quality, by providing a thorough update on MACS-related osteoporosis (MACS-ROP). Room for research in this area is large, and management of this comorbidity still needs to be elucidated.