Effects of Abnormal Steroid Metabolome on Bone Strength and Quality, Bone Density, Bone Remodeling, and Body Composition in Patients With MACS and Healthy Volunteers.

In this study, we will determine whether patients with MACS (versus healthy age and sex matched controls) demonstrate: 1) decreased bone strength and quality disproportionate to the decrease of bone density and 2) abnormalities in the steroid metabolome correlate with the degree of abnormalities in bone parameters. In a cross-sectional study of 75 patients with MACS and 75 age- and sex-matched healthy controls, we will determine the relationship of the steroid metabolome to measurements of bone density, quality and strength, bone turnover markers, as well as body composition. All patients will be interviewed in regards to their health, to include questions on bone health, frailty, cognition (NIH toolbox), and quality of life. We will measure 1) BMD (bone mineral density) at the lumbar spine, hip and radius and body composition using dual-energy X ray absorptiometry (DXA), 2) radial and tibial bone microstructure by high-resolution peripheral quantitative computed tomography (HR-pQCT), 4) bone turnover markers (osteocalcin, PINP, CTx, sclerostin). 5) Age reader measurement, 6) hand grip measurement, 7) 6 minute walk test. All patients will provide a 24 h urine for steroid metabolome analysis. For primary outcomes, we will determine if steroid metabolome profiling better predicts abnormal bone strength (as measured by trabecular bone volume/tissue volume [BV/TV] ratio).