Beyond bone mineral density, FRAX-based tailor-made intervention thresholds for therapeutic decision in subjects on glucocorticoid A nationwide osteoporosis survey

Glucocorticoid-induced osteoporosis (GIOP) is the most common cause of secondary osteoporosis and confers a substantial risk for future fractures. Several recent guidelines for GIOP management have recommended the use of intervention thresholds to direct pharmacological therapy in those at high risk of fracture. The aim of this study was to analyze the characteristics of subjects on a glucocorticoid (GC) and to implement the Fracture Risk Assessment Tool (FRAX)-based intervention threshold for therapeutic decision-making. This was a cohort substudy of a nationwide osteoporosis screening program conducted in Taiwan from 2008 to 2011. All participants were requested to complete a questionnaire including FRAX elements, and antiosteoporosis medication (AOM) history was assessed before bone mineral density (BMD) measurement. GC users were recruited as the study group. Controls comprised randomly selected age-and sex-matched non-GC users. Individual intervention threshold (IIT) was set at individual-specific FRAX probability of a major osteoporotic fracture, relative to subjects with prior fractures. The characteristics and calculated IIT of all participants were analyzed. A total of 8704 participants were enrolled, including GC users (n=807) and controls (n=7897). There was no significant difference in BMD between GC users and controls. Clinical fracture risks, including previous fracture, parental hip fracture, rheumatoid arthritis, and secondary osteoporosis were higher in GC users than in controls. GC users had a higher 10-year probability of either major or hip fracture than controls. The proportion of GC users with a 10-year probability of major osteoporotic fracture above IIT was higher than in controls (75.0% vs 10.6%; P< 0.001). Only 20.3% of GC users and 30.5% of controls whose fracture risk was above IIT reported taking AOM. These findings suggest that more GC users should receive active intervention based on IIT, regardless of BMD. However, less than one-fourth of GC users whose fracture risk was above IIT received AOM, indicating that GIOP is markedly undertreated. We recommend commencing AOM for GIOP according to IIT, instead of BMD alone.