UC Davis

We proposed the term "dysmobility syndrome" (DS) to identify individuals with impaired musculoskeletal health, a risk factor for falls and fractures. Whether DS is associated with increased risk of incident fracture is unknown. The Osteoporotic Fractures in Men (MrOS) study enrolled 5994 men ages ≥65 years, between March 2000 and April 2002. We used baseline data to determine whether DS increased fracture risk, independent of the Fracture Risk Assessment Tool (FRAX). Men met DS criteria at baseline if they had three or more of the following: appendicular lean mass/height² <7.26 kg/m² , total body fat >30%, spine or hip T-score ≤ -2.5, grip strength <30 kg, gait speed <1.0 m/s, and one or more fall within 12 months. We examined whether baseline DS increased the risk of hip and major osteoporotic fractures (MOFs) over a median of 14 years (IQR, 9 to 15 years). Among 5834 men mean age 74 ± 6 years, 471 (8%) had DS and 635 (11%) experienced an MOF, including 274 (5%) hip fractures. Age (per SD increase) conferred an HR of 1.72 (95% CI, 1.59 to 1.86), DS conferred an HR of 3.45 (95% CI, 2.78 to 4.29) and FRAX calculated with BMD (per %) conferred an HR of 1.10 (95% CI, 1.08 to 1.11) for MOF. Prediction of MOF using the FRAX score provided a concordance value of 0.67 ± 0.012 (concordance values are mean ± SE). Concordance increased to 0.69 ± 0.012 by adding DS and to 0.70 ± 0.012 by adding DS and age to the multivariate model. Kaplan-Meier curves indicated that men with both DS and a FRAX risk above the National Osteoporosis Foundation (NOF) treatment thresholds had higher MOF (HR 6.23; 95% CI, 3.10 to 12.54) and hip (HR 7.73; 95% CI, 5.95 to 10.04) fracture risk than men with neither condition. We suggest further studies to determine the optimal criteria for DS, and to test DS as a predictor of falls and fractures, especially in women. © 2018 American Society for Bone and Mineral Research.