Dysmobility Syndrome Independently Increases Fracture Risk in the Osteoporotic Fractures in Men (MrOS) Prospective Cohort Study

Abstract

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.

Keywords: DYSMOBILITY SYNDROME; FALLS; FRAX; MUSCLE; OBESITY; OSTEOPOROSIS; SARCOPENIA.

Conflict of interest statement

Disclosures: No authors had any conflict of interest regarding the work under consideration for publication. Outside of the submitted work the authors report the following: Bjoern Buehring received grant support from Kinemed and the Extendicare Foundation, consultancy fees from GE/Lunar and Lilly, payment for development for educational presentations from Clinical Care Options, payment for lectures from AANS and travel support from UCB and Janssen. Steve Cummings received consulting fees from Radius and Amgen. Nancy Lane received consulting fees from Amgen, Radius, Novartis and Roche. Neil Binkley received consultancy fees from Amgen, Radius and Viking and grant funding from Novartis and Viking. Kristine Ensrud served as a consultant on a Data Monitoring Committee for Merck, Sharpe, & Dohme. Drs. Hansen, Lewis and Cawthon do not report any conflict of interest outside of the submitted work.

© 2018 American Society for Bone and Mineral Research.

Figures

Figure 1:. Percent of Men with Incident Major Osteoporotic Fracture and Hip Fracture by Baseline Dysmobility Syndrome Score.

The figure depicts the proportion of men with incident major osteoporotic fractures, including hip fractures, as a function of the number of baseline criteria for DS (DS score). Only one man had a DS score of six; this data point is omitted. Increasing DS score was associated with increased odds of major osteoporotic fractures (p

Figure 2:. Cumulative Major Osteoporotic Fractures (2a) and Hip (2b) Fractures:

2a.) For this analysis, men were divided into one of four groups: those with both a high overall MOF FRAX score and DS (n=27), a high FRAX score but no DS (n=97), DS but not a high FRAX score (n=444) and men with neither condition (referent, n=5266). Men with both DS and a FRAX MOF score ≥20% experienced more fractures than the referent (Table 4, p

Figure 2:. Cumulative Major Osteoporotic Fractures (2a) and Hip (2b) Fractures:

2a.) For this analysis, men were divided into one of four groups: those with both a high overall MOF FRAX score and DS (n=27), a high FRAX score but no DS (n=97), DS but not a high FRAX score (n=444) and men with neither condition (referent, n=5266). Men with both DS and a FRAX MOF score ≥20% experienced more fractures than the referent (Table 4, p