Background: Two major factors associated with skeletal fracture in older persons are intrinsic bone strength and risk of falling. This study examined the role of Timed Up and Go (TUG) test performance, a validated predictor of falling, and hip areal bone mineral density (BMD), a validated predictor of bone strength in fracture prediction in a 10-year longitudinal study.
Methods: The study participants were 1126 women (mean [SD] age at baseline, 75.0 [2.6] years) living in Perth, Western Australia. Assessments included TUG test at baseline and dual-energy x-ray absorptiometry total hip areal BMD measurement at year 1. Incident clinical osteoporotic fracture over 10 years was confirmed by radiographic records. Complete incident hip fracture data were obtained from a hospital morbidity database.
Results: One-third (32.7%) of participants had slow TUG test performance (>10.2 seconds), and 54.2% of participants had low hip areal BMD (T-score of less than -1). Relative to risks among participants having normal TUG test performance and normal BMD, risks of nonvertebral fracture and hip fracture were significantly higher among participants who had slow TUG test performance and normal hip BMD (nonvertebral fracture hazard ratio [HR], 1.84; hip fracture HR, 2.48) or both slow TUG test performance and low hip BMD (nonvertebral fracture HR, 2.51; hip fracture HR, 4.68). For nonvertebral fracture and hip fracture, the population-attributable risks of slow TUG test performance with normal hip BMD were 19.3% and 32.3%, of normal TUG test performance with low hip BMD were 31.3% and 50.3%, and of both slow TUG test performance and low hip BMD were 30.1% and 55.9%, respectively.
Conclusion: TUG test performance is an independent risk factor for incident nonvertebral fracture and a feasible inexpensive physical performance assessment for use in clinical practice to screen patients with increased risk of fracture.