Mr Saliu Balogun1, Prof. Tania Winzenberg1, Dr Karen Wills1, Dr David Scott2,3, Dr Michele Callisaya1,2, Prof Graeme Jones1, Dr Dawn Aitken1
1Menzies Institute For Medical Research, University Of Tasmania, Hobart, Australia, 2Department of Medicine, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Australia, 3Australian Institute for Musculoskeletal Science, Melbourne Medical School (Western Campus), the University of Melbourne, , St Albans, Australia
Aim: This study aims to examine whether low muscle mass (sarcopenia) or strength (dynapenia), in the presence of osteoporosis/osteopenia, increase fracture and mortality risk over 10 years in community-dwelling older adults.
Methods: Data for 1032 participants (52% women; mean age 62.9±7.4 years) studied at baseline, 2.5, 5 and 10 years (SD) were analysed. Mortality was ascertained from the death registry and fractures were self-reported. Muscle mass was assessed as appendicular lean mass (ALM) using dual energy X-ray absorptiometry, normalised to body mass index (BMI). Muscle strength was assessed as hand grip strength (HGS) using dynamometer. Osteosarcopenia and osteodynapenia were defined as the lowest 20% of the sex-specific distribution for muscle mass or strength respectively, and T-scores of the total femur and/or L1-L4 < –1.
Results: Incident fracture and mortality over 10 years were 17% and 15% respectively. Incident fracture was significantly higher among osteodynapenic (RR=2.07, 95% CI: 1.26–3.39) but not osteosarcopenic participants (RR 1.48, 95% CI: 0.83-2.64). In contrast, mortality was significantly higher among osteosarcopenic (RR=1.49, 95% CI: 1.01–2.21) but not osteodynapenic participants (RR=1.03, 95% CI: 0.68–1.57).
Conclusion: In the presence of osteoporosis/osteopenia, low muscle mass increase mortality risk whereas low muscle strength increase fracture risk. This finding demonstrates the significance of combined assessments of osteopenia/osteoporosis with muscle mass or strength in order to identify a subset of older people who are at a significantly higher risk of fracture and mortality respectively.
Saliu Balogun is a Physiotherapist and a final year PhD candidate at the Menzies Institute for Medical Research, University of Tasmania. In 2012, he was awarded the prestigious British Commonwealth scholarship to study for his master’s degree in Gerontology at the Centre for Research on Ageing University of Southampton. Saliu completed his Bachelor of Physiotherapy degree at the College of Medicine, University of Lagos.