David Scott1,2, Markus J Seibel3, Robert Cumming4,5,6, Vasi Naganathan5, Fiona Blyth5, David G Le Couteur5,7, David J Handelsman8, Benjumin Hsu8, Louise M Waite5, Vasant Hirani5,9. 1. School of Clinical Sciences at Monash Health, Monash University, Clayton, Victoria, Australia. 2. Department of Medicine and Australian Institute of Musculoskeletal Science, Melbourne Medical School - Western Campus, The University of Melbourne, St Albans, Victoria, Australia. 3. Bone Research Program, ANZAC Research Institute, and Department of Endocrinology & Metabolism, Concord Hospital, University of Sydney, New South Wales, Australia. 4. School of Public Health, University of Sydney, New South Wales, Australia. 5. Centre for Education and Research on Ageing and Alzheimer's Institute, Concord Hospital, Concord Clinical School, Faculty of Medicine and Health, Concord Hospital, University of Sydney, New South Wales, Australia. 6. The ARC Centre of Excellence in Population Ageing Research, University of Sydney, New South Wales, Australia. 7. ANZAC Research Institute & Charles Perkins Centre, University of Sydney, New South Wales, Australia. 8. Department of Andrology, Concord Hospital & ANZAC Research Institute, University of Sydney, New South Wales, Australia. 9. School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, New South Wales, Australia.
Abstract
BACKGROUND: Weight loss increases fracture risk in older adults. We aimed to determine associations of 2-year body composition trajectories with subsequent falls and fractures in older men. METHODS: We measured appendicular lean mass (ALM) and total fat mass (FM) by dual-energy X-ray absorptiometry at baseline and Year 2 in 1,326 community-dwelling men aged ≥70 and older. Body composition trajectories were determined from residuals of a linear regression of change in ALM on change in FM (higher values indicate maintenance of ALM over FM), and a categorical variable for change in ALM and FM (did not lose [≥-5% change] versus lost [<-5% change]). Bone mineral density (BMD), hand grip strength, and gait speed were assessed at Years 2 and 5. After Year 2, incident fractures (confirmed by radiographical reports) and falls were recorded for 6.8 years. RESULTS: Compared with men who did not lose ALM or FM, men who did not lose ALM but lost FM, and men who lost both ALM and FM, had reduced falls (-24% and -34%, respectively; both p < .05). Men who lost ALM but did not lose FM had increased falls (incidence rate ratio = 1.73; 95% CI 1.37-2.18). ALM/FM change residuals were associated with improved lumbar spine BMD (B = 0.007; 95% CI 0.002-0.012 g/cm2 per SD increase) and gait speed (0.015; 0.001-0.029 m/s), and reduced hip fractures (hazard ratio = 0.68; 95% CI 0.47-0.99). CONCLUSIONS: Fracture risk may be increased in older men who lose higher ALM relative to FM. Weight loss interventions for obese older men should target maintenance of lean mass.
BACKGROUND:Weight loss increases fracture risk in older adults. We aimed to determine associations of 2-year body composition trajectories with subsequent falls and fractures in older men. METHODS: We measured appendicular lean mass (ALM) and total fat mass (FM) by dual-energy X-ray absorptiometry at baseline and Year 2 in 1,326 community-dwelling men aged ≥70 and older. Body composition trajectories were determined from residuals of a linear regression of change in ALM on change in FM (higher values indicate maintenance of ALM over FM), and a categorical variable for change in ALM and FM (did not lose [≥-5% change] versus lost [<-5% change]). Bone mineral density (BMD), hand grip strength, and gait speed were assessed at Years 2 and 5. After Year 2, incident fractures (confirmed by radiographical reports) and falls were recorded for 6.8 years. RESULTS: Compared with men who did not lose ALM or FM, men who did not lose ALM but lost FM, and men who lost both ALM and FM, had reduced falls (-24% and -34%, respectively; both p < .05). Men who lost ALM but did not lose FM had increased falls (incidence rate ratio = 1.73; 95% CI 1.37-2.18). ALM/FM change residuals were associated with improved lumbar spine BMD (B = 0.007; 95% CI 0.002-0.012 g/cm2 per SD increase) and gait speed (0.015; 0.001-0.029 m/s), and reduced hip fractures (hazard ratio = 0.68; 95% CI 0.47-0.99). CONCLUSIONS:Fracture risk may be increased in older men who lose higher ALM relative to FM. Weight loss interventions for obese older men should target maintenance of lean mass.