Abstract
BACKGROUND: Osteosarcopenia, defined as the co-existence of osteopenia/osteoporosis and sarcopenia, may influence frailty risk in older adults. However, the longitudinal association between osteosarcopenia or its components and frailty remain unclear. This study aimed to address this. METHODS: Data from a prospective cohort study of community-dwelling adults in Australia. Frailty was defined by the presence of ≥ 3 components based on Fried criteria: exhaustion, slow gait speed, low grip strength, unintentional weight loss, and low physical activity. Osteosarcopenia was defined by osteopenia/osteoporosis (WHO criteria) and sarcopenia (European Working Group on Sarcopenia in Older People [EWGSOP2] and Sarcopenia Definition and Outcome consortium [SDOC]). Multivariable logistic regression models evaluated the associations between osteosarcopenia, its components and frailty. RESULTS: Of 300 enrolled, 151 (mean age: 65.1years, 59.6%women) completed follow-up (median: 4.8 years). Among 143 non-frails at baseline, 13 (9.1%) transitioned to frailty. Osteosarcopenia (versus non-osteosarcopenia) was associated with frailty irrespective of the definition used: EWGSOP2: OR = 9.53, 95%CI 2.53-35.92; SDOC: OR = 9.19, 95%CI 2.19-38.56). Grip strength reduction by 1 kg (OR = 0.92, 95%CI 0.84-1.00) and gait speed reduction by 0.1 m/sec (OR = 0.67, 95%CI 0.53-0.85) were associated with 8% and 33% lower odds of frailty, respectively, whereas bone mineral density or lean mass was not. An interaction between bone-muscle function and frailty risk was observed (p < 0.011), whereby higher values of grip strength were associated with lower odds of frailty when bone density was lower. CONCLUSION: In this prospective cohort study, osteosarcopenia increased the risk of frailty. Our interaction analysis suggests therapies targeting bone density and grip strength may mitigate frailty.