Association Between the Decline in Muscle Health and the Decline in Bone Health in Older Individuals from the SarcoPhAge Cohort

The longitudinal relationship between bone health and muscle health is scarcely explored. We aimed to explore the relationship between bone decline and muscle decline over 1 year in older individuals. We used data from the SarcoPhAge cohort, which aims to identify the consequences of sarcopenia. In this way, this study also highlights the yearly changes in muscle mass (by dual-energy absorptiometry), muscle weakness (by grip strength), and/or physical performance (by the short physical performance battery test). Measurements of areal bone mineral density (aBMD), enabling the diagnosis of osteoporosis, and bone microarchitecture (by means of the trabecular bone score) were also performed each year. A 1-year clinically relevant decline in bone and muscle health components was evidenced using the Edwards–Nunnally index. Among the 232 participants with complete data (75.5 ± 5.4 years, 57.8% women), we observed an association between a clinically relevant decline in the skeletal muscle mass index (SMI) and a decrease in aBMD (adjusted OR = 2.12 [1.14–2.51] for the spine, 2.42 [1.10–5.34] for the hip and 2.12 [1.04–5.81] for the neck), as well as a significant association between SMI and deterioration of the skeletal microarchitecture (aOR = 3.99 [2.07–7.70]). A clinically relevant decline in muscle strength was associated with a decrease in spine aBMD (aOR = 2.93 [1.21–7.12]) and hip aBMD (aOR = 3.42 [1.37–7.64]) only. The decline in muscle performance was related to the decline in bone microarchitecture only (aOR = 2.52 [1.23–5.17]). Individuals with incident sarcopenia had an approximately fivefold higher risk of concomitantly developing osteoporosis. A dynamic relationship between impaired muscle and bone health was observed, with an obvious association between the concomitant incidences of osteoporosis and sarcopenia.