Bone, muscle, and physical function measures in older adults according to levels of social disadvantage: a cross-sectional study

Summary: This cross-sectional study of 300 older adults (aged ≥ 50 years) found that less education, lower income, and health care card ownership are associated with reduced bone, muscle, and physical function measures. This underscores the need for targeted preventive strategies for osteoporosis and sarcopenia that address socioeconomic-related disparities. Purpose: The prevalence of chronic diseases follows a social gradient, although this is unclear in musculoskeletal conditions. This study aims to examine the association between social disadvantage and diagnostic measures of osteoporosis and sarcopenia in community-dwelling older adults. Methods: A single-centre, cross-sectional study was conducted in adults (≥ 50 years) residing in the metropolitan region of Melbourne, Australia. Data on socio-demographic variables were collected via self-reported questionnaires. Social disadvantage variables included education, income, employment status, health care card ownership, and area-level socioeconomic status. Outcomes of interest were bone mineral density (BMD), appendicular lean body mass (ALM/h²), hand grip strength, lower limb strength, and physical performance (gait speed; short physical performance battery; leg power). Multivariable linear regression was used to analyse associations between social disadvantage and outcome measures. Results: A total of 300 participants were recruited (mean age: 66.8 years; 61.7% female). Post-secondary education was associated with higher BMD (β = 0.29; 95% CI: 0.01–0.58), ALM/h² (β = 0.29; 95% CI: 0.08–0.51), handgrip strength (β = 2.25; 95% CI: 0.57–4.52), gait speed (β = 0.08; 95% CI: 0.01–0.15), and leg power (β = 41.7; 95% CI: 11.3–71.9). Positive associations in these outcomes were also correlated with higher income and not having a health care card. Employment status and area-level socioeconomic status showed limited associations with most outcomes. Conclusion: This study demonstrates that social disadvantage is associated with poorer bone, muscle, and physical function in older adults. Targeted interventions that address socioeconomic-related disparities may support effective prevention of osteoporosis and sarcopenia later in life.