Self-perceptions of aging and sarcopenia in older adults: the mediating role of IADL.

OBJECTIVE: Sarcopenia, marked by declines in muscle mass and function, poses a major risk to healthy aging. Self-perceptions of aging (SPA) reflect individuals' attitudes toward their own aging and may influence health outcomes. This study examined the relationship between SPA and sarcopenia, focusing on the mediating role of instrumental activities of daily living (IADL).

METHODS: Data were drawn from adults aged 50 years and above participating in the 2014, 2016, and 2018 waves of the Health and Retirement Study. SPA was measured in 2014 using an 8-item scale. IADL were assessed in 2016 using five functional items. Sarcopenia was defined based on the revised criteria from the European Working Group on Sarcopenia in Older People. Generalized structural equation modeling estimated direct, indirect, and total effects.

RESULTS: Over 4 years, higher SPA was associated with a lower risk of sarcopenia (OR = 0.78, 95% CI: 0.65, 0.93,  = 0.007). Mediation analysis showed that IADL partially explained this relationship. SPA was significantly associated with grip strength, but not gait speed or muscle mass.

CONCLUSION: IADL may serve as a behavioral pathway linking SPA to sarcopenia. Promoting positive aging beliefs and functional independence could aid in sarcopenia prevention.