Influence of sarcopenia on functional independence and depression in older adults: a cross-sectional study

Differences in physical function, encompassing activities of daily living (ADL) and instrumental activities of daily living (IADL), and depression were evaluated across degrees of sarcopenic severity in older adults. A total of 236 participants (78.72±6.92 years), comprising 101 men and 135 women, were classified into four groups: no sarcopenia (23.7%), possible sarcopenia (26.3%), sarcopenia (28.0%), and severe sarcopenia (22.0%). Sarcopenic measures included calf girth, grip strength, 5-time chair stand test, and appendicular skeletal muscle mass. Functional status was assessed using Barthel Index for ADL and Lawton & Brody index for IADL, while depression was measured using the Geriatric Depression Scale-15. All sarcopenic indices differed significantly between groups, with large effect sizes (η ² =0.340-0.532). ADL and IADL declined with increasing sarcopenic severity, and after age and sex adjustments, physical function (all P<0.001) and depressive symptoms remained significantly different across groups. Analysis of covariance showed that age was independently associated with ADL, IADL, and depression. The association between sarcopenia severity and ADL differed by sex (P=0.011), whereas the relationships of sarcopenia severity with IADL and depression were not influenced by sex. These findings suggest that greater sarcopenia severity is associated with poorer physical function and a higher burden of depressive symptoms. However, while the relationship between sarcopenia severity and ADL appears to be influenced by sex, the associations of IADL and depression with sarcopenia severity seem to be largely driven by age rather than sex.