To examine the combined association of physical inactivity and depressive symptoms with the progression to sarcopenia in community-dwelling older adults.

A 4-year follow-up longitudinal study.

Community-dwelling older adults living in Japan, who were not sarcopenic at baseline.

The participants were 2,538 community-dwelling older adults and with a mean age of 70.9 ± 4.6 years, of whom 1,327 (52.3%) were women.

Sarcopenia, defined according to the European Working Group on Sarcopenia in Older People 2, was assessed at baseline and at the 4-year follow-up. Participants were divided into four groups according to their inactivity and depressive symptoms. Physical inactivity was assessed using two face–to–face questions regarding the frequency of regular exercise, sports, and light exercise per week. Depressive symptoms were defined as a score of six or higher on the Geriatric Depression Scale 15-item version. Logistic regression analysis was used to determine whether inactivity and depressive symptoms were associated with progression to sarcopenia 4 years later. For participants who could not be followed and participants with missing data in the follow-up assessment, the data at the follow-up assessment were imputed using the multiple imputations.

After 4 years, 518 participants (20.4%) with complete data progressed to sarcopenia. The rate of progression to sarcopenia after multiple imputations was 23.4%. Logistic regression analysis after multiple imputations showed that the group with both factors was significantly associated with the progression to sarcopenia [Odds ratio, 1.64 (95% Confidence interval 1.11–2.44), p = 0.014]. By contrast, no significant association was found for either inactivity or depressive symptoms alone.

This study indicates that the coexistence of physical inactivity and depressive symptoms may contribute to the progression of sarcopenia. Addressing both physical and mental factors, rather than limiting the problem to a single factor, may be essential for preventing sarcopenia.