The impact of sarcopenia on incident homebound status among community-dwelling older adults: A prospective cohort study

Objectives: Whether sarcopenia predicts incident homebound status remains unclear. This prospective cohort study aimed to determine the impact of sarcopenia on the incidence of homebound status in community-dwelling older adults. Methods: The study included 3958 community-dwelling elderly people aged >= 65 years who were not homebound at baseline. Sarcopenia was defined as the presence of both poor muscle function (low physical performance or low muscle strength) and low muscle mass. Potential confounding factors, such as physical status, mental status, and level of social participation, were also assessed. Fifteen months after the baseline measurements, data regarding the incidence of homebound status were obtained using a postal survey. Results: In the 15-month follow-up survey, 83 participants (2.1%, 95% confidence interval = 1.6-2.5) were reported to have become homebound. A multiple logistic regression analysis indicated that age (odds ratio = 1.06, 95% confidence interval = 1.02-1.10), sarcopenia (1.98, 1.04-3.77), and limited contact with friends (1.82, 1.03-3.23) were independently associated with an increased risk of becoming homebound. In a stratified analysis for age group, a significant odds ratio for low level of social role (2.50, 1.06-5.91) was observed in young-old subjects (aged 65-74 years), whereas significant odds ratios for sarcopenia (2.80, 1.33-5.91) and physical inactivity (2.85, 1.28-6.37) were observed in old-old subjects (aged 75 years and over). Conclusion: Sarcopenia had a strong impact on the risk of becoming homebound. Particularly in old-old subjects, sarcopenia and physical inactivity may impair people's ability to engage in activities outside the home much more than either their mental status or their level of social participation.