Changes in Social Interactions and Sleep Status of Older People in the Japanese Community

This study examined the relationship between changes in social interactions and sleep status, specifically sleep duration and restoration, among older adults in Japan to inform interventions for healthy aging. A 6-year longitudinal study (2017–2023) was conducted under the Community Empowerment and Care Project in suburban Japan. A total of 473 older adults with normal sleep in 2017 were followed. Sleep duration (< 6 h defined as deprivation) and sleep restoration (subjective restfulness) were assessed according to national guidelines. Social interaction was measured using the 18-item Index of Social Interaction (ISI). Changes in the ISI were analyzed continuously and categorically. Lo-gistic regression models were used to examine the association between ISI changes and sleep outcomes. After six years, 16.3% of the participants experienced sleep deprivation, and 26.2% reported non-restorative sleep. Declining ISI scores were significantly asso-ciated with a higher risk of sleep deprivation and non-restorative sleep. Persistently low or declining ISI scores increased the odds of poor sleep. A one-point ISI increase re-duced the risk of sleep deprivation and non-restorative sleep, even after adjusting for confounders. Negative or persistently low social interaction is linked to worse sleep outcomes; maintaining or improving social interaction may protect sleep quality.