A Six-Year Longitudinal Cohort Study Assessing the Association Between Social Interaction Trajectories and Sleep Health in Older Adults

Summary

This 6-year longitudinal study uses a standardized index to show that declining social engagement is significantly associated with an increased risk of sleep deprivation and non-restorative sleep among community-dwelling older adults, highlighting the potential value of social interaction screening in healthy aging.

Abstract

Sleep disturbances, including sleep deprivation and non-restorative sleep, pose a severe public health burden for aging populations. While social isolation is a recognized risk factor, rigorous longitudinal studies evaluating the prospective association between dynamic changes in social interaction and subsequent sleep health are lacking. This study details a 6-year longitudinal cohort study involving 473 community-dwelling older adults in Japan who exhibited normal baseline sleep. Social interactions were systematically evaluated using the standardized 18-item Index of Social Interaction. Participants were tracked from 2017 to 2023 to categorize their social trajectories into distinct subgroups, such as persistently high, declining, improving, or persistently low. Sleep duration and restoration were concurrently assessed using national health guidelines. Multivariable logistic regression models were constructed to evaluate the longitudinal relationship of these social trajectories with sleep outcomes, adjusting for baseline demographic, physical, and lifestyle covariates. The study observed that individuals experiencing a longitudinal decline in social interaction, or those remaining persistently isolated, faced a more than two-fold increased risk of developing sleep deprivation and non-restorative sleep compared to those maintaining robust social networks. Conversely, an incremental increase in continuous social interaction scores was significantly associated with a reduced risk of adverse sleep outcomes. These longitudinal findings offer observational evidence regarding the psychosocial determinants of sleep. Integrating standardized social interaction metrics into routine community health surveillance may facilitate early, targeted interventions to support sleep health and promote healthy aging.

Introduction

In modern society, the lack of proper sleep has emerged as a critical public health problem, with the course of insomnia in older adults increasingly demonstrating a trend toward chronic development¹. A systematic evaluation has established that sleep disorders significantly elevate an individual’s risk of developing severe psychiatric conditions, including depression and accelerated cognitive decline². Recognizing the severity of this issue, the Ministry of Health, Labor and Welfare (MHLW) in Japan established the basic policy of Health Japan 21. Within this framework, the national health goals concerning sleep ar....

Protocol

This longitudinal cohort study was conducted in a suburban Japanese community as part of the Community Empowerment and Care (CEC) project and was approved by the Ethics Committee of the University of Tsukuba, Japan (Approval No. 1331-7). The research adhered to the principles of the Declaration of Helsinki, and written informed consent was obtained from all participants before study enrollment.

1. Participant recruitment and selection

A total of 473 community-dwelling older adults who completed the 6-year follow-up were enrolled based on predefined criteria. Participants were initially recruited....

Results

Participant characteristics and study flow
The participant selection process for this 6-year longitudinal study is detailed in Figure 1. Of the initial 2,350 community-dwelling older adults invited to the 2017 baseline survey, 1,188 were excluded due to missing core data, loss of independent living, or pre-existing sleep issues (sleep deprivation or non-restorative sleep). This resulted in a baseline cohort of 1,162 individuals with normal sleep status. During the 6-year.......

Discussion

Through a standardized 6-year longitudinal assessment, this study demonstrated that dynamic changes in the social interaction trajectories of older adults are prospectively associated with their subsequent sleep status. The results indicate that maintaining or improving social interactions is associated with a reduced risk of sleep deprivation and non-restorative sleep (NRS). Conversely, a reduction in social activities or prolonged social isolation more than doubles the risk of adverse sleep outcomes within this observa.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
IBM SPSS Statistics (Version 26.0)	IBM Corp.	RRID: SCR_019096
Index of Social Interaction (ISI) Questionnaire	Developed by Anme et al.	Anme, T.,et al.31
Kihon Checklist	Ministry of Health, Labour and Welfare, Japan	Satake, S. et al.30
Microsoft Excel	Microsoft Corporation	RRID: SCR_016137