Aging Medicine and Healthcare · Oct 23, 2026
Cluster-based patterns of sedentary time and health characteristics in community-dwelling older adults
By ANDO S, Iwamura M, Yamashina Y et al.
ABSTRACT Background: Sedentary behavior (SB), defined as low-energy activities performed while sitting or reclining, is a major health risk factor in older adults. Although total sedentary time is linked to adverse outcomes, the effects of its precise timing remain unclear. Objectives: We aimed to identify the diurnal patterns of SB and examine their associations with physical function and depressive symptoms in community-dwelling older adults. Methods: A total of 111 older adults (mean age 73.1 ± 5.8 years; 24 men, 87 women) wore a triaxial accelerometer for 7 consecutive days to assess SB, light-intensity physical activity, and moderate-to-vigorous physical activity. Sedentary time was analyzed in six 3-h intervals from 06:00 to 24:00. Principal component analysis and K-means clustering identified distinct SB patterns. Physical function was measured grip strength and walking speed and depressive symptoms were assessed using the Geriatric Depression Scale. Results: Three clusters were identified: high-activity (HA), nighttime-sedentary (NS), and daytime-sedentary (DS). HA participants had shorter daytime sedentary periods, higher physical activity, and greater functional capacity. DS participants exhibited prolonged daytime SB and higher depressive symptom scores, whereas NS participants showed intermediate characteristics. Conclusion: Timing of SB, beyond total sedentary time, is associated with physical and psychological outcomes in older adults. The DS pattern was associated with higher depressive symptoms, warranting further investigation as a potential focus. These behavioral patterns may also represent potential markers for geriatric syndromes such as frailty and sarcopenia. Longitudinal studies are required to clarify the causal relationships and inform intervention development.