Associations of Reallocating Sedentary Time to Physical Activity and Sleep with Physical and Mental Health of Older Adults.

INTRODUCTION

Twenty-four-hour movement behaviors: moderate-to-vigorous physical activity (MVPA), light physical activity (LPA), sedentary behavior (SB), and sleep are crucial factors affecting older adults' health. Using a compositional data analysis approach, this study examined the associations of time spent in these four movement behaviors with cardiometabolic health, physical fitness, and mental health among older adults. Furthermore, this study identified the estimated changes in aforementioned health outcomes by reallocating SB time to other movement behaviors.

METHODS

A population-based cross-sectional study of 4562 participants (67.68 ± 5.03 yr; 55.8% female) were implemented in Hubei China between July 25 and November 19, 2020. Measures included demographics, movement behaviors, cardiometabolic indicators (body mass index, waist circumference, waist-hip ratio, percentage body fat, systolic and diastolic blood pressure), physical fitness, and mental health outcomes (depressive symptoms and loneliness). Compositional data analyses were implemented in R.

RESULTS

MVPA and sleep time were associated with greater health outcomes (all P < 0.001), except blood pressure ( P = 0.13-0.83). LPA time was associated with waist circumference ( B = 0.313, P = 0.009), waist-hip ratio ( B = 0.003, P = 0.003), physical fitness ( B = 0.36, P < 0.001), and mental health indicators (both P < 0.001). Reallocating 30-min SB to MVPA and sleep was associated with predicated improvements in all health outcomes, except blood pressure, whereas reallocating 30-min SB to LPA resulted in predicted improvements in physical fitness (0.187 units), depressive symptoms (-0.264 units), and loneliness (-0.395 units). For dose-effect relationships, reallocating 5-60 min of SB to MVPA showed greatest benefits for all health outcomes.

CONCLUSIONS

This study provides timely empirical evidence for future interventions and policymaking on promoting healthy aging during the post-COVID-19 era. The findings underline the importance of including 24-h movement behaviors in future health promotion among older adults.