運用等時置換模型探討高齡者身體活動取代靜態行為與失能風險之關聯性

Abstract

研究目的：促進輕強度與中高強度的身體活動並減少靜態行為，對於高齡者的生理功能，以及總體健康的提升有著正向促進的效益。然而，在過去的研究中，不同強度身體活動的時間組合對於失能風險的關聯性並無進一步的研究。因此，本研究旨在探討使用輕強度或中高強度的身體活動取代靜態行為和失能風險的關聯性，並著重探究輕強度與中高強度身體活動之不同時間組合與失能風險的關聯性。研究方法：220位65歲以上的高齡者 (平均年齡：76.91歲) 納入於本研究並進行分析。以三軸加速規 (ActiGraph wGT3X-BT) 測量日常生活中的輕強度、中高強度身體活動以及每日靜態行為時間。高齡者之失能風險測量則運用工具性日常生活活動之量表進行評估。輕強度、中高強度身體活動取代靜態行為時間與失能風險之關聯性，使用等時置換模型進行研究分析。研究結果：在高齡族群中，靜態行為與較高的失能風險有顯著相關，輕強度身體活動與中高強度身體活動則均與較低的失能風險有相關性。運用輕強度身體活動取代靜態行為時間與高齡者較低的失能風險有相關 (勝算比=0.658, 95% 信賴區間=0.457-0.949)，然而，中高強度身體活動取代靜態行為時間則並未發現相關性。在不同強度身體活動之時間組合中，每一組取代靜態行為的身體活動組合均與高齡者較低的失能風險有顯著關聯性。研究結論：為達到預防失能的目標，本研究建議高齡族群需多加累積日常生活中輕強度的身體活動來取代靜態行為，以及可以結合輕強度身體活動與其他強度的活動來取代靜態行為。建議未來研究可運用縱貫性研究設計，來檢驗本研究之發現。Objectives: Promoting light-intensity physical activity (LPA), moderate-to vigorous-intensity physical activity (MVPA) and spending less time in sedentary behavior (SB) had positive effects on physical function and improve overall health in elderly. However, previous studies had not examined the association of mixed share time with different intensities of physical activity (PA) and the risk of disability. Thus, we examined the associations of replacing SB with LPA or MVPA, including the mixed share time with LPA and MVPA on disability.Methods: A total of 220 older adults aged 65 years or over (mean age: 76.91) were included and analyzed. Tri-axial accelerometer (ActiGraph wGT3X-BT) was used to record the daily PA of LPA and MVPA as well as the daily SB. The risk of disability in elderly was examined with the Instrumental Activities of Daily Living Scale (IADLs). Isotemporal substitution analysis was conducted to examine the associations of replacing SB with LPA, MVPA and time replacement on disability.Results: In the older population, the result of SB was associated with higher risk of disability, and the results of LPA and MVPA were all associated with lower risk of disability. Replacing the time spent in SB with LPA was associated with lower risk of disability in elderly (Odds ratio, [OR]=0.658, 95% Confidence Interval [CI]=0.457-0.949), however, no association was found with MVPA. In the combinations of time with different intensities of PA, each PA combination of replacing SB all significantly had the association with lower risk of disability in older adults.Conclusion: For achieving the goal of disability prevention, this study suggested that older adults could accumulate more LPA to replace SB in daily life and to combine LPA with other intensities of PA to replace SB. It was also suggested that future research could use a longitudinal design, to confirm our results.