高齡者整體及不同時段的身體活動與功能性體適能表現之關聯性研究

Abstract

背景：高齡者在老化的過程中，可能因事故、器官老化或罹患疾病，經歷暫時地或永久地「失能 (Disability)」的風險較高。增進身體活動為過往預防失能的主要手段，高齡者在日常生活中有較多自主運用的時間，可自行決定自己的生活型態，根據人體晝夜規律 (circadian rhythm) 之理論，身體活動的時間點可以作為校正周邊時鐘的校時器 (zeitgeber)，然而，目前尚未有研究探討高齡者進行身體活動之合適的時間點對於肌肉功能表現之關聯。研究目的與方法：本論文將以臺北市居住於社區的高齡者或醫院門診的高齡者作為研究對象，試圖運用三軸加速規 (triaxial accelerometer)，來測量其「整體」身體活動量及「不同時段」的身體活動量佔比 (包含：「輕度」與「中高強度」身體活動) ，探討其與高齡者的功能性體適能表現 (包含：「握力」、「基本移動能力」、「走路速度」與「下肢肌力」) 之關聯性。本論文將分為兩個研究，研究一探討「整體」與「不同時段」之輕度及中高強度身體活動和功能性體適能表現之關聯性，研究二，使用「等時替代模型 (Isotemporal substitution analysis)」，進一步探討在「整體」或「特定時段」以三十分鐘的輕度身體活動或中高強度身體活動取代相同時間的靜態行為與功能性體適能之關聯性。結果：在研究一，整體的每日平均中高強度身體活動與握力表現與起身三公尺行走測試表現有顯著正向相關。在不同時段的分析結果則是發現，下午時段的輕度身體活動百分比與起身三公尺行走測試表現有顯著正相關，而晚上時段的輕強度身體活動百分比與起身三公尺行走測試表現及六公尺步行測試表現有顯著正相關。在研究二，整體時間、下午時段與晚上時段以輕度身體活動取代靜態行為，對於握力、三公尺起走測試、六公尺行走測試表現有正向相關。在整體時間、早上與下午時段以輕度身體活動取代靜態行為，對於五次坐站測試表現有正向相關。在整體時間、早上與下午時段以中高強度身體活動取代靜態行為，對於六公尺行走測試表現有正向相關。結論：高齡者在整體或特定時段 (特別是早上或下午) 進行身體活動或進行身體活動取代靜態行為確實與功能性體適能表現在有正向相關，未來的健康促進活動或相關衛教策略可以著重在建議高齡者在日常生活或白天時段當中盡量以任何身體活動取代靜態行為以預防肌肉功能下降並預防失能。

Background: In the aging process, older adults are at a heightened risk of experiencing temporary or permanent"disability" due to accidents, organ degeneration, or the onset of diseases. Physical activity has been a primary preventive measure against disability in the past. Given that older adults have more discretionary time in their daily lives, they have the autonomy to dictate their lifestyle. According to the theory of circadian rhythms, the timing of physical activity can serve as a zeitgeber, or time cue, for adjusting peripheral clocks. However, there is currently a lack of research investigating the optimal timing of physical activity in relation to muscle function performance in older adults.Methods: This study aims to investigate the community-dwelling older adults or older outpatients in Taipei City as the research subjects. Utilizing a triaxial accelerometer, the study measures both the"overall" and "time-specific" proportions of physical activity levels, including "light" and "moderate-to-high intensity" activities. The research explores the association between these activity levels and functional fitness performance in older adults, including "grip strength," "basic mobility," "walking speed," and "lower limb muscle strength." The study is divided into two parts: Study 1 examined the relationship between "overall" and "time-specific" light and moderate-to-high intensity physical activities and functional fitness performance in community-dwelling older adults. Study 2 employed"Isotemporal Substitution Analysis" to further investigate the correlation between replacing the same duration of sedentary behavior with thirty minutes of light or moderate-to-high intensity physical activity, either "overall" or during "specific time periods," and functional fitness performance in older outpatients. Results: In Study 1, overall moderate-to-high-intensity physical activity was significantly positively correlated with grip strength performance and the TUG test. Upon analyzing different time periods, it was found that the percentage of light physical activity in the afternoon was significantly positively correlated with TUG test performance. Additionally, the percentage of light-to-moderate physical activity in the evening was significantly positively correlated with both TUG test and 6-meter walk test performances. In Study 2, replacing sedentary behavior with light physical activity during overall time, afternoon, and evening periods was positively correlated with grip strength, TUG test, and 6-meter walk test performances. During overall time, morning, and afternoon periods, replacing sedentary behavior with light physical activity was positively correlated with the five times sit-to-stand test performance. Replacing 30 min of sedentary behavior with MVPA during overall time, morning, and afternoon periods was positively associated with 6-Meter Walk Test performance.Conclusion: Engaging in physical activity, either overall or during specific time periods (during the morning or the afteroon), has indeed been positively associated with functional fitness performance in older adults. Future health promotion activities or related educational strategies can focus on advising older adults to replace sedentary behavior with any form of physical activity during their daily lives or daytime hours. This is aimed at preventing the decline in muscle function and mitigating the risk of disability.