運動訓練對睡眠品質不佳中老年人睡眠品質及心跳變異性的效果

Abstract

研究背景與目的：睡眠品質不佳是老化常見的健康問題之一，研究也顯示睡眠時間過長或過短與日後心血管疾病風險增加有關。透過心跳變異性量測可了解睡眠品質不佳對心臟自主神經的影響。目前已有文獻顯示運動訓練能改善睡眠品質，但針對中老年人的報告較不足，且國內外也少有研究探討運動訓練對睡眠品質不佳者心跳變異性的影響。因此本研究目的為探討運動訓練改善睡眠品質不佳中老年人睡眠品質與心跳變異性之成效。研究方法：徵召40位睡眠品質不佳的中老年人（平均年齡61.7±7.0；33位女性）參與本研究，隨機分配至運動訓練組和控制組。運動訓練組需接受為期12週、每週3次、每次50分鐘的運動訓練（30分鐘有氧運動訓練和運動前後各10分鐘伸展運動）與睡眠衛生教育。控制組僅接受睡眠衛生教育。訓練期間內兩組受試者均維持日常之飲食、運動習慣和藥物服用。每位受試者在12週訓練前後均分別接受身體組成分析（生物電阻抗分析法）、睡眠品質（匹茲堡睡眠品質量表與腕錶型活動記錄儀）、最大運動測試、心跳變異性分析，和身體活動量（七日回憶活動量問卷）測試。本研究採用SPSS 19.0版本進行資料分析，以敘述性統計、重複量數二因子變異數分析（two-way ANOVA repeated measures）比較運動訓練組及控制組兩組測量值之組間及前後差異，並以斯皮爾曼等級相關係數檢定（Spearman's rank correlation coefficient）睡眠品質與心跳變異性之相關性，最後再以多元迴歸統計（multiple regression analysis）分析影響睡眠品質改善的主要因素。本研究定義雙尾檢定顯著水準於α=0.05。結果：經過12週介入後，運動組的匹茲堡睡眠品質量表總分（p=0.003）及各分項分數均較控制組顯著下降（p＜0.05），腕錶型活動紀錄儀所測得之睡眠潛伏期時間也顯著降低（p=0.004）。運動組休息時心跳變異性包括標準化低頻功率（p＜0.001）、標準化高頻功率（p=0.001）及低頻/高頻功率（p=0.043）均較控制組顯著改善。運動後心跳變異性則無組間差異。除此之外，運動組在收縮壓（p=0.037）、最大攝氧量（p=0.003）和憂鬱量表分數（p=0.014）均較前測值顯著改善。斯皮爾曼等級相關係數檢定顯示睡眠品質改變量與標準化低、高頻功率和低頻/高頻功率改變量呈低度至中度相關（r=0.34-0.49）。多元回歸分析顯示，僅運動參與能負向預測睡眠品質分數的改變量（β=-0.628, p＜0.001；F=6,543，p＜0.001）。結論：運動訓練搭配睡眠衛生教育的介入能有效改善睡眠品質不佳中老年人睡眠品質和心跳變異性。

Background and purpose: Poor sleep quality is common in older adults. Population studies have shown that both short and long duration of sleep are associated with an increased risk of developing cardiovascular diseases. Recently, cardiac autonomic dysfunction has been measured by means of heart rate variability (HRV) analysis. Some studies have demonstrated that regular exercise training can improve sleep quality. However, the efficacy of exercise on autonomic modulation in middle-aged and older adults with poor sleep quality has not been established. Therefore, the purpose of this study is to investigate the effect of exercise training on sleep quality and HRV in middle-aged and older adults with poor sleep quality. Methods: Forty middle-age and older adults with poor sleep quality (mean age 61.7±7.0 years; 33 women and 7 men) participated in this study. They are randomized assigned into exercise group or control group. Each exercise training program consisted of 30 minutes of supervised aerobic exercise training and 20 minutes of stretching class three times a week for 12 weeks. All the subjects were instructed not to change their dietary intake, daily activity, and medication during 12-week period. Outcome measures include body composition (bioelectrical impedance analysis, BIA), sleep quality (Pittsburgh sleep quality index (PSQI) and actigraph recordings), maximal exercise testing, HRV analysis, and physical activity measurements (7-day Physical Activity Recall Scale). SPSS version 19.0 was used for data analysis. Two-way ANOVA repeated measures test was used to analysis between-group differences of all parameters. Spearman's rank correlation coefficient was used to test the correlations between the outcome parameters. Multiple regression analysis was used to examine the factors associated with sleep quality improvements. The α level was set at 0.05. Results: The exercise training group got improvements in sleep quality on the global PSQI (p=0.003) and PSQI sub-scores (p<0.05) compared to the control group. Sleep latency measured by wrist actigraph monitor was also shown significantly decreased in the exercise group compared to those of the control group. Resting HRV was significantly improved in normalization of lower frequency (p＜0.001), normalization of higher frequency (p=0.001) and LF/HF (p=0.043). However, HRV after maximal exercise testing did not differ significantly between two groups. The exercise training group also had reductions in systolic blood pressure (p=0.037), depression scales (p=0.014), and improvements in maximal oxygen uptake (p=0.003) after exercise training. Spearman's rank correlation coefficient analysis showed weak to moderate correlation exists between sleep quality and the normalization of lower frequency, normalization of higher frequency and LF/HF (r=0.34-0.49). Multiple regression analysis indicated that only exercise participation can predict the change of sleep quality (β=-0.628, p<0.001;F=6,543,p<0.001). Conclusion：Our findings indicated that moderate-intensity exercise training has a significantly effect on sleep quality and normalized cardiac autonomic function. These findings suggest that physical exercise therapy could be an alternative or complementary approach to existing therapies for sleep problems.