社區老人心房顫動與衰弱相關性之研究

Abstract

研究背景與目的：心房顫動（atrial fibrillation, AF）為臨床最常見之心律不整。過去針對住院病人進行的研究指出，心房顫動除了本身疾病對病患生理功能的負擔外，還會對患者造成其他影響，包括病人住院期間變長、衰弱比例增高，以及出院後六個月內死亡率較高等；而社區調查也發現心房顫動長者的認知功能、功能性測驗，以及行走速度都相較同年齡健康者差。然而過去探討社區老人心房顫動對身體功能影響的文獻不足，更缺乏心房顫動與衰弱相關性之探討。鑑於人口老化及心房顫動的盛行率逐年提高，本研究將探討社區老人心房顫動與衰弱之相關性。研究方法：本研究採用橫斷面設計，受試者來源為台大醫院內科門診與大台北地區有意願參與研究的65歲以上老人。受試者需接受心電圖檢查或醫師診斷，判斷是否為心房顫動。評估項目包括：身體功能評估（握力、五公尺步行所需時間，與計時起走測驗）、臺灣版國際身體活動量問卷（international physical activity questionnaire, IPAQ, Taiwan version）、心血管健康研究（cardiovascular health study, CHS）衰弱評估，以及Edmonton衰弱問卷（Edmonton frail scale）。統計分析使用SPSS第18版（SPSS Inc, Version 18.0. Chicago: SPSS Inc.）進行分析。分別利用獨立樣本t檢定（independent t test）與卡方檢定分析（chi square analysis）比較有無心房顫動兩組受試者與不同嚴重程度心房顫動患者組內的連續性數值與類別資料差異，再以多邏輯迴歸（multiple logistic regression）分析心房顫動與衰弱程度的關聯性。所有顯著信賴水準定為0.05。研究結果：本實驗一共徵收207位社區長者，38位為心房顫動患者。心房顫動組和心律規律組相比，男性握力（26.76 ± 8.25與32.96 ± 6.85公斤）、五公尺步行所需時間（5.06 ± 1.47與4.42 ± 1.06秒）、每秒步行速度（1.05 ± 0.25與1.19 ± 0.25公尺/秒）、計時起走測驗（8.82 ± 2.44與7.04 ± 1.94秒），以及CHS衰弱評估之非健壯人數百分比依臺灣常模（50%與24%）和美國常模（69%與36%）皆有顯著組間差異。CHS衰弱評估中，心房顫動組的肌力下降人數百分比（47%與26%）和低身體活動量人數百分比（21%與8%），顯著較心律規律組高。Edmonton衰弱問卷中，心房顫動組的認知測驗答錯人數百分比（39%與25%）、過去一年住院次數（26%與9%）與使用多重藥物百分比（42%與17%），顯著較心律規律組高。迴歸分析顯示心房顫動是預測社區非健壯長者的獨立影響因子（勝算比：3.84，95%信賴區間：1.81 – 8.14）。依據實驗時心律做子群分析，實驗時心房顫動組和實驗室時竇性組相比，男性握力（24.39 ± 8.80與32.64 ± 6.91公斤）、五公尺步行測驗（5.40 ± 1.76與4.44 ± 1.02秒）、以及計時起走測驗（9.37 ± 3.01與7.12 ± 1.90秒），皆顯著較差且組間差距增加。此外，迴歸分析顯示實驗時心房顫動與社區非健壯長者的勝算比提高至5.59（1.97 – 15.81）。結論：心房顫動患者與心律規則的社區長者相比，多項身體功能測驗以及衰弱程度分佈有顯著差異 ; 此外心房顫動是預測社區非健壯長者的獨立影響因子。但本研究心房顫動合併衰弱的人數較少，未來仍須更大樣本數的研究探討心房顫動與社區長者衰弱的關聯性。

Background and purpose: Atrial fibrillation (AF) is the most common arrhythmias. Besides the disease burden itself, research investigating hospitalized patients have indicated there are deleterious effects of AF, including longer stay days for hospitalization, higher rates of frailty and increasing mortality rate after discharged in six months. Few research found that elderly with AF had lower cognitive function, physical function and slower walking speed compared with the health ones in community. However, there is only limited articles investigating the impact of AF on physical function of community-dwelling elderly, and the relationship between AF and frailty is also lack of discussion. According to the aging society and increasing prevalence of both AF and frailty, this research would investigate the relationship between AF and frailty in community-dwelling elderly. Methods: The study was a cross-sectional study. Subjects older than 65 years old were recruited from clinics of department of internal medicine, in National Taiwan University and communities in Taipei. All the subjects from community underwent the test of ECG to measure AF. Patients from the clinic were allocated to AF group based on the diagnosis history. Assessment items included physical function (grip strength, time spent for five-meter walk test, and timed up and go test), international physical activity questionnaire (IPAQ) Taiwan version, CHS frailty assessment, and Edmonton frail scale. SPSS version 18.0 (SPSS Inc, Version 18.0. Chicago: SPSS Inc.) was used for statistical analysis. The independent t test and chi square analysis were used to examine the difference of continuous and categorical data between groups, respectively. Then the multiple logistic regression was used to examine the correlation between AF and frailty. All the significant levels were set at 0.05. Results: The study included 207 community-dwelling elderly, 38 of them were patients with AF. Compared with regular heart rhythm group, there were significant differences in grip strength of male subjects (26.76 ± 8.25 vs 32.96 ± 6.85 kilogram), time spent for five-meter walking test (5.06 ± 1.47 vs 4.42 ± 1.06 seconds), walk speed (1.05 ± 0.25 vs 1.19 ± 0.25 meter/second), timed up and go test (8.82 ± 2.44 vs 7.04 ± 1.94 seconds), and the percentage of the numbers of non-robust subjects among groups based on the CHS frailty assessment criteria of Taiwan (50% vs 24%) and US (69% vs. 37%) in AF group. There were significant higher percentage of the numbers in weakness (47% vs 26%) and low level of physical activity (21% vs 8%) in AF group in CHS frailty assessment. In Edmonton frail scale, there were significant higher percentage of the number in making mistake in the question of cognitive domain (39% vs 25%), number of been admitted to hospital (26% vs 9%) and use more than 5 or more different medication (42% vs 17%) in AF group. The multiple logistic regression model showed that AF was an independent predictor for non-robust community-dwelling elderly (odds ratio: 3.84, 95% confidence interval: 1.81 - 8.14) in community-dwelling elderly. Subgroup analysis found the larger differences in grip strength of male subjects (24.39 ± 8.80 vs 32.64 ± 6.91 kilogram), time spent for five-meter walking test (5.40 ± 1.76 vs 4.44 ± 1.02 seconds), and timed up and go test (9.37 ± 3.01 vs 7.12 ± 1.90 seconds). Furthermore, the multiple logistic regression model showed that the odds ratio of During-AF raised to 5.59 (95% confidence interval: 1.97 - 15.81). Conclusions: Compared with the community-dwelling elderly with regular heart rhythm, there were significant difference in several physical function and frailty status in patients with AF. Also, AF was an independent predictor of non-robust community-dwelling elderly. However, the number of patients with AF combined frailty is few in the research, future studies are needed to recruit larger samples to examine the relationship between AF and frailty.