回復期冠動脈疾患患者における身体活動量と下肢筋力との関連について  [in Japanese] Relationships between Physical Activity and Lower Extremity Muscle Strength at Entry into Recovery Phase by Patients with Coronary Artery Disease  [in Japanese]

【目的】回復期冠動脈疾患患者の身体活動量(PA)の実態とその関連要因を明らかにすること。【方法】対象は,急性心筋梗塞発症および冠動脈バイパス術後1か月時点の冠動脈疾患外来患者50例である。基礎疾患および属性,PA,最高酸素摂取量(peak VO_2),下肢筋力(膝伸展筋力)を調査,測定した。【結果】各指標の平均値±標準偏差は,PA:7893.3±2914.5歩/日,peak VO_2:24.8±5.9ml/kg/min,下肢筋力:1.7±0.4Nm/kgであった。PAとpeak VO_2間にr=0.32(p=0.02),PAと下肢筋力の間にr=0.41(p=0.03)の相関関係を認めた。重回帰分析の結果,PAの関連要因として下肢筋力が抽出された(r=0.48,R^2=0.23,p=0.02)。【結論】回復期冠動脈疾患患者のPAは7893歩で,その関連要因として下肢筋力が示された。

Objective: The purpose of this study was to explore the factors that were associated with physical activity (PA) in patients with coronary artery disease (CAD) at entry into recovery phase of cardiac rehabilitation. Methods: The sample population of this cross-sectional study was comprised of 50 patients and included both patients that had experienced acute myocardial infarction and those that had received coronary artery bypass grafting (42 men, 8 women; mean age, 62.0±9.4 yrs.). PA (average steps per week) as a caloric expenditure, knee-extension muscle strength as an index of lower extremity muscle strength and peak oxygen uptake (peak VO_2) were measured in order to assess physiological outcomes at 1 month after acute myocardial infarction or coronary artery bypass grafting. Results: The mean values of physiologic outcomes were as follows, PA; 7893.3±2914.5 (average steps per week), knee-extension muscle strength; 1.7±0.4(Nm/kg), peak VO_2; 24.8±5.9(ml/kg/min). Knee-extension muscle strength and peak VO_2 were significantly associated with PA (r=0.41, p=0.03, r=0.32, p=0.02). Regression analysis showed that the knee-extension muscle strength contributed significantly to the prediction of PA (r=0.48, R^2=0.23, p=0.02). Conclusions: The results of our study indicate that PA was 7893.3±2914.5 (average steps per week) and that knee-extension muscle strength in cardiac patients may have influenced PA in patients with CAD.