[O-RS-01-2] Relationship between physical activity, muscle thickness and echo intensity in patients with chronic obstructive pulmonary diseases：A cross-sectional study.
Keywords:physical activity, COPD, echo intensity
【Purpose】
This study aimed to identify the relationship between physical activity（PA）, muscle thickness（MT）and echo intensity（EI）in patients with chronic obstructive pulmonary disease（COPD）.
【Methods】
This was a cross-sectional study. In total 13 patients with COPD（mean age 73.9±7.6 years, height 163.2±5.1 cm, body weight 59.9±12.2 kg）were recruited from a community in this study. PAs were measured using a pedometer attached on the waist for a week. Quadriceps muscle strength was measured using a hand held dynamometer. MT and EI were recorded by ultrasonography imaging. The patients lay in the supine position with their knee extended at 0° and muscle relaxed. MT was calculated as the length between the deep aponeurosis of vastus intermediate and surface aponeurosis of vastus intermediate at three difference points of the image. Each ultrasonography image data was the mean value recoded. EI of quadriceps was measured using image analysis software（ImageJ）. Spearman's correlation coefficient was used for statistical analysis of the relevance of PA, quadriceps muscle strength, MT, and EI. The study was approved by the regional ethics committee and conducted in accordance with the Declaration of Helsinki.
【Results】
Higher PA was significantly associated with quadriceps muscle strength（r=0.79, p＜0.01）and EI of quadriceps（r=-0.68, p＜0.05）. There was no significant correlation between PA and MT.
【Discussion】
Our results showed that higher PA in patients with COPD was associated with higher MT and lower EI of quadriceps. Lower EI of quadriceps indicates that the muscle cell gap has little connective tissue, less fat, low extracellular fluid, which are associated with muscle strength. Our study indicates that improvement in muscle quality is a requirement for high PA.
This study aimed to identify the relationship between physical activity（PA）, muscle thickness（MT）and echo intensity（EI）in patients with chronic obstructive pulmonary disease（COPD）.
【Methods】
This was a cross-sectional study. In total 13 patients with COPD（mean age 73.9±7.6 years, height 163.2±5.1 cm, body weight 59.9±12.2 kg）were recruited from a community in this study. PAs were measured using a pedometer attached on the waist for a week. Quadriceps muscle strength was measured using a hand held dynamometer. MT and EI were recorded by ultrasonography imaging. The patients lay in the supine position with their knee extended at 0° and muscle relaxed. MT was calculated as the length between the deep aponeurosis of vastus intermediate and surface aponeurosis of vastus intermediate at three difference points of the image. Each ultrasonography image data was the mean value recoded. EI of quadriceps was measured using image analysis software（ImageJ）. Spearman's correlation coefficient was used for statistical analysis of the relevance of PA, quadriceps muscle strength, MT, and EI. The study was approved by the regional ethics committee and conducted in accordance with the Declaration of Helsinki.
【Results】
Higher PA was significantly associated with quadriceps muscle strength（r=0.79, p＜0.01）and EI of quadriceps（r=-0.68, p＜0.05）. There was no significant correlation between PA and MT.
【Discussion】
Our results showed that higher PA in patients with COPD was associated with higher MT and lower EI of quadriceps. Lower EI of quadriceps indicates that the muscle cell gap has little connective tissue, less fat, low extracellular fluid, which are associated with muscle strength. Our study indicates that improvement in muscle quality is a requirement for high PA.