Cardiopulmonary Endurance of Hospitalized Older Adults With Chronic Obstructive Pulmonary Disease

Background Chronic obstructive pulmonary disease (COPD) could lead to poor cardiopulmonary endurance, which affects quality of life and increases the risk of rehospitalization or mortality. However, studies investigating associated factors of cardiopulmonary endurance for COPD inpatients are scant. Objective The aim of the study was to investigate whether and how age, gender, COPD severity, body composition, dyspnea, respiratory muscle strength, and lower limb muscle strength and endurance were related to cardiopulmonary endurance in elderly inpatients with COPD. Methods This was a cross-sectional study using a systematic sampling of older inpatients. Data of demographic characteristics such as age, gender, and disease severity were collected, and body mass index was calculated. Degrees of dyspnea were assessed by the modified Medical Research Council Dyspnea Scale. Respiratory muscle strength was reflected by the maximal inspiratory pressure and the maximal expiratory pressure. Lower limb muscle strength and endurance were assessed by a handheld dynamometer and a 30-second sit-to-stand test, respectively. Finally, cardiopulmonary endurance was assessed by a 6-minute walk test. Results A total of 83 older COPD inpatients participated. The mean age was 74.01 +/- 6.93 years. Cardiopulmonary endurance was associated with age, COPD severity, dyspnea, respiratory muscle strength, lower limb muscle strength, and endurance. Predictors of cardiopulmonary endurance were disease severity, dyspnea, and lower limb muscle endurance. These predictors explained 53% of the variance in cardiopulmonary endurance in older inpatients with COPD. Discussion Cardiopulmonary endurance of hospitalized older adults with COPD should be strengthened by improving conditions of disease severity, dyspnea, and lower limb muscle endurance.