The Association with Exercise Capacity and Anemia in Chronic Airway Disease

Rationale:  Anemia is frequently accompanied with many chronic diseases, which may contribute to dyspnea and exercise limitation in chronic airway disease patients. The aim of this study was to investigate the association of anemia and degree of dyspnea and exercise capacity in COPD patients.

Methods: A total 87 male COPD patients were enrolled. Subjects were divided as anemic (n=6) and non-anemic groups (n=81) by the WHO criteria, which meant that the Hemoglobin concentration was below 13 g/dL in men. We compared the clinical characteristics of two groups. We measured the shortness of breath using the modified Medical research Council Dyspnea scale (mMRCs) and COPD assessment test (CAT). The exercise capacity was assessed by six minute walking distance (6MWD). The Saint George Respiratory Questionnaire was used to investigate HRQL.

Results: Anemic patients (7.4%) showed a significantly lower 6MWD (293.17 ±82.60m, 380.15 ± 91.97m, P=0.03). There were no differences in age, smoking habits, dyspnea scales including mMRC score, CAT score, lung function and quality of life between the two groups. However, there was no significant correlation with Hemoglobin concentration and 6 MWD.

Conclusions: Anemia was related to a reduction of exercise capacity in COPD. Further studies about the relation of anemia and other parameter of exercise capacity including muscle strength and muscle mass are needed.