Abstract
Background: The presence of anemia has been associated with reduced performance in 6 minute walk test among patients with Chronic Obstructive Pulmonary Disease (COPD).
Aim: To investigate, for the first time, the impact of Anemia of Chronic Disease (ACD) on exercise capacity among COPD patients, utilising cardiopulmonary exercise testing (CPET).
Methods: It is a case-control study. Cases (27 stable COPD outpatients who were identified to fulfill clinical and laboratory criteria of ACD) and 27 matched by age, height, sex, FEV1 and current smoking status non-anemic stable COPD controls underwent maximal CPET. Student's T-test for independent samples was used for statistical comparisons between the groups; level of p<0.05 was considered significant.
Results: Cases (92.6% males; 64.8±8 years old; FEV1%predicted=42.3±10) compared to controls (92.6% males; 65.3±7.2 years old; FEV1%predicted=42.8±12.8) achieved lower: a) peak%predicted oxygen uptake (59.5±17.2 vs 71.3±11.9; p<0.01), b) peak work rate (67±24.9 vs 86.1±29.4 watts; p<0.05), c) peak%predicted work rate (54.9±21.4 vs 68.7±20,8; p<0.05), d) peak oxygen pulse (8.8±2 vs 10.4±2.9 ml/beats; p<0.05) and e) peak%predicted oxygen pulse (69.1±17.3 vs 82±18.2; p=0.01). There was also a trend for a lower%predicted anaerobic threshold (p=0.062) in the group of cases. Rest gas exchange values and exercise parameters indicative of respiratory limitation (such as peak minute ventilation, peak respiratory rate and tidal volume to inspiratory capacity ratio) did not differ between the groups.
Conclusions: The presence of ACD significantly impairs the exercise capacity of COPD patients.
- © 2011 ERS