Fatigue in COPD and the impact of respiratory symptoms and heart disease--a population-based study.

BACKGROUND: Fatigue is reported in COPD and in heart disease; however, there are hardly any population based data on the relationship between these conditions. AIM: To describe fatigue in relation to COPD by disease severity and to evaluate the impact of respiratory symptoms and heart disease.
METHODS: Data were collected in 2007 from the OLIN COPD study; 564 subjects with COPD (FEV1/FVC < 0.70) and a distribution of disease severity representative for the general population, and 786 subjects without COPD. The Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale was used to assess fatigue (0-52); lower scores represent worse fatigue.
RESULTS: Median FACIT-F score was 44.0 in COPD defined by merely spirometric criteria and 42.0 in COPD also reporting respiratory symptoms, significantly lower compared to 46.0 in non-COPD (p = 0.006 and p < 0.001), and decreased by disease severity. The score was lower in COPD stage ≥ II and in COPD with respiratory symptoms already from stage I when compared to non-COPD. Subjects with heart disease reported lower scores than those without heart disease in COPD by all stages and in non-COPD. COPD with respiratory symptoms stage ≥II remained a significant risk factor for clinically significant fatigue also when adjusted for gender, age, heart disease and smoking habits (stage II OR 1.65, CI 1.17-2.31 and stage III-IV OR 2.66, CI 1.11-6.36).
CONCLUSION: Fatigue is common in COPD, and is affected by respiratory symptoms and concomitant heart disease. In COPD with respiratory symptoms stage ≥ II, there is an increased risk for clinically significant fatigue.