Fatigue in COPD influenced by multiple contributing factors

Fatigue in people with chronic obstructive pulmonary disease (COPD) may be caused by factors such as shortness of breath, sleep quality, pain, and fatigue-related catastrophizing, according to the FAntasTIGUE study.

In the study, individuals who reported more dyspnoea, poorer sleep quality, more fatigue catastrophizing, and more pain were more likely to report higher levels of fatigue. A statistical model based on these four variables was able to explain 46.5 percent of the variation in fatigue scores, reported lead study author Dr Maarten Van Herch of Maastricht University Medical Centre, Maastricht, Netherlands. [ERS 2023, abstract 2612]

“Fatigue is a subjective, unpleasant symptom that ranges from tiredness to exhaustion and interferes with the affected individuals’ ability to function to their normal capacity,” said Van Herch. [Int J Nurs Stud 1996;33:519-529]

Highly prevalent in COPD, fatigue is present in about half of the people with COPD. Despite this, the contributing factors of fatigue in this population remain unclear and have hardly been studied in an integrated analysis, he added. [Ther Adv Respir Dis 2019;13:1753466619878128]

Van Herch believes that data from FAntasTIGUE may be used to guide intervention strategies. He called for studies to assess whether such interventions could reduce fatigue in the COPD population.

Study details

FAntasTIGUE included 247 patients (mean age 67.3 years, 59.5 percent men, mean body mass index 26.2 kg/m², 21.5 percent current smokers) with clinically stable COPD who had FEV1/FVC* ratio of <0.7, no moderate exacerbations over <4 weeks preceding enrollment, and fatigue data available. Mean baseline values were 57.2 percent predicted for FEV1, 116.3 percent predicted for total lung capacity, 153.4 percent predicted for residual volume, and 59.8 percent predicted for single-breath diffusing capacity of the lung for carbon monoxide. The mean Charlson comorbidity index score was 2.0.

Subjective fatigue was assessed using the Checklist for Individual Strength-Fatigue (CIS) questionnaire score, which ranged from 8 to 56 points, with higher points indicating greater fatigue. Factors that potentially contributed to fatigue were categorized as follows: personal, COPD-related, physical, psychological, systemic, and symptoms.

Half of the patients (51 percent) had severe fatigue (CIS-F score ≥36 points). Marital status, Charlson comorbidity score, diffusion capacity, number of moderate exacerbations in the last year, dyspnoea, sleep quality, pain, exercise capacity, fatigue-catastrophizing, depressive symptoms, calcium, and leukocyte count emerged as contributing factors of fatigue in multivariate stepwise regression models.

However, only dyspnoea, sleep quality, pain, and fatigue-catastrophizing remained significantly associated with fatigue in the final model.

*Ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs