Fatigue in COPD: a Longitudinal, Multidimensional Perspective

Fatigue is a pervasive, debilitating symptom of chronic obstructive pulmonary disease (COPD) that significantly impacts patients' overall health and quality of life. However, its underlying mechanisms and associations with physical, psychological, behavioral, and other health factors remain unclear. This study investigated longitudinal associations between fatigue and these factors in COPD.

A total of 247 COPD patients (mean age, 67.3 ± 8.1 years; 60% male; mean forced expiratory volume in 1 s (FEV1) 57 ± 21% predicted) from primary and secondary care were enrolled in a longitudinal observational study. Two-wave autoregressive cross-lagged panel models (ARCLM) examined relationships between fatigue and associated factors at baseline and 1 year later.

Severe fatigue was prevalent in 53% of participants at baseline, with no significant change at follow-up. ARCLM findings indicated that baseline physical activity was the only predictor of reduced fatigue after 1 year. Moreover, higher baseline fatigue predicted poorer health-related quality of life, more severe dyspnea, and greater dyspnea-related emotional distress at follow-up. Although the initial focus was on fatigue, the analysis revealed a complex network of longitudinal relationships between multiple studied variables extending beyond fatigue.

Physical activity was the only direct predictor of fatigue, while fatigue directly influenced dyspnea, dyspnea-related emotions, and health-related quality of life. This study highlights the important role of fatigue within a complex network of physical, psychological, health status, and behavioral factors. The complexity of the interrelatedness of these factors suggests that single-target interventions are unlikely to be effective. Rather, integrated interventions, such as pulmonary rehabilitation, are needed.