Factors associated with experience of fatigue, and functional limitations due to fatigue in patients with stable COPD

Abstract

Background:The aim of this study was to determine the influence of selected physiological, psychological and situational factors on experience of fatigue, and functional limitations due to fatigue in patients with stable chronic obstructive pulmonary disease (COPD).Methods:In total 101 patients with COPD and 34 control patients were assessed for experience of fatigue, functional limitation due to fatigue (Fatigue Impact Scale), physiological [lung function, 6-minute walk distance (6MWD), body mass index (BMI), dyspnoea, interleukin (IL)-6, IL-8, high sensitivity C-reactive protein (hs-CRP), surfactant protein D], psychological (anxiety, depression, insomnia), situational variables (age, sex, smoking, living alone, education), and quality of life.Results:Fatigue was more common in patients with COPD than in control patients (72% versus 56%, p < 0.001). Patients with COPD and fatigue had lower lung function, shorter 6MWD, more dyspnoea, anxiety and depressive symptoms, and worse health status compared with patients without fatigue (all p < 0.01). No differences were found for markers of systemic inflammation. In logistic regression, experience of fatigue was associated with depression [odds ratio (OR) 1.69, 95% confidence interval (CI) 1.28–2.25) and insomnia (OR 1.75, 95% CI 1.19–2.54). In linear regression models, depression, surfactant protein D and dyspnoea explained 35% (R2) of the variation in physical impact of fatigue. Current smoking and depression explained 33% (R2) of the cognitive impact of fatigue. Depression and surfactant protein D explained 48% (R2) of the psychosocial impact of fatigue.Conclusions:Experiences of fatigue and functional limitation due to fatigue seem to be related mainly to psychological but also to physiological influencing factors, with depressive symptoms, insomnia problems and dyspnoea as the most prominent factors. Systemic inflammation was not associated with perception of fatigue but surfactant protein D was connected to some dimensions of the impact of fatigue

Patterns and predictors of exhaustion episodes in patients with stable COPD: A longitudinal study

“…Nevertheless, our study also showed that other demographic factors, including age, education level and living alone, were inconsistently associated. These results were consistent with those reported in previous studies on fatigue in patients with COPD . It is worth noting, however, the lack of significant statistical effects of “living alone”, despite its relevance (around 4 times the OR of exhaustion).…”

“…Therefore, exhaustion has been mostly described in relation to health conditions, like heart disease or stroke, and it is considered an entity separate from other symptoms . In contrast, exhaustion remains poorly investigated in COPD as an entity extreme of fatigue, because mostly, all range of the experience of fatigue has been studied like a whole . Recently, exhaustion has been described in its own right, because interest has increased in the fragility syndrome, in which exhaustion is a basic characteristic …”

“…Despite the frequency and negative impact of exhaustion among patients with COPD, as cited above, little is known about how exhaustion persists and remits over time, or what factors might predict the onset of new episodes. The COPD‐related literature has indicated that the experience and the physical impact of fatigue, is cross‐sectionally associated with a combination of non‐respiratory and respiratory factors (ie, depression, dyspnoea, exacerbation frequency, health status) . However, predictors of the concept of exhaustion might differ from fatigue, and furthermore, they must be addressed longitudinally.…”

“…2,[8][9][10][11] In contrast, exhaustion remains poorly investigated in COPD as an entity extreme of fatigue, because mostly, all range of the experience of fatigue has been studied like a whole. 12 Recently, exhaustion has been described in its own right, because interest has increased in the fragility syndrome, in which exhaustion is a basic characteristic. 3,4 Despite the frequency and negative impact of exhaustion among patients with COPD, as cited above, [3][4][5][6] little is known about how exhaustion persists and remits over time, or what factors might predict the onset of new episodes.…”

“…The COPD-related literature has indicated that the experience and the physical impact of fatigue, is crosssectionally associated with a combination of non-respiratory and respiratory factors (ie, depression, dyspnoea, exacerbation frequency, health status). 12,13 However, predictors of the concept of exhaustion might differ from fatigue, and furthermore, they must be addressed longitudinally. On the other hand, longitudinal studies from geriatric research 2 have indicated that exhaustion is more likely to persist in older patients with non-respiratory factors, like poor self-reported health, depression, obesity and history of stroke.…”