Severe Fatigue in Uncontrolled Asthma: Contributing Factors and Impact of Rehabilitation

Abstract

BackgroundFatigue is a major concern for patients with severe asthma. ObjectiveThis observational study aims to assess fatigue severity and associated factors, to explore the effect of pulmonary rehabilitation on fatigue, and to investigate which factors predict persistent severe fatigue. MethodsPatients with severe, uncontrolled asthma referred for alpine altitude climate treatment (AACT) between 2007 and 2018 were systematically assessed pre- and post-rehabilitation regarding clinical, inflammatory, functional, and psychological characteristics. Fatigue severity was assessed by Checklist Individual Strength (CIS-Fatigue). Multivariable regression analyses were used to identify factors associated with fatigue severity and persistence. Results420 patients were assessed of whom 91% reported severe fatigue (CIS-Fatigue ≥36). Stepwise multiple regression explained 35% of variance in initial fatigue severity. Significant contributing factors were higher ACQ (36%), sleeping problems (21%), female sex (19%), reflux (12%) and lower FENO (12%). AACT led to significant improvements in CIS-Fatigue (median(IQR) 50(11) to 27(21)) (p<0.001), ACQ (3.0(1.3) to 1.2(1.3)) (p<0.001), and other asthma outcomes. However, 27% of patients reported persistent severe fatigue, correlating with less improvement in asthma outcomes. Daily oral corticosteroid (OCS) use OR(95%CI) 2.4(1.4-4.1), sleeping problems OR(95%CI) 2.7(1.6-4.5), initial very severe fatigue OR(95%CI) 3.1(1.6-6.3), and older age OR(95%CI) 1.02 (1.0-1.04) were independent predictors of persistent severe fatigue. ConclusionSevere fatigue is highly prevalent in patients with severe, uncontrolled asthma. Alpine altitude climate treatment results in recovered fatigue and improved asthma control in most patients. Predicting factors of persistent fatigue suggest exploring the effect of targeted treatment strategies beyond the asthma domain.