Fatigue and Excessive Daytime Sleepiness in Sarcoidosis: Prevalence, Predictors, and Relationships between the Two Symptoms.

BACKGROUND: Fatigue is common among patients with sarcoidosis. The etiology of this problem is unknown and multifactorial. Fatigue can be confounded with excessive daytime sleepiness (EDS). Fatigue and sleepiness have rarely been studied simultaneously in sarcoidosis patients.

OBJECTIVES: The aim of this study was the confounder-adjusted estimation of risks for severe fatigue and EDS in a large population of sarcoidosis patients and the development of multivariate predictors from this population.

METHODS: 1,197 German sarcoidosis patients were examined using the Epworth Sleepiness Scale (ESS), the Fatigue Assessment Scale (FAS), the Hospital Anxiety and Depression Scale (HADS), and the Medical Research Council (MRC) dyspnea scale.

RESULTS: 16.5% (123 patients) had EDS (ESS ≥16), 16.4% had severe fatigue (FAS ≥35), and 6.3% had both extreme findings. In a multivariate logistic regression model, predictors of the risk of EDS were a history of sleep apnea (odds ratio [OR] 2.46, 95% confidence interval [CI] 1.5-3.9), dyspnea MRC grade ≥2 (OR 2.29, 95% CI 1.5-3.5), and organ involvement of 4-7 organs (OR 1.60, 95% CI 1.1-2.4). Significantly associated with higher risk of severe fatigue were the following: conspicuous depression (OR 5.95, 95% CI 4.1-8.7), conspicuous anxiety (OR 2.38, 95% CI 1.6-3.4), and muscle pain (OR 1.92, 95% CI 1.32-2.75). The logit models for severe fatigue with and without simultaneous EDS differed only slightly.

CONCLUSION: An extreme form of fatigue and/or sleepiness was found in 27% of all sarcoidosis patients questioned. Because there is a certain overlap, both should be examined simultaneously to allow for a combined assessment.