A new study reports that 16.5% of sarcoidosis patients experience EDS (excessive daytime sleepiness), 16.4% experience severe fatigue, and 6.3% of patients report both symptoms.
The study titled, “Fatigue and Excessive Daytime Sleepiness in Sarcoidosis: Prevalence, Predictors, and Relationships between the Two Symptoms,” was published in the journal Respiration.
Fatigue is a frequent symptom of sarcoidosis and it has reported frequencies of 50-85% in patients with sarcoidosis. The cause behind increased incidences of being fatigued is unknown, but may be attributed to a wide range of reasons including systemic inflammation, which is the hallmark of sarcoidosis. Other causes may include metabolic disorders, psycho-social conditions, or fatigue due to particular drug treatments.
Patients with sarcoidosis also tend to have higher rates of sleep disorders. Epidemiological studies have determined there is a 10.8-23% prevalence of EDS in the general population, which is characterized by patients falling asleep in monotonous situations. Individuals with medical disorders tend to have a higher prevalence, and greater than 50% of patients with sarcoidosis exhibit EDS.
Fatigue often is incorrectly used to describe EDS, as there is an overlap between the two disorders; however, these are two different symptoms.
In order to treat patients with targeted therapy, it is important to know the risk factors that could lead to fatigue, EDS or a combination of both.
To date, fatigue and EDS have been studied only separately in the context of sarcoidosis. So, this study was conducted to determine the predictors of fatigue and EDS in this patient population.
Researchers at the University of Leipzig in Germany examined sleepiness, fatigue, anxiety, depression, and dyspnea in 1,197 German sarcoidosis patients using the ESS (Epworth Sleepiness Scale), the FAS (Fatigue Assesment Scale), the HADS (Hospital Anxiety and Depression Scale), and the MRC (Medical Research Council) dyspnea scale. Dyspnea refers to difficult or labored breathing.
Results showed that overall, 26.6% of patients had severe fatigue and/or EDS. In total 16.5% of patients had EDS, which is characterized by an ESS score of 16 or above, and 16.4% had severe fatigue, which is denoted by a FAS score of 35 or higher. In total, 6.3% of patients had both severe fatigue and EDS.
Researchers discovered there was only a slight connection between EDS and fatigue, and therefore, the occurrence of one could not predict the occurrence of the other.
Additionally, researchers found that the risk factors for developing EDS included a history of sleep apnea, a dyspnea MRC grade greater than or equal to 2, and sarcoidosis affecting four to seven organs.
For development of severe fatigue, the risk factors included conspicuous depression and anxiety, as determined by the HADS questionnaire, and the presence of muscle pain. Dyspnea also was found to be a predictor of fatigue. However, its influence was greater in EDS than in fatigue. Dyspnea, in fact, is an indicator of the severity of sarcoidosis with a higher grade linked to a stronger impairment of the patient.
There were some limitations to this study, as noted by the authors, including the fact that the data obtained through questionnaires were based on the subjective answers of patients. Furthermore, some of the diseases, such as sleep apnea, actually might be significantly higher than noted in the patient’s medical history.
Nevertheless, taken together, the results suggest that EDS and severe fatigue are prevalent in patients with sarcoidosis. In addition, because these disorders can be caused by a variety of risk factors, their identification could allow the establishment of a particular combination of therapeutic strategies and eventually lead to an improvement in patients’ lives.extreme daytime sleepiness