Factors associated with fatigue in sarcoidosis.

BACKGROUND Fatigue is a frequent symptom of patients with sarcoidosis. The origin of fatigue associated with sarcoidosis is unclear. The aim of this study was to assess the impact of affected organs, medication, and comorbidity on fatigue related to sarcoidosis. METHOD In collaboration with the German Sarcoidosis Society, a sample of 1,197 subjects diagnosed with sarcoidosis was examined. The participants completed a questionnaire that contained the Fatigue Assessment Scale and the Multidimensional Fatigue Inventory. RESULTS In this study, muscles, bones, and nerves were most strongly associated with fatigue. Patients receiving prednisolone showed heightened fatigue levels. However, the association between the duration of prednisolone therapy and fatigue was weak. The concomitant diseases, pulmonary hypertension and sleep apnea, showed the greatest impact elevating fatigue (effect sizes d > 0.50). In the combined regression analysis, comorbidity was the most important predictor of fatigue. CONCLUSIONS It is important to consider that multiple clinical factors, especially comorbidities, contribute to the high degrees of fatigue in sarcoidosis.