PS8:158 Developing a cause differentiation of fatigue in patients with systemic lupus erythematosus (sle) – a retrospective single centre analysis

Fatigue is the main symptom in up to 80% of SLE patients. Its origin is presumably multifactorial and it is an important factor in the reduced quality of life. This study tries to identify possible causes of fatigue in SLE patients. In preparation of this study, the literature discussing fatigue in SLE patients was reviewed to identify possible associated factors. These and supposed additional factors were then investigated in a retrospective study of 332 SLE outpatients from the Policlinic for Rheumatology of the medical faculty of the Heinrich-Heine-University Dusseldorf. This study population included 297 females and 35 males aged 19–81 years with an average disease duration of 13 years (range 0–41 years). Patient data were collected during their baseline visits in 2014 and 2015. The Fatigue Severity Scale (FSS) was used to measure fatigue. This instrument covers nine items associated with fatigue and allows patients to assess its severity on a scale from 1–7. An average result in the FSS≥4 points is considered as severe fatigue. In this population the average result of the FSS was 3.76 points (range 0.89–7.0), in total 44% of all patients reached 4 points or more. In a univariate logistic regression a pathological result in the FSS≥4 was then compared with patients’ demographic and clinical data such as age, gender, disease activity and duration, depression, physical activity, pain, anaemia, vitamin D deficiency, sleep quality, target organ damage, obesity, hypothyroidism, infection, and current medication. A linear regression analysis was adjusted for potential confounders such as age, sex and disease activity using the Systemic Lupus Erythematosus Activity Questionnaire (SLAQ). Multiple significant correlations of fatigue could be demonstrated with age, gender, sleep disorders, pain, physical activity, disease activity, obesity, NSAIDs intake, physical and psychological well-being, overall health status and restrictions on everyday life. The 5 strongest associations with fatigue are given in the table. Based on these results, further research should be conducted to analyse the mentioned factors in more detail. It remains an interesting hypothesis that therapy aimed to improve one or more associated factors identified will also improve patients’ reported fatigue.