Predictors of fatigue and severe fatigue in a large international cohort of patients with systemic lupus erythematosus and a systematic review of the literature

OBJECTIVE Fatigue is reported in up to 90% of patients with SLE. This study was conducted to identify the determinants associated with fatigue in a large cohort of patients with SLE, as well as to provide a systematic review of the literature. METHODS Patients from the Lupus BioBank of the upper Rhein, a large German-French cohort of SLE patients, were included in the FATILUP study if they fulfilled the 1997 ACR criteria for SLE and had Fatigue Scale for Motor and Cognitive Functions scores collected. Multivariate logistic regression analyses were performed to assess the determinants of fatigue and severe fatigue. RESULTS A total of 570 patients were included (89.1% female). The median age was 42 years (interquartile range 25-75: 34-52). The median value of the SAfety of Estrogens in Lupus Erythematosus National Assessment (SELENA)-SLEDAI was 2 (0-4). Fatigue was reported by 386 patients (67.7%) and severe fatigue by 209 (36.7%). In multivariate analyses, fatigue was associated with depression [odds ratio (OR): 4.72 (95% CI: 1.39-16.05), P = 0.01], anxiety [OR: 4.49 (95% CI: 2.60-7.77), P < 0.0001], glucocorticoid treatment [OR: 1.59 (95% CI 1.05-2.41), P = 0.04], SELENA-SLEDAI scores [OR: 1.05 (95% CI: 1.00-1.12) per 1 point increase, P = 0.043] and age at sampling [OR: 1.01 (95% CI: 1.00-1.03) per 1 year increase, P = 0.03]. Severe fatigue was independently associated with anxiety (P < 0.0001), depression (P < 0.0001), glucocorticoid treatment (P = 0.047) and age at sampling (P = 0.03). CONCLUSION Both fatigue and severe fatigue are common symptoms in SLE, and are strongly associated with depression and anxiety. Disease activity and the use of glucocorticoids were also independently associated with fatigue, although more weakly.