Fatigue in systemic lupus erythematosus: contributions of disease activity, pain, depression, and perceived social support.

OBJECTIVE: Pain and psychological distress are associated with fatigue, and social support may play a buffering role in the adjustment to a chronic disease. Investigations of the relationship between fatigue and disease activity in chronic diseases have provided inconclusive findings. The influence of medications on perceived fatigue remains unclear. We investigated the relationship between pain, depression, fatigue, and disease activity in patients with systemic lupus erythematosus (SLE).
METHODS: Participants (n = 127) completed a psychosocial questionnaire during routine clinic visits. Hierarchical multiple regression analysis was conducted to predict the contribution of disease activity, pain, depression (Beck Depression Inventory), and perceived social support to fatigue.
RESULTS: Disease activity as measured by SLE Disease Activity Index (SLEDAI) did not significantly predict self-reported levels of fatigue. Medication usage did not predict fatigue levels. Pain and depression were both unique positive predictors of fatigue. Controlling for pain and depression, perceived social support contributed negatively to the variance in fatigue scores, suggesting a buffering effect. This model reliably explained 42% of the variance in fatigue scores.
CONCLUSION: Our results emphasize the importance of depression, pain, and perceived social support in predicting reported fatigue levels in patients with SLE. In contrast, disease activity measured by SLEDAI does not appear to account for fatigue in SLE. Understanding the effect of psychosocial factors on fatigue in SLE may improve patient outcomes through psychosocial interventions aimed at reducing pain and increasing coping skills and social support.