Physical activity ameliorates fatigue in systemic lupus erythematosus (SLE) patients by an unknown mechanism. Adipokines, which are influenced by adiposity and physical activity, may be associated with patient-reported fatigue. We describe cross-sectional associations between adipokines and fatigue, physical activity, and SLE disease activity. We measured adipokines, self-reported fatigue, and objective physical activity in 129 SLE patients. Fatigue was assessed with the Fatigue Severity Scale (FSS) and Patient Reported Outcomes Measurement Information System® (PROMIS®) Fatigue score. Disease activity was measured with the Safety of Estrogens in Systemic Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI). Participants wore an accelerometer for 7 days to measure physical activity. Leptin, adiponectin, and resistin were measured in stored serum with a Luminex bead-based assay. Multivariable regression models assessed relationships between fatigue and adipokines, and Spearman correlation coefficients summarized associations between adipokines, physical activity, and SELENA-SLEDAI. Median adipokine levels were: leptin 30.5 ng/ml (Interquartile Range 14.0, 56.6), adiponectin 11.6 μg/ml (7.2, 16.8) and resistin 1.4 ng/ml (1.0, 2.2). Associations between adipokines and FSS or PROMIS fatigue were not significant. Body mass index (BMI) ≥ 30 kg/m2 was associated with FSS and PROMIS fatigue in regression analyses (p < 0.05). Weak correlations between leptin, adiponectin, leptin/adiponectin (L/A) ratio, and physical activity and between adiponectin and SELENA-SLEDAI score were not significant after adjusting for BMI. Adipokines were not associated with fatigue in SLE. Adipokines were correlated with physical activity (leptin, adiponectin, L/A ratio) and SLE disease activity (adiponectin), but most of these associations were explained by BMI.
Keywords: Adipokines; Fatigue; Physical activity; Systemic lupus erythematosus.