Mobility, sleep quality, depression and anxiety as correlates of fatigue in childhood-onset systemic lupus erythematosus

Objective Fatigue is a prevalent and debilitating symptom in childhood-onset systemic lupus erythematosus (cSLE), yet evidence regarding its burden and associated factors remains limited. This study aimed to assess fatigue and identify factors associated with fatigue in patients with cSLE. Methods We conducted a cross-sectional study of 167 patients with cSLE recruited from Shenzhen Children’s Hospital between January and December 2025. Fatigue was assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Fatigue Short Form-10a v2.0. Mobility, anxiety, depression, peer relationships, pain intensity, sleep quality, and clinical characteristics were also assessed. Group differences were examined using the Mann–Whitney U or Kruskal–Wallis H test, associations were evaluated using Spearman rank correlation analysis, and multivariable linear regression was performed to identify factors independently associated with fatigue. A stepwise regression model was additionally conducted as a sensitivity analysis. Results The median (IQR) fatigue score was 47.90 (39.00–54.50), and 77 participants (46.1%) experienced at least mild fatigue. Fatigue was positively correlated with depression, anxiety, poorer sleep quality, and pain intensity and negatively correlated with mobility and peer relationships. In the primary multivariable model, lower mobility scores (β = −0.335, P < 0.001), poorer sleep quality (β = 0.261, P < 0.001), higher depression scores (β = 0.230, P = 0.002), and higher anxiety scores (β = 0.155, P = 0.035) were independently associated with greater fatigue. Conventional immunotherapy combined with biologic agents was associated with lower fatigue scores (β = −0.149, P = 0.014), although this variable was not retained in the sensitivity analysis. The primary model explained 64.0% of the variance in fatigue. Conclusions Fatigue is common in cSLE and is independently associated with mobility, sleep quality, depression, and anxiety. These findings support a multidimensional view of fatigue in cSLE and highlight the importance of considering physical functioning, sleep quality, and psychological symptoms alongside disease-related factors in comprehensive pediatric rheumatology care.