Objectives: To assess nutritional status regarding selenium in adolescents with Juvenile Systemic Lupus Erythematosus (jSLE) and analyze possible associations with disease activity, insulin resistance and lipid profile.
Methods: This was an observational, cross-sectional study of 31 female adolescents with jSLE and 31 healthy female volunteers as a comparison group. We obtained demographic, anthropometric (weight, stature, waist, and neck circumferences), and clinical data (disease activity measured by SLEDAI-2K) from both groups; laboratory data including: lipid profile, plasma selenium, erythrocyte glutathione peroxidase activity (GPx), plasma malondialdehyde (MDA), ultrasensitive C-reactive protein (usCRP), insulin levels, and glycemia (Homeostasis Model Assessment for Insulin Resistance-HOMA-IR).
Results: Mean age at diagnosis of jSLE group was 15.9±1.7 years, with mean disease duration of 3.6±2.6 years. 48% of patients and controls had below-reference Se levels (≤46mcg/L). GPx was more frequently below reference levels (<4.171U/L) in the jSLE group, compared to controls. A ROC curve was used to assess the power of the variables to discriminate between both groups; insulin (AUC = 0.712; CI 95% 0.584-0.840), waist-to-height ratio (AUC = 0.704; CI 95% 0.572-0.837), and HOMA-IR (AUC = 0.689; CI 95% 0.556-0.822) were the variables with the greatest discriminatory power. Linear regression showed an independent inverse association between Se levels and c-LDL; no such correlation was found for GPx activity. SLEDAI-2 K and HOMA-IR showed no association with levels of Se and GPx activity.
Conclusions: Approximately, 50% of jSLE adolescents had below reference Se levels. The frequency of inadequate GPx values was higher in patients, compared to controls. There was an independent inverse association between Se and c-LDL levels in both groups; this was not the case for HOMA-IR and SLEDAI-2K. The data show the importance of assessing Se nutritional status in jSLE patients.
Keywords: Children; selenium; systemic lupus erythematosus.