The association between dietary antioxidants, superoxide dismutase activity, and serum levels of inflammatory factors in children with ADHD

Introduction: Recent studies have identified Attention Deficit Hyperactivity Disorder (ADHD) as an inflammatory condition with immunological and oxidative responses. Therefore, it is necessary to examine these factors in the patients. This study aimed to investigate the relationship between the dietary intakes of antioxidants, SOD activity and the serum levels of inflammatory factors in children with ADHD. Methods: This study was a retrospective case-control study with 64 ADHD children aged 6 to 13 years. The demographic questionnaire, FFQ, and Baecke physical activity questionnaire were used. SOD activity and the serum level of inflammatory factors (homocysteine, IL-6, and CRP) were measured in all patients. Based on the values obtained from CRP, 32 patients were included in the case group (CRP≥1 mg/L) and 32 patients in the control group (0≤CRP<1 mg/L). Results: There was no significant difference between the two groups as regards age, sex, weight, height, body mass index (BMI). In the case group, the mean SOD activity score (P=0.034), the physical activity score (P=0.04) and the zinc intake (P=0.02) and homocysteine levels were higher than they were in the control group (P=0.001). Among the variables in the presence of each other, the best predictors were homocysteine (OR: 1.34, 95% CI: 1.082-1.670, P=0.029) and physical activity (OR: 0.85, 95% CI: 0.761-0.952, P=0.022) respectively, and in the presence of these two variables, other variables were not significant predictors. Conclusion: The present study showed that the level of inflammatory factors in the case group was significantly higher than the control group. Homocysteine and physical activity can predict the inflammatory status induced by CRP. Decreasing the antioxidant activity of SOD with increasing CRP levels, indicates oxidative stress associated with inflammation in these patients.

Keywords:

antioxidants , inflammation , C-reactive protein , ADHD , child