Objective: Previous studies indicated that maternal thyroid dysfunction increase the offspring’s risk for attention deficit/hyperactivity disorder (ADHD). However, the relationship between thyroid function and symptoms in children with ADHD remains unclear.
Methods: A total of 49 children with ADHD were enrolled. The Conners 3 scale was used to estimate the symptoms associated with ADHD. Correlation between thyroid hormones and the scores of the Conners 3 scale was evaluated by Pearson correlation analysis. Then, ADHD children were divided into two groups according to the hyperactivity index (HI) of the Conners 3 scale: ADHD children with hyperactivity behaviors (HB) (HI > 1.5) and ADHD children without HB (HI < 1.5). The demographic characteristics, thyroid hormones, and routine laboratory parameters between the two groups were collected. To distinguish HI-related factors, a univariate analysis and a binary logistic regression predictive model were used. The discriminative ability of thyroid stimulating hormone (TSH) in predicting ADHD children with HB from ADHD children without HB was investigated using the receiver operating characteristic (ROC) curve method.
Results: The levels of TSH were positively correlated to the scores of the Conners 3 scale (r = 0.338, P = 0.033) and HI (r = 0.371, P = 0.019). Moreover, the levels of TSH, serum ferritin, and lactic acid were significantly increased in ADHD children with HB compared to ADHD children without HB (all P < 0.05). Furthermore, the results of binary logistic regression found that TSH (OR 2.243 (CL 1.052– 4.783)) and lactic acid (OR 1.018 (CI 1.003– 1.032)) were independently associated with HI. Additionally, ROC analysis indicated the potential diagnostic value of TSH in discriminating ADHD children with HB from ADHD children without HB with an AUC of 0.684.
Conclusion: These results suggested that the serum TSH levels may be related to the HB in children with ADHD.
Keywords: thyroid function, children, attention deficit/hyperactivity disorder, thyroid stimulating hormone, lactic acid, hyperactivity behaviors