Langrock C, et al. - The researchers aimed to investigate whether overweight children with attention-deficit/hyperactivity disorder (ADHD) showed higher thyroid-stimulating hormone (TSH) and free triiodothyronine (fT3) concentrations compared to overweight children without ADHD. They confirmed the relation between overweight and thyroid hormones. However, findings pointed against the hypothesis that thyroid hormones could link overweight and ADHD in children.

Methods

• The researchers analyzed TSH, fT3, fT4, and leptin levels in 230 children (60.9% boys, 9.3 ± 1.7 years old, 35.7% migration background).
• They divided children into 4 groups (I = 26 overweight children with ADHD, II = 56 normal-weight children with ADHD, III = 66 overweight children without ADHD, and IV = 82 normal-weight children without ADHD).
• They determined the severity of ADHD by the parent version of the Connors 3 rating scales.

Results

• With regard to TSH, fT3, or fT4 concentrations, overweight children with ADHD did not differ significantly from overweight children without ADHD.
• Moreover, comparing the thyroid hormones between the 4 groups showed no significant differences for TSH and fT4 concentrations.
• Compared to normal-weight children without ADHD, fT3 concentrations were significantly higher in normal-weight children with ADHD.
• In multiple regression analyses adjusted for age, gender, and migration background, inattention and hyperactivity/impulsivity scores were not significantly related to TSH or fT3.
• In these analyses, TSH was correlated with BMI SDS (β coefficient 0.19 ± 0.12, P=0.002) and leptin (exp[β coefficient] 1.87 ± 1.36, P < 0.001).
• Furthermore, fT3 (β coefficient 0.06 ± 0.05, P=0.009) and leptin (exp[β coefficient] 1.17 ± 1.13, P=0.009) were correlated with BMI SDS.