Serum levels of glucose, thyroid stimulating hormone, and free thyroxine in boys diagnosed with attention deficit hyperactivity disorder: a cross-sectional pilot study

TL;DR

This study found that boys with ADHD have different levels of glucose, thyroid hormones, and TSH compared to healthy boys, suggesting a possible link between ADHD symptoms and hormonal patterns.

Contribution

The study is novel in exploring the association between ADHD in boys and specific serum biochemical markers like glucose, TSH, and FT4.

Findings

ADHD participants had lower glucose and FT4 levels and higher TSH levels compared to controls.

TSH levels were significantly correlated with hyperactivity and impulsivity symptoms in ADHD boys.

Elevated FT4 levels were associated with a lower likelihood of ADHD diagnosis.

Abstract

Although attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, its aetiology remains unclear. We aimed to establish a relationship between ADHD diagnosis and serum levels of glucose, free thyroxine (FT4), and thyroid stimulating hormone (TSH) in primary school aged boys.

In a cross-sectional study, we enrolled 133 participants aged 6.5–12.5 years, 67 of whom met DSM-5 criteria for ADHD and 66 healthy age-matched boys. The ADHDT test (ADHDT) was used to assess ADHD symptoms and the Wechsler Intelligence Scale for Children – Revised was used to exclude participants with cognitive deficits. The ADHD participants were tested using the Iowa Conners’ Teacher Rating Scale.

The ADHD participants had lower glucose levels, higher TSH values, and significantly lower FT4 values than the control group. The multiple logistic regression analysis showed that TSH is a parameter that is 2.7% more likely to occur in the ADHD group. We found a significant correlation between the TSH level and the symptoms of hyperactivity (r = 0.318, p = 0.009) and impulsivity (r = 0.275, p = 0.024) as well as between the glucose level and the symptoms of hyperactivity (r = 0.312, p = 0.010).

Certain ADHD symptoms may correlate with certain hormonal patterns. Our results suggest that the likelihood of suffering from ADHD was lower when FT4 levels were elevated. One biochemical parameter that was significantly and independently associated with the diagnosis of ADHD was the serum TSH level.

On June 26, 2018, at its VI session in 2018, the Ethics Committee of the Institute for Mental Health in Belgrade, Serbia, has considered and unanimously approved the conduct of the research, under the number 1704/1.

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