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Unique metabolic signature in baby teeth linked to ADHD, autism

Researchers identified metabolic signatures in baby teeth that were unique to ADHD, autism spectrum disorder and both neurodevelopment conditions, according to a study published in Translational Psychiatry.

"Environmental epidemiologists typically study exposure to essential and toxic elements by examining how much of a given element a child was exposed to, but our work indicates that the way a child metabolizes environmental exposures is essential to healthy neurodevelopment," Paul Curtin, PhD, assistant professor at the Icahn School of Medicine at Mount Sinai, said in a press release.

Researchers conducted recurrence quantification analysis to examine whether cycles of essential and toxic elements were dysregulated during prenatal and early postnatal development in ADHD, and if these profiles differentiate individuals with ADHD from those with ASD as well as ADHD/ASD combined presentation in a sample of Swedish twins (n = 74).

Using tooth biomarkers, they measured the detailed temporal profiles of exposure to 10 metals over the prenatal and early childhood periods in 13 children with ADHD, eight with ASD, 12 with combined ADHD/ASD and 41 neurotypical controls.

In ADHD cases, Curtin and colleagues reported consistently reduced regularity (determinism) in the elements cobalt (beta=–0.03; P=.017), lead (beta=–0.03; P=.016) and vanadium (beta=–0.03; P=.01), with a tendency reduced determinism in copper (beta=–0.03; P=.054).

“These results indicate that in ADHD cases there is instability in the cyclic metabolic activity of these elements, relative to what occurs in typically developing twins,” they wrote in the full study.

The investigators also observed a significant reduction in the duration and complexity of some elemental cycles among ADHD cases, including lead (beta=–0.38; P=.016) and vanadium (beta=–0.25; P=.01) compared to controls. In addition, they found decreased entropy in cobalt (beta=–0.13, P=.017), lead (beta=–0.18; P=0.016), and vanadium (beta=–0.15; P=.008).

The results showed that birth weight had a significant effect on both zinc determinism (beta=–0.00002; P=.03) and zinc entropy (beta=–0.0001; P=.03). Furthermore, analysis indicated that elemental pathways and dynamical features were specific to ADHD vs. ASD, and unique characteristics were tied to the combined presentation of ADHD/ASD.

"The discovery that autism spectrum disorder, ADHD, and the combined presentation of autism and ADHD each have a unique metabolic signature can inform future studies on what might cause the disorders,” Curtin said in the release. “It could help us determine the pathways implicated in the different diseases, which, in turn, could inform the development of treatment and prevention strategies.” – by Savannah Demko

Disclosure: The authors report no relevant financial disclosures.