Androgen disruption by dioxin exposure in 5-year-old Vietnamese children: Decrease in serum testosterone level

Area of Science:

• Environmental Health
• Endocrinology
• Toxicology

Background:

• Dioxins are suspected endocrine disruptors, with previous research indicating lower dehydroepiandrosterone (DHEA) in Vietnamese children exposed to dioxins.
• Understanding dioxin's impact on steroidogenesis is crucial for assessing long-term health risks in exposed populations.

Purpose of the Study:

• To investigate the influence of dioxin exposure on androgen biosynthesis in 5-year-old children from dioxin hotspot and non-sprayed areas in Vietnam.
• To examine the correlation between dioxin levels and specific steroid hormones and the activity of key steroidogenic enzymes.

Main Methods:

• Maternal breast milk dioxin levels were measured using gas chromatography/high-resolution mass spectrometry.
• Serum samples from 5-year-old children were analyzed for seven steroid hormones using liquid chromatography/mass spectrometry.
• Activities of steroidogenic enzymes, including CYP17 lyase and 17β-HSD, were assessed.

Main Results:

• Children from the dioxin hotspot area exhibited significantly lower levels of dehydroepiandrosterone (DHEA) and testosterone (T).
• Dioxin levels showed negative correlations with DHEA and T, and altered activities of CYP17 lyase and 17β-HSD.
• Elevated androstenedione (A-dione) levels and 3β-HSD activity were positively correlated with dioxin exposure.

Conclusions:

• Dioxin exposure is associated with suppressed levels of DHEA and T in 5-year-old children.
• Dioxins appear to inhibit the activity of steroidogenic enzymes like CYP17 lyase and 17β-HSD, impacting androgen biosynthesis.
• Findings highlight the potential for dioxins to disrupt endocrine function and steroid hormone production in early childhood.