Phthalate Metabolites and Thyroid Hormone Levels in Men
Author Information
Author(s): John D. Meeker, Antonia M. Calafat, Russ Hauser
Primary Institution: Department of Environmental Health Sciences, University of Michigan
Hypothesis
The study investigates the relationship between urinary concentrations of phthalate metabolites and levels of thyroid hormones in adult men.
Conclusion
Urinary MEHP concentrations may be associated with altered free T4 and/or total T3 levels in adult men.
Supporting Evidence
- An inverse association was found between MEHP urinary concentrations and free T4 and T3 serum levels.
- The relationships did not appear to be linear when MEHP concentrations were categorized by quintiles.
- An IQR increase in MEHP was associated with a 0.021-ng/mL decrease in T3.
Takeaway
This study found that certain chemicals in our bodies, called phthalates, might change how our thyroid hormones work, which are important for our growth and energy.
Methodology
Urine and blood samples were collected from 408 men to measure phthalate metabolites and thyroid hormone levels.
Potential Biases
Potential for reverse causation where thyroid status may affect DEHP and/or MEHP metabolism.
Limitations
The study did not measure levels of total T4 and free T3, which may have provided additional insights.
Participant Demographics
Most participants were white (85%) and had never smoked (72%), with a mean age of 36 years.
Statistical Information
P-Value
0.04
Confidence Interval
95% CI, –0.18 to –0.03 for free T4; 95% CI, –0.042 to –0.001 for total T3
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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