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Association between perfluoroalkyl substances exposure and thyroid function in adults: A meta-analysis
Min Joo Kim1, Shinje Moon2, Byung-Chul Oh3
1Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Plos One
|May 11, 2018
Summary
Per- and polyfluoroalkyl substances (PFASs) exposure is linked to altered thyroid hormones, particularly total T4. The impact of PFASs on thyroid function varies with chemical concentration, highlighting potential health risks.
Area of Science:
- Environmental Health
- Endocrinology
- Toxicology
Background:
- Per- and polyfluoroalkyl substances (PFASs) are ubiquitous industrial chemicals with widespread human exposure.
- Epidemiological evidence suggests a potential link between PFAS exposure and thyroid hormone disruption, but findings remain inconclusive.
Purpose of the Study:
- To conduct a comprehensive meta-analysis investigating the association between exposure to specific PFASs (PFOS, PFOA, PFHxS) and thyroid hormone levels in adults.
Main Methods:
- Systematic literature search of databases for studies on PFASs (PFOS, PFOA, PFHxS) and adult thyroid hormone levels.
- Inclusion of twelve articles for meta-analysis, calculating pooled z values from correlation or regression coefficients.
Main Results:
- Perfluorooctanesulfonic acid (PFOS) showed a positive correlation with free thyroxine (T4) and, at intermediate concentrations, with thyroid-stimulating hormone (TSH), while negatively correlating with total T4 and total triiodothyronine (T3).
- Perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS) demonstrated negative correlations with total T4.
- No significant association between PFASs and thyroid hormones was found in a subgroup analysis of pregnant women.
Conclusions:
- Meta-analysis indicates a negative association between PFAS exposure and total T4 levels.
- The effect of PFASs on thyroid hormones is concentration-dependent, suggesting complex toxicological interactions.
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