Association Between Per- and Polyfluoroalkyl Substance Exposures and Thyroid Homeostasis Parameters
Xinwen Yu1, Yufei Liu1, Meiying Wang1
1Department of Endocrinology, The Second Affiliated Hospital of Air Force Medical University, Xi'an 710038, Shaanxi, China.
Context:
Prevailing studies have shown the disruption effect of per- and polyfluoroalkyl substances (PFAS) on thyroid homeostasis. However, most studies have focused on individual thyroid hormones.
Objective:
To explore the associations between PFAS exposures and thyroid homeostasis parameters.
Methods:
A total of 2386 adults from National Health and Nutrition Examination Survey (2007-2008 and 2011-2012) were included. Thyroid homeostasis parameters included central and peripheral thyroid hormone sensitivity, calculated by thyroid hormones. Multivariable survey-weighted linear regressions were performed to determine the association between PFAS exposure and thyroid homeostasis parameters. The weighted quantile sum (WQS) and the quantile g-computation (QGC) models were used to estimate the mixed effects of coexposures to PFAS.
Results:
The ratio of free T3/free T4 (FT3/FT4) and the sum activity of peripheral deiodinases (SPINA-GD) were positively associated with perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid, perfluorononanoic acid, and perfluorohexane sulfonic acid, respectively. However, no significant associations were observed between PFAS exposure and central thyroid sensitivity parameters. PFAS coexposure was positively associated with FT3/FT4 (β = 0.013, P < .001) and SPINA-GD (β = 1.230, P < .001) in WQS models. Consistently, PFAS concentrations per quantile were linked to an increase in FT3/FT4 (β = 0.004, P = .002) and SPINA-GD (β = 0.392, P = .008) in QGC models, with PFOA having the highest weight in all models.
Conclusion:
This study revealed that PFAS exposures may affect peripheral thyroid hormone sensitivity instead of central among US general adults, enhancing our understanding of the correlation between PFAS exposure and thyroid hormones and providing insights into potential health implications.
Related Concept Videos
01:20Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The...
01:18Functions of Thyroid Hormones
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
01:22Target Cell Response to Hormones
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
01:36Types of Toxins
Air pollutants, primarily gases, pose significant threats to respiratory health, leading to conditions like hypoxia, lung cancer, and in extreme cases, death.
Environmental pollutants like...
01:23The Thyroid Gland
The follicles have a central cavity lined by simple cuboidal to squamous epithelial cells called follicular cells. These cells produce the glycoprotein...
01:17Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...