ESPE Abstracts

Background: Exposure to per- and polyfluoroalkyl substances (PFASs) may interfere with thyroid function in the general population and disturb the timing of puberty onset.

Objectives: We investigated the possible relationship between PFASs and thyroid hormone (THs) exposure in girls with central precocious puberty (CPP).

Methods: In a prospective study initially established for assessing CPP, 627 serum samples were collected with (n= 226) and without (n= 401) CPP. The concentrations of 25 PFASs, thyroxin (T4), 3,5,3’-triiodothyronine (T3), and 3,3’,5’-triiodothyronine (rT3) were measured. We used logistic regression to examine the association of THs with the odds of having CPP and multiple linear regression to analyze the associations between THs and various PFASs in the CPP and control groups.

Results: The levels of T4 in the CPP group were significantly lower than those in the control group, and the levels of T3 and rT3 were significantly higher than those in the control group. After adjusting for confounders, T3 concentrations were associated with 1.526-fold increased odds of having CPP [odds ratio (OR) = 1.526, 95% confidence interval (CI):1.216–1.914]. In the CPP cohort, perfluoroheptanoic acid (PFHpA), perfluoro (2-ethoxyethane) sulphonic acid (PFEESA), and fluorotelomer phosphate diester (6:2/8:2 diPAP) were inversely associated with T3; perfluorobutanoic acid (PFBA) was inversely associated with T4, and PFEESA and 6:2/8:2 diPAP positively associated with T4; PFBA was positively associated with rT3, and perfluorooctane sulfonic acid (PFOS) was inversely associated with rT. In the control cohort, perfluorobutanesulfonic acid (PFBS) was positively associated with T3, and PFEESA and 6:2/8:2 diPAP were inversely associated with T3, and these PFASs had an adverse association with T4. Perfluorohexanoic acid (PFHxA) was positively associated with rT3, and 6:2/8:2 diPAP was negatively associated with rT3.

Conclusion: In this study, different measurements of PFASs and THs were observed in the CPP and control groups. Discrepancies in exposure to PFASs were associated with THs in the CPP cohort and healthy girls. Further research is necessary to investigate the mechanism by which PFASs affect the timing of puberty onset and thyroid function.