Evaluation of the relationship between thyroid hormone levels and bisphenol a in children aged 6-14 years

Introduction: Bisphenol A (BPA) is a synthetic high-production monomer used in polycarbonate plastics and epoxy resins in a wide variety of consumer products. Bisphenol A can disrupt normal thyroid function in many ways, including interactions affecting cellular signaling and gene expression (transcription). The aim of this study is to investigate the relationship between bisphenol A (BPA) and thyroid hormone levels in children aged 6-14 years. Method: The study is a case-control study conducted with 102 participants between September 2023 and April 2024 in collaboration with the Department of Public Health at Çukurova University Faculty of Medicine, Çukurova University Balcalı Hospital, Department of Pediatric Endocrinology, and the Department of Pediatrics in Adana. Children aged 6-14 years were included in the study. Data collection tools included a sociodemographic form, a questionnaire on prenatal and postnatal nutrition, blood parameters (TSH, T4), and urinary parameters (BPA and its substitutes). IBM SPSS Statistics Version 20.0 package program was used for statistical analysis. Analyses included t-tests, Mann-Whitney U tests, Pearson correlation tests, Spearman correlation analysis, chi-square tests, IU method, and ROC analyses. A value of p<0.05 was considered statistically significant. Results: According to the study results, BPS levels in the case group were found to be significantly higher than in the control group (p<0.006). A negative correlation was found between BPS levels and T4 (r=-0.302, p=0.035). The total BP value was found to be significantly higher in the case group compared to the control group (p<0.001). A weak positive correlation (r=0.258, p=0.041) was found between total BP value and TSH, and a moderate negative correlation (r=-0.463, p<0.001) was found between total BP value and T4. The optimal cutoff value for urinary BP-total level was found to be 1.3 (ng/ml), and values above this were diagnostically accepted for hypothyroidism. For this cutoff value, sensitivity was 83.7%, specificity was 75%, positive predictive value was 87.8%, negative predictive value was 68.2%, and the area under the curve was 0.848 (Method IU). Conclusion: At the end of this study, it was concluded that bisphenol exposure might have adverse effects on thyroid hormones in children and that urinary BP-total level could be used as a potential indicator of hypothyroidism. Additionally, it was determined that further research and public awareness are needed to reduce bisphenol exposure. Keywords: BPA, Hypothyroidism, Children