The association between urinary levels of organic phosphorus insecticide exposure and subclinical thyroid disorders

Abstract

Objective Studies have shown that exposure to organophosphorus pesticides (OPPs) may disrupt thyroid endocrine function in animal models and in agroforestry practitioners, leading to subclinical hyperthyroidism (SHyper). However, the relationship between exposure to OPPs and SHyper in the general population remains unclear. This research aims to investigate the relationship between OPPs exposure and SHyper in the general population. Methods This was a cross-sectional study involving data from three cycles of the National Health and Nutrition Examination Survey (NHANES), which ultimately analysed 4779 participants who met the inclusion criteria. OPPs exposure was estimated by measuring urinary composition of two OPPs metabolites (3,5,6-trichloropyridinol and paranitrophenol). Logistic regression models were employed to assess the correlation between OPPs metabolites and SHyper. Subgroup analyses were conducted based on gender, age, and body mass index (BMI), and interactions with OPPs were investigated. Results The adjusted logistic regression model showed that p-nitrophenol (PNP) was significantly and positively correlated with SHyper. PNP was positively associated with SHyper in the third and highest quartile groups compared with patients in the lowest quartile. Subgroup analyses found that both OPPs metabolites were associated with SHyper in the elderly and in those with a BMI less than 25. In addition, PNP was significantly associated with SHyper in females and those with a BMI greater than 30. With respect to SHyper, there were interactions between metabolites of OPPs and BMI and between PNP and sex. Conclusions Our study suggests that exposure to PNP and 3,5,6-trichloropyridinol (TCPy) may increase the risk of SHyper, highlighting the potential role of exposure to OPPs in SHyper.