Relationship between organophosphate and pyrethroid pesticides and metabolic syndrome in Korean farmers

Background: The global use of pesticides steadily increased until the early 2010s. Pesticides play a significant role in agriculture in Korea. Metabolic syndrome is more prevalent in rural areas than in urban areas. This study explored the potential association between organophosphate and pyrethroid pesticide exposure and metabolic syndrome.

Methods: This study enrolled 1,317 individuals who participated in the Pesticide Exposure and Intoxication Study conducted by the Dankook University Hospital Center for Farmers' Safety and Health from 2014 to 2019. Urinary levels of dimethylphosphate, dimethylthiophosphat, diethylphosphate, and diethylthiophosphate were measured to assess organophosphate pesticide exposure and urinary levels cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid, and 3-phenoxybenzoic acid were measured to assess pyrethroid pesticide exposure.

Results: The odds ratio for the 4th quartile group of organophosphate metabolites concentration was 1.48 (95% confidence interval: 1.06-2.09) compared to the 1st quartile group after adjustment for general factors. In addition, a positive trend was observed across the quartile groups of organophosphate metabolites concentration. A positive trend was noted across the quartile groups of organophosphate metabolites in males, while no significant association was observed in females. Furthermore, no significant associations were observed between metabolic syndrome and pyrethroid metabolites concentration.

Conclusions: A positive correlation was observed between the prevalence of metabolic syndrome and the concentrations of urinary organophosphate metabolites, consistent with previous research finding. This association may be attributed to the action of organophosphates as acetylcholinesterase inhibitors, stimulating beta cells in the islets of Langerhans. This can lead to alterations in lipid metabolism and insulin resistance, ultimately leading to metabolic syndrome development. Metabolic syndrome is a major contributor to cardiovascular disease; therefore, it is necessary to identify the risk factors unique to rural areas, such as pesticide exposure.