The association between 2,4-D and serum testosterone levels: NHANES 2013-2014

Background Previous studies have investigated associations between herbicides such as 2,4-Dichlorophenoxyacetic acid (2,4-D) and dyshormonogenesis, specifically low testosterone, in human, rodent, and cell models, but results have been conflicting and inconclusive. Methods Using data from a cross-sectional study of 456 adult men in the 2013-2014 NHANES survey cycle, we examined the relationship between urinary concentrations of 2,4-D and serum testosterone levels. Results Multivariable regression models adjusting for potential confounders revealed a significant, negative association between urinary 2,4-D and mean serum testosterone among U.S. adult males (beta = - 11.4 ng/dL, p = 0.02). Multivariable logistic regression models using a cutoff defining abnormally low testosterone (i.e., serum testosterone < 300 ng/dL) revealed no significant associations between 2,4-D and the odds of low testosterone. Conclusion These findings expand on previous literature implicating a role for 2,4-D in the etiology of low testosterone and dyshormonogenesis. Future studies are warranted to corroborate these findings, determine clinical significance, and to investigate the proposed potential biological mechanisms underlying this association.

Automated summary

This study investigated the relationship between urinary concentrations of 2,4-D and serum testosterone levels among U.S. adult males, finding a significant negative association. However, no significant associations were found between 2,4-D and the odds of low testosterone based on a cutoff defining abnormally low testosterone levels. Further research is needed to confirm these findings and explore potential biological mechanisms.