Effects of the endocrine disruptor vinclozolin in male reproduction: a systematic review and meta-analysis

Endocrine-disrupting chemicals have become an issue of scientific and public discussion. Vinclozolin (VNZ) is a fungicide that competitively antagonizes the binding of natural androgens to their receptor, disturbing the function of tissues that are sensitive to these hormones, as is the case of the male reproductive organs. A systematic review with meta-analyses of rodent studies was conducted to answer the following question: Does exposure to VNZ affect sperm parameters and testicular/epididymal weight? The methodology was prespecified according to the Cochrane Handbook for Systematic Reviews and PRISMA recommendations. Sixteen articles met the inclusion criteria, comprising a total of 1189 animals. The risk of publication bias was assessed using the Trim and Fill adjustment, funnel plot, and Egger regression test. Heterogeneity and inconsistency across the findings were tested using the Q-statistic and I-2 of Higgins, respectively. Sensitivity was also analyzed. Statistical analysis was performed on Comprehensive Meta-Analysis software (Version 2.0), using random models and weighted mean differences along with a 95% confidence interval. Sperm motility, counts, daily sperm production (evidence of publication bias), and epididymis weight were decreased in VNZ-treated animals. Exposure length and dose, as well as the time point of exposure, influenced the obtained results. Despite the moderate/high heterogeneity observed, the sensitivity analysis overall demonstrated the robustness of the findings. The quality scores of the included studies were superior to 4 in a total of 9, then classified as good. The obtained data corroborate the capability of VNZ exposure to disrupt spermatogenic output and compromise male fertility. Summary sentence A systematic review with meta-analysis was conducted to understand how the exposure to VNZ affects fertility-related outcomes such as sperm quality parameters and testicular/epididymal weight. [GRAPHICS]

Automated summary

Endocrine-disrupting chemical Vinclozolin was found to decrease sperm quality parameters and testicular/epididymal weight in exposed animals. Exposure length, dose, and time point influenced the results, with overall robustness observed in sensitivity analysis despite moderate/high heterogeneity. Studies included were of good quality, with data supporting the disruption of spermatogenic output and male fertility by Vinclozolin exposure.