P-009 Impact of organophosphate pesticide exposure on human semen quality and circulating testosterone: a systematic review and meta-analysis

Abstract Study question Does exposure to organophosphate pesticides (OP pesticides) alter human semen quality and circulating testosterone levels? Summary answer Exposure to OP pesticides reduced sperm count, concentration, total and progressive motility, and normal sperm morphology, possibly via a testosterone-independent mechanism. What is known already OP pesticides have been associated with a decline in semen quality, although there are still considerable arguments about the magnitude of the association. Also, human data on semen quality and male reproductive hormones in association with OP pesticide exposure is limited and inconsistent. Study design, size, duration This study provides a systematic review and meta-analysis of the impacts of OP pesticide on semen quality and male reproductive hormones. Participants/materials, setting, methods This study was conducted according to PRISMA guidelines. Following a pre-defined strategic protocol, 1, 001 studies were screened and 9 articles were identified as eligible for this study. Two of the studies were from China, and one each from Japan, Peru, France, Mexico, Malaysia, Venezuela, and Iran. Two of the studies did not specify the types of OP pesticide used, while the remaining 7 did. Main results and the role of chance A total of 766 male subjects (349 exposed to OP pesticide and 417 unexposed controls) were included in the meta-analysis. There was no significant difference in the ejaculate volume, seminal fluid volume, sperm multiple anomaly index, and leukocytes levels of the OP-exposed subjects compared to the control. In addition, OP pesticide exposure did not significantly affect serum concentrations of FSH, LH, and testosterone in subjects who were exposed to OP pesticide compared to their unexposed counterparts. However, we found a significant reduction in the sperm count, sperm concentration, progressive sperm motility, total sperm motility, and normal sperm morphology of OP pesticide-exposed subjects compared to the unexposed subjects. However, after subtype and sensitivity analyses, exposure to OP pesticide did not significantly reduce sperm count. In addition, after sensitivity analysis, OP pesticide exposure did not significantly alter progressive sperm motility. Limitations, reasons for caution The non-inclusion of non-English publications in this study and the scarcity of well-designed studies to be included might have limited the pooled sample size and inadequately explored the impacts of OP. Also, the included studies are from a few countries, which may not necessarily be a good global representative. Wider implications of the findings The present comprehensive meta-analysis clearly demonstrates that exposure to OP pesticide causes reduced sperm count, concentration, total and progressive motility, and normal sperm morphology, possibly via a testosterone-independent mechanism. These findings strengthen existing evidence in the literature on the negative impacts OP pesticide exposure on semen quality. Trial registration number Not applicable