The effects of postnatal exposure of endocrine disruptors on testicular function: a systematic review and a meta-analysis
Despite many epidemiological studies having been conducted, the impact of postnatal exposure of endocrine disruptors (EDs) on testicular function remains a controversial issue.
To systematically review the literature and perform a quantitative synthesis to evaluate the effect of EDs on testicular function.
Materials and methods
A comprehensive search was conducted in the MEDLINE, Scopus, and CENTRAL databases. Eligible for the systematic review were observational (cross-sectional and cohort) studies with (i) adult men who had a high probability of postnatal exposure to EDs (“exposed”), (ii) adult men who had a low probability of postnatal exposure to EDs (“non-exposed”), and (iii) an outcome of interest [seminal parameters and reproductive hormone concentrations]. The continuous outcomes in each of the studies were synthesized by the random effects model and expressed as standardized mean difference (SMD) with 95% confidence interval (CI).
Thirteen studies, including 959 exposed and 907 non-exposed men, fulfilled the inclusion criteria. Exposure to EDs was associated with decreased LH [SMD − 0.17, 95% CI − 0.33 to − 0.02, 10 studies (616 exposed, 563 non-exposed), I2 40%, p = 0.09], progressive motility [SMD − 0.45, 95% CI − 0.77 to − 0.13, three studies (133 cases, 153 controls), I2 38%, p = 0.20], and normal morphology [SMD − 0.50, 95% CI − 0.85 to − 0.14, eight studies (562 cases, 540 controls), I2 87%, p < 0.01] compared with non-exposure. No difference was observed between the other study groups.
Postnatal exposure to EDs is associated with decreased semen quality. Nevertheless, there is no evidence that a disruption of testicular function mediates the deterioration in semen quality.
KeywordsEndocrine disruptors Hormone disruption Male infertility Sperm parameters
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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