title: Effect of endocrine disruptors on male reproduction in humans: why the evidence is still lacking?
abstract: The so-called "endocrine disruption hypothesis" suggests that exposures to endocrine disruption (EDs) during fetal, neonatal and adult life may interfere with the development of reproductive organs and alter semen quality and reproductive hormone production. Even though animal studies provide substantial evidence of adverse effects of EDs on male reproductive system, epidemiological studies in humans arrive at conflicting results. The aim of the present study was to systematically review the literature to locate methodological characteristics of the studies that struggle the formation of an association between EDs and human male reproduction. Such characteristics include: (i) definition of the exposed and the non-exposed population, (ii) age, (iii) insufficient control for confounders, (iv) ED assay and threshold, (v) time parameters of ED exposure, and (vi) study outcomes. Additional issues are: (i) the late effect of an early exposure, (ii) the multiple exposure effect, and (iii) the fact the same ED may exhibit different modes of action. Unfortunately, the nature of the field precludes the conduction of randomized-controlled trials, which could result to etiological associations between EDs and human male reproduction. Consequently, there is a great need to conduct well-designed studies of case-control or cohort type to evaluate EDs effects on human male reproductive health, and apply possible measures that could limit dangerous exposures.
authors.affiliation: Unit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Thessaloniki, Greece.|Second Department of Obstetrics and Gynecology, Athens University Medical School, Athens, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Bliatka
authors.affiliation: Unit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Lymperi
authors.affiliation: Second Department of Obstetrics and Gynecology, Athens University Medical School, Athens, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Mastorakos
authors.affiliation: Unit of Reproductive Endocrinology, First Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: D G
authors.initials: DG
authors.lastname: Goulis
mesh_terms: D052244:Endocrine Disruptors / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects; D006801:Humans; D008297:Male; D012098:Reproduction / Q000187:drug effects*; D060728:Reproductive Health
chemical_list: D052244:Endocrine Disruptors
keywords: endocrine disrupters; epidemiology; male reproductive system; methodology