Urinary Bisphenol A Levels and Male Fertility

Abstract

Bisphenol A (BPA) is a high-production volume industrial chemical found in many consumer products. BPA is a suspected potent endocrine disruptor, with endocrine-disrupting properties demonstrated in animal studies. Few human studies have examined bisphenol A exposure in relation to male fertility and, results are divergent. The aim of the study is to examine the associations between urinary BPA concentration and male fertility. Bisphenol A urinary concentrations were measured using gas chromatography coupled with tandem mass spectrometry in 315 men under 45 years of age with normal sperm concentration (⩾15 mln/ml) recruited from a male reproductive health clinic. Participants were interviewed and provided a semen sample. BPA was detected in 98.10% of urine samples, with a median concentration of 1.87 µg/l (1.63 µg/ g creatinine). A multiple linear regression analysis identified a positive association between the urinary concentrations of bisphenol A 25th–50th percentile and total sperm sex chromosome disomy (p = .004). Also when modeled as continuous variable urinary BPA concentration increased total sperm sex chromosome disomy (p = .01). Urinary concentration of BPA also increase the percentage of immature sperm (HDS) (p = .018) and decrease motility (p = .03). The study provides evidence that exposure to BPA is associated with poorer semen quality. Future studies are needed to confirm these findings.

Cross Sectional Study on Exposure to BPA and Phthalates and Semen Parameters in Men Attending a Fertility Center

“…Nevertheless, the presented study did not highlight any statistically significant link between the urinary levels of BPA and alterations of the parameters of seminal fluid, as conversely documented in various literature studies. This could be due to the particularly reduced levels of BPA herein recorded, on average 0.24 ± 0.43 µg/g creatinine, compared to those identified in the literature with values two [80] to ten [34] or twenty times higher [40].…”

“…According to Lassen et al [33] the association between BPA levels and reproductive hormones would support an anti-androgenic effect with deleterious consequences on motile spermatozoa (−6.7%, confidence interval-CI −11.76/1.63 95%), data confirmed also by Radwan et al [34].…”

“…To use as a model for human testicular dysgenesis syndrome, pregnant rats were exposed to DnBP and a suppression of intratesticular testosterone, a focal aggregation of Leyding cells and ectopic Sertoli cells were obtained [27]. Also, the possible molecular mechanism of MnBP was investigated in vitro and even at low dose, an increased Sertoli cells proliferation emerged [28].Among other chemicals, evidence from previous studies showed that also bisphenol A (BPA), a precursor to important plastics like polycarbonates and epoxy resins, could interact with the endocrine system [29,30] and semen quality as well [31,32] even if the present evidence is controversial.According to Lassen et al [33] the association between BPA levels and reproductive hormones would support an anti-androgenic effect with deleterious consequences on motile spermatozoa (−6.7%, confidence interval-CI −11.76/1.63 95%), data confirmed also by Radwan et al [34].BPA induced, in in vivo studies, testicular dysfunction and alteration of Sertoli cell viability [35], testicular apoptosis in male rats [36]; after BPA exposure spermatogenic cells were disorganized and degenerated, spermatids had fragmented pyknotic nuclei and a significant decrease in the rate of proliferation of germ cells was present [37].In an epidemiological survey on 215 young health adults, the urinary BPA levels were significantly and inversely associated with sperm concentration and total sperm count [38]. In recent surveys [39,40] sperm concentration, morphology and motility were negatively associated with BPA urinary levels.…”

Bisphenol A and Male Fertility: Myths and Realities

“…In another study on 191 Czech men with infertile marriages, seminal BPA, but not plasma BPA, levels were negatively associated with sperm concentration, sperm count, and, to a lesser extent, normal sperm morphology (118). More recently, Radwan et al (119) reported that urinary concentration of BPA in 315 men with normal sperm concentration according to the WHO 2010 criteria (124) was negatively associated with sperm motility and positively associated with the percentage of sperm sex chromosome disomy. Finally, in a recent report on a preconception cohort of 161 men without known subfertility, higher urinary BPA concentrations were found in the group of men with abnormal sperm tail morphology, whereas no association was found with sperm count, and no information was provided about other semen parameters (121).…”

“…Due to the obvious lack of controlled clinical trials investigating the effects of BPA on human male fertility, information is largely inferred from findings of observational epidemiological studies that, with a few exceptions, used semen quality as a surrogate endpoint, producing divergent results likely due to heterogeneity in the extent of BPA exposure, sample sizes, type of population, and enrollment setting ( Table 1). Some studies included men from the general population (112)(113)(114)(115), others included men attending fertility clinics with (116)(117)(118)(119)(120) or without known subfertility (121); one study was restricted to men with proven fertility (122). Only in two studies were men with occupational exposure to BPA included (111,112).…”