Urinary bisphenol-A concentration in infertile Japanese women and its association with endometriosis: A cross-sectional study

Abstract

Objectives: Bisphenol A (BPA), a raw material commonly used in the manufacture of resins such as polycarbonate and epoxy, is a possible xenoestrogen that is hypothesized to disrupt the human endocrine system. Humans are widely exposed to BPA. We investigated the urinary concentration of BPA in infertile Japanese women and its possible association with endometriosis.Materials and Methods: We recruited 166 women (aged 20-45) who had complained of infertility and visited a university hospital in Tokyo. The subjects were interviewed and their urine samples were obtained prior to a laparoscopic diagnosis of endometriosis between January 2000 and December 2001. Urinary total BPA concentration in 140 eligible urine samples was then measured using enzymatic deconjugation of glucuronide and sulfate and high-performance liquid chromatography isotopedilution tandem mass spectrometry.Results: Median (25th-75th percentile) unadjusted and creatinine-adjusted urinary BPA concentrations were 1.6 (0.69-2.8) μg/L and 0.80 (0.45-1.3) μg/g creatinine. No significant monotonic association of endometriosis with urinary BPA concentration was observed. Median urinary BPA concentration in women with stage 0-I endometriosis (0.74 μg/g creatinine) did not significantly differ from that in those with stage II-IV endometriosis (0.93 μg/g creatinine) (p for difference=0.24).Conclusions: This study, based on a larger number of samples than those in previous studies in Japan and using the most reliable analytical method currently available, showed that urinary concentrations of BPA in women who consulted a physician for infertility were not higher than those in other populations. Moreover, no association between urinary BPA concentration and endometriosis was found in this cross-sectional study.

Long-term study of urinary bisphenol A in elementary school children

“…Further, in animal reproduction studies, effects on F1 and F2 generations have also been seen, such as reproductive system effects and behavioral Environ Health Prev Med (2008) 13:332-337 333 abnormalities in animal experiments using mice and rats [8,9,11,21,22]. Moreover, human epidemiological studies have suggested the possibility of an association with a variety of disorders, including effects on the reproductive system, such as hypospadia, undescended testes, and endometriosis [15,19,23,24]; neural development and behavior [12,25]; sex hormones [12,24]; and allergic conditions [26]. In terms of the risk of BPA to infants and children, an expert panel at the Center for the Evaluation of Risks to Human Reproduction of the National Toxicology Program in the United States recently expressed ''some concern that exposure to Bisphenol A causes neural and behavioral effects'' and ''minimal concern that exposure to Bisphenol A potentially causes accelerations in puberty'' [27].…”

“…Determination of urinary BPA levels was done using LC-MS/MS [19] on account of its highly reliable identification.…”

“…Further, the possibility of cross-reaction with BPArelated substances has been noted [27,37]. Here, therefore, we decided to measure BPA levels using LC-MS/MS [19], a highly sensitive technique with high reproducibility.…”

“…We partially modified the method of Itoh et al [19] to measure urinary BPA. Using 200-ll urine samples, we deconjugated by treatment with betaglucuronidase/sulfatase, followed by solid-phase extraction and analysis using isotope-dilution LC-MS/MS.…”

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“…Only a few studies investigating the association between BPA exposure and reproductive/developmental disorders in human subjects have been published since 2007 (Itoh et al, 2007;Padmanabhan et al, 2008;Wolff et al, 2008;Braun et al, 2009;Cobellis et al, 2009;Yang et al, 2009;Li et al, 2010a, b;Meeker et al, 2010;Mendiola et al, 2010;MokLin et al, 2010). Itoh et al (2007) reported no association between urinary BPA concentrations and endometriosis in a cross-sectional study of 140 infertile Japanese women.…”