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Li D.,Kaiser Permanente | Zhou Z.,Fudan University | Qing D.,Shanghai Institute of Planned Parenthood Research | He Y.,Fudan University | And 13 more authors.
Human Reproduction | Year: 2010

Background: Animal studies have suggested that bisphenol-A (BPA) is a potential human endocrine disrupter; but evidence from human studies is needed. Methods: We conducted an occupational cohort study to examine the effect of occupational exposure to BPA on the risk of male sexual dysfunction. Current workers from BPA-exposed and control factories were recruited. The exposed workers were exposed to very high BPA levels in their workplace. Male sexual function was ascertained through in-person interviews using a standard male sexual function inventory. Results: BPA-exposed workers had consistently higher risk of male sexual dysfunction across all domains of male sexual function than the unexposed workers. After controlling for matching variables and potential confounders, exposed workers had a significantly increased risk of reduced sexual desire [odds ratios (OR) = 3.9, 95 confidence interval: 1.8-8.6), erectile difficulty (OR = 4.5, 95 CI 2.1-9.8), ejaculation difficulty (OR = 7.1, 95 CI 2.9-17.6), and reduced satisfaction with sex life (OR = 3.9, 95 CI 2.3-6.6). A dose-response relationship was observed with an increasing level of cumulative BPA exposure associated with a higher risk of sexual dysfunction. Furthermore, compared with the unexposed workers, BPA-exposed workers reported significantly higher frequencies of reduced sexual function within 1 year of employment in the BPA-exposed factories. Conclusions: Our findings provide the first evidence that exposure to BPA in the workplace could have an adverse effect on male sexual dysfunction.

Li D.-K.,Kaiser Permanente | Zhou Z.,Fudan University | Miao M.,Shanghai Institute of Planned Parenthood Research | He Y.,Fudan University | And 7 more authors.
Fertility and Sterility | Year: 2011

Objective: To determine whether urine bisphenol-A (BPA) levels are associated with lower semen quality. Design: Cohort study. Setting: Four regions in China where high exposure to BPA in the workplace existed. Patient(s): 218 men with and without BPA exposure in the workplace. Intervention(s): None. Main Outcome Measure(s): Semen parameters. Result(s): After adjustment for potential confounders using linear regression, increasing urine BPA level was statistically significantly associated with [1] decreased sperm concentration, [2] decreased total sperm count, [3] decreased sperm vitality, and [4] decreased sperm motility. Compared with men who did not have detectable urine BPA levels, those with detectable urine BPA had more than three times the risk of lowered sperm concentration and lower sperm vitality, more than four times the risk of lower sperm count, and more than twice the risk of lower sperm motility. The urine BPA level was not associated with semen volume or abnormal sperm morphology. Similar dose-response associations were observed among men with environmental BPA exposure at levels comparable with those in the U.S population. Despite a markedly reduced sample size, the inverse correlation between increased urine BPA levels and decreased sperm concentration and total sperm count remained statistically significant. Conclusion(s): These results provide the first epidemiologic evidence of an adverse effect of BPA on semen quality. © 2011 American Society for Reproductive Medicine, Published by Elsevier Inc.

Li D.-K.,Kaiser Permanente | Zhou Z.,Fudan University | Miao M.,Shanghai Institute of Planned Parenthood Research | He Y.,Fudan University | And 11 more authors.
Journal of Andrology | Year: 2010

The adverse effect of bisphenol-A (BPA) on the male reproductive system observed in animal studies has not been well examined in human populations. BPA is potentially a serious public health problem because of its widely detected presence in the human body. This study was conducted among 427 male workers in regions where high levels of BPA exposure existed. All participants provided urine samples, which were tested for BPA concentration using high-performance liquid chromatography. Male sexual dysfunction was ascertained using standard male sexual function inventories. Male sexual dysfunction was measured in 4 domains using 7 indices. After controlling for potential confounders using linear regression, increasing urine BPA level was associated with worsening male sexual function on a continuous scale. All 7 indices demonstrated this negative linear correlation. Increasing urine BPA level was associated with decreased sexual desire (P < .001), more difficulty having an erection (P < .001), lower ejaculation strength (P < .001), and lower level of overall satisfaction with sex life (P < .01). A similar negative correlation was also observed among participants exposed to BPA from only environmental sources (no occupational exposure to BPA), although the estimates in this group were less stable because of a smaller sample size. Our results reveal a correlation between a biological measure of urine BPA level and declining male sexual function. This finding may enhance the understanding of the BPA effect in human populations, and may have important public health implications given the widespread human exposure to BPA. Copyright © American Society of Andrology.

Li D.-K.,Kaiser Permanente | Li D.-K.,Stanford University | Miao M.,Shanghai Institute of Planned Parenthood Research | Zhou Z.J.,Fudan University | And 6 more authors.
PLoS ONE | Year: 2013

Bisphenol-A (BPA) is a potential endocrine disruptor impacting metabolic processes and increasing the risk of obesity. To determine whether urine BPA level is associated with overweight/obesity in school-age children, we examined 1,326 students in grades 4-12 from three schools (one elementary, one middle, and one high school) in Shanghai. More than 98% of eligible students participated. Total urine BPA concentration was measured and anthropometric measures were taken by trained research staff. Information on risk factors for childhood obesity was collected for potential confounders. Age- and gender-specific weight greater than 90th percentile of the underlying population was the outcome measure. After adjustment for potential confounders, a higher urine BPA level (≥2 μg/L), at the level corresponding to the median urine BPA level in the U.S. population, was associated with more than two-fold increased risk of having weight >90th percentile among girls aged 9-12 (adjusted odds ratio (aOR) = 2.32, 95% confidence interval: 1.15-4.65). The association showed a dose-response relationship with increasing urine BPA level associated with further increased risk of overweight (p = 0.006 for trend test). Other anthropometric measures of obesity showed similar results. The same association was not observed among boys. This gender difference of BPA effect was consistent with findings from experimental studies and previous epidemiological studies. Our study suggests that BPA could be a potential new environmental obesogen. Widespread exposure to BPA in the human population may also be contributing to the worldwide obesity epidemic. © 2013 Li et al.

Li Y.,Shanghai Institute of Planned Parenthood Research | Wu J.,Shanghai Institute of Planned Parenthood Research | Zhou W.,National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices | Gao E.,Shanghai Institute of Planned Parenthood Research
International Journal of Environmental Health Research | Year: 2016

Cadmium (Cd) is a heavy metal with toxicant to reproductive functions. The aim of this study was to explore the effects of environmental exposure to Cd on human semen quality. A total of 587 men from the general population, aged from 20 to 59 years old, and without occupational exposure to Cd were recruited from three provinces in China to participate in the study. The median of serum Cd was 1.9 μg/L (P25-P75:1.1-2.9). In case Cd was less than or equal to 6.3 μg/L (P95) and the semen parameters were logarithmically transformed, the inverse associations between Cd and semen volume (- 0.03 ± 0.007), progressive motility (- 0.01 ± 0.004), and sperm morphology (- 0.04 ± 0.004) were found across the whole group, after adjusting for age group, occupation, season of semen sample collection, abstinence intervals, smoking, alcohol drinking, and body mass index. Our findings indicate that higher Cd may reduce the semen volume, progressive motility, and morphology among men without occupational exposure to Cd. © 2015 Taylor & Francis.

Xie S.,Shanghai Institute of Planned Parenthood Research | Xie S.,National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices | Zhu Y.,Shanghai Institute of Planned Parenthood Research | Zhu Y.,National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices | And 9 more authors.
Reproductive Biology and Endocrinology | Year: 2010

Background: As one of the chlorinated antifertility compounds, alpha-chlorohydrin (ACH) can inhibit glyceraldehyde-3-phosphate dehydrogenase (G3PDH) activity in epididymal sperm and affect sperm energy metabolism, maturation and fertilization, eventually leading to male infertility. Further studies demonstrated that the inhibitory effect of ACH on G3PDH is not only confined to epididymal sperm but also to the epididymis. Moreover, little investigation on gene expression changes in the epididymis after ACH treatment has been conducted. Therefore, gene expression studies may indicate new epididymal targets related to sperm maturation and fertility through the analysis of ACH-treated infertile animals.Methods: Rats were treated with ACH for ten consecutive days, and then each male rat copulated with two female rats in proestrus. Then sperm maturation and other fertility parameters were analyzed. Furthermore, we identified epididymal-specific genes that are associated with fertility between control and ACH groups using an Affymetrix Rat 230 2.0 oligo-microarray. Finally, we performed RT-PCR analysis for several differentially expressed genes to validate the alteration in gene expression observed by oligonucleotide microarray.Results: Among all the differentially expressed genes, we analyzed and screened the down-regulated genes associated with metabolism processes, which are considered the major targets of ACH action. Simultaneously, the genes that were up-regulated by chlorohydrin were detected. The genes that negatively regulate sperm maturation and fertility include apoptosis and immune-related genes and have not been reported previously. The overall results of PCR analysis for selected genes were consistent with the array data.Conclusions: In this study, we have described the genome-wide profiles of gene expression in the epididymides of infertile rats induced by ACH, which could become potential epididymal specific targets for male contraception and infertility treatment. © 2010 Xie et al; licensee BioMed Central Ltd.

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