Associations between genetically predicted concentrations of circulating inflammatory cytokines and the risk of ten pregnancy-related adverse outcomes: A two-sample Mendelian randomization study.

BACKGROUND: Evidence from increasing observational studies indicates that systemic inflammation plays a role in pregnancy-related adverse events. However, the causal associations between them are largely unclear. To investigate the potential causal effects of genetically regulated concentrations of inflammatory cytokines on the risk of adverse pregnancy outcomes, we performed a Mendelian randomization (MR) analysis. METHODS: The cis-protein quantitative trait loci for the 47 inflammatory cytokines derived from the latest genome-wide association studies (GWASs) consisting of 31,112 European individuals were used as the instrumental variables. The latest GWAS summary data for the ten adverse pregnancy events were obtained from the FinnGen project (samples ranging from 141,014 to 190,879). The inverse-variance weighted regression or Ward ratio was used as the primary MR analysis method. Sensitivity analyses based on the other five methods were performed to verify MR results. A replication MR analysis was conducted to further clarify the significant associations using data from the UK Biobank. RESULTS: Twenty-three of the 220 associations were nominally significant (P < 0.05). Among them, seven robust associations survived the Bonferroni correction and passed sensitivity analyses, including positive associations of soluble intercellular adhesion molecule (sICAM-1) with the risk of excessive vomiting in pregnancy, preeclampsia (PE), and pregnancy hypertension (PH), vascular endothelial growth factor with the risk of medical abortion, macrophage colony-stimulating factor (MCSF) with the risk of spontaneous abortion (SA), and an inverse association of macrophage inflammatory protein-1α with the risk of medical abortion. The associations of MCSF with SA, and sICAM-1 with both PE and PH were further confirmed in the replication analysis. CONCLUSIONS: This study provides further evidence of the role of systemic inflammation, especially endothelial dysfunction in the pathology of adverse pregnancy events, and the identified cytokines warrant in-depth research to explore their underlying mechanisms of action and to evaluate their potential as targets for disease screening, prevention, and treatment in the future.

Sperm telomere length is associated with sperm nuclear DNA integrity and mitochondrial DNA abnormalities among healthy male college students in Chongqing, China.

STUDY QUESTION: Is sperm telomere length (STL) associated with sperm nuclear DNA damage and mitochondrial DNA abnormalities? SUMMARY ANSWER: Sperm telomere length is related to sperm nuclear DNA integrity and mitochondrial DNA abnormalities in healthy young college students. WHAT IS KNOWN ALREADY: Many studies have revealed the correlations between sperm genetic alterations in both the nucleus and mitochondria and sperm functionality, however, the possible associations between the telomere, an important component of chromosome, and conventional indicators of mitochondrial DNA and nuclear DNA changes have not been investigated. STUDY DESIGN, SIZE, DURATION: A prospective cohort study, Male Reproductive Health in Chongqing College Students (MARHCS), was conducted from June 2013 to June 2015. We pooled data collected from the follow-up study in 2014 and a total of 444 participants were included. PARTICIPANTS/MATERIALS, SETTING, METHODS: STL was measured by quantitative (Q)-PCR. Sperm nuclear DNA integrity was determined using sperm chromatin structure assay (SCSA) and comet assay. Mitochondrial DNA damage was assessed by mitochondrial DNA copy number (mtDNAcn) evaluated with Q-PCR, and mtDNA integrity was determined with long PCR. MAIN RESULTS AND THE ROLE OF CHANCE: The univariable-linear regression analysis revealed that STL was significantly positively correlated with markers of sperm nuclear DNA damage including the DNA fragmentation index (DFI) and comet parameters (the percentage of DNA in the tail, tail length, comet length, and tail moment). Additionally, STL was also significantly positively correlated with mtDNAcn and significantly negatively correlated with mtDNA integrity. After adjustment for potential confounders, these relationships remained appreciable. Moreover, we investigated potential effects of biometric factors, including age, parental age at conception, and BMI on STL and found that STL was increased with paternal age at conception. LIMITATIONS, REASONS FOR CAUTION: A mechanistic explanation of the correlation between STL, sperm nuclear DNA integrity, and mtDNA abnormalities cannot be provided with a cross-sectional study design, so well-designed longitudinal studies are still necessary. In addition, a single semen samples were provided and were not all obtained at the same time point, which may increase the intraindividual bias in this study. WIDER IMPLICATIONS OF THE FINDINGS: The findings extend the literature including assessment of mitochondrial dysfunction, sperm nuclear DNA damage, and telomere length and provide new insights into the relevance of STL in male reproduction. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Natural Science Foundation of China (No. 82073590), the National Natural Science Foundation of China (No. 81903363), the National Natural Science Foundation of China (No. 82130097), and the National Key R&D Program of China (2022YFC2702900). The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Generating adverse outcome pathway (AOP) of inorganic arsenic-induced adult male reproductive impairment via integration of phenotypic analysis in comparative toxicogenomics database (CTD) and AOP wiki.

BACKGROUND: Inorganic arsenic (iAs) is a worldwide environmental pollutant which exerts complicated and various toxic effects in organisms. Increasingly epidemic studies have revealed the association between iAs exposure and adult male reproductive impairment. Consistent with the proposal for toxicity testing in the 21st century (TT21C), the adverse outcome pathway (AOP) framework may help unravel the iAs-caused molecular and functional changes leading to male reproductive impairment. METHOD: Combining CTD's phenotype-disease inference data, iAs-phenotypes were anchored to five male reproductive diseases induced by iAs, and local network topological algorithm was applied in prioritizing their interference significance. Through integrating analysis in AOP Wiki knowledge base, filtered phenotypes were linked to key events consisting of AOPs and assembled together based on evidentially upstream and downstream relationships. RESULTS: A subset of 655 phenotypes were filtered from CTD as potential key events and showed a significant coherence in five reproductive diseases wherein 39 significant phenotypes showed a good clustering features involving cell cycle, ROS and mitochondria function. Two AOP subnetworks were enriched in AOP Wiki where testosterone reduction and apoptosis of sperm served as focus events respectively. Besides, a candidates list of molecular initialing events was provided of which glucocorticoid receptor activation was overall assessed as an example. CONCLUSION: This study applied computational and bioinformatics methods in generating AOPs for arsenic reproductive toxicity, which identified the imperative roles of testosterone reduction, response to ROS, spermatogenesis and provided a global view about their internal association. Furthermore, this study helped address the existing knowledge gaps for future experimental verification.

Adverse effects of circadian desynchrony on the male reproductive system: an epidemiological and experimental study.

STUDY QUESTION: Is circadian desynchrony a risk factor of male reproductive damage in semen parameters and/or reproductive hormones? SUMMARY ANSWER: Circadian desynchrony correlates with decrease of sperm count, which was improved when circadian desynchrony was attenuated. WHAT IS KNOWN ALREADY: Circadian desynchrony caused by work (shift work) and non-work-related reasons is prevalent worldwide and has been found to be associated with decreased female fertility, but whether it harms male reproductive health is unclear. STUDY DESIGN, SIZE, DURATION: A hybrid research was conducted. (i) A cross-sectional study of 1346 Chinese men in 2007 was used to analyze the association between semen/hormone biomarkers and work-related circadian desynchrony, which was divided into rotating shift work and permanent shift work against non-shift work. (ii) A cohort of 796 Chinese undergraduates from 2013 to 2014 was used to analyzed the association between semen/hormone biomarkers and non-work-related circadian desynchrony (between school days and days off). (iii) The biomarker identified simultaneously in both populations was further validated in male C57BL/6J mice housed under conditions simulating circadian desynchrony. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 17 semen/hormone biomarkers were compared among rotating shift workers and permanent shift workers against non-shift workers in the 1346 reproductive-age Chinese men. A total of 14 semen/hormone biomarker was analyzed in the undergraduate cohort for correlation with non-work-related circadian desynchrony (measured by Munich Chronotype Questionnaire) in 2013 and 2014 and compared between the 2 years. Photoperiod-shifting method was used to establish the mouse model, in which the biomarker was examined and molecular mechanism was explored by apoptosis analysis, DNA content analysis, transcriptome sequencing, real-time PCR and western blotting. MAIN RESULTS AND THE ROLE OF CHANCE: Among the semen/hormone biomarkers, sperm count was found to be lower in rotating shift workers, who had a higher risk of low sperm count defined by Chinese Ministry of Health (total sperm/ejaculate < 120 × 106) than non-shift workers (odds ratio = 1.26, 95% CI 1.05-1.52). This biomarker was replicated in the undergraduate cohort, where each hour of circadian desynchrony was associated with 1.16 (95% CI 1.02-1.31) fold odds of low sperm count, and sperm count increased during 2014 in men who reduced circadian desynchrony after 2013. A decrease of sperm count with circadian desynchrony and its recovery after removal of circadian desynchrony was also observed in the mouse model. During asynchrony, increased apoptosis was found in seminiferous tubules and the marker genes of post-spermatocyte stage cells were down-regulated. The most enriched functional pathway was homologous recombination, which happened during meiosis. LIMITATIONS, REASONS FOR CAUTION: The study of human beings was observational while the animal study has potential difference in circadian desynchrony exposure and species susceptibility. Further researches are needed to clarify the causal relationship in men. WIDER IMPLICATIONS OF THE FINDINGS: These findings provide novel insight to the effect of circadian desynchrony on male reproductive health and a potential strategy for prevention of reproductive damage. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the National Key R&D Program of China [2017YFC1002001] and National Natural Science Foundation of China [81871208]. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NA.

Mitochondrial functionality modifies human sperm acrosin activity, acrosome reaction capability and chromatin integrity.

STUDY QUESTION: In addition to sperm motility, which major biological characteristics of sperm fertility potential are associated with mitochondrial functionality? SUMMARY ANSWER: Sperm fertilization capacities, including acrosin activity, acrosome reaction (AR) capability and chromatin integrity, are related to the mitochondria functionality as evaluated by the mitochondrial membrane potential (MMP). WHAT IS KNOWN ALREADY: Correlative studies suggest a potential role of sperm MMP in predicting sperm fertilization ability and ensuring sperm motility. However, researches characterizing other determinants of sperm fertility potential according to MMP are lacking. STUDY DESIGN, SIZE, DURATION: The sperm MMP was examined in 627 young college students in the Male Reproductive Health in Chongqing College Students (MARHCS) cohort study in 2014. Among these participants, acrosin activity and chromatin integrity were measured in 378 and 604 subjects, respectively. These two determinants of sperm fertility potential were first compared among high-, moderate- and low-MMP groups in the college population. The effects of MMP collapse caused by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) on acrosin activity, AR, DNA fragmentation, reactive oxygen species (ROS) production, and ATP content in human spermatozoa were evaluated in vitro. PARTICIPANTS/MATERIALS, SETTING, METHODS: The sperm MMP was evaluated by using JC-1 staining, acrosin activity was measured using a N-α-benzoyl-dl-arginine-para-nitroanilide HCl (BAPNA) substrate method, the integrity of chromatin represented by DNA fragmentation index (DFI) was measured by sperm chromatin structure assay (SCSA), AR was evaluated with chlortetracycline staining, and intracellular ROS production was evaluated with dihydroethidium. ATP concentration was determined with luciferase. Measurements were performed by spectrophotometry or flow cytometry. MAIN RESULTS AND THE ROLE OF CHANCE: Nonparametric analysis revealed significantly higher acrosin activity and a lower DFI in subjects with moderate or high MMP compared to those with low MMP. After adjustment for potential confounders, increases of 7.9 and 44.4% in sperm acrosin activity and deceases of 12.0 and 25.2% in the sperm DFI were found in the moderate- and high-MMP groups, respectively. The MMP dissipation induced by CCCP caused significant declines in acrosin activity and AR capacity and increased DFI in human spermatozoa. Moreover, sperm MMP dissipation induced ROS overproduction and decreased ATP content. LIMITATIONS, REASONS FOR CAUTION: We cannot exclude a contribution of leukocytes to ROS production and no size gating was used to exclude these cells from the FACS measurements. No simultaneous live-dead staining was done and a contribution of dead sperm to the MMP and acrosome assays cannot be excluded. WIDER IMPLICATIONS OF THE FINDINGS: Mitochondrial functionality might be necessary to maintain sperm acrosin activity, AR and chromatin integrity. Tests of mitochondrial functionality should be developed and used independently of or in addition to conventional semen parameters in infertility diagnosis or risk-assessment processes. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the Key Program of the National Natural Science Foundation of China (No. 81630087) and the National Natural Science Foundation of China (No. 81703254). None of the authors have any competing interests to declare.

Mechanisms of Stress-Induced Spermatogenesis Impairment in Male Rats Following Unpredictable Chronic Mild Stress (uCMS).

The negative association between psychological stress and male fertility has been known for many years. This study was aimed at (i) identifying spermatogenesis impairment induced by psychological stress in rats and (ii) exploring the role of glucocorticoid receptor (GR) signaling in these adverse effects (if they exist). Male Sprague Dawley rats were exposed to a six-week period of unpredictable chronic mild stress (uCMS) along with cotreatment of GR antagonist RU486 (1 mg/kg/day). Testicular damage was assessed by testicular pathological evaluation, epididymal sperm concentration, serum testosterone levels, testicular apoptotic cell measurements, and cell cycle progression analyses. Rats in the uCMS group had decreased levels of serum testosterone and decreased epididymal sperm concentration. The uCMS-treated rats also had decreased numbers of spermatids and increased levels of apoptotic seminiferous tubules; additionally, cell cycle progression of spermatogonia was arrested at the G0/G1 phase. Furthermore, uCMS exposure caused an increase in serum corticosterone level and activated GR signaling in the testes including upregulated GR expression. RU486 treatment suppressed GR signaling and alleviated the damaging effects of stress, resulting in an increased epididymal sperm concentration. Overall, this work demonstrated for the first time that the activation of GR signaling mediates stress-induced spermatogenesis impairment and that this outcome is related to cell apoptosis and cell cycle arrest in germ cells.

Semen Quality in Chinese College Students: Associations With Depression and Physical Activity in a Cross-Sectional Study.

OBJECTIVE: Behavioral and psychosocial factors have been associated with a decline of the quality of semen. However, the relationship of depression and physical activity (PA) with semen quality remains unclear. METHODS: Data were obtained from 587 young male Chinese college students in June 2013. Participants completed a questionnaire assessing life-style factors, the Zung self-rated depression scale, and three items related to PA. They underwent a physical examination and provided a semen sample and a blood sample for reproductive hormones (testosterone, estrogen, progesterone, follicle-stimulating hormone, luteinizing hormone, and prolactin). RESULTS: Men with high depression scores (n = 63, 10.7%) had lower sperm concentration (M (SD) = 66.9 (74.5) versus 72.6 (56.9) [10/ml], p = .043) and total sperm count (M (SD) = 241.6 (299.7) versus 257.0 (204.0) [10], p = .024) than nondepressed men. Participants with low PA levels (n = 99, 16.9%) had lower total sperm count (M (SD) = 204.4 (153.7) versus 265.8 (225.8) [10/ml], p = .017) than participants with higher activity levels. After adjusting for potential confounders, depressed men had 18.90% (95% confidence interval [CI] = 1.14%-33.47%) lower sperm concentration and 21.84% (95% CI = 3.39%-36.90%) lower total sperm count than nondepressed men. Men with low PA levels had 23.03% (95% CI = 2.80%-46.89%) lower total sperm count than physically active participants. An interaction effect between depression and PA on sperm concentration was detected (p = .033). There were no significant associations of depression and PA with reproductive hormones (p > .05). CONCLUSIONS: Depression and low levels of PA are associated with lower levels of semen quality, which may have implications for reproductive health.

Sleep duration is associated with sperm chromatin integrity among young men in Chongqing, China.

This study explores whether sleep duration is associated with sperm chromatin integrity. To do so, we conducted a three-phase panel study of 796 male volunteers from colleges in Chongqing (China) from 2013 to 2015. Sleep duration was measured using a modified Munich Chronotype Questionnaire. Sperm DNA integrity was examined via Sperm Chromatin Structure Assay and Comet assay. Setting 7-7.5 h day-1 of sleep duration as a reference, either longer or shorter sleep duration was associated negatively with high DNA stainability (HDS) (P = 0.009), which reflected the immaturity of sperm chromatin. The volunteers with > 9.0 h day-1 sleep and those with ≤ 6.5 h day-1 sleep had 40.7 and 30.3% lower HDS than did volunteers with 7-7.5 h day-1 sleep. No association was found between sleep duration and DNA fragmentation index or Comet assay parameters. This study suggests that sleep duration is associated with sperm chromatin integrity. Further studies are required to validate these findings and investigate the mechanism underlying this association.

Exposures to Atmospheric PM10 and PM10-2.5 Affect Male Semen Quality: Results of MARHCS Study.

Studies have shown that the effects of ambient particulate matter (PM) may be related to particle's size. However, results on the relationships between different PM and reproductive health are controversial. To explore the impacts of various PM fractions on male reproductive health, a total of 796 eligible subjects recruited in 2013 baseline investigation. In addition, there were 656 (82.4%) and 568 (71.3%) subjects participated follow-up surveys in 2014 and 2015, respectively. We used multivariable regression analysis and mixed-effect model to investigate the associations between air pollutants PM10, PM10-2.5, and PM2.5 exposures and semen quality, sperm DNA fragmentation and serum reproductive hormones of subjects. In the preliminary regression analysis, PM10, PM10-2.5, and PM2.5 exposure all associated with sperm concentration, morphology, sperm high DNA stainability (HDS), serum estradiol and testosterone levels. However, in mixed models, we only found that PM10 exposure were negatively associated with sperm normal morphology (95% CI: -14.13, -24.47) but positively associated with sperm progressive motility (95% CI: 23.00, 8.49), and PM10-2.5 exposure was inversely associated with sperm concentration (95% CI: -9.06, -27.31) after multiplicity adjustment. Our results provide the evidence that air PM10 and PM10-2.5 exposures, not PM2.5, are risk factors of semen quality.

Anogenital distance is associated with serum reproductive hormones, but not with semen quality in young men.

STUDY QUESTION: Is anogenital distance associated with semen parameters and serum reproductive hormone levels in males? SUMMARY ANSWER: Anogenital distance is associated with serum reproductive hormones, but not with semen quality. WHAT IS KNOWN ALREADY: Epidemiological studies have suggested that anogenital distance (AGD) may be associated with testicular dysfunction in adult men. However, the role of AGD in estimating male reproductive function remains unclear. STUDY DESIGN, SIZE, DURATION: We examined the associations between AGD and semen parameters and reproductive hormones levels in 656 young college students in a Male Reproductive Health in Chongqing College Students (MARHCSs) cohort study in June of 2014. PARTICIPANTS/MATERIALS, SETTING, METHODS: In this study, two variants of AGD (AGDAP and AGDAS) were measured in 656 university students. Serum levels of testosterone (T), estradiol (E2), progesterone (P), prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), sex hormone-binding globulin (SHBG) and inhibin-B; and semen quality outcomes, including semen volume, sperm concentration, total sperm number, sperm progressive motility, total motility and morphology, were assessed. The associations between AGD and semen parameters/reproductive hormones levels were analyzed using multiple regression analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Both AGDAS and AGDAP were not associated with any semen parameters. In the non-parametric correlation analysis, AGDAP were correlated with sperm progressive motility and reproductive hormones of E2, testosterone, SHBG and the testosterone/LH ratio. However, body mass index (BMI) also significantly correlated with serum testosterone ( ITALIC! r = -0.216, ITALIC! P = <0.0001) and SHBG ( ITALIC! r = -0.229, ITALIC! P = <0.001). In the multiple regression models, AGDAP was negatively associated with the serum E2 level (95% CI, -0.198 to -0.043; ITALIC! P = 0.002) and positively associated with the ratio of T/E2 (95% CI, 0.004-0.011; ITALIC! P = 0.001) after an adjustment for BMI and other confounders. LIMITATIONS, REASONS FOR CAUTION: Using only a single semen sample to predict male reproductive function over a longer period is a potential limitation of the present study. The other limitation is the cross-sectional nature of the study design. Longitudinal data from an extended follow-up on a large cohort would be more definitive. WIDER IMPLICATIONS OF THE FINDINGS: Our results do not support previous studies where AGD is associated with male semen quality. The utility of AGD in predicting reproductive outcomes in adult males should thus be considered prudently. STUDY FUNDING/COMPETING INTERESTS: This study was supported by the Key Program of Natural Science Funding of China (no. 81130051), Young Scientist Program of NSFC (no. 81502788) and the National Scientific and Technological Support Program of China (no. 2013BAI12B02). None of authors had any competing interests to declare.

The effect of two cryopreservation methods on human sperm DNA damage.

Several methods are currently available for selection when conducting sperm cryopreservation, however, these methods might cause different degrees of damage on sperm DNA. The aim of the this study is to compare the effects of storage at -80 °C (in ultra-low temperature refrigerator) and at -196 °C (in liquid nitrogen) on sperm DNA damage, thus to provide a reference for choosing the right method according to different aims. We randomly collected 28 semen samples from college students of Chongqing city. The samples stored at -80 °C were neat semen samples and the samples stored at -196 °C were mixed with additional cryoprotectants. Each sample was subjected to two freezing-thawing cycles, and the sperm DNA damage levels of fresh and thawed samples were measured by single cell gel electrophoresis (SCGE) and sperm chromatin structure assay (SCSA). Both SCGE and SCSA assays showed cryopreservation induced significant damage to sperm DNA. However, storage at -196 °C lead to more severe damage to sperm DNA than storage at -80 °C measured by SCSA. Sperm DNA damage increased simultaneously with the higher frequency of freezing-thawing cycles. We concluded that storage of neat semen samples at -80 °C had milder damage to sperm DNA than storage at -196 °C mixed with cryoprotectants. To avoid additional sperm DNA damage, repeated freezing and thawing should be prevented.

Inducible knockout of Twist1 in young and adult mice prolongs hair growth cycle and has mild effects on general health, supporting Twist1 as a preferential cancer target.

Twist1 promotes epithelial-mesenchymal transition, invasion, metastasis, stemness, and chemotherapy resistance in cancer cells and thus is a potential target for cancer therapy. However, Twist1-null mice are embryonic lethal, and people with one Twist1 germline mutant allele develop Saethre-Chotzen syndrome; it is questionable whether Twist1 can be targeted in patients without severe adverse effects. We found that Twist1 is expressed in several tissues, including fibroblasts of the mammary glands and dermal papilla cells of the hair follicles. We developed a tamoxifen-inducible Twist1 knockout mouse model; Twist1 knockout in 6-week-old female mice did not affect mammary gland morphogenesis and function during pregnancy and lactation. In both males and females, the knockout did not influence body weight gain, heart rate, or total lean and fat components. The knockout also did not alter blood pressure in males, although it slightly reduced blood pressure in females. Although Twist1 is not cyclically expressed in dermal papilla cells, knockout of Twist1 at postnatal day 13 (when hair follicles have developed) drastically extended the anagen phase and accelerated hair growth. These results indicate that Twist1 is not essential for maintaining an overall healthy condition in young and adult mice and that loss of function facilitates hair growth in adulthood, supporting Twist1 as a preferential target for cancer therapy.

Exposure to di-2-ethylhexyl phthalate and breast neoplasm incidence: A cohort study.

BACKGROUND: Phthalates are ubiquitous environmental endocrine disruptors. As the predominant phthalate, di-2-ethylhexyl phthalate (DEHP) has been considered possibly carcinogenic to humans but large-scale longitudinal evidence is needed to further clarify its carcinogenicity. OBJECTIVES: To examine the association between DEHP exposure and incidence of breast malignant neoplasm, carcinoma in situ and benign neoplasm. METHODS: A total of 273,295 women from UK Biobank cohort were followed up for a median of 13.5 years. Disease information was collected from National Health Service Cancer Registry and National Death Index. Baseline and yearly-average level of DEHP exposure were estimated for each individual by linking chemical monitoring record of European Environment Agency with home address of the participants by Kriging interpolation model. Cox proportional hazard model was employed to estimate the association between DEHP exposure and breast neoplasms. RESULTS: The median (IQR) of baseline and yearly-average DEHP concentration were 8000.25 (interquartile range: 6657.85-11,948.83) and 8000.25 (interquartile range: 1819.93-11,359.55) µg/L. The highest quartile of baseline DEHP was associated with 1.11 fold risk of carcinoma in situ (95 % CI, 1.00, 1.23, p < 0.001) and 1.27 fold risk of benign neoplasm (95 % CI, 1.05, 1.54, p < 0.001). As for yearly-average exposure, each quartile of DEHP was positively associated with higher risk of malignant neoplasm (HR, 1.05; 95 % CI, 1.03, 1.07, p < 0.001), carcinoma in situ (HR, 1.08; 95 % CI, 1.04, 1.11, p < 0.001) and benign neoplasm (HR, 1.13; 95 % CI, 1.07, 1.20, p < 0.001). Stratification analysis showed no significant modification effects on the DEHP-neoplasm relationship by menopausal status or ethnicity but a suggestive higher risk in younger women and those who underwent oral contraceptive pill therapy. In sensitivity analysis, the associations remained when excluding the cases diagnosed within 2 years post baseline. CONCLUSIONS: Real-world level of DEHP exposure was associated with higher risk of breast neoplasms. Because of the health risks associated with DEHP, its release to the environment should be managed.

The Influence of Airborne Particulate Matter on the Risk of Gestational Diabetes Mellitus: A Large Retrospective Study in Chongqing, China.

Emerging research findings suggest that airborne particulate matter might be a risk factor for gestational diabetes mellitus (GDM). However, the concentration-response relationships and the susceptible time windows for different types of particulate matter may vary. In this retrospective analysis, we employ a novel robust approach to assess the crucial time windows regarding the prevalence of GDM and to distinguish the susceptibility of three GDM subtypes to air pollution exposure. This study included 16,303 pregnant women who received routine antenatal care in 2018-2021 at the Maternal and Child Health Hospital in Chongqing, China. In total, 2482 women (15.2%) were diagnosed with GDM. We assessed the individual daily average exposure to air pollution, including PM2.5, PM10, O3, NO2, SO2, and CO based on the volunteers' addresses. We used high-accuracy gridded air pollution data generated by machine learning models to assess particulate matter per maternal exposure levels. We further analyzed the association of pre-pregnancy, early, and mid-pregnancy exposure to environmental pollutants using a generalized additive model (GAM) and distributed lag nonlinear models (DLNMs) to analyze the association between exposure at specific gestational weeks and the risk of GDM. We observed that, during the first trimester, per IQR increases for PM10 and PM2.5 exposure were associated with increased GDM risk (PM10: OR = 1.19, 95%CI: 1.07~1.33; PM2.5: OR = 1.32, 95%CI: 1.15~1.50) and isolated post-load hyperglycemia (GDM-IPH) risk (PM10: OR = 1.23, 95%CI: 1.09~1.39; PM2.5: OR = 1.38, 95%CI: 1.18~1.61). Second-trimester O3 exposure was positively correlated with the associated risk of GDM, while pre-pregnancy and first-trimester exposure was negatively associated with the risk of GDM-IPH. Exposure to SO2 in the second trimester was negatively associated with the risk of GDM-IPH. However, there were no observed associations between NO2 and CO exposure and the risk of GDM and its subgroups. Our results suggest that maternal exposure to particulate matter during early pregnancy and exposure to O3 in the second trimester might increase the risk of GDM, and GDM-IPH is the susceptible GDM subtype to airborne particulate matter exposure.

Semen damage contributed over 50 % to air-pollutant-induced infertility: A prospective cohort study of 3940 men in China.

OBJECTIVE: To investigate the contribution of ambient air pollutants-induced semen damage to infertility risk, after identifying dose-response relationship between pollutants and semen parameters and susceptibility window. METHODS: In Preconception Reproductive Health and Birth Outcomes Cohort, 3940 male volunteers aged 22-49 were recruited from November 2018 to April 2021. At enrollment, resident address information was obtained and semen parameters were examined. During prospective follow-up, infertility was defined as failure to achieve pregnancy after unprotected intercourse within 12 months. Full coverage of ambient pollutant (PM2.5, PM10, SO2, NO2, O3, CO) concentrations was estimated by machine learning algorithms and assigned to individual level. Association between pollutants and semen parameters was analyzed by single- and two-pollutant linear regression. Four potential susceptibility windows were analyzed: lag 0-9d, lag 10-14d, lag 70-90d and lag 0-90d. Pollutant joint effects on semen parameters were analyzed by Bayesian kernel machine regression. Mediating effect of semen parameters on the association between pollutants and infertility was analyzed. False-positive rate was controlled by Bonferroni correction. RESULTS: Single- and two-pollutant models showed SO2, O3, PMs and NO2 were negatively associated with progressive motility, total motility and sperm morphology, among which, each IQR increase in SO2 at lag 0-90d was associated with -4.13 %(95%CI:-6.25 %, -1.95 %, P < 0.001) change of normal morphology, and O3 at lag 0-90d was negatively associated with progressive motility and total motility (ß = -3.64 %, 95%CI:-5.63 %, -1.61 %; ß = -2.24 %, 95%CI:-3.38 %, -1.08 %, P < 0.001). Joint effect analysis showed a negative effect on sperm concentration and a suggestive effect on vitality. Mediating effect analysis showed sperm normal morphology had a substantial mediating effect in the association of SO2 with infertility (59.68 %, P < 0.001). CONCLUSION: Multiple air pollutants may introduce semen quality in the population at entire window of spermatogenesis, among which SO2 needs especial attention, as its damage on sperm morphology may increase risk of infertility.

Chromosomal damage and polymorphisms of metabolic genes among 1, 3-butadiene-exposed workers in a matched study in China.

1, 3-Butadiene (BD) is a high-efficiency carcinogen in rodents and was classified as a human carcinogen in 2008 by the International Agency for Research on Cancer. However, its ability to induce genetic damage and the influence of metabolic polymorphisms to such damage in humans are both controversial claims. This study was conducted to investigate the relationships between exposure to BD, the polymorphisms of metabolic genes and the chromosomal damage in 45 pairs of occupationally exposed workers in a BD product workshop and matched control workers in an administrative office and circulatory water workshop in China. Exposure to BD was evaluated by personal sampling and stationary sampling. Different chromosomal damage endpoints in peripheral blood lymphocytes were determined using the cytokinesis-blocked micronucleus (CBMN) cytome assay; polymorphisms of metabolic genes [cytochrome P450 2E1 (CYP2E1), glutathione S-transferases (GST) and microsomal epoxide hydrolase (mEH)] in BD-exposed group were detected by polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism analysis. The results show that the average BD measurements of the exposed group were significantly higher than those for the control group (a personal sampling and stationary sampling, respectively). The BD-exposed workers exhibited increased frequencies of micronuclei (MNi) (8.00 ± 3.78‰ versus 5.62 ± 2.41‰) and nucleoplasmic bridges (NPBs) (2.58 ± 2.79‰ versus 1.13 ± 1.34‰) and a decreased nuclear division index (2.20 ± 0.14 versus 2.35 ± 0.27) when compared subjects in the control group. Meanwhile, BD-exposed workers carrying CYP2E1 c1c2/c2c2 or mEH intermediate (I)/high (H) group had a significantly higher NPB frequency than those carrying CYP2E1 c1c1 [frequency ratio (FR) = 2.60, 95% confidence interval (CI) 1.72-3.93; P < 0.0001) or the mEH low(S) group (FR = 2.06, 95% CI% 1.17-3.62; P < 0.05), respectively. Our study suggests that MNi and NPB frequency in CBMN cytome assay could be potential genotoxic biomarkers for BD exposure in humans. The polymorphism of CYP2E1 and mEH could also affect the chromosomal instability of BD workers.

Pre-pregnancy BMI was associated with gestational depressive phenotypes in a population of 12,099 women in Chongqing, China.

Objective: To investigate the association between pre-pregnancy body mass index (BMI) and gestational depressive phenotypes. Methods: The pregnant women receiving the first prenatal examination (4th -13th week of gestation) in Chongqing Health Center for Women and Children were recruited between February 2020 and September 2021. Depressive phenotypes was assessed by the Patient Health Questionnaire (PHQ-9) and the Symptom Checklist 90 (SCL-90) scale at recruitment. Pre-pregnancy weight and height were self-reported by the participants. Demographic and obstetric characteristics were obtained from the hospital information system. The association between pre-pregnancy BMI and the scores of PHQ-9 or SCL-90 scale was investigated by uni-variate analysis with Kruskal-Wallis test and by multi-variate analysis with linear regression model with adjustment of age, parity, smoking, alcohol consumption, and assisted reproduction. The association between pre-pregnancy BMI and PHQ-9 or SCL-90 diagnosed depressive phenotypes was analyzed by Chi-square test and logistic regression respectively. Results: A total of 12,099 pregnant women were included, where 100% of them filled out the PHQ-9 scale and 99.6% filled out the SCL-90 scale, and 47.26% and 4.62% of the pregnant women had depressive phenotypes, respectively. Women with higher pre-pregnancy BMI had lower depressive phenotypes scores during pregnancy. Multivariable analysis of the PHQ-9 scale showed that overweight/obese subjects had a higher incidence of depressive phenotypes compared with subjects with normal BMI (OR=0.803, 95% CI [0.723, 0.892]). In a stratified analysis assessed by the PHQ-9, women who were overweight/obese prior to pregnancy were less likely to develop depressive phenotypes during pregnancy than women who were normal weight prior to pregnancy, regardless of whether they were nulliparous (OR=0.795, 95%CI[0.696,0.908]) or multiparous (OR=0.809, 95%CI[0.0.681,0.962]), while in the three age groups of 25-29 years, 30-34 years and ≥35 years, pre-pregnancy overweight/obesity were associated with lower risk of gestational depressive phenotypes. However, analysis of the SCL-90 scale showed no statistical association between depressive symptom and BMI. No substantial interaction was observed between BMI and parity or age. Conclusions: Increased pre-pregnancy BMI may be associated with reduced risk of gestational depressive phenotypes in Chinese women. Independent studies are warranted to validate the findings of the present study.

Sleep Quality is an Independent Predictor of Blood Glucose and Gestational Diabetes Mellitus: A Longitudinal Study of 4550 Chinese Women.

Purpose: To investigate whether pregnant women's subjective sleep quality during the first trimester independently predicted blood glucose and gestational diabetes mellitus (GDM). Methods: A total of 4550 pregnant women in the first trimester were enrolled in Chongqing Health Center for Women and Children, China, from January to October 2020.The Pittsburgh Sleep Quality Index (PSQI) was used to measure subjective sleep quality. Depression symptoms and anxiety were measured with the Patient Health Questionnaire-9 (PHQ-9) and General Anxiety Disorder-7 (GAD-7). Oral glucose tolerance tests (OGTT) and blood glucose area under the curve (AUC) were used for estimation of blood glucose and diagnosis of GDM during the second trimester. Linear, mixed model, and logistic regression were used to analyze the association between PSQI and blood glucose as well as GDM. Results: 946/4550 were diagnosed with GDM (20.8%). In the mixed model analysis, the blood glucose level of the highest-scoring group (PSQI score = 18) was 1.94 (95% CI: 0.45~3.43, P = 0.011) mmol/L higher than that of the lowest-scoring group (PSQI score = 0). After adjusting for potential confounders, a one-point PSQI score increase was associated with a 0.014 (95% CI: 0.001~0.027, P = 0.039) mmol/L increase in blood glucose level. Blood glucose AUC was also positively associated with PSQI scores (ß = 0.034, 95% CI: 0.003~0.064, P = 0.030). The results for the logistic regression model showed that PSQI was marginal positively correlated with GDM (OR = 1.146, 95% CI: 0.995~1.321, P = 0.059) when age and BMI were not controlled for. When investigating the association between PSQI and the GDM-diagnosed time window, the 1-h diagnosed GDM had a borderline positive correlation with PSQI (OR = 1.182, 95% CI: 0.993~1.405, P = 0.060). Conclusion: Sleep quality during the first trimester may be a risk factor for elevated blood glucose and GDM later in gestation.

Flow Cytometric Analysis of Biomarkers for Detecting Human Sperm Functional Defects.

The conventional semen parameter analysis is widely used to assess male fertility. However, studies have found that ~15% of infertile patients show no abnormalities in conventional semen parameters. Additional technologies are needed to explain the idiopathic infertility and detect subtle sperm defects. Currently, biomarkers of sperm function, including sperm apoptosis, mitochondrial membrane potential (MMP), and DNA damage, reveal sperm physiology at the molecular level and are capable of predicting male fertility. With flow cytometry (FCM) techniques, each of these markers can be rapidly, accurately, and precisely measured in human semen samples, but time costs substantially increase and results could be obstructed if all the biomarkers need to be tested with a single cytometer. In this protocol, after collection and immediate incubation at 37 °C for liquefication, semen samples were further analyzed for sperm apoptosis using Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining. The MMP was labeled with 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-benzimidazolylcarbocyanine iodide (JC-1) probe, and DNA damage was assessed using the sperm chromatin structure assay (SCSA) with acridine orange (AO) staining. Thus, flow cytometric analysis of sperm function markers can be a practical and reliable toolkit for the diagnosis of infertility and evaluation of sperm function at both bench and bed.

Association of Folic Acid Supplementation in Early Pregnancy with Risk of Gestational Diabetes Mellitus: A Longitudinal Study.

BACKGROUND: Gestational diabetes mellitus (GDM) may lead to many adverse effects on women and their offspring. METHOD: 24,429 pregnant women were enrolled during early pregnancy from January 2018 to December 2021. The self-reported intake of folic acid supplements was assessed via a questionnaire. Oral glucose tolerance tests were used for the diagnosis of GDM. The association between intake or not, dose, and duration of folic acid and GDM risk was assessed. RESULTS: 6396 (26.18%) women were diagnosed with GDM. In the univariate models, folic acid was found to be correlated with total GDM risk (OR = 0.82, 95% CI: 0.70~0.95, p = 0.009). After adjusting for potential confounders, the association with total GDM risk was not significant, but the association of folic acid with 2-h PBG diagnosed GDM risk was consistently significant (OR = 0.75, 95% CI: 0.63~0.90, p = 0.002). No significant association between the dose and duration of folic acid supplementation and GDM risk was observed in the analyses. CONCLUSION: Folic acid supplementation might be a protective factor for the risk of GDM caused by the high level of postprandial blood glucose, but the dose or duration-related association between folic acid supplementation and GDM risk is not clear.