Phthalate exposure as a hidden risk factor for uterine leiomyoma in adult women: Accumulated evidence from observational studies.

BACKGROUND: There is evidence that exposure to phthalate in women may increase the risk of uterine leiomyomas. Whereas, the association between exposure to phthalate and the incidence of uterine leiomyoma remained inconclusive. METHODS: A meta-analysis was performed to evaluate their relationship. Literature eligible for inclusion was found in PubMed, EMBASE, Web of Science, and WanFang Medical Database. Pooled odds ratio (OR) with 95 % confidence interval (CI) was calculated to assess the risk for effect estimate for each phthalate. RESULTS: A total of fourteen observational studies with 5777 subjects of adult women were included in this study. In the pooled analysis, we found an elevated risk of uterine leiomyoma among women who were exposed to higher levels of di-2-ethylhexyl phthalate (DEHP) (OR 1.61, 95 % CI: 1.18-2.20), as estimated indirectly from the molar summation of its urinary metabolite concentrations. In addition, a positive association was observed between the occurrence of uterine leiomyoma and exposure to low molecular weight phthalate mixture (OR 1.08, 95 % CI: 1.00-1.15), as well as high molecular weight phthalate mixture (OR 1.08, 95 % CI: 1.01-1.15), as quantified by integrating the effect estimates of individual metabolite from each study. Urinary levels of DEHP metabolites, monobenzyl phthalate, mono-(3-carboxypropyl) phthalate, mono-isobutyl phthalate, mono-n-butyl phthalate, monoethyl phthalate, and monomethyl phthalate were not appreciably correlated with the risk of uterine leiomyoma. CONCLUSION: Our results indicated that exposure to DEHP, and co-exposure to high or low molecular weight phthalate mixture might be potential risk factors for uterine leiomyoma in adult women. Owing to the indirect estimation of association, when interpreting these findings, cautions should be taken.

Induction of fibrosis following exposure to bisphenol A and its analogues in 3D human uterine leiomyoma cultures.

Bisphenol A (BPA) and its analogues (BPAF, BPS) are ubiquitous environmental contaminants used as plastic additives in various daily life products, with many concerns on their role as environmental estrogens. Uterine leiomyomas (fibroids) are highly prevalent gynecologic tumors with progressive fibrosis. Fibroids are hormone-responsive and may be the target of environmental estrogens. However, the effects of BPA, BPAF, and BPS exposure on uterine fibrosis are largely unknown. Here, we evaluated fibrosis and the crucial role of TGF-beta signaling in human fibroid tumors, the profibrotic effects of BPA, BPAF or BPS in a human 3D uterine leiomyoma (ht-UtLM) in vitro model, and the long-term outcomes of BPAF exposure in rat uterus. In 3D ht-UtLM spheroids, BPA, BPAF, and BPS all promoted cell proliferation and fibrosis by increasing the production of extracellular matrices. Further mechanistic analysis showed the profibrotic effects were induced by TGF-beta signaling activation mainly through SMAD2/3 pathway and crosstalk with multiple non-SMAD pathways. Furthermore, the profibrotic effects of BPAF were supported by observation of uterine fibrosis in vivo in rats following long-term BPAF exposure. Overall, the 3D ht-UtLM spheroid can be an important model for investigating environment-induced fibrosis in uterine fibroids. BPA and its analogues can induce fibrosis via TGF-beta signaling.

A systematic review of association between use of hair products and benign and malignant gynecological conditions.

Hair products often contain chemicals like para-phenylenediamine (PPD) and endocrine-disrupting chemicals (EDCs); giving rise to concerns about the possible adverse effects such as hormonal disturbances and carcinogenicity. The objective of this systematic review was to evaluate the association between the use of different hair products and benign and malignant gynecological conditions. Studies were identified from three databases including PubMed, Embase, and Scopus, and evaluated in accordance with PRISMA guidelines. The risk of bias was assessed using the Newcastle-Ottawa Scale. A total of 17 English-language studies met the inclusion criteria. Associations of hair relaxer or hair dye use with breast and ovarian cancer were observed in at least one well-designed study, but these findings were not consistent across studies. Further sub-analysis showed 1.08 times (95 % CI: 1.01-1.15) increased risk of breast cancer in females with permanent hair dye use. Chang et al. reported strong association between uterine cancer risk and hair relaxer use (HR 1.8, 95 % CI: 1.12-2.88), with no observed association with hair dye use. Studies conducted by Wise et al. and James-Todd et al. for benign gynecological conditions; including uterine leiomyoma (IRR 1.17, 95 % CI: 1.06-1.30), early onset of menarche (RR 1.4, 95 % CI: 1.1-1.9), and decreased fecundability (FR 0.89, 95 % CI: 0.81-0.98) revealed positive associations with hair relaxer use, but these findings were based on small sample sizes. In summary, the available evidence regarding personal use of hair products and gynecological conditions is insufficient to determine whether a positive association exists.

Chronic exposure of mice to phthalates enhances TGF beta signaling and promotes uterine fibrosis.

Phthalates are synthetic chemicals widely used as plasticizers and stabilizers in various consumer products. Because of the extensive production and use of phthalates, humans are exposed to these chemicals daily. While most studies focus on a single phthalate, humans are exposed to a mixture of phthalates on a regular basis. The impact of continuous exposure to phthalate mixture on uterus is largely unknown. Thus, we conducted studies in which adult female mice were exposed for 6 months to 0.15 ppm and 1.5 ppm of a mixture of phthalates via chow ad libitum. Our studies revealed that consumption of phthalate mixture at 0.15 ppm and 1.5 ppm for 6 months led to a significant increase in the thickness of the myometrial layer compared to control. Further investigation employing RNA-sequencing revealed an elevated transforming growth factor beta (TGF-ß) signaling in the uteri of mice fed with phthalate mixture. TGF-ß signaling is associated with the development of fibrosis, a consequence of excessive accumulation of extracellular matrix components, such as collagen fibers in a tissue. Consistent with this observation, we found a higher incidence of collagen deposition in uteri of mice exposed to phthalate mixture compared to unexposed controls. Second Harmonic Generation (SHG) imaging showed disorganized collagen fibers and nanoindentation indicated a local increase in uterine stiffness upon exposure to phthalate mixture. Collectively, our results demonstrate that chronic exposure to phthalate mixture can have adverse effects on uterine homeostasis.

TGFß signaling links early life endocrine-disrupting chemicals exposure to suppression of nucleotide excision repair in rat myometrial stem cells.

Environmental exposure to endocrine-disrupting chemicals (EDCs) is linked to the development of uterine fibroids (UFs) in women. UFs, non-cancerous tumors, are thought to originate from abnormal myometrial stem cells (MMSCs). Defective DNA repair capacity may contribute to the emergence of mutations that promote tumor growth. The multifunctional cytokine TGFß1 is associated with UF progression and DNA damage repair pathways. To investigate the impact of EDC exposure on TGFß1 and nucleotide excision repair (NER) pathways, we isolated MMSCs from 5-month-old Eker rats exposed neonatally to diethylstilbestrol (DES), an EDC, or to vehicle (VEH). EDC-MMSCs exhibited overactivated TGFß1 signaling and reduced mRNA and protein levels of NER pathway components compared to VEH-MMSCs. EDC-MMSCs also demonstrated impaired NER capacity. Exposing VEH-MMSCs to TGFß1 decreased NER capacity while inhibiting TGFß signaling in EDC-MMSCs restored it. RNA-seq analysis and further validation revealed decreased expression of Uvrag, a tumor suppressor gene involved in DNA damage recognition, in VEH-MMSCs treated with TGFß1, but increased expression in EDC-MMSCs after TGFß signaling inhibition. Overall, we demonstrated that the overactivation of the TGFß pathway links early life exposure to EDCs with impaired NER capacity, which would lead to increased genetic instability, arise of mutations, and fibroid tumorigenesis. We demonstrated that the overactivation of the TGFß pathway links early life exposure to EDCs with impaired NER capacity, which would lead to increased fibroid incidence.

Developmental reprogramming of myometrial stem cells by endocrine disruptor linking to risk of uterine fibroids.

BACKGROUND: The stage, when tissues and organs are growing, is very vulnerable to environmental influences, but it's not clear how exposure during this time causes changes to the epigenome and increases the risk of hormone-related illnesses like uterine fibroids (UFs). METHODS: Developmental reprogramming of myometrial stem cells (MMSCs), the putative origin from which UFs originate, was investigated in vitro and in the Eker rat model by RNA-seq, ChIP-seq, RRBS, gain/loss of function analysis, and luciferase activity assays. RESULTS: When exposed to the endocrine-disrupting chemical (EDC) diethylstilbestrol during Eker rat development, MMSCs undergo a reprogramming of their estrogen-responsive transcriptome. The reprogrammed genes in MMSCs are known as estrogen-responsive genes (ERGs) and are activated by mixed lineage leukemia protein-1 (MLL1) and DNA hypo-methylation mechanisms. Additionally, we observed a notable elevation in the expression of ERGs in MMSCs from Eker rats exposed to natural steroids after developmental exposure to EDC, thereby augmenting estrogen activity. CONCLUSION: Our studies identify epigenetic mechanisms of MLL1/DNA hypo-methylation-mediated MMSC reprogramming. EDC exposure epigenetically targets MMSCs and leads to persistent changes in the expression of a subset of ERGs, imparting a hormonal imprint on the ERGs, resulting in a "hyper-estrogenic" phenotype, and increasing the hormone-dependent risk of UFs.

Oxidatively generated DNA damage mediates the associations of exposure to phthalates with uterine fibroids and endometriosis: Findings from TREE cohort.

BACKGROUND: Epidemiological studies on phthalate exposures in associations with uterine fibroids (UF) and endometriosis (EMT) are inconsistent. The underlying mechanisms are poorly understood. OBJECTIVES: To investigate the relationships of urinary phthalate metabolites with UF and EMT risks, and further to examine the mediating role of oxidative stress. METHODS: This study included 83 and 47 women separately diagnosed with UF and EMT, as well as 226 controls from the Tongji Reproductive and Environmental (TREE) cohort. Two spot urine samples from each woman were analyzed for two oxidative stress indicators and eight urinary phthalate metabolites. Unconditional logistic regression models or multivariate regression models were fitted to evaluate the associations among phthalate exposures, oxidative stress indicators, and the risks of UF and EMT. The potential mediating role of oxidative stress was estimated by the mediation analyses. RESULTS: We observed that each ln-unit increase in urinary mono-benzyl phthalate (MBzP) concentrations was associated with increased UF risk [adjusted OR (aOR): 1.56, 95% CI: 1.20, 2.02], and that each ln-unit increase in urinary MBzP (aOR: 1.48, 95% CI: 1.09, 1.99), mono-isobutyl phthalate (MiBP) (aOR: 1.83, 95% CI: 1.19, 2.82), and mono-2-ethylhexyl phthalate (MEHP) (aOR: 1.66, 95% CI: 1.19, 2.31) concentrations were associated with increased EMT risk (all FDR-adjusted P < 0.05). Moreover, we observed that all tested urinary phthalate metabolites were positively associated with two oxidative stress indicators [4-hydroxy-2-nonenal-mercapturic acid (4-HNE-MA) and 8-hydroxy-2-deoxyguanosine (8-OHdG)], in which 8-OHdG was associated with increased risks of UF and EMT (all FDR-adjusted P < 0.05). The mediation analyses showed that 8-OHdG mediated the positive relationships of MBzP with UF risk, and of MiBP, MBzP, and MEHP with EMT risk, with the estimated intermediary proportion ranging from 32.7% to 48.1%. CONCLUSIONS: Oxidatively generated DNA damage may mediate the positive associations of certain phthalate exposures with the risks of UF and EMT. However, further investigation is warranted to confirm these findings.

A plain language summary of the safety of relugolix combination therapy and improvement in symptoms in women with uterine fibroids from the LIBERTY 1 and LIBERTY 2 studies.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of research studies (known as clinical trials) called LIBERTY 1 and LIBERTY 2. The LIBERTY 1 and LIBERTY 2 studies looked at how well a medication called relugolix combination therapy worked to reduce heavy bleeding at the time of menstruation compared with placebo. The studies also looked at what side effects were reported in women with uterine fibroids and heavy menstrual bleeding. WHAT WERE THE RESULTS?: Researchers looked at 388 adult women in the LIBERTY 1 study and 382 adult women in the LIBERTY 2 study. All women had heavy menstrual bleeding with uterine fibroids before the start of the LIBERTY 1 and LIBERTY 2 studies. The women were given one of three treatments during the studies: relugolix combination therapy or placebo for 24 weeks, or delayed relugolix combination therapy (relugolix alone for the first 12 weeks, then relugolix combination therapy for the last 12 weeks of the studies). More women taking relugolix combination therapy in the LIBERTY 1 study (73%) and LIBERTY 2 study (71%) had menstrual blood loss of less than one-third of a cup (80 mL) and had reduction of at least 50% less blood loss during their last menstrual period after 24 weeks of taking the medicine compared with placebo (LIBERTY 1: 19% and LIBERTY 2: 15%). The women taking relugolix combination therapy also had less pain than those taking placebo. Side effects were similar across treatment groups. Headaches and hot flushes were the most common side effects. WHAT DO THE RESULTS MEAN?: More women with uterine fibroids taking relugolix combination therapy for 24 weeks were likely to have fewer uterine fibroid symptoms than women receiving placebo. Clinical Trial Registration: NCT03049735 (LIBERTY 1); NCT03103087 (LIBERTY 2).

Comparison of the efficacy of gossypol acetate enantiomers in rats with uterine leiomyoma.

Gossypol acetate (GA), as the product of racemic gossypol and acetic acid conjugated by hydrogen bond, is hydrolyzed into gossypol to exert its effect on treating uterine leiomyoma (UL), which has been listed in China. But hypokalemia and mild changes of liver function limit its clinical application. It had been reported that the biological activities of gossypol optical isomers were different. In this study, we aimed to clarify whether there were differences in the efficacy of gossypol enantiomers and whether a single gossypol optical isomer could alleviate adverse reactions in the treatment of UL. The results indicated that (-)-GA and (+)-GA had significant therapeutic effect on rats with UL. Interestingly, (-)-GA could better significantly ameliorate the pathological structure, inhibit the secretion of estrogen, and downregulate the expression of estrogen receptor-alpha (ER-α) and progesterone receptor (PR) than (+)-GA. Additionally, (-)-GA could better evidently decrease the symptoms of abnormally elevated inflammatory factors caused by UL. In contrast, (-)-GA and (+)-GA had certain effects on potassium ion concentration in serum, liver and kidney function, and the effects of (+)-GA on liver function were more obvious than (-)-GA. These findings will be of great significance to the drug development of gossypol optical isomers.

Endocrine-disrupting chemicals and epigenetic reprogramming in developmental origin of uterine fibroids.

Endocrine-disrupting chemicals (EDCs) are a class of exogenous substances that mimic the effects of hormones in the body, inducing hormonal dysregulation and contributing to various disorders. Epigenome regulation has emerged as an important mechanism for maintaining organ function in health and disease. Dissecting epigenomic and resultant gene expression changes provides unprecedented insight into the chromatin state, which underlines disease development and shapes risk and phenotypic plasticity in response to the environment and internal cues. The cutting-edge, high throughput technologies provide new routes to understanding the etiology of disease and new footholds on the promising path to better treatment and disease prevention. We have recently revealed that myometrial stem cells (MMSCs), the cell origin of UFs, are the target of developmental EDC exposure. The EDC-induced epigenetic changes in MMSCs identified by multi-omics approaches include DNA methylation and histone modification modulated by DNA methyltransferases and MLL1, which characterized the molecular mechanism underlying EDC-related risk in hormone-dependent UFs. Future studies are needed to determine the link between real-life exposures to EDCs and their impact on the development of human diseases and transgenerational epigenetic inheritance, which can help explore strategies that may prevent adverse outcomes linked to EDC exposure.

Mono-(2-ethyl-5-hydroxyhexyl) phthalate promotes uterine leiomyoma cell survival through tryptophan-kynurenine-AHR pathway activation.

Uterine leiomyoma is the most common tumor in women and causes severe morbidity in 15 to 30% of reproductive-age women. Epidemiological studies consistently indicate a correlation between leiomyoma development and exposure to endocrine-disrupting chemical phthalates, especially di-(2-ethylhexyl) phthalate (DEHP); however, the underlying mechanisms are unknown. Here, among the most commonly encountered phthalate metabolites, we found the strongest association between the urine levels of mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), the principal DEHP metabolite, and the risk of uterine leiomyoma diagnosis (n = 712 patients). The treatment of primary leiomyoma and smooth muscle cells (n = 29) with various mixtures of phthalate metabolites, at concentrations equivalent to those detected in urine samples, significantly increased cell viability and decreased apoptosis. MEHHP had the strongest effects on both cell viability and apoptosis. MEHHP increased cellular tryptophan and kynurenine levels strikingly and induced the expression of the tryptophan transporters SLC7A5 and SLC7A8, as well as, tryptophan 2,3-dioxygenase (TDO2), the key enzyme catalyzing the conversion of tryptophan to kynurenine that is the endogenous ligand of aryl hydrocarbon receptor (AHR). MEHHP stimulated nuclear localization of AHR and up-regulated the expression of CYP1A1 and CYP1B1, two prototype targets of AHR. siRNA knockdown or pharmacological inhibition of SLC7A5/SLC7A8, TDO2, or AHR abolished MEHHP-mediated effects on leiomyoma cell survival. These findings indicate that MEHHP promotes leiomyoma cell survival by activating the tryptophan-kynurenine-AHR pathway. This study pinpoints MEHHP exposure as a high-risk factor for leiomyoma growth, uncovers a mechanism by which exposure to environmental phthalate impacts leiomyoma pathogenesis, and may lead to the development of novel druggable targets.

Association of environmental phenols with endometriosis and uterine leiomyoma: An analysis of NHANES, 2003-2006.

Exposure to phenols is widespread since they are found in many everyday products. Given that phenols are considered endocrine disrupting chemicals with the potential to interfere with hormonal activities, they could have adverse effects on female reproductive health. We analyzed cross-sectional data from the National Health and Nutrition Examination Survey (NHANES), 2003-2006 to examine the association between phenols and endometriosis and uterine leiomyoma (fibroids). Levels of bisphenol A (BPA), benzophenone-3, and triclosan were measured using urine samples, and information on endometriosis and fibroids diagnoses as well as other relevant characteristics were ascertained using self-reported questionnaires. Multivariate logistic regression with odds ratios (ORs) and 95 % confidence intervals (CIs) were used to quantify the association between each phenol and female gynecologic condition. Our study included 700 women, of which 53 women had endometriosis and 107 women had fibroids. We found exposure to BPA to be statistically significantly positively associated with endometriosis (p = 0.05); women in the highest exposure quartile had over the three times the odds of having endometriosis relative to women in the lowest quartile (OR=3.58, 95 % CI 1.00-12.89). None of the phenols considered were significantly associated with fibroids. Overall, exposure to BPA increased the odds of having endometriosis, and there appeared to be a dose-response relationship. This suggests that BPA may play a role in the pathogenesis of endometriosis although the cross-sectional nature of NHANES data is a methodological limitation. Additional research on the impact of endocrine disrupting chemicals, like phenols, on female reproductive health should be conducted.

Interdisciplinary model-informed drug development for extending duration of elagolix treatment in patients with uterine fibroids.

AIM: Elagolix, a gonadotropin-releasing hormone receptor antagonist, was recently approved for heavy menstrual bleeding associated with uterine fibroids (UF, Oriahnn) at a dose of 300 mg twice daily (BID) in combination with add-back therapy (oestradiol 1 mg/norethindrone acetate 0.5 mg [E2/NETA] once daily) for 24 months use. The limited duration of treatment is related to elagolix dose- and duration-dependent decrease in oestrogen that is mechanistically linked to changes in bone mineral density (BMD). The work herein supported the extended treatment duration of 24 months. METHODS: An integrated exposure-response and epidemiological modelling framework of elagolix effects on femoral neck BMD (FN-BMD), informed by real-world data and phase 3 clinical trials data, was developed to predict the time course and magnitude of changes in BMD and its relation to risk of bone fracture in women with UF. RESULTS: Model results indicated that women treated with elagolix 300 mg BID + E2/NETA in the long term (ie, >24 months) may experience less than 1% loss in FN-BMD per year, relative to placebo. The exposure-response model simulations and clinical risk factors were used to estimate 10-year risk of fractures using the clinically validated Fracture Risk Assessment Tool (FRAX). The impact of elagolix 300 mg BID + E2/NETA treatment on the 10-year risk of hip or major osteoporotic fractures estimated from the FRAX model was minimal compared to that of placebo. CONCLUSION: The elagolix integrated exposure-BMD analysis and translation to fracture risk provided an interdisciplinary model-informed drug development framework for clinical benefit-risk evaluation and enabled approval of longer treatment duration to benefit the patient.

Depot Medroxyprogesterone Acetate Use and the Development and Progression of Uterine Leiomyoma.

OBJECTIVE: Investigate the association between use of depot medroxyprogesterone acetate (DMPA) (an injectable progestin-only contraceptive) and leiomyoma development. METHODS: We conducted a cohort study in the Detroit, Michigan, area that involved four clinic visits at 20-month intervals over 5 years (2010-2018) and used a standardized ultrasonography protocol to prospectively measure leiomyomas 0.5 cm or more in diameter. Participants were 1,693 self-identified Black women aged 23-35 years with no prior leiomyoma diagnosis and no hysterectomy. For this substudy, years since last use of DMPA was ascertained from questionnaire data at every visit. Leiomyoma incidence was defined as the first visit with an observed leiomyoma among women who were leiomyoma-free at enrollment. Depot medroxyprogesterone acetate associations were examined with Cox models. Leiomyoma growth was calculated as the change in log-volume for leiomyomas matched at successive visits and was modeled using linear mixed models accounting for clustered data. Leiomyoma loss, defined as a reduction in leiomyoma number in successive visits, was modeled using Poisson regression. All models used time-varying exposure and covariates. RESULTS: Of participants with at least one follow-up visit (N=1,610), 42.9% had ever used DMPA. Participants exposed to DMPA within the previous 2 years experienced reduced leiomyoma development during the subsequent observation interval compared with never users, including lower leiomyoma incidence (5.2% vs 10.7%), adjusted hazard ratio 0.6 (95% CI 0.4-1.0), 42.0% lower leiomyoma growth (95% CI -51.4 to -30.7) and 60% greater leiomyoma loss (adjusted risk ratio 1.6, 95% CI 1.1-2.2). Excess leiomyoma loss was also seen for those who used DMPA 2-4 years before the visit compared with never users, 2.1-fold increase (95% CI 1.4-3.1). CONCLUSION: Recent use of DMPA was associated with reduced leiomyoma development and increased leiomyoma loss. Such changes in early leiomyoma development in young women could delay symptom onset and reduce the need for invasive treatment.

Short-term tetrabromobisphenol A exposure promotes fibrosis of human uterine fibroid cells in a 3D culture system through TGF-beta signaling.

Tetrabromobisphenol A (TBBPA), a derivative of BPA, is a ubiquitous environmental contaminant with weak estrogenic properties. In women, uterine fibroids are highly prevalent estrogen-responsive tumors often with excessive accumulation of extracellular matrix (ECM) and may be the target of environmental estrogens. We have found that BPA has profibrotic effects in vitro, in addition to previous reports of the in vivo fibrotic effects of BPA in mouse uterus. However, the role of TBBPA in fibrosis is unclear. To investigate the effects of TBBPA on uterine fibrosis, we developed a 3D human uterine leiomyoma (ht-UtLM) spheroid culture model. Cell proliferation was evaluated in 3D ht-UtLM spheroids following TBBPA (10-6 -200 µM) administration at 48 h. Fibrosis was assessed using a Masson's Trichrome stain and light microscopy at 7 days of TBBPA (10-3  µM) treatment. Differential expression of ECM and fibrosis genes were determined using RT² Profiler™ PCR arrays. Network and pathway analyses were conducted using Ingenuity Pathway Analysis. The activation of pathway proteins was analyzed by a transforming growth factor-beta (TGFB) protein array. We found that TBBPA increased cell proliferation and promoted fibrosis in 3D ht-UtLM spheroids with increased deposition of collagens. TBBPA upregulated the expression of profibrotic genes and corresponding proteins associated with the TGFB pathway. TBBPA activated TGFB signaling through phosphorylation of TGFBR1 and downstream effectors-small mothers against decapentaplegic -2 and -3 proteins (SMAD2 and SMAD3). The 3D ht-UtLM spheroid model is an effective system for studying environmental agents on human uterine fibrosis. TBBPA can promote fibrosis in uterine fibroid through TGFB/SMAD signaling.

Assessment of the safe and efficacious dose of the selective progesterone receptor modulator vilaprisan for the treatment of patients with uterine fibroids by exposure-response modelling and simulation.

AIMS: We report population pharmacokinetic (popPK) and exposure-response (E-R) analyses for efficacy (induced amenorrhoea [IA]) and safety (unbound oestradiol [E2] concentrations) of the selective progesterone receptor modulator vilaprisan. Results were used to inform the dose for the Phase 3 programme in patients with uterine fibroids. METHODS: A popPK model was developed using data from Phase 1 and 2 studies (including ASTEROID 1 and 2). The relationship between vilaprisan exposure (steady-state AUC) and IA after oral administration of 0.5, 1, 2 or 4 mg/day over 3 months was analysed in ASTEROID 1 using logistic regression and qualified in ASTEROID 2 by comparing simulated and observed probability for IA after 2 mg/day. The exposure-E2 relationship was analysed visually. RESULTS: Vilaprisan clearance was 22.7% lower in obese vs non-obese patients. The E-R relationship for IA in ASTEROID 1 was steep and consistent with ASTEROID 2, with a maximum probability (Pmax ) of 59% (95% CI: 49-68%). The exposure at which 50% of Pmax is obtained was 36.9 µg*h/L (95% CI: 27.7-48.7 µg*h/L). Simulations showed that 36% of the patients will be below 90% of Pmax for IA after 1 mg/day compared to 2% after 2 mg/day. E2 levels tended to decrease with increasing exposure. While E2 levels remained largely within the physiologic follicular phase range, the clinical relevance of this decrease will be evaluated in long-term studies. CONCLUSIONS: A 2 mg/day dose was selected for Phase 3 as E-R analyses show this dose results in a close to maximum probability for IA, without any safety concerns noted.

Combined Exposure to Multiple Endocrine Disruptors and Uterine Leiomyomata and Endometriosis in US Women.

Background: Uterine leiomyomata (UL) and endometriosis (EM) are common gynecological diseases damaging the reproductive health of fertile women. Among all the potential factors, environmental endocrine-disrupting chemicals are insufficiently addressed considering the multiple pollutants and mixture exposure. Methods: Women aged 20 to 54 years old in the National Health and Nutrition Examination Survey (NHANES) 2001-2006, having a complete measurement of ten commonly exposed endocrine-disrupting chemicals (including urinary phthalate metabolites, equol, and whole blood heavy metals) and answered questions about UL and EM were included (N=1204). Multivariable logistic regression model, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models were implemented to analyze the combined effect of chemicals on the overall association with UL and EM. Results: In single chemical analysis, equol (OR: 1.90, 95% CI: 1.11, 3.27) and mercury (Hg) (OR: 1.91, 95% CI: 1.14, 3.25) were found positively associated with UL in tertile 3 vs. tertile 1. In WQS regression and BKMR models, the significant positive association between WQS index and UL (OR: 2.54, 95% CI: 1.52, 4.29) was identified and the positive relationship between equol and Hg exposure and UL were further verified. Besides, the mixture evaluation models (WQS and BKMR) also found MEHP negatively associated with UL. Although none of the single chemicals in tertile 3 were significantly associated with EM, the WQS index had a marginally positive association with EM (OR: 2.01, 95% CI: 0.98, 4.15), and a significant positive association was identified in subanalysis with participants restricted to premenopausal women (OR: 2.18, 95% CI: 1.03, 4.70). MIBP and MBzP weighted high in model of EM and MEHP weighted the lowest. Conclusion: Comparing results from these three statistical models, the associations between equol, Hg, and MEHP exposure with UL as well as the associations of MIBP, MBzP, and MEHP exposure with EM warrant further research.

Impact of Contraception on Uterine Fibroids.

Background and Objectives: Uterine fibroids develop in 25-40% of women of childbearing age; however, there are discrepancies resulting from population and socioeconomic differences. The pathogenesis of fibroids is not clear. The aim of the study was to assess the potential connection between the use of oral contraceptives and the occurrence of uterine fibroids in women of childbearing age. Materials and Methods: In this prospective, survey, case-control study, data were collected from Caucasian female patients (mean age = 30) using a questionnaire concerning the onset, duration and form of hormonal contraception, and medical and obstetrical history. The questionnaires were handed personally to hospitalized patients as well as distributed through Google forms on social media. Results: In a study group (n = 140) of patients using hormonal contraception, 37.8% of them were diagnosed with uterine fibroids, whereas among the patients not using hormonal contraception (n = 206), uterine fibroids were diagnosed in 59.6% of the patients. The most common hormonal contraception was two-component hormonal tablets used by 93.3% of the patients. Taking contraceptives was a uterine fibroids protective factor (OR = 0.4, p = 0.007). In the study group, 5.5% of the patients were pregnant and 60.42% were diagnosed with uterine fibroids (OR = 4.4, p < 0.000001). Conclusion: Contraception was found to be a protective factor for uterine fibroids among the women surveyed. The presented data confirm the theory about the hormonal dependence of uterine fibroids.

Perfluoroalkyl substances (PFAS) in drinking water and risk for polycystic ovarian syndrome, uterine leiomyoma, and endometriosis: A Swedish cohort study.

BACKGROUND: Perfluorinated substances (PFAS) are chemicals with endocrine disruptive properties that may interfere with the female reproductive system. However, few studies have explored the association between benign gynecological diseases and high PFAS exposure. OBJECTIVES: The aim of this study was to investigate the possible associations between PFAS exposure and subsequent diagnosis of polycystic ovarian syndrome (PCOS), uterine leiomyoma (fibroids), and endometriosis in a cohort exposed to PFAS through drinking water. MATERIAL AND METHODS: In 2013, high levels (with sum of PFAS above 10,000 ng/L), dominated by perfluorooctanesulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS), were found in the drinking water from one of the two waterworks in Ronneby, Sweden. The contamination came from firefighting foams used at a nearby airfield. Females of all ages (n = 29,106) who had ever resided in the municipality between 1985 and 2013 formed a cohort. Individual exposure was assessed based on municipality waterworks distribution data linked to annual residential address data; 27% of the females had ever lived at an address with PFAS-contaminated water. Gynecological health outcomes were retrieved from the Swedish National Patient Register. The Cox proportional hazards model was used to estimate the association between exposure and each diagnosis. RESULTS: There were in all 161 cases of PCOS, 1,122 cases of uterine leiomyoma, and 373 cases of endometriosis. In women aged 20-50 years (n = 18,503), those with the highest estimated PFAS exposure had increased hazard ratios (HR) for PCOS (HR = 2.18; 95% confidence interval (CI) 1.43, 3.34) and uterine leiomyoma (HR = 1.28; 95% CI 0.95, 1.74). No increased HR for endometriosis was found (HR = 0.74; 95% CI 0.42, 1.29). CONCLUSIONS: Exposure to high levels of PFAS in drinking water was associated with increased risk of PCOS and possibly uterine leiomyoma, but not endometriosis. The findings for PCOS are consistent with prior studies reporting positive associations between PCOS and PFAS exposure at background levels.

Therapeutic modality of induced uterine leiomyoma with shock waves in rats: The uterine blood flow, circulating ovarian hormones and histopathological findings.

Uterine leiomyoma is the most common benign pelvic tumor and the primary indication for hysterectomy. We hypothesized tumor softening and shrinking through shock waves mechanobiological influence on fibroblasts of the induced leiomyoma in rats. Three rats served as control from thirty-three female Wistar rats subjected to leiomyoma induction using mono-sodium glutamate and estradiol benzoate. After assessing uterine leiomyoma development with Doppler ultrasonography, blood and tissue samples were collected for hormonal and histopathological analysis. Of the fifteen rats treated with shock waves, five rats were sacrificed after receiving two sessions (2S), another five rats were sacrificed after receiving four sessions (4S), and the last five rats were sacrificed after two weeks recovery period (recovered 4S). From the fifteen non-treated leiomyoma group, five rats were sacrificed after Doppler ultrasound assessment (Leiomyoma), another five rats were sacrificed with the 4S group (Leiomyoma 1Wk recovery), and the last five rats were sacrificed with the recovered 4S group (Recovered leiomyoma). The collected blood samples, estradiol (E2), Estrogen receptor, progesterone (P4), and progesterone receptor (PGR), were assayed. Total cholesterol, protein, albumin, and globulin were measured. Uterine arteries' blood flow velocities, indices, and volume were obtained. Tissue samples were stained with smooth muscle actin (SMA), trichrome-three, and (hematoxylin and eosin). Rats developed leiomyoma had the highest (P = 0.0001) gross and sonographic uterine horns diameters, uterine weight, uterine coefficient, E2, and ER. Both trichrome-three and SMA staining confirmed the leiomyoma development and the response to shock waves treatment. In conclusion, low-intensity shock waves proved curative to the induced leiomyoma.