Tobacco smoking and risk of endometriosis: a systematic review and meta-analysis

Association Between the Oxidative Balance Score and Endometriosis: A Population-Based Study

Purpose

To investigate the association between the oxidative balance score (OBS) and endometriosis.

Methods

This cross-sectional study used four cycles of the National Health and Nutrition Examination Survey (NHANES) (1999-2000, 2001-2002, 2003-2004, and 2005-2006). OBS involved 16 dietary nutrients and 4 lifestyle factors, including 5 pro-oxidants and 15 anti-oxidants. According to weighted quartiles, the OBS was divided into four categories: < 12.54, 12.54-18.70, 18.71-24.68, and > 24.68. Endometriosis was diagnosed based on a question from the reproductive health questionnaire. Weighted multivariate logistic analysis was used to investigate the association between OBS and endometriosis. Subgroup analysis was performed based on menstrual regularity and female hormone use.

Results

A total of 5095 women were included, with 1140 (22.37%), 1232 (24.18%), 1224 (24.02%), and 1499 (29.42%) women in the OBS < 12.54, of 12.54-18.70, of 18.71-24.68, and > 24.68 categories, respectively. After adjusting age, race, family poverty-to-income ratio (PIR), education level, uterine fibroids, menstrual regularity, oophorectomy, female hormone use, hypertension, dyslipidemia, and steroid drug, a high OBS (> 24.68) was found to be associated with lower odds of endometriosis [odds ratio (OR) = 0.70, 95% confidence interval (CI): 0.50-0.97, P = 0.033] compared to a low OBS (< 12.54). The similar result was also found in women with irregular menstruation (OR = 0.58, 95% CI: 0.37-0.91, P = 0.020) and with female hormone use (OR = 0.71, 95% CI: 0.52-0.98, P = 0.037).

Conclusion

A high OBS was associated with lower odds of endometriosis, especially in women with irregular menstruation and female hormone use.

Pathogenesis of Endometriosis and Endometriosis-Associated Cancers

Endometriosis is a hormone-dependent, chronic inflammatory condition that affects 5-10% of reproductive-aged women. It is a complex disorder characterized by the growth of endometrial-like tissue outside the uterus, which can cause chronic pelvic pain and infertility. Despite its prevalence, the underlying molecular mechanisms of this disease remain poorly understood. Current treatment options are limited and focus mainly on suppressing lesion activity rather than eliminating it entirely. Although endometriosis is generally considered a benign condition, substantial evidence suggests that it increases the risk of developing specific subtypes of ovarian cancer. The discovery of cancer driver mutations in endometriotic lesions indicates that endometriosis may share molecular pathways with cancer. Moreover, the application of single-cell and spatial genomics, along with the development of organoid models, has started to illuminate the molecular mechanisms underlying disease etiology. This review aims to summarize the key genetic mutations and alterations that drive the development and progression of endometriosis to malignancy. We also review the significant recent advances in the understanding of the molecular basis of the disorder, as well as novel approaches and in vitro models that offer new avenues for improving our understanding of disease pathology and for developing new targeted therapies.

Associations between endometriosis and adverse pregnancy and perinatal outcomes: a population-based cohort study

PURPOSE

To examine the association between endometriosis and adverse pregnancy and perinatal outcomes (preeclampsia, placenta previa, and preterm birth).

METHODS

A population-based retrospective cohort study was conducted among 468,778 eligible women who contributed 912,747 singleton livebirths between 1980 and 2015 in Western Australia (WA). We used probabilistically linked perinatal and hospital separation data from the WA data linkage system's Midwives Notification System and Hospital Morbidity Data Collection databases. We used a doubly robust estimator by combining the inverse probability weighting with the outcome regression model to estimate adjusted risk ratios (RR) and 95% confidence intervals (CIs).

RESULTS

There were 19,476 singleton livebirths among 8874 women diagnosed with endometriosis. Using a doubly robust estimator, we found pregnancies in women with endometriosis to be associated with an increased risk of preeclampsia with RR of 1.18, 95% CI 1.11-1.26, placenta previa (RR 1.59, 95% CI 1.42-1.79) and preterm birth (RR 1.45, 95% CI 1.37-1.54). The observed association persisted after stratified by the use of Medically Assisted Reproduction, with a slightly elevated risk among pregnancies conceived spontaneously.

CONCLUSIONS

In this large population-based cohort, endometriosis is associated with an increased risk of preeclampsia, placenta previa, and preterm birth, independent of the use of Medically Assisted Reproduction. This may help to enhance future obstetric care among this population.

Psychometric evaluation of the endometriosis impact questionnaire (EIQ) in an Iranian population

BACKGROUND

Endometriosis is a benign and chronic gynecological estrogen-dependent disease. Considering the prevalence and the importance of measuring the long-term effects of endometriosis in affected women's lives t the EIQ scale was designed and psychometrically analyzed in English in Australia, in three recall periods (last 12 months, 1 to 5 years ago and more than 5 years ago). It has never been used in Iran and its validity and reliability have not been assessed either. Therefore, the present study aimed to translate and investigate the psychometric properties of the EIQ.

METHODS

In this study, 200 women were selected through random sampling in 2022. After forward and backward translation, the face validity, content validity, and construct validity of EIQ (through Corrected Item-Total Correlation) were examined. To assess the reliability of the scale, both internal consistency (Cronbach's alpha) and test-retest stability methods were employed.

RESULTS

Impact Score with a score above 1.5 was approved. CVI and CVR values of the EIQ tool were 0.97 and 0.94, respectively. The Item to total Correlation confirmed the construct validity of all seven dimensions of the tool, more than the cut-off (0.3) except lifestyle. Cronbach's alpha coefficient and Intra Correlation Coefficient (ICC) were acceptable for all dimensions.

CONCLUSION

The Persian version of EIQ is a valid and reliable scale. This tool is valid and reliable for investigating the long-term impact of endometriosis in Iranian society.

Clinical course of multiple sclerosis with comorbid endometriosis: A matched cohort study

BACKGROUND

Endometriosis (EMS) is pain syndrome in which endometrial tissue grows outside the uterus. EMS is associated with an increased risk of multiple sclerosis (MS), a demyelinating disease of the central nervous system.

OBJECTIVE

To characterize clinical phenotypes of a cohort of patients with both EMS and MS compared to a cohort of matched controls with only MS.

METHODS

We retrospectively identified patients with EMS and MS at Beth Israel Deaconess Medical Center (BIDMC). We collected data on EMS treatments and analyzed differences in histories of gynecological cancer, smoking, fatigue, anxiety, depression, headache, and neuropathic pain compared to matched controls. We used Wilcoxon signed rank tests for paired samples to compare Expanded Disability Status Scores (EDSS) and timed 25-foot walk values (T25FW).

RESULTS

Using a case-control methodology, we found significantly increased EDSS (p < 0.001) and T25FW (p = 0.01) in the EMS-MS group compared to the MS group. More patients in the EMS-MS group had histories of smoking, anxiety, depression, and headaches, while more patients in the MS group had histories of fatigue and neuropathic pain.

CONCLUSION

When controlling for age, race, and MS therapy, those with EMS-MS experience more MS disability than controls, suggesting this population requires more monitoring and efficacious treatment.

Are Adenomyosis and Endometriosis Phenotypes of the Same Disease Process?

In recent literature reviews, we concluded that the possibility that endometrial molecular aberrations are the sole or a necessary determinant of endometriosis and the Tissue Injury and Repair (TIAR) theory are yet to be convincingly proven. Here, we critically examine the theory that adenomyosis and endometriosis represent different phenotypes of a single disease. A common etiopathology for adenomyosis and endometriosis has been suggested because both conditions entail the presence of endometrial tissue at locations other than the lining of the uterus. There are wide differences in reported disease incidence and prevalence and, consequently, in estimates of the coexistence of both conditions. There are some similarities but also differences in their clinical features and predisposing factors. Each condition has a range of subtypes. These differences alone pose the question of whether subtypes of endometriosis and adenomyosis have different etiopathologies, and, in turn, this raises the question of whether they all share a common etiology. It is debatable whether the recognized differences between the eutopic endometrium in adenomyosis and endometriosis compared to those in unaffected women are the cause or the effect of the disease. The finding of common mutations, particularly of KRAS, lend support to the notion of shared predisposing factors, but this alone is insufficient evidence of causation.

An Evaluation of the Effect of Lifestyle on the Incidence of Endometriosis

Introduction:Although endometriosis is prevalent among women of reproductive age, the risk factors or indicators associated with its development have remained mostly unknown. The present study aimed at evaluating the effect of lifestyle on the incidence of endometriosis. Methods:In this observational investigation, which adopted a case-control design, a total of 264 participants, comprising 132 patients with endometriosis and 132 individuals without that disease, were selected and evaluated. The data collection form was filled with participants' demographic details. Subjects in both groups completed a lifestyle questionnaire, which assessed various lifestyle factors such as physical activity, alcohol and coffee consumption, and smoking. Then, the frequency of these lifestyle indicators was compared between the two groups. Collected data were analyzed using the statistical software SPSS, version 26. Results: In the group of women diagnosed with endometriosis, 6.06% reported a family history of that disease. Additionally, the prevalence of smoking was 13.64% in the case group and 5.30% in the control one. The chi-square test indicated a significant difference in the level of appropriate physical activity between the two groups, with the case group demonstrating a significantly lower level of physical activity. The lifestyle of 27.27% of patients with endometriosis was categorized as poor, while 52.28% had a moderate lifestyle and 20.45% a favorable lifestyle. The results of the chi-square test revealed a significant association between lifestyle and prevalence of endometriosis. Conclusion:Overall, there is a difference between the lifestyle of women with endometriosis and other individuals, and lifestyle can be used as a significant predictor for the development of endometriosis.

Associations and gastrointestinal symptoms in women with endometriosis in comparison to women with irritable bowel syndrome: a study based on a population cohort

BACKGROUND

Endometriosis and irritable bowel syndrome (IBS) have similar symptoms, pathogenesis, and risk factors. These diagnoses often coexist and are frequently misdiagnosed leading to diagnostic delays. This study of a population-based cohort aimed to investigate associations relating to endometriosis and IBS and to compare gastrointestinal symptoms between endometriosis and IBS.

METHOD

The study cohort included women from the Malmö Offspring Study with information about endometriosis and IBS diagnoses from the National Board of Health and Welfare. The participants answered a questionnaire about lifestyle habits, medical and drug history, and self-reported IBS. The visual analog scale for IBS was used to estimate gastrointestinal symptoms the past 2 weeks. Endometriosis diagnosis and self-reported IBS were used as dependent variables to study associations with age, body mass index (BMI), education, occupation, marital status, smoking, alcohol habits, and physical activity using logistic regression. Mann-Whitney U Test or Kruskal-Wallis tests were used to calculate the differences in symptoms between groups.

RESULTS

Of the 2,200 women with information from medical records, 72 participants had endometriosis; 21 (29.2%) of these had self-reported IBS. Of the 1,915 participants who had answered the questionnaire, 436 (22.8%) had self-reported IBS. Endometriosis was associated with IBS (OR:1.86; 95%CI:1.06-3.26; p = 0.029), as well as with age 50-59 years (OR:6.92; 95%CI:1.97-24.32; p = 0.003), age ≥ 60 years (OR:6.27; 95%CI:1.56-25.17; p = 0.010), sick leave (OR:2.43; 95%CI:1.08-5.48; p = 0.033), and former smoking (OR:3.02; 95%CI:1.19-7.68; p = 0.020). There was an inverse association with BMI (OR:0.36; 95%CI:0.14-4.91; p = 0.031). IBS was associated with endometriosis (OR:1.77; 95%CI:1.02-3.07; p = 0.041) and sick leave (OR:1.77; 95%CI:1.14-2.73; p = 0.010), with a tendency to association with smoking (OR:1.30; 95%CI:0.98-1.72; p = 0.071). When excluding participants using drugs associated with IBS, the condition was associated with current smoking (OR:1.39; 95%CI:1.03-1.89; p = 0.033) and inversely with age 50-59 years (OR:0.58; 95%CI:0.38-0.90; p = 0.015). There were differences in the gastrointestinal symptoms between IBS and healthy participants, but not between endometriosis and IBS or healthy participants.

CONCLUSION

There were associations between endometriosis and IBS, without differences in gastrointestinal symptoms. Both IBS and endometriosis were associated with smoking and sick leave. Whether the associations reflect causality or depend on common risk factors and pathogenesis remains to be determined.

Predictive Model for the Non-Invasive Diagnosis of Endometriosis Based on Clinical Parameters

OBJECTIVES

Are other pain symptoms in addition to dysmenorrhea, dyspareunia, dyschezia, dysuria, and chronic pelvic pain correlated to endometriosis and suitable for a clinical prediction model?

METHODS

We conducted a prospective study from 2016 to 2022, including a total of 269 women with numerous pain symptoms and other parameters. All women filled out two questionnaires and were examined by palpation and transvaginal ultrasound (TVUS). In cases of suspected deep endometriosis, magnetic resonance imaging (MRI) was performed. After the operation, endometriosis was diagnosed by histological examination.

RESULTS

All in all, 30 significant parameters and 6 significant numeric rating scale (NRS) scores associated with endometriosis could be identified: 7 pain adjectives, 8 endometriosis-associated pain symptoms, 5 pain localizations, 6 parameters from the PainDETECT, consumption of analgesics, and allergies. Furthermore, longer pain duration (before, during, and after menstruation) was observed in women with endometriosis compared to women without endometriosis (34.0% vs. 12.3%, respectively). Although no specific pain for endometriosis could be identified for all women, a subgroup with endometriosis reported radiating pain to the thighs/legs in contrast to a lower number of women without endometriosis (33.9% vs. 15.2%, respectively). Furthermore, a subgroup of women with endometriosis suffered from dysuria compared to patients without endometriosis (32.2% vs. 4.3%, respectively). Remarkably, the numbers of significant parameters were significantly higher in women with endometriosis compared to women without endometriosis (14.10 ± 4.2 vs. 7.75 ± 5.8, respectively). A decision tree was developed, resulting in 0.904 sensitivity, 0.750 specificity, 0.874 positive predictive values (PPV), 0.802 negative predictive values (NPV), 28.235 odds ratio (OR), and 4.423 relative risks (RR). The PPV of 0.874 is comparable to the positive prediction of endometriosis by the clinicians of 0.86 (177/205).

CONCLUSIONS

The presented predictive model will enable a non-invasive diagnosis of endometriosis and can also be used by both patients and clinicians for surveillance of the disease before and after surgery. In cases of positivety, as evaluated by the questionnaire, patients can then seek advice again. Similarly, patients without an operation but with medical therapy can be monitored with the questionnaire.

New concepts on the etiology of endometriosis

Endometriosis is a serious, chronic disorder where endometrial tissue grows outside the uterus, causing severe pelvic pain and infertility. It affects 11% of women. Endometriosis is a multifactorial disorder of unclear etiology, although retrograde menstruation plays a major role. It has a genetic component with over 40 genetic risk factors mapped, although their mechanism of action is still emerging. New evidence suggests a role for retrograde menstruation of endometrial stem/progenitor cells, now that identifying markers of these cells are available. Recent lineage tracing and tissue clearing microscopy and 3D reconstruction has provided new understanding of endometrial glandular structure, particularly the horizontal orientation and interconnection of basalis glands. New sequencing technologies, particularly whole genome DNA sequencing are revealing somatic mutations, including in cancer driver genes, in normal and eutopic endometrium of patients with endometriosis, as well as ectopic endometriotic lesions. Methylome sequencing is offering insight into the regulation of genes and the role of the environmental factors. Single cell RNA sequencing reveals the transcriptome of individual endometrial cells, shedding new light on the diversity and range of cellular subpopulations of the major cell types present in the endometrium and in endometriotic lesions. New endometrial epithelial organoid cultures replicating glandular epithelium are providing tractable models for studying endometriosis. Organoids derived from menstrual fluid offer a non-invasive source of endometrial tissue and a new avenue for testing drugs and developing personalized medicine for treating endometriosis. These new approaches are rapidly advancing our understanding of endometriosis etiology.

Endometriosis: Update of Pathophysiology, (Epi) Genetic and Environmental Involvement

Endometriosis is a chronic disease caused by ectopic endometrial tissue. Endometriotic implants induce inflammation, leading to chronic pain and impaired fertility. Characterized by their dependence on estradiol (via estrogen receptor β (ESRβ)) and their resistance to progesterone, endometriotic implants produce their own source of estradiol through active aromatase. Steroidogenic factor-1 (SF1) is a key transcription factor that promotes aromatase synthesis. The expression of SF1 and ESRβ is enhanced by the demethylation of their promoter in progenitor cells of the female reproductive system. High local concentrations of estrogen are involved in the chronic inflammatory environment favoring the implantation and development of endometriotic implants. Similar local conditions can promote, directly and indirectly, the appearance and development of genital cancer. Recently, certain components of the microbiota have been identified as potentially promoting a high level of estrogen in the blood. Many environmental factors are also suspected of increasing the estrogen concentration, especially prenatal exposure to estrogen-like endocrine disruptors such as DES and bisphenol A. Phthalates are also suspected of promoting endometriosis but throughmeans other than binding to estradiol receptors. The impact of dioxin or tobacco seems to be more controversial.

Endometriosis and environmental factors: a critical review

This review provides an overview of current knowledge on the relationship between various environmental factors and endometriosis. We successively searched for a given exposure factor combined with the word "endometriosis." The literature was comprehensively analyzed and summarized by quoting only the most important and recent studies on each exposition factor. The data focused primarily on endocrine disruptors, such as dioxins and polychlorinated biphenyls, that appear to have the strongest effect. Intriguing data suggest a link with night work, sun exposure and red meat consumption. For the other risk factors studied, particularly those related to lifestyle (tobacco consumption, alcohol, coffee, soy, physical exercise), the data are not sufficient to draw conclusions. In summary, the epidemiological evidence does not support a strong, scientific link between exposure to environmental factors and endometriosis. The complexity of this disease requires advanced study designs and standardized methodology. Future studies should be carefully designed to address these issues to advance our understanding of the impact of the environment and its consequences on endometriosis.

ESHRE guideline: endometriosis

STUDY QUESTION

How should endometriosis be diagnosed and managed based on the best available evidence from published literature?

SUMMARY ANSWER

The current guideline provides 109 recommendations on diagnosis, treatments for pain and infertility, management of disease recurrence, asymptomatic or extrapelvic disease, endometriosis in adolescents and postmenopausal women, prevention and the association with cancer.

WHAT IS KNOWN ALREADY

Endometriosis is a chronic condition with a plethora of presentations in terms of not only the occurrence of lesions, but also the presence of signs and symptoms. The most important symptoms include pain and infertility.

STUDY DESIGN SIZE DURATION

The guideline was developed according to the structured methodology for development of ESHRE guidelines. After formulation of key questions by a group of experts, literature searches and assessments were performed. Papers published up to 1 December 2020 and written in English were included in the literature review.

PARTICIPANTS/MATERIALS SETTING METHODS

Based on the collected evidence, recommendations were formulated and discussed within specialist subgroups and then presented to the core guideline development group (GDG) until consensus was reached. A stakeholder review was organized after finalization of the draft. The final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

This guideline aims to help clinicians to apply best care for women with endometriosis. Although studies mostly focus on women of reproductive age, the guideline also addresses endometriosis in adolescents and postmenopausal women. The guideline outlines the diagnostic process for endometriosis, which challenges laparoscopy and histology as gold standard diagnostic tests. The options for treatment of endometriosis-associated pain symptoms include analgesics, medical treatments and surgery. Non-pharmacological treatments are also discussed. For management of endometriosis-associated infertility, surgical treatment and/or medically assisted reproduction are feasible. While most of the more recent studies confirm previous ESHRE recommendations, there are five topics in which significant changes to recommendations were required and changes in clinical practice are to be expected.

LIMITATIONS REASONS FOR CAUTION

The guideline describes different management options but, based on existing evidence, no firm recommendations could be formulated on the most appropriate treatments. Also, for specific clinical issues, such as asymptomatic endometriosis or extrapelvic endometriosis, the evidence is too scarce to make evidence-based recommendations.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in endometriosis care, based on the best evidence currently available. In addition, a list of research recommendations is provided to stimulate further studies in endometriosis.

STUDY FUNDING/COMPETING INTERESTS

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payments. C.M.B. reports grants from Bayer Healthcare and the European Commission; Participation on a Data Safety Monitoring Board or Advisory Board with ObsEva (Data Safety Monitoring Group) and Myovant (Scientific Advisory Group). A.B. reports grants from FEMaLE executive board member and European Commission Horizon 2020 grant; consulting fees from Ethicon Endo Surgery, Medtronic; honoraria for lectures from Ethicon; and support for meeting attendance from Gedeon Richter; A.H. reports grants from MRC, NIHR, CSO, Roche Diagnostics, Astra Zeneca, Ferring; Consulting fees from Roche Diagnostics, Nordic Pharma, Chugai and Benevolent Al Bio Limited all paid to the institution; a pending patent on Serum endometriosis biomarker; he is also Chair of TSC for STOP-OHSS and CERM trials. O.H. reports consulting fees and speaker's fees from Gedeon Richter and Bayer AG; support for attending meetings from Gedeon-Richter, and leadership roles at the Finnish Society for Obstetrics and Gynecology and the Nordic federation of the societies of obstetrics and gynecology. L.K. reports consulting fees from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; honoraria for lectures from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; support for attending meetings from Gedeon Richter, AstraZeneca, Novartis, Dr KADE/Besins, Palleos Healthcare, Roche, Mithra; he also has a leadership role in the German Society of Gynecological Endocrinology (DGGEF). M.K. reports grants from French Foundation for Medical Research (FRM), Australian Ministry of Health, Medical Research Future Fund and French National Cancer Institute; support for meeting attendance from European Society for Gynaecological Endoscopy (ESGE), European Congress on Endometriosis (EEC) and ESHRE; She is an advisory Board Member, FEMaLe Project (Finding Endometriosis Using Machine Learning), Scientific Committee Chair for the French Foundation for Research on Endometriosis and Scientific Committee Chair for the ComPaRe-Endometriosis cohort. A.N. reports grants from Merck SA and Ferring; speaker fees from Merck SA and Ferring; support for meeting attendance from Merck SA; Participation on a Data Safety Monitoring Board or Advisory Board with Nordic Pharma and Merck SA; she also is a board member of medical advisory board, Endometriosis Society, the Netherlands (patients advocacy group) and an executive board member of the World Endometriosis Society. E.S. reports grants from National Institute for Health Research UK, Rosetrees Trust, Barts and the London Charity; Royalties from De Gruyter (book editor); consulting fees from Hologic; speakers fees from Hologic, Johnson & Johnson, Medtronic, Intuitive, Olympus and Karl Storz; Participation in the Medicines for Women's Health Expert Advisory Group with Medicines and Healthcare Products Regulatory Agency (MHRA); he is also Ambassador for the World Endometriosis Society. C.T. reports grants from Merck SA; Consulting fees from Gedeon Richter, Nordic Pharma and Merck SA; speaker fees from Merck SA, all paid to the institution; and support for meeting attendance from Ferring, Gedeon Richter and Merck SA. The other authors have no conflicts of interest to declare.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgement to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose (Full disclaimer available at www.eshre.eu/guidelines.).

Endometriosis and cardiovascular disease

Endometriosis is a chronic gynaecological disease affecting 1 in 10 reproductive-age women. It is defined as the presence of endometrium-like tissue outside the uterus. Beyond this placid anatomical definition, endometriosis is a complex, hormonal, inflammatory, and systemic condition that poses significant familial, psychological, and economic burden. The interaction between the cardiovascular system and endometriosis has become a field of interest as the underlying mutual mechanisms become better understood. On the basis of accumulating fundamental and clinical evidence, it is likely that there exists a close relationship between endometriosis and the cardiovascular system. Therefore, investigating the endometriosis-cardiovascular interaction is highly clinically significant. In this review, we highlight our current understanding of the pathophysiology of endometriosis with systemic hormonal, pro-inflammatory, pro-angiogenic, immunologic, and genetic processes beyond the peritoneal microenvironment. Additionally, we provide current clinical evidence about how endometriosis interacts with cardiovascular risk factors and cardiovascular disease (CVD). To date, only small associations between endometriosis and CVD have been reported in observational studies, inherently limited by the potential influence of unmeasured confounding. Cardiovascular disease in women with endometriosis remains understudied, under-recognized, and underdiagnosed. More detailed study of the cardiovascular-endometriosis interaction is needed to fully understand its clinical relevance, underlying pathophysiology, possible means of early diagnosis and prevention.

Overview of the Effect of Complementary Medicine on Treating or Mitigating the Risk of Endometriosis

OBJECTIVE

 Endometriosis is a hormone-dependent chronic inflammatory disease with symptoms such as pelvic pain, which affect the physical, emotional, and social health of women in reproductive age. The current overview article aims to explore the effect of complementary medicine on the treatment or in mitigating the risk of endometriosis.

METHODS

 This is an overview article done in Iran. Two separate researchers systematically searched 3 databases (Medline, Scopus, and Cochrane Central Register Trials) until September 2020. The methodological quality of each study was assessed using the assessment of multiple systematic reviews (AMSTAR) tool.

RESULTS

 The results of two reviews suggested that physical activity, tobacco smoking, diet, coffee and caffeine intake had no effect on mitigating the risk of endometriosis or improving its treatment, but acupuncture successfully reduced pain and related marker (serum CA-125) levels.

CONCLUSION

 As endometriosis is an annoying disease with many complications and is hard to diagnose and treat, related studies in complementary medicine can help patients with endometriosis. Based on the relevant literature review, among the complementary medicine available for the treatment or to mitigate the risk of endometriosis, only acupuncture seems to alleviate the pain of endometriosis.

Lifestyle and Chronic Pain in the Pelvis: State of the Art and Future Directions

During their lifespan, many women are exposed to pain in the pelvis in relation to menstruation and pregnancy. Such pelvic pain is often considered normal and inherently linked to being a woman, which in turn leads to insufficiently offered treatment for treatable aspects related to their pain experience. Nonetheless, severe dysmenorrhea (pain during menstruation) as seen in endometriosis and pregnancy-related pelvic girdle pain, have a high impact on daily activities, school attendance and work ability. In the context of any type of chronic pain, accumulating evidence shows that an unhealthy lifestyle is associated with pain development and pain severity. Furthermore, unhealthy lifestyle habits are a suggested perpetuating factor of chronic pain. This is of specific relevance during lifespan, since a low physical activity level, poor sleep, or periods of (di)stress are all common in challenging periods of women’s lives (e.g., during menstruation, during pregnancy, in the postpartum period). This state-of-the-art paper aims to review the role of lifestyle factors on pain in the pelvis, and the added value of a lifestyle intervention on pain in women with pelvic pain. Based on the current evidence, the benefits of physical activity and exercise for women with pain in the pelvis are supported to some extent. The available evidence on lifestyle factors such as sleep, (di)stress, diet, and tobacco/alcohol use is, however, inconclusive. Very few studies are available, and the studies which are available are of general low quality. Since the role of lifestyle on the development and maintenance of pain in the pelvis, and the value of lifestyle interventions for women with pain in the pelvis are currently poorly studied, a research agenda is presented. There are a number of rationales to study the effect of promoting a healthy lifestyle (early) in a woman’s life with regard to the prevention and management of pain in the pelvis. Indeed, lifestyle interventions might have, amongst others, anti-inflammatory, stress-reducing and/or sleep-improving effects, which might positively affect the experience of pain. Research to disentangle the relationship between lifestyle factors, such as physical activity level, sleep, diet, smoking, and psychological distress, and the experience of pain in the pelvis is, therefore, needed. Studies which address the development of management strategies for adapting lifestyles that are specifically tailored to women with pain in the pelvis, and as such take hormonal status, life events and context, into account, are required. Towards clinicians, we suggest making use of the window of opportunity to prevent a potential transition from localized or periodic pain in the pelvis (e.g., dysmenorrhea or pain during pregnancy and after delivery) towards persistent chronic pain, by promoting a healthy lifestyle and applying appropriate pain management.

Environmental Risk Factors for Endometriosis: An Umbrella Review of a Meta-Analysis of 354 Observational Studies With Over 5 Million Populations

Background: The association between a diverse array of environmental risk factors and the risk of endometriosis is contradictory. Objective: To summarize the evidence of associations between environmental risk factors and the risk of endometriosis. Methods: Databases such as PubMed, EMBASE, Web of Science, and ClinicalTrial.gov were systematically searched in June 2020. Meta-analyses of observational studies investigated any environmental exposure (non-genetic) and endometriosis risk. For each article, we estimated the summary effect size, 95% CIs, and the 95% prediction interval (PI). We also estimated the between-study heterogeneity expressed by I ², evidence for small-study effects, and evidence of excess significance bias. Results: About 12 eligible articles (featuring 143,422 cases and 5,112,967 participants) yielded data on 40 unique environmental risk factors, including life styles (n = 16), reproductive factors (n = 3), early life factors (n = 4), and a range of other risk factors [e.g., phthalate metabolites, endocrine-disrupting chemicals, and body mass index (BMI)]. About 25 of these 40 associations (62.5%) were statistically significant (p < 0.05) under random-effects models. Evidence for an association was indicated for alcohol intake [relative risk (RR): 1.25; 95% CI: 1.11-1.41] and the exposure to endocrine disruptor chemicals (EDCs) (RR: 1.41; 95% CI: 1.23-1.60) while 15 associations presented only weak evidence. Conclusions: Our analyses showed that alcohol intake and exposure to endocrine-disrupting chemicals may be potential risk factors for endometriosis and supported by suggestive epidemiological evidence. However, it was evident that there was substantial heterogeneity and/or bias between the different studies featured in various meta-analyses included in this review; therefore, the outcomes of our analysis should be interpreted cautiously.

Familial risk for endometriosis and its interaction with smoking, age at menarche and body mass index: a population-based cohort study among siblings

OBJECTIVE

To quantify familial risk of endometriosis among full siblings and examine interactions between family history and smoking, age at menarche or body mass index (BMI).

DESIGN, SETTING AND POPULATION

Population-based nationwide cohort study.

METHODS

Using data from the Korean National Health Insurance and Screening Programme databases on kinship, healthcare utilisation, lifestyle and anthropometrics, we identified 2 109 288 women with full siblings and their environmental risk factors from 2002 to 2018. Familial risks were estimated using Cox proportional-hazards models, represented as incidence risk ratios (IRR) with 95% CI. Interaction between family history and smoking, age at menarche or BMI were assessed on an additive scale.

MAIN OUTCOME MEASURES

IRR of endometriosis among women with and without affected siblings.

RESULTS

From 19 195 women with affected siblings, 1126 developed endometriosis with an incidence of 35.45/10 000 person-years. Familial risk of endometriosis with versus without affected siblings was increased to IRR 2.75 (95% CI 2.25-3.36), and the highest risk was with affected twins (IRR 6.98; 95% CI 4.19-11.62). Women with both a family history and either smoking, early menarche or low BMI had a significantly higher risk of endometriosis compared with the general population and can be regarded as a high-risk group, the IRRs were 4.28 (95% CI 2.43-7.55), 3.47 (95% CI 2.82-4.26) and 3.09 (95% CI 2.68-3.56), respectively. Substantial effect modification of the associations was noted by smoking and early menarche, as their combined risk with family history exceeded the sum of their individual risks, which was also statistically significant.

CONCLUSION

Genetic factors are the primary contributor to the familial aggregation of endometriosis. Significant gene-environment interaction exists between family history and smoking or early menarche.

Cigarette Smoking and Estrogen-Related Cancer

Cigarette smoking is a known cause of many cancers, yet epidemiologic studies have found protective associations with the risk of four "estrogen-related" malignancies: endometrial cancer, endometrioid and clear cell ovarian cancers, and thyroid cancer. This review considers epidemiologic and biological aspects of these associations, focusing particularly on estrogen signaling, and contrasts them with those for breast cancer, another estrogen-related malignancy. The observational findings regarding the inverse associations are consistent and remain after adjustment for possible confounding factors. In general, women who smoke do not have lower circulating estrogen levels than nonsmokers, eliminating one possible explanation for reduced risks of these malignancies. For endometrial and endometrioid ovarian cancer, the negative associations could plausibly be explained by interference with signaling through the estrogen receptor α. However, this is unlikely to explain the lower risks of thyroid and clear cell ovarian cancers. For thyroid cancer, an anti-inflammatory effect of nicotine and reduced TSH levels from smoking have been proposed explanations for the inverse association, but both lack convincing evidence. While the overall impact of cigarette smoking is overwhelmingly negative, protective associations such as those discussed here can provide potential clues to disease etiology, treatment, and prevention.

From Environmental to Possible Occupational Exposure to Risk Factors: What Role Do They Play in the Etiology of Endometriosis?

Endometriosis is a gynecological disorder characterized by the presence of endometrial stroma and glands outside the uterine cavity. A systematic review of the literature was conducted to clarify, starting from environmental exposure data, whether possible occupational risk factors may correlate with the onset of the disease. The guidelines for reporting systematic reviews of the “PRISMA” statement were followed and two databases, Scopus and PubMed, were used. Of the 422 studies selected with specific keywords, 32 publications were eligible, 28 of which referred to chemical agents and 4 related to night work. Conflicting data emerged among these studies. Although some compounds seemed to be more involved than others in the onset of endometriosis. Association with exposure to organochlorine compounds is the most supported by the epidemiological data, while other pesticide exposure did not show any clear correlation. Likewise, the hypothesis of a correlation with perfluoroalkyls exposure is not currently supported by data. The involvement of metals as risk factors has not been confirmed, while the role of night work, in the case of long service, seems to play an etiological role. In order to clarify the potential occupational risk of endometriosis development, well-designed studies are needed to evaluate the potential association between chemical compounds and disease etiology.

An Evidence-Based Review of Elagolix for the Treatment of Pain Secondary to Endometriosis

Purpose of Review

This is a review of elagolix use for pain related to endometriosis. It summarizes the background and recent data available about the pathogenesis of endometriosis and pain that is secondary to this syndrome. It then reviews the evidence to support the use of elagolix and the indications for use.

Recent Findings

Endometriosis occurs in 10% of reproductive-age women and is a common source of chronic pelvic pain, infertility, and co-morbid disorders. It usually presents with some combination of dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility. Treatment options may be surgical or hormonal. Traditional treatment is divided into medical and surgical. The latter, though effective, is reserved for surgical emergencies and patients failing medical management. Medical management with NSAIDs is usually limited in efficacy. It is generally based on hormonal suppression leading to atrophy of endometrial lesions. Elagolix (Orlissa) is a GnRH antagonist that suppressed the entire hypophysis-gonadal axis. Reduced levels of estrogen and progesterone lead to involution of the endometrial lesions and improvement in symptoms. Clinical trials showed that elagolix is effective in treating dysmenorrhea and non-menstrual pain that is secondary to endometriosis. It is well tolerated and has a relatively safe usage profile. Studies up to 12 months long showed continued efficacy and reduction in dysmenorrhea of up to 75%, with 50%-60% reduction in non-menstrual pain. Elagolix was found effective when compared to both placebo and alternative treatments.

Summary

Endometriosis is a common syndrome that causes significant pain, morbidity, and disability, as well as financial loss. Elagolix is an effective drug in treating the symptoms of endometriosis and is a relatively safe option. Phase 4 studies will be required to evaluate the safety and efficacy of long term chronic use.

Endometriosis Associated Infertility: A Critical Review and Analysis on Etiopathogenesis and Therapeutic Approaches

Endometriosis represents a frequently diagnosed gynecological affliction in the reproductive timespan of women, defined by symptoms ranging from pelvic pain to infertility. A complex interplay between the genetic profile, hormonal activity, menstrual cyclicity, inflammation status, and immunological factors define the phenotypic presentation of endometriosis. To date, imaging techniques represent the gold standard in diagnosing endometriosis, of which transvaginal ultrasonography and magnetic resonance imaging bring the most value to the diagnostic step. Current medical treatment options for endometriosis-associated infertility focus on either stimulating the follicular development and ovulation or on inhibiting the growth and development of endometriotic lesions. Techniques of assisted reproduction consisting of superovulation with in vitro fertilization or intrauterine insemination represent effective treatment alternatives that improve fertility in patients suffering from endometriosis. Emerging therapies such as the usage of antioxidant molecules and stem cells still need future research to prove the therapeutic efficacy in this pathology.

The -1195A>G polymorphism in Ciclooxygenase-2 gene is associated with lower risk of endometriosis

OBJECTIVES

This study aimed to evaluate the potential role of the PTGS2 single nucleotide polymorphisms (SNPs) -1195 A>G and +8473 T>C in endometriosis' development, and characterizing their association with the prognostic features of the disease.

STUDY DESIGN

DNA from 254 women with endometriosis and 267 controls, recruited from two reference hospitals from the Brazilian public health system, were genotyped using TaqMan allelic discrimination assays. The association between SNPs and endometriosis features was evaluated by multivariate logistic regression, using the adjusted odds ratios (OR) with their respective 95% confidence intervals (95% CI).

RESULTS AND CONCLUSION

There were significant differences between cases and controls regarding age (P < 0.001), body mass index (BMI) (P = 0.001), educational level (P < 0.001), physical activity (P = 0.003), smoking status (P < 0.001), contraception use (P = 0.02), family history of endometriosis (P = 0.002) and all symptoms (P < 0.001). The distribution of -1195 A > G was statistically different between the groups, suggesting a lower risk of developing the disease for the carriers of the -1195 GG genotype (OR = 0.19; 95% CI = 0.04 - 0.93). No differences were found for the +8473 T>C between the two groups and neither in prognostic features of the disease for both PTGS2 SNPs. In conclusion, PTGS2 -1195A>G SNP was negatively associated with development of endometriosis and the two groups were statistically different regarding age, BMI, educational level, physical activity, smoking status, contraception use, history of endometriosis and all endometriosis symptoms.

Associations of perinatal characteristics with endometriosis: a nationwide birth cohort study

BACKGROUND

Perinatal characteristics are associated with subsequent risk of several chronic diseases. Previous studies regarding endometriosis were based on small samples and retrospective data and were limited by unmeasured confounding bias, leading to conflicting and inconclusive findings. We investigated the associations of maternal and birth characteristics with risk of endometriosis among Swedish women of reproductive age.

METHODS

This total-population register-based cohort study consisted of 628 312 singleton women born in Sweden between 1973 and 1987, who were followed for diagnosed endometriosis from age 15 years until the end of 2012. Multivariable Cox regression was applied to examine associations with perinatal characteristics. Residual unmeasured confounding was assessed through within-family and E-value analyses.

RESULTS

During follow-up, 8262 women received an endometriosis diagnosis. There were clear dose-response/linear associations of endometriosis with lower maternal education, endometriosis in the mother [adjusted hazard ratio (aHR): 2.24, 95% confidence interval (CI): 2.04-2.46], maternal smoking during pregnancy (aHR: 1.18, 95% CI: 1.04-1.33 for moderate smoker and aHR: 1.36, 95% CI: 1.18-1.57 for heavy smoker vs non-smoker), lower birthweight, and lower birthweight-for-gestational age (aHR: 0.93 per standard deviation increase, 95% CI: 0.91-0.95). Within-family and E-value analyses suggested that these perinatal characteristics are robust predictors of the incidence of endometriosis. We also found that an estimated 26% of the association between maternal smoking and early-onset endometriosis could be explained by birthweight-for-gestational age.

CONCLUSION

This study finds support for fetal origins of endometriosis, in that exposure to adverse environment or restricted development during the perinatal period may increase the risk. Further research is needed to provide an understanding of the underlying mechanisms.

Smoke, alcohol and drug addiction and female fertility

BACKGROUND

Considerable interest has been gathered on the relevant impact of preventable factors, including incorrect lifestyle and unhealthy habits, on female fertility. Smoking, alcohol and addictive drugs consumption represent a major concern, given the broad range of diseases which might be favored or exacerbated by these dependable attitudes. Despite the well-characterized effects of prenatal exposure on pregnancy outcomes and fetus health, a substantial proportion of women of reproductive age is still concerned with these habits. At present, the impact of smoke, alcohol and addictive drugs on women fertility, and, particularly, the specific targets and underlying mechanisms, are still poorly understood or debated, mainly due to the scarcity of well-designed studies, and to numerous biases.

OBJECTIVE

The current review will provide a comprehensive overview of clinical and experimental studies in humans and animals addressing the impact of smoke, alcohol and addictive drugs on female fertility, by also embracing effects on ovary, oviduct, and uterus, with particular reference to primary endpoints such as ovarian reserve, steroidogenesis, ovulation and menstrual cycle, oviduct function and uterus receptivity and implantation. A brief focus on polycystic ovary syndrome and endometriosis will be also included.

METHODS

A Pubmed literature search was performed with selected keywords; articles were individually retrieved by each author. No limitation was set for publication date. Articles in languages other than English were excluded. Additional articles were retrieved from references list of selected manuscripts.

RESULTS AND CONCLUSIONS

Currently, the most consistent evidences of a detrimental effect of smoke, alcohol and addictive drugs on specific domains of the female reproductive function are provided by experimental studies in animals. Overall, clinical studies suggest that smoking is associated to decreased fertility, although causal inference should be further demonstrated. Studies addressing the effect of alcohol consumption on female fertility provide conflicting results, although the majority reported lack of a correlation. Extremely scarce studies investigated the effects of addictive drugs on female fertility, and the specific actions of selected drugs have been difficult to address, due to multidrug consumption.

Mortality of midlife women with surgically verified endometriosis—a cohort study including 2.5 million person-years of observation

STUDY QUESTION

Is all-cause and cause-specific mortality increased among women with surgically verified endometriosis?

SUMMARY ANSWER

The all-cause and cause-specific mortality in midlife was lower throughout the follow-up among women with surgically verified endometriosis compared to the reference cohort.

WHAT IS KNOWN ALREADY

Endometriosis has been associated with an increased risk of comorbidities such as certain cancers and cardiovascular diseases. These diseases are also common causes of death; however, little is known about the mortality of women with endometriosis.

STUDY DESIGN, SIZE, DURATION

A nationwide retrospective cohort study of women with surgically verified diagnosis of endometriosis was compared to the reference cohort in Finland (1987–2012). Follow-up ended at death or 31 December 2014. During the median follow-up of 17 years, 2.5 million person-years accumulated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Forty-nine thousand nine hundred and fifty-six women with at least one record of surgically verified diagnosis of endometriosis in the Finnish Hospital Discharge Register between 1987 and 2012 were compared to a reference cohort of 98 824 age- and municipality-matched women. The age (mean ± standard deviation) of the endometriosis cohort was 36.4 ± 9.0 and 53.6 ± 12.1 years at the beginning and at the end of the follow-up, respectively. By using the Poisson regression models the crude and adjusted all-cause and cause-specific mortality rate ratios (MRR) and 95% confidence intervals (CI) were assessed. Calendar time, age, time since the start of follow-up, educational level, and parity adjusted were considered in the multivariate analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1656 and 4291 deaths occurred in the endometriosis and reference cohorts, respectively. A lower all-cause mortality was observed for the endometriosis cohort (adjusted MRR, 0.73 [95% CI 0.69 to 0.77])—there were four deaths less per 1000 women over 10 years. A lower cause-specific mortality contributed to this: the adjusted MRR was 0.88 (95% CI 0.81 to 0.96) for any cancer and 0.55 (95% CI 0.47 to 0.65) for cardiovascular diseases, including 0.52 (95% CI 0.42 to 0.64) for ischemic heart disease and 0.60 (95% CI 0.47 to 0.76) for cerebrovascular disease. Mortality due to alcohol, accidents and violence, respiratory, and digestive disease-related causes was also decreased.

LIMITATIONS, REASONS FOR CAUSATION

These results are limited to women with endometriosis diagnosed by surgery. In addition, the study does not extend into the oldest age groups. The results might be explained by the characteristics and factors related to women’s lifestyle, and/or increased medical attention and care received, rather than the disease itself.

WIDER IMPLICATIONS OF THE FINDINGS

These reassuring data are valuable to women with endometriosis and to their health care providers. Nonetheless, more studies are needed to address the causality.

STUDY FUNDING/COMPETING INTEREST

This research was funded by the Hospital District of Helsinki and Uusimaa and The Finnish Medical Foundation. None of the authors report any competing interest in relation to the present work; all the authors have completed the disclosure form.

Influence of early-life factors on the development of endometriosis

Objective: Our aim was to study the association between early-life factors and the development of endometriosis. Methods: This case-control study included 440 women with surgically confirmed endometriosis (cases) and 880 women without endometriosis (controls). Information on early-life factors was ascertained retrospectively by in-person interviews with participants and their mothers. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between endometriosis and maternal and paternal characteristics and foetal and infant exposures were estimated using unconditional logistic regression, adjusting for frequency matching and confounding variables. Results: We observed that women who were not breastfed as infants had twice the risk of endometriosis compared with women who were breastfed (adjusted OR 2.0; 95% CI 1.6, 4.5). Our data suggested an increased endometriosis risk with neonatal vaginal bleeding (adjusted OR 1.9; 95% CI 1.2, 4.3) and paternal smoking (adjusted OR 1.8; 95% CI 1.1, 4.9). Although the CIs included the null hypothesis value, caesarean section (adjusted OR 1.7; 95% CI 1.0, 3.5) and prematurity (adjusted OR 1.4; 95% CI 0.8, 3.7) were probably associated with the incidence of endometriosis. Conclusions: Some early-life factors including breastfeeding, neonatal vaginal bleeding and paternal smoking were associated with subsequent, surgically confirmed endometriosis in this cohort of Chinese women.

Modifiable life style factors and risk for incident endometriosis

BACKGROUND

Caffeine, alcohol, smoking and physical activity are known to alter sex steroid synthesis, which may affect hormone-dependent gynaecologic disease risk, such as endometriosis; however, few studies have assessed life style factors prior to endometriosis diagnosis.

METHODS

Four hundred and seventy three women, ages 18-44 years, underwent laparoscopy or laparotomy, regardless of clinical indication, at 14 clinic sites, 2007-2009. Women with prior surgically confirmed endometriosis were excluded. Life style factors were assessed prior to surgery. Adjusted risk ratios (RR) of endometriosis by caffeine, alcohol, smoking (serum cotinine), and physical activity were estimated, adjusting for age, marital status, education, race/ethnicity, age at menarche, gravidity, BMI, study site, and other life style factors.

RESULTS

There were no associations between women with endometriosis and alcohol consumption (RR 0.9, 95% CI 0.7, 1.3), caffeine consumption (RR 1.1, 95% CI 0.8, 1.5), or smoking (serum cotinine <10 vs ≥10 ng/mL; RR 1.0, 95% CI 0.7, 1.6). Similar null findings were found between endometriosis and weekly occurrences of physical activity and total walking, moderate, and vigorous activity; a modest trend was found between total daily sitting time and increased endometriosis risk.

CONCLUSIONS

This study, which is unique in its capture of life style exposures prior to incident endometriosis diagnosis, largely found no association between alcohol, caffeine, smoking, and physical activity and risk of endometriosis.

[Specific clinical signs suggestive of endometriosis (excluding adenomyosis) and questionnaires of symptoms, pain and quality of life: CNGOF-HAS Endometriosis Guidelines]

In case of consultation for chronic pelvic pain or suspicion of endometriosis, it is recommended to evaluate the pain (intensity, resonance) and to search out the evocative and localizing symptoms of endometriosis (Grade B). The main symptoms suggestive of endometriosis are: severe dysmenorrhea (NP2), deep dyspareunia (NP2), painful defecation during menstruation (NP2), urinary tract symptoms during menstruation (NP2) and infertility (NP2). In patients with chronic pelvic pain, it is recommended to search deep infiltrating endometriosis in patients with painful defecation during menstruation or severe deep dyspareunia (Grade B). It is recommended to search symptoms suggestive of sensitization in painful patients with endometriosis (Grade B). When suggestive symptoms of endometriosis are present, a directed gynecological examination is recommended, where possible, including examination of the posterior vaginal cul-de-sac (Grade C). In assessing pain intensity or evaluating analgesic effectiveness of a treatment, it is recommended to use a scale to measure the intensity of pain (Grade A). In the management of symptomatic endometriosis, it is recommended to evaluate the quality of life (Grade C).

Variability of genome-wide DNA methylation and mRNA expression profiles in reproductive and endocrine disease related tissues

Genome-wide association studies in the fields of reproductive medicine and endocrinology are yielding robust genetic variants associated with disease. Integrated genomic, transcriptomic, and epigenomic molecular profiling studies are common methodologies used to understand the biologic pathways perturbed by these variants. However, molecular profiling resources do not include the tissue most relevant to many female reproductive traits, the endometrium, while the parameters influencing variability of results from its molecular profiling are unclear. We investigated the sources of DNA methylation and RNA expression profile variability in endometrium (n = 135), endometriotic disease tissue (endometriosis), and subcutaneous abdominal fat samples from 24 women, quantifying between-individual, within-tissue (cellular heterogeneity), and technical variation. DNA samples (n = 96) were analyzed using Illumina HumanMethlylation450 BeadChip arrays; RNA samples (n = 39) were analyzed using H12-expression arrays. Variance-component analyses showed that, for the top 10–50% variable DNA methylation/RNA expression sites, between-individual variation far exceeded within-tissue and technical variation. Menstrual-phase accounted for most variability in methylation/expression patterns in endometrium (P_m = 7.8 × 10⁻³, P_e = 8.4 × 10⁻⁵) but not in fat and endometriotic tissue; age was significantly associated with DNA methylation profile of endometrium (P_m = 9 × 10⁻⁵) and endometriotic disease tissue (P_m = 2.4 × 10⁻⁵); and smoking was significantly associated with DNA methylation in adipose tissue (P_m = 1.8 × 10⁻³). Hierarchical cluster analysis showed significantly different methylation signatures between endometrium and endometriotic tissue enriched for WNT signaling, angiogenesis, cadherin signaling, and gonadotropin-releasing-hormone-receptor pathways. Differential DNA methylation/expression analyses suggested detection of a limited number of sites with large fold changes (FC > 4), but power calculations accounting for different sources of variability showed that for robust detection >500 tissue samples are required. These results enable appropriate study design for large-scale expression and methylation tissue-based profiling relevant to many reproductive and endocrine traits.

Associations between internal exposure levels of persistent organic pollutants in adipose tissue and deep infiltrating endometriosis with or without concurrent ovarian endometrioma

Endometriosis is a gynaecological disease characterized by the presence of ectopic endometrial tissue. Histologically, it appears as different sub-types, being peritoneal endometriosis, ovarian endometrioma (OvE) and deep infiltrating endometriosis (DIE), which are of major relevance due to their varying clinical presentations. A number of persistent organic pollutants (POPs) have been associated with the onset of endometriosis, yet the overall set of existing studies remains fairly divergent. In this preliminary case-control study we aimed to assess the potential associations between the internal exposure to POPs and the presence of DIE with or without concurrent OvE. Adipose tissue and serum samples were collected from surgically confirmed cases (n=55) and controls (n=44) enrolled during 2013 and 2015 in Pays de la Loire, France. Targeted pollutants (76 historical or more emerging POPs including dioxins, polychlorobiphenyls (PCB), polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), hexabromocyclododecanes (HBCDs) and organochlorine pesticides (OCPs) were quantified by chromatography coupled to mass spectrometry. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated from unconditional logistic regression adjusted for known confounding variables. The results showed significant associations between DIE and adipose tissue levels of 1.2.3.7.8 - PeCDD, OCDF, PCB 105, 114, 118 and 123, PBDE 183, PBB 153, and several OCPs including trans‑nonachlor, cis‑heptachlor epoxide, dieldrin, β-hexachlorocyclohexane and hexachlorobenzene. The largest associations were observed for OCDF followed by cis‑heptachlor epoxide, exhibiting adjusted ORs (95% CI) of 5.42 (2.73-12.85) and 5.36 (2.44-14.84) per 1-SD increase, respectively. The stratified analysis comparing both disease sub-types suggested that adipose tissue exposure markers may be more associated with DIE concurrent with OvE, however these results need to be confirmed in a larger population.