Global, regional, and national endometriosis trends from 1990 to 2017

New Potential Pharmacological Options for Endometriosis Associated Pain

Endometriosis is a chronic inflammatory disorder characterized by the abnormal growth of endometrial-like tissue outside the uterine cavity, affecting 10-15% of women of reproductive age. Pain is the most common symptom. Treatment options include surgery, which has limited effectiveness and high recurrence rates, and pharmacotherapy. Hormonal therapies, commonly used for symptom management, can have side effects and contraceptive outcomes, contributing to the infertility associated with endometriosis, with pain and lesions often reappearing after treatment cessation. Among its etiological factors, immunological and inflammatory dysregulation plays a significant role, representing an interesting target for developing new therapeutic strategies. This review critically analyzes recent studies to provide an updated synthesis of ongoing research into potential new pharmacotherapies focusing on lesion progression, pain relief, and improving quality of life. Immunotherapy, natural anti-inflammatory and antioxidant compounds and drug repurposing show promise in addressing the limitations of current treatments by targeting immunological factors, potentially offering non-invasive solutions for managing pain and infertility in endometriosis. Promising results have been obtained from in vitro and animal model studies, but clinical trials are still limited. More effort is needed to translate these findings into clinical practice to effectively reduce disease progression, alleviate pain symptoms and preserve the reproductive capacity, improving patients' overall wellbeing.

Global, regional, and national burden of premenstrual syndrome, 1990-2019: an analysis based on the Global Burden of Disease Study 2019

STUDY QUESTION

What is the burden of premenstrual syndrome (PMS) at the global, regional, and national levels across 21 regions and 204 countries and territories?

SUMMARY ANSWER

Over the past few decades, the global prevalent cases of PMS have grown significantly from 652.5 million in 1990 to 956.0 million in 2019, representing a 46.5% increase.

WHAT IS KNOWN ALREADY

PMS, which affects almost half of reproductive women worldwide, has substantial social, occupational, academic, and psychological effects on women's lives. However, no comprehensive and detailed epidemiological estimates of PMS by age and socio-demographic index (SDI) at global, regional, and national levels have been reported.

STUDY DESIGN, SIZE, DURATION

An age- and SDI-stratified systematic analysis of the prevalence and years lived with disability (YLD) of PMS by age and SDI across 21 regions and 204 countries and territories has been performed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The prevalence and YLD of PMS from 1990 to 2019 were retrieved directly from the Global Burden of Diseases (GBD) 2019 study. The number, rates per 100 000 persons, and average annual percentage changes (AAPCs) of prevalence and YLD were estimated at the global, regional, and national levels.

MAIN RESULTS AND THE ROLE OF CHANCE

Globally, the prevalent cases of PMS increased by 46.5% from 652.5 million in 1990 to 956.0 million in 2019; in contrast, however, the age-standardized prevalence rate was approximately stable at 24 431.15/100 000 persons in 1990 and 24 406.51/100 000 persons in 2019 (AAPC, 0[95% CI: -0.01 to 0.01]). Globally, the YLD was 8.0 million in 2019 and 5.4 million in 1990, with a sizable increase over the past 30 years. The age-standardized YLD rate was stable (AAPC 0.01, P = 0.182), at 203.45/100 000 persons in 1990 and 203.76/100 000 persons in 2019. The age-standardized burden estimates were the highest in the low-middle SDI regions and the lowest in the high SDI regions. Peaks in burden rate estimates were all observed in the 40-44 years age group. Regional age-standardized burden estimates were the highest in South Asia and the lowest in Western Sub-Saharan Africa. The national age-standardized burden estimates were the highest in Pakistan and the lowest in Niger.

LIMITATIONS, REASONS FOR CAUTION

The accuracy of the results depended on the quality and quantity of the GBD 2019 data. Fortunately, the GBD study endeavoured to retrieve data globally and applied multiple models to optimize the completeness, accuracy, and reliability of the data. In addition, the GBD study took the country as its basic unit and neglected the influence of race. Further study is warranted to compare differences in PMS burden associated with race. Finally, no data are available on the aetiology and risk information related to PMS, which might help us to better understand the trends and age distribution of PMS and help local governments formulate more detailed policies and comprehensive interventions.

WIDER IMPLICATIONS OF THE FINDINGS

Although the age-standardized prevalence/YLD rate has been stable over the past 30 years, the absolute number of prevalent cases and YLD grew significantly worldwide from 1990 to 2019. Public health-related policies should be implemented to reduce the prevalence and alleviate the symptoms of PMS. Lifestyle changes and cognitive-behavioral therapy are critical in helping to reduce the burden of PMS.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Key Research and Development Program of China (grant number 2022YFC2704100) and the National Natural Science Foundation of China (No. 82001498, No. 82371648). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Development of an Italian National Epidemiological Register on Endometriosis Based on Administrative Data

Background/Objectives: Endometriosis is a female chronic inflammatory disease in which endometrial tissue develops outside the uterine cavity. It is a complex pathology, which significantly contributes to morbidity in premenopausal women, leading to chronic pain, infertility, and subfertility negatively impacting physical and emotional well-being and the overall quality of life. The public health burden of endometriosis remains elusive and challenging to determine, and this uncertainty can lead to inadequate healthcare services and treatments. The objective was to estimate the incidence and prevalence of endometriosis in Italy using the hospital discharge records database via a population-based retrospective study, nationwide between 2011 and 2020. Methods: From the National Hospital Discharge Database, we selected all admissions with a diagnosis of endometriosis (ICD-9-CM, codes 617.x), supported by the presence of a procedure code of laparoscopy or any other surgical procedure allowing for direct visualisation of the lesions. The main outcomes measured: incidence and prevalence of endometriosis were estimated for the entire 2011-2020 period and by individual year, analysing the time trend and variability in different geographical areas of Italy. Results: There were a total of 134,667,646 women aged 15-50 years with one or more hospitalisations for endometriosis in all Italian hospitals. The incidence of endometriosis in Italy during this period was 0.839 per 1000 women (CI95% 0.834-0.844), exhibiting a statistically significant decreasing trend over the years. A discernible north-south gradient was observed, with higher rates documented in the northern regions. The prevalence rate stood at 14.0 per 1000 during the same period, and a similar north-south geographical gradient was identifiable in the prevalence rates as well. Conclusions: The utilization of national-level hospital data enables the generation of incidence and prevalence data for endometriosis without variations in methods and definitions, facilitating the evaluation of temporal trends and regional comparisons. Understanding and quantifying this phenomenon is essential for appropriate healthcare planning in various Italian regions.

Beyond physical pain: A large-scale cohort study on endometriosis trends and mental health correlates

BACKGROUND

This study investigates the increased prevalence of endometriosis in Israel and its association with psychiatric comorbidities, focusing on the timing of psychiatric diagnoses in relation to endometriosis diagnosis.

METHODS

Employing a retrospective cohort analysis, we reviewed data from 1,291,963 patients in a large scale medical database, identifying 24,259 cases (1.88%) of endometriosis. The analysis included demographic details, ICD-10 diagnoses of endometriosis and mental health conditions, and medication use patterns.

RESULTS

A marked rise in endometriosis diagnosis was observed, particularly among women born between 1973 and 1978. Those with endometriosis were more likely to have psychiatric disorders-such as mood disorders, anxiety, PTSD, and eating disorders-than the control group, with the majority of psychiatric diagnoses occurring prior to endometriosis detection, except for PTSD. The study also highlighted significant sociocultural and socioeconomic disparities in endometriosis diagnosis, suggesting barriers to healthcare access and the influence of cultural factors. Limitations include potential biases from the retrospective design and the specific context of Israel's healthcare system, which may limit generalizability.

CONCLUSIONS

The significant rise in endometriosis and its strong association with psychiatric comorbidities, predominantly preceding the diagnosis of endometriosis, underscores the necessity for integrated care approaches. The disparities in diagnosis rates call for culturally sensitive healthcare practices and early psychiatric interventions.

Diet associations in endometriosis: a critical narrative assessment with special reference to gluten

Endometriosis is characterized by the presence of endometrium-like tissue outside the uterus. The etiology remains largely unknown. Despite adequate treatment, patients can still experience symptoms or side effects resulting in therapy incompliance and in self-management strategies such as dietary measures is increasing. A gluten free diet is thought to be contributory in reducing endometriosis-related pain, thereby optimizing quality of life. However, data is conflicting and currently provides no evidence for causality. This narrative review aims to put the effect of dietary self-management strategies on endometriosis in a balanced perspective, especially the effect of gluten and a gluten free diet. Several studies have found a strong overlap in symptoms, metabolic and immune responses associated with endometriosis and those associated with celiac disease, ulcerative colitis, Crohn's disease, irritable bowel syndrome and non-celiac wheat sensitivity. However, it remains unclear whether these diseases and/or disorders are causal to an increased risk of endometriosis. Some studies have found a positive effect on the risk of endometriosis, endometriosis-related symptoms and quality of life (QoL) when women either avoided certain nutrients or foods, or applied a specific nutrient supplementation. This includes the avoidance of red meat and omega-3, an increasing intake of foods rich in anti-oxidants, micronutrients and dietary fibers (e.g., fruit, vegetables) and the appliance of a gluten free diet. However, data from the available studies were generally graded of low quality and it was noted that placebo and/or nocebo effects influenced the reported positive effects. In addition, such effects were no longer seen when adjusting for confounders such as overweight, when a translation was made from in vitro to in vivo, or when the nutrients were not supplemented as isolated sources but as part of a mixed daily diet. Finally, some studies showed that long-term adherence to a gluten free diet is often associated with an impaired diet quality and nutrient intake, leading to negative health outcomes and reduced QoL. Concluding, scientific evidence on the efficacy of dietary interventions on well-defined clinical endpoints of endometriosis is lacking and recommending a gluten free diet to women solely diagnosed with endometriosis should therefore not be advised.

Spatiotemporal Trends and Age-Period-Cohort Analysis for the Burden of Endometriosis-Related Infertility: An Analysis of the Global Burden of Disease Study 2019

BACKGROUND

Endometriosis is a common nonfatal gynecological disease, and infertility is one of its main dangers. Endometriosis-related infertility causes serious damage to women's health and places a burden on women of reproductive age. The aim of this study was to describe the current burden of endometriosis-associated infertility and to analyze its spatiotemporal trends.

METHODS

Age-standardized prevalence rate (ASPR) data from 1990 to 2019 for Endometriosis-related primary infertility (ERPI) and secondary infertility (ERSI) were obtained from the Global Burden of Disease Study (GBD) 2019. These data spanning three decades cover the global, sociodemographic index (SDI) regions, GBD regions, and 204 countries and territories. Spatiotemporal trends were analyzed by calculating the estimated annual percentage change (EAPC) and using a time-period-cohort model.

RESULTS

Globally, the ASPR of ERPI and ERSI showed a weak downward trend from 1990 to 2019, with EAPCs of -1.25 (95% CI: -1.39 to -1.11) and -0.6 (95% CI: -0.67 to -0.53), respectively. The spatiotemporal trends in ERPI and ERSI varied substantially between regions and age groups. When endometriosis-related infertility burden was linked to SDI values, a strong negative correlation was observed between the ASPR of ERSI and its EAPC and SDI values. When modeling with age-period-cohort, ERPI burden was found to be highest at ages 20-25 years, while ERSI burden was persistently higher at ages 20-45 years. Using 2000-2004 as the reference period, both ERPI and ERSI burden decreased with each year among women. Significant variability in burden between regions was found for the birth cohort factor.

CONCLUSIONS

The global burden of endometriosis-related infertility declined minimally from 1990 to 2019. However, this burden varied considerably across regions, age groups, periods, and birth cohorts. The results of this study reflect spatiotemporal trends in the burden of endometriosis-related infertility over the study period and may be used to help improve health management, develop timely and effective prevention and control strategies, and provide epidemiologic theoretical evidence for reducing the burden for endometriosis-related infertility.

An Appraisal of the Tissue Injury and Repair (TIAR) Theory on the Pathogenesis of Endometriosis and Adenomyosis

As understanding their pathogenesis remains elusive, both endometriosis and adenomyosis are often referred to as "enigmatic diseases". The uncertainty and heightened interest are reflected in the range of expressed views and opinions. There is a sense of urgency because of the entailed patient suffering. The plethora of opinions calls for a critical analysis of proposed theories, both old and new. A series of papers published since 2009 proposed that both endometriosis and adenomyosis originate from the same aberrations occurring within the uterus. This came to be recognized as the tissue injury and repair theory, and the newly coined term "archimetrosis" posits that the two diseases share the same origin. While the theory opens an interesting channel for exploration, its claim as a unifying theory necessitates a critical appraisal. We, thus, undertook this review of the theory and analyzed its underpinnings based on a comprehensive review of the literature. Our appraisal indicates that the theory is open to a range of criticisms. Chief among these is the need for confirmatory evidence of features of abnormal uterine contractility and the lack of data addressing the question of causality. In addition, the theory has, as yet, no supporting epidemiological evidence, which is a major weakness. The theory suffers as it is not open to the test of falsifiability, and it lacks the ability to make useful predictions. It has not addressed the questions, such as why only a small percentage of women develop adenomyosis or endometriosis, given the ubiquity of uterine peristalsis. On the other hand, the triggers and prevention of hyper- or dys-peristalsis become critical to a theory of causation. We conclude that additional supportive evidence is required for the theory to be accepted.

MiR-518c-3p alleviates endometriosis by inhibiting ectopic endometrial migration and epithelial-mesenchymal transition via targeting ZNF608

PURPOSE

The present study was performed to clarify the regulatory mechanism of miR-518c-3p in the progression of endometriosis (EMs).

METHODS

MicroRNAs (miRNAs) potentially acting on EMs were predicted by bioinformatics databases and validated in normal and ectopic endometrium. The miR-518c-3p mimics were transfected into endometrial stromal cells (ESCs), and cell growth, death, and proliferation marker proteins expression were detected. The targeting relationship of miR-518c-3p with zinc finger protein 608 (ZNF608) was validated by luciferase reporter assay. ESCs were incubated with miR-518c-3p mimics alone or co-transfected with pcDNA-ZNF608, and growth, death, as well as proliferation and epithelial-mesenchymal transition (EMT) marker protein expression were detected. A rat model of EMs overexpressing miR-518c-3p alone or ZNF608 simultaneously was constructed to detect ectopic endometrial cell apoptosis and cyst volume in rats.

RESULTS

MiR-518c-3p expression was downregulated in ectopic endometrium. MiR-518c-3p mimic inhibited migration, invasion and proliferation of ESCs, and promoted apoptosis. MiR-518c-3p targeted the 3'UTR of ZNF608. ZNF608 expression was upregulated in ESCs and ectopic endometrium, and the regulatory effect of pcDNA-ZNF608 on ESCs was opposite to that of miR-518c-3p mimics. ZNF608 overexpressing rats had greater endometrial cyst weight and volume, and decreased endometrial apoptosis compared with miR-518c-3p overexpressing alone.

CONCLUSION

MiR-518c-3p inhibited growth, metastasis and EMT of ESCs and decreased ectopic endometrial area in rats with EMs by targeting ZNF608.

Tissue Engineering in Gynecology

Female gynecological organ dysfunction can cause infertility and psychological distress, decreasing the quality of life of affected women. Incidence is constantly increasing due to growing rates of cancer and increase of childbearing age in the developed world. Current treatments are often unable to restore organ function, and occasionally are the cause of female infertility. Alternative treatment options are currently being developed in order to face the inadequacy of current practices. In this review, pathologies and current treatments of gynecological organs (ovaries, uterus, and vagina) are described. State-of-the-art of tissue engineering alternatives to common practices are evaluated with a focus on in vivo models. Tissue engineering is an ever-expanding field, integrating various domains of modern science to create sophisticated tissue substitutes in the hope of repairing or replacing dysfunctional organs using autologous cells. Its application to gynecology has the potential of restoring female fertility and sexual wellbeing.

Hyaluronic Acid-Modified Nanoplatforms as a Vector for Targeted Delivery of Autophagy-Related Gene to the Endometriotic Lesions in Mice

This investigation probed endometriosis treatment using targeted nanoparticles (NPs) to modulate autophagic activity. To that end, a novel form of polymer-based NP gene delivery platform consisting of polyethyleneimine (PEI) conjugated to stearic acid (SA) and nucleotides (DNA/siRNAs) and enclosed by hyaluronic acid (HA) was prepared. CD44 is highly upregulated in cystic lesions, and HA–CD44 binding in this specific nanoplatform was used to achieve targeted drug delivery to CD44-expression endometriotic tissues. The expression of autophagy-related genes was modulated to explore the importance of this process in the development of endometriosis. By inducing autophagic activity, we were able to reduce the size of endometriotic cysts and suppress the development of ectopic endometrium. To further confirm the relationship between autophagic activity and this disease in humans and animals, numbers of autophagic vesicles and autophagic protein expression were assessed in lesion tissue samples from patients, revealing there may be consistency between animal and human data. Overall, these data revealed the ability of this (PEI–SA/DNA) HA gene delivery system to regulate autophagic activity and, thereby, aid in the treatment of endometriosis.

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.

Long-term trends in the incidence of endometriosis in China from 1990 to 2019: a joinpoint and age-period-cohort analysis

BACKGROUND

Trends in the incidence of endometriosis in China remain unknown. The purpose of this study was to examine the trends in the incidence of endometriosis and the effects of age, period, and cohort on them.

METHODS

Trends in endometriosis incidence were estimated using joinpoint regression. Age-period-cohort analysis was used to analyze the effects of age, period, and cohort on these trends. Endometriosis incidences in China (1990-2019) were retrieved from the Global Burden of Disease Study 2019. Annual percentage change and average annual percent change (AAPC) were analyzed by joinpoint regression, and relative risks were analyzed using an age-period-cohort model.

RESULTS

Age-standardized incidence rates (ASIRs) declined between 1990 and 2019 in China, with an overall AAPC of -1.2% (95% CI: -1.20, -1.10). Compared to 1990, the ASIR in 2019 decreased by almost 30%. Moreover, the joinpoint regression analysis revealed that endometriosis ASIRs showed a downward trend across all age groups. A significant age-related effect was seen for endometriosis incidence among young women aged 15-24 years, which then decreased with advancing age. Consistently, the effect of the period on endometriosis incidence showed a declining trend, and the effect of birth cohort decreased by 0.53 (42.7%) from 1938-1942 to 1998-2002.

CONCLUSIONS

Endometriosis ASIRs declined from 1990 to 2019. The effects of period and birth cohort on endometriosis incidence exhibited a declining trend across all age groups. The effect of age on endometriosis incidence showed an increasing trend before the age of 24, followed by a decreasing trend with subsequent advancing age.

Systematic Review and Meta-Analysis of Incidence and Prevalence of Endometriosis

There is still much controversy regarding the epidemiology of endometriosis. The objective of this work is to conduct a systematic review, and if possible, proceed with a meta-analysis of studies that have analyzed the incidence and prevalence of this condition among women in the general population. The inclusion criteria were papers published after 1997 that had reported data of the incidence or prevalence of endometriosis. The PubMed search engine was used to identify papers meeting the inclusion criteria from 1997 to 2019, with an additional manual search for the identification of potentially eligible studies. The search was limited to papers published in English. The risk of bias was assessed according to the Joanna Briggs Institute Critical Appraisal Checklist. As a result, 27 papers, which included a total of 28,660,652 women, were classified according to the type of design and sources of information in five subgroups. Pooled estimates of prevalence for studies with self-reported data were 0.05 (95% CI: 0.03; 0.06), 0.01 for population-based integrated information systems (95% CI: 0.01; 0.02), and 0.04 (95% CI 0.04; 0.05) in studies using other designs. The pooled incidence rate of endometriosis was: 1.36 per 1000 person-years (PY) (95% CI: 1.09; 1.63) for studies based on hospital discharges, 3.53 per 1000 PY (95% CI: 2.06; 4.99) for cohort studies, and 1.89 per 1000 PY (95% CI: 1.42; 2.37) for population-based integrated information systems. Meta-analysis indicated high heterogeneity based on I-squared statistics. This significant variability may not only be due to methodological issues and the specific limitations of the different designs and data analyzed, including case definitions and subject selection strategies, but also to the inherent heterogeneity of endometriosis. Epidemiological studies with appropriate study designs remain necessary to provide a valid estimation of the population burden of endometriosis.