Arterial stiffness is increased in young women with endometriosis

Endometriosis and cardiovascular disease: A systematic review and meta-analysis

OBJECTIVES

Endometriosis is a benign, estrogen-dependent, chronic inflammatory disease and is the commonest cause of chronic pelvic pain in younger women. Cardiovascular disease is the main cause of death worldwide. Because the relationship between endometriosis and CV disease is not well established, we performed a systematic review of longitudinal studies that assessed the occurrence of cardiovascular events in women with endometriosis compared to those without endometriosis.

STUDY DESIGN

Systematic review with meta-analysis of longitudinal cohort/nested case-control studies with endometriosis patients and controls. A search was conducted of the MEDLINE, CENTRAL, and Embase databases from inception to November 2022. Random-effects meta-analysis was performed to estimate pooled hazard ratios (HR) and 95 % confidence intervals (95%CI).

MAIN OUTCOME MEASURE

Cardiovascular outcomes such as ischemic heart disease and cerebrovascular disease.

RESULTS

Six cohort studies were included, with a total of 254,929 participants. Meta-analysis showed that endometriosis was associated with a significantly increased risk of ischemic heart disease (HR 1.50, 95%CI 1.37-1.65; I² = 0 %) and cerebrovascular disease (HR 1.17, 95%CI 1.07-1.29; I² = 0 %). The one study that examined the relationship between cardiovascular mortality and endometriosis found a decreased risk in women with endometriosis relative to women without endometriosis (HR 0.55 (95%CI 0.47-0.65)).

CONCLUSIONS

Endometriosis is associated with a significantly increased risk of cardiovascular disease, namely ischemic heart disease and cerebrovascular disease. Further studies are required to determine if endometriosis and/or its treatments are risk factors (particularly for cardiovascular mortality), and whether preventive measures could reduce the burden of cardiovascular disease in women with endometriosis. Study protocol registered at PROSPERO: CRD42022298830.

Evaluation of atherosclerosis-related biomarkers during perimenopause: A prospective cohort study in women with endometriosis

AIM

Endometriosis is linked to asymptomatic atherosclerosis and increases the risk of cardiovascular disease (CVD). Vascular function tests are used to assess atherosclerosis, an important indicator of CVD development. In this study, we aimed to evaluate atherosclerosis-related biomarkers, such as vascular function tests and laboratory data, in perimenopausal women with endometriosis.

METHODS

This prospective cohort study enrolled 207 women (≥40 years old) with endometriosis. Laboratory data, ankle brachial index (ABI), and cardio-ankle vascular index (CAVI) were evaluated.

RESULTS

The mean age, CAVI, and ABI of the participants at the initial examination were 45.02 years, 6.9 ± 0.6, and 1.07 ± 0.06, respectively. In multiple regression analysis, no factor was associated with CAVI, but ABI was significantly correlated with elevated total cholesterol (TC), low-density lipoprotein cholesterol, and estradiol (partial regression coefficient [β] = -0.00074, p = 0.017; β = -0.00075, p = 0.033; and β = -0.00022, p = 0.015, respectively). The annual rate of change in CAVI showed a positive correlation with TC and pentosidine and a negative correlation with history of hormone therapy. Neither correlation was strong. In a comparison of three groups classified by the annual rate of change in CAVI, the group with the severe change had a higher level of pentosidine. In adjusted multinomial logistic regression analysis, high pentosidine levels were a risk factor for increased rate of change in CAVI.

CONCLUSIONS

The association between CAVI and serum markers related to lipid metabolism and ovarian function was mild. Longitudinal analysis of CAVI showed an association with pentosidine, which may be helpful in assessing atherosclerosis risk in women with endometriosis during perimenopause.

Endometriosis promotes atherosclerosis in a murine model

BACKGROUND

Epidemiologic studies have demonstrated an association between endometriosis and the subsequent development of cardiovascular disease. The direct effect of endometriosis on the progression of atherosclerotic, if any, has not been previously characterized. Endometriosis leads to systemic inflammation that could have consequences for cardiovascular health. Here, we reported the effects of endometriosis on the development of atherosclerosis in a murine model.

OBJECTIVE

This study aimed to determine the contribution of endometriosis in promoting cardiovascular disease in a murine model of endometriosis.

STUDY DESIGN

Endometriosis was induced in 18 apolipoprotein E-null mice, the standard murine model used to study atherosclerosis. Mice of the same strain were used as controls (n=18) and underwent sham surgery without inducing endometriosis. The formation of endometriotic lesions was confirmed after 25 weeks of induction. Atherosclerotic lesions were subjected to hematoxylin and eosin staining followed by measurement of the aortic root luminal area and wall thickness. The whole aorta was isolated, and Oil Red O staining was performed to quantify the lipid deposits or plaque formation; moreover, biochemical assays were carried out in serum to determine the levels of lipids and inflammatory-related cytokines.

RESULTS

Apolipoprotein E mice with endometriosis exhibited increased aortic atherosclerosis compared with controls as measured using Oil Red O staining (7.9% vs 3.1%, respectively; P=.0004). Mice with endometriosis showed a significant 50% decrease in the aortic luminal area compared with sham mice (0.85 mm² vs 1.46 mm²; P=.03) and a significant increase in aortic root wall thickness (0.22 mm vs 0.15 mm; P=.04). There was no difference in the lipoprotein profile (P<.05) between mice with endometriosis and sham mice. The serum levels of inflammatory cytokines interleukin 1 alpha, interleukin 6, interferon gamma, and vascular endothelial growth factor were significantly (P<.05)increased in the endometriosis mice.

CONCLUSION

Our study used a murine model to determine the effect of endometriosis on atherosclerosis. Inflammation-related cytokines interleukin 1 alpha, interleukin 6, interferon gamma, and vascular endothelial growth factor (angiogenic factor) released by endometriotic lesions may contribute to the increased cardiovascular risks in women with endometriosis. To reduce the risk of cardiovascular disease, early identification and treatment of endometriosis are essential. Future treatments targeting inflammatory cytokines may help reduce the long-term risk of cardiovascular disease in women with endometriosis.

Reduced cardiovascular risks in women with endometriosis or polycystic ovary syndrome carrying a common functional IGF1R variant

STUDY QUESTION

Is the increased future cardiovascular risk seen in women with endometriosis or polycystic ovary syndrome (PCOS) mitigated by functional insulin-like growth factor-1 receptor (IGF1R) single-nucleotide polymorphism (SNP) rs2016347 as previously shown in women with hypertensive disorders of pregnancy?

SUMMARY ANSWER

This cohort study found that women with endometriosis or PCOS who carry a T allele of IGF1R SNP rs2016347 had a reduced future risk of developing cardiovascular disease (CVD) and associated risk factors, with risk reduction dependent on cohort era.

WHAT IS KNOWN ALREADY

Women with endometriosis or PCOS have been shown to have an increased future risk of CVD and associated risk factors with limited predictive ability.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study took place in the Nurses' Health Study 2 (NHS2), which enrolled 116 430 participants in 1989 who were followed through 2015. The study population was analyzed in its entirety, and subdivided into entry (pre-1989) and after entry (post-1989) exposure cohorts. All NHS2 participants were eligible for inclusion in the study, 9599 (8.2%) were excluded for missing covariates.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The NHS2 enrolled female registered nurses from 14 different states who ranged in age from 25 to 42 years at study entry. Data were collected from entry and biennial questionnaires, and analysis conducted from November 2020 to June 2021. Cox proportional hazard models were used to assess risk of CVD, hypertension (HTN), hypercholesterolemia (HC) and type 2 diabetes, both with and without genotyping for rs2016347.

MAIN RESULTS AND THE ROLE OF CHANCE

While women without endometriosis or PCOS, as a whole, demonstrated no impact of genotype on risk in either cohort, women with endometriosis carrying a T allele had a lower risk of CVD (hazard ratio (HR), 0.48; 95% CI, 0.27-0.86, P = 0.02) and HTN (HR, 0.80; 95% CI, 0.66-0.97, P = 0.03) in the pre-1989 cohort, while those in the post-1989 cohort had a decrease in risk for HC (HR, 0.76; 95% CI, 0.62-0.94, P = 0.01). Women with PCOS in the post-1989 cohort showed a significant protective impact of the T allele on HTN (HR, 0.44; 95% CI, 0.27-0.73, P = 0.002) and HC (HR, 0.62; 95% CI, 0.40-0.95, P = 0.03).

LIMITATIONS, REASONS FOR CAUTION

Data on specific endometriosis lesion locations or disease stage, as well as on PCOS phenotypes were lacking. In addition, data on systemic medical treatments beyond the use of oral contraceptives were missing, and these treatments may have confounded the results.

WIDER IMPLICATIONS OF THE FINDINGS

These findings implicate systemic dysregulation of the insulin-like growth factor-1 axis in the development of HTN, HC and clinical CVD in endometriosis and PCOS, suggesting a common underlying pathogenetic mechanism.

STUDY FUNDING/COMPETING INTEREST(S)

The NHS2 infrastructure for questionnaire data collection was supported by National Institute of Health (NIH) grant U01CA176726. This work was also supported in part by NIH and National Cancer Institute grant U24CA210990; as well, research effort and publication costs were supported by the Elizabeth MA Stevens donor funds provided to the Buck Institute for Research on Aging. The authors declare they have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Endometriosis and Impaired Placentation: A Prospective Cohort Study Comparing Uterine Arteries Doppler Pulsatility Index in Pregnancies of Patients with and without Moderate-Severe Disease

The aim of this study was to evaluate if moderate-severe endometriosis impairs uterine arteries pulsatility index (UtA-PI) during pregnancy when compared to unaffected controls. In this prospective cohort study, pregnant women with stage III–IV endometriosis according to the revised American Fertility Society (r-AFS) classification were matched for body mass index and parity in a 1:2 ratio with unaffected controls. UtA-PIs were assessed at 11–14, 19–22 and 26–34 weeks of gestation following major reference guidelines. A General Linear Model (GLM) was implemented to evaluate the association between endometriosis and UtA-PI Z-scores. Significantly higher third trimester UtA-PI Z-scores were observed in patients with r-AFS stage III–IV endometriosis when compared to controls (p = 0.024). In the GLM, endometriosis (p = 0.026) and maternal age (p = 0.007) were associated with increased third trimester UtA-PI Z-scores, whereas conception by in-vitro fertilization with frozen-thawed embryo transfer significantly decreased UtA-PI measures (p = 0.011). According to these results, r-AFS stage III–IV endometriosis is associated with a clinically measurable impaired late placental perfusion. Closer follow-up may be recommended in pregnant patients affected by moderate-severe endometriosis in order to attempt prediction and prevention of adverse pregnancy and perinatal outcomes due to a defective late placental perfusion.

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.

Endometriosis Is Associated with an Increased Risk of Coronary Artery Disease in Asian Women

Endometriosis is a common systemic chronic inflammatory disease. Inflammation is the key mechanism responsible for the development of endothelial dysfunction and atherosclerosis. We aimed to investigate the risk of coronary artery disease (CAD) among Asian women with endometriosis. This retrospective population-based cohort study included patients with endometriosis diagnosed from 2000 to 2012 and registered in the Longitudinal Health Insurance Database, Taiwan. The comparison cohort (those without endometriosis) were selected (1:4) by matching the age frequency and the index year. We followed up the patients until the diagnosis of CAD (ICD-9-CM codes: 410-414, A270, and A279), withdrawal from the National Health Insurance system, death, or the end of the study. We used a multivariable-adjusted Cox proportional hazard model for evaluating the risk of CAD. We included 19,454 patients with endometriosis and 77,816 women as a comparison group. The mean age of the women at the diagnosis of endometriosis was 37.4 years. A total of 3245 women developed CAD in both groups during a median follow-up of 7 years. The incidence of CAD was higher in women with endometriosis than in those without (5.96 vs. 4.38 per 10,000 person-years; adjusted hazard ratio [95% confidence interval], 1.34 [1.22-1.47]). In conclusion, Asian women with endometriosis had a significantly higher risk of CAD. Further large-scale studies are needed to elucidate the cause-effect relationship between endometriosis and CAD.

Long-term Health Consequences of Endometriosis - Pathways and Mediation by Treatment

Purpose of review

The purpose of this review is to discuss the most up to date research on endometriosis and chronic disease risk, highlighting the role treatments for endometriosis may play in these associations.

Recent findings

Previous studies have shown a consistent association between endometriosis and risk for epithelial ovarian cancer but the association with other cancers is less clear. Current research indicates that endometriosis may in be associated with risk of systemic lupus erythematosus, and potentially other autoimmune diseases. Limited evidence is also present for the association between endometriosis and cardiovascular disease and related conditions (e.g,. hypertension, hypercholesterolemia). A potential explanation for a portion of the increased risk of chronic diseases among women with endometriosis may relate to treatments for endometriosis impacting these outcomes.

Summary

Given the prevalence of endometriosis, understanding the relation between endometriosis and other chronic diseases has the potential to impact the health of many women. However, few high-quality studies with limited biases and adequate follow-up currently exist. Future multi-disciplinary research in prospective cohorts, with ample follow-up time, and detailed information on endometriosis characteristics and treatment is critical to advancing our understanding of this disease and its consequences.

Endometriosis: The Role of Iron Overload and Ferroptosis

Iron is an essential element for cell survival, and iron deficiency is a known risk factor for many reproductive disorders. Paradoxically, such disorders are also seen more commonly under conditions of iron excess. Here, we focus on the problem of iron overload in women's health, using endometriosis as a model system. We propose (i) that a primary defect in endometriosis is abnormal eutopic endometrium characterized by resistance to ferroptosis, a process of iron-mediated non-apoptotic programmed cell death, which allows cells spread via retrograde menstruation to survive, implant, and establish endometriotic lesions within the abdominal cavity, and (ii) that dysregulated iron homeostasis may be critical to the subsequent pathophysiology of endometriotic lesions with localized iron overload and inflammation. We further investigate the association between endometriosis and hypercholesterolemia and suggest that an interaction between the mevalonate cholesterol biosynthetic pathway and ferroptosis signaling may provide a molecular basis to explain how it is that, in some women, endometrial tissues survive and thrive under ferroptotic pressure, colonize at ectopic sites, and expand into endometriotic lesions.

Atherosclerotic cardiovascular disease in women with endometriosis: a systematic review of risk factors and prospects for early surveillance

Endometriosis and atherosclerotic cardiovascular disease (ASCVD) share similar pathogenic mechanisms. Hence, this systematic review evaluates the association between endometriosis and lifetime ASCVD risk including co-prevalence with dyslipidaemia, atherosclerosis and non-invasive markers of endothelial dysfunction. The electronic databases Embase, PubMed, MEDLINE, Cochrane Register of Trials and ClinicalTrials.gov were systematically searched for relevant articles. Two prospective cohort studies demonstrated an increased lifetime ASCVD risk after controlling for demographic and lifestyle confounders in women with endometriosis, as measured by higher incidence of myocardial infarction (relative risk [RR] 1.52), angiography-confirmed angina (RR 1.91), or requiring coronary artery bypass graft surgery (RR 1.35). Among 10 studies that included 407 patients with surgically proven endometriosis and 557 controls, RR of developing hypercholesterolemia and hypertension were 1.25 and 1.14, respectively, while higher serum lipoprotein a and lower paraoxonase 1 levels were found in women with endometriosis that was negatively correlated with stage of disease (r = -0.74, P < 0.0001). Hence, currently available evidence suggests that women with endometriosis are at higher lifetime risk of developing ASCVD than women without endometriosis. However, robust causal evidence is still lacking and future studies are needed to determine whether women with endometriosis represent a high-risk population for lifelong ASCVD risk.

Sex differences in mechanisms of arterial stiffness

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Infertility: a marker of future health risk in women?

Infertility, may be a harbinger for future health risk in women, including early mortality. Fertility status itself could serve as an early biomarker, (present in a woman's reproductive years) for risk stratification later in life. The relationship between infertility and early mortality involves the impact of nulliparity on future adverse health events, potential sequelae from the underlying cause(s) of infertility, the risks of fertility treatments, as well as the potential for risk reduction from a healthy pregnancy. This complex interplay coupled with difficulties ascertaining infertility on a population level has presented unique challenges to assessing infertility and early mortality risk. With further study, a better understanding the role of fertility status in health at various stages of life may provide unique opportunities for surveillance and risk reduction.

The complex relationship between body mass index and endometriosis

There is an inverse relationship between endometriosis and a women’s body mass index. To date, the precise mechanisms and aetiological basis linking body mass index with endometriosis remain unknown. Although an increased incidence of endometriosis is observed in women with low body mass indices; endometriosis is associated with conditions common to obesity (hypercholesterolemia, hypertension and coronary heart disease). In the context of endometriosis, further research is necessary in women with surgically confirmed disease to improve clinical advice and patient outcomes.

The association of body mass index with endometriosis and disease severity in women with pain

Introduction:

There is a well-established inverse relationship between body mass index and frequency of endometriosis. However, these population-based studies have relied mostly on self-reported cases of endometriosis, rather than surgically confirmed endometriosis where disease severity has been objectively assessed. The aim of the current retrospective study was to establish whether the established relationship between endometriosis and low body mass index was independent of disease severity.

Methods:

Women with menstrual and/or pelvic pain undergoing laparoscopy for suspected endometriosis were recruited for this retrospective study (n = 509). Women were grouped by body mass index (kg/m2) according to World Health Organization criteria: underweight (<18.5), normal (18.5–24.99), pre-obese (25–29.99) or obese (≥30). Endometriosis was scored according to the revised American Fertility Society system. Data were analysed based on body mass index and endometriosis status to identify any relationship between body mass index and disease.

Results:

The average body mass index of women with endometriosis was 25.0 kg/m2. The body mass index distribution of women with endometriosis differed relative to women in the general population. As expected, fewer obese women had endometriosis than in the lower body mass index categories. However, the obese women who did have endometriosis had significantly higher revised American Fertility Society scores compared to women with normal and pre-obese body mass indices.

Discussion:

Our results are consistent with the established finding of an inverse relationship between body mass index and endometriosis. The novel finding from this study is that obesity is associated with increased disease severity and reduced frequency of stage I endometriosis. It remains unclear what role body mass index has in the cause or effect of endometriosis; we speculate that body mass index may be useful for sub-classifying the disease.