Risk factors associated with endometriosis: importance of study population for characterizing disease in the ENDO Study

Associations among body size across the life course, adult height and endometriosis

STUDY QUESTION

Are body size across the life course and adult height associated with endometriosis?

SUMMARY ANSWER

Endometriosis is associated with lean body size during childhood, adolescence and adulthood; tall total adult height; and tall sitting height.

WHAT IS KNOWN ALREADY

The literature suggests that both adult body size and height are associated with endometriosis risk, but few studies have investigated the role of body size across the life course. Additionally, no study has investigated the relationships between components of height and endometriosis.

STUDY DESIGN, SIZE, DURATION

We used a nested case-control design within E3N (Etude Epidémiologique auprès de femmes de l'Education Nationale), a prospective cohort of French women. Data were updated every 2-3 years through self-administered questionnaires. Odds ratios (ORs) and 95% CIs were computed using logistic regression models adjusted for a priori confounding factors.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2416 endometriosis cases were reported as surgically ascertained among the 61 208 included women.

MAIN RESULTS AND THE ROLE OF CHANCE

The odds of endometriosis were lower among women who reported having a large versus lean body size at 8 years (P for trend = 0.003), at menarche (P for trend < 0.0001) and at ages 20-25 years (P for trend < 0.0001). Women in the highest quartiles of height had statistically significantly increased odds of endometriosis compared to those in the lowest (<158 cm) (162-164 cm: OR = 1.28, 95% CI = 1.12-1.46; ≥165 cm: OR = 1.33, 95% CI = 1.18-1.49, P for trend < 0.0001). Statistically significantly increased odds were also observed among women with a taller sitting height (OR = 1.24, 95% CI = 1.05-1.47, P for trend = 0.01). Leg length was not statistically significantly associated with endometriosis.

LIMITATIONS REASONS FOR CAUTION

Endometriosis cases may be prone to misclassification; however, we restricted our case definition to surgically-confirmed cases, which showed a high validation rate. Body size is based on retrospective self-report, which may be subject to recall bias.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this study suggest that endometriosis is positively associated with lean body size across the life course and total adult height. They also suggest that components of height are associated with endometriosis, which should be investigated further.

STUDY FUNDING/COMPETING INTEREST(S)

The Mutuelle Générale de l'Education Nationale (MGEN); the European Community; the French League against Cancer (LNCC); Gustave Roussy; the French Institute of Health and Medical Research (Inserm). L.V.F. was supported by a T32 grant (#HD060454) in reproductive, perinatal and pediatric epidemiology from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Cancer Institute (3R25CA057711) National Institutes of Health. M.K. was supported by a Marie Curie Fellowship within the seventh European Community Framework Programme (#PIOF-GA-2011-302078). The authors have no conflicts of interest to declare.

Association between body mass index and endometriosis risk: a meta-analysis

Background

Epidemiological studies have sought to establish a relationship between a woman's current body mass index and endometriosis, but with varying results. This meta-analysis was to summarize the current epidemiological evidence.

Methods

Pertinent studies were identified by searching PubMed and Web of Science through November 2016. Study-specific risk estimates were combined using fixed or random effects models depending on whether significant heterogeneity was detected.

Results

A total of 11 studies (two cohort studies and nine case-control studies) was included in the meta-analysis. The pooled relative risk of endometriosis was 0.67 (95% CI: 0.53, 0.84) for each 5 kg/m² increase in current body mass index, with statistical significant heterogeneity across the studies (P <0.001, I² =86.9%). Compared with normal weight women, the pooled relative risk for obese women was 0.89 (95% CI: 0.83, 0.96), which was lower than that for overweight women (relative risk =0.97; 95% CI: 0.91, 1.05). The combined estimate was robust across subgroup and sensitivity analyses and no observed publication bias was detected.

Conclusion

This study suggested that higher body mass index may be associated with lower risk of endometriosis. Further work will need to focus on elucidating underlying biologic mechanism that contribute to the initiation of endometriosis.

Quantitative bias analysis of a reported association between perfluoroalkyl substances (PFAS) and endometriosis: The influence of oral contraceptive use

An association between serum levels of perfluoroalkyl substances (PFAS) and endometriosis has recently been reported in an epidemiologic study. Oral contraceptive use to treat dysmenorrhea (pelvic pain associated with endometriosis) could potentially influence this association by reducing menstrual fluid loss, a route of excretion for PFAS. In this study, we aimed to evaluate the influence of differential oral contraceptive use on the association between PFAS and endometriosis. We used a published life-stage physiologically based pharmacokinetic (PBPK) model to simulate plasma levels of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from birth to age at study participation (range 18-44years). In the simulated population, PFAS level distributions matched those for controls in the epidemiologic study. Prevalence and geometric mean duration (standard deviation [SD]) of oral contraceptive use in the simulated women were based on data from the National Health and Nutrition Examination Survey; among the women with endometriosis the values were, respectively, 29% and 6.8 (3.1) years; among those without endometriosis these values were 18% and 5.3 (2.8) years. In simulations, menstrual fluid loss (ml/cycle) in women taking oral contraceptives was assumed to be 56% of loss in non-users. We evaluated the association between simulated plasma PFAS concentration and endometriosis in the simulated population using logistic regression. Based on the simulations, the association between PFAS levels and endometriosis attributable to differential contraceptive use had an odds ratio (95% CI) of 1.05 (1.02, 1.07) for a log_e unit increase in PFOA and 1.03 (1.02, 1.05) for PFOS. In comparison, the epidemiologic study reported odds ratios of 1.62 (0.99, 2.66) for PFOA and 1.25 (0.87, 1.80) for PFOS. Our results suggest that the influence of oral contraceptive use on the association between PFAS levels and endometriosis is relatively small.

Strong Association Between Endometriosis and Symptomatic Leiomyomas

Background and Objectives:

The relationship between leiomyoma and endometriosis is poorly understood. Both contribute to considerable pain and may cause subfertility or infertility in women. We conducted this retrospective study to assess the rate of coexistence of endometriosis in women with symptomatic leiomyoma. The primary outcome measured was the coexistence of histology-proven endometriosis in women with symptomatic leiomyoma.

Methods:

This is a retrospective review of a data-based collection of medical records of 244 patients treated at a tertiary medical center, who were evaluated for symptomatic leiomyoma from March 2011 through December 2015. Of those, 208 patients underwent laparoscopic or laparoscopic-assisted myomectomy or hysterectomy. All patients provided consent for possible concomitant diagnosis and treatment of endometriosis. The remaining 36 patients underwent medical therapy and were excluded from the study. All patients who had myomectomy or supracervical hysterectomy underwent minilaparotomy for extracorporeal morcellation and specimen removal beginning in April 2012.

Results:

Of the 208 patients with the presenting chief concern of symptomatic leiomyoma and who underwent surgical therapy, 181 had concomitant diagnoses of leiomyoma and endometriosis, whereas 27 had leiomyoma. Of the 27 patients, 9 also had adenomyosis. Patients with only fibroid tumors were, on average, 4.0 years older than those with endometriosis and fibroids (mean age, 44 vs 40 ± SD). Patients with both pathologies were also more likely to present with pelvic pain and nulliparity than those with fibroid tumors alone.

Conclusions:

In our patient population, 87.1% of patients with a chief concern of symptomatic fibroids also had a diagnosis of histology-proven endometriosis, which affirms the need for concomitant diagnosis and intraoperative treatment of both conditions. Overlooking the coexistence of endometriosis in women with symptomatic leiomyoma may lead to suboptimal treatment of fertility and persistent pelvic pain. It is important for physicians to be aware of the possibility of this association and to thoroughly evaluate the abdomen and pelvis for endometriosis at the time of myomectomy or hysterectomy in an effort to avoid the need for reoperation.

Endometriosis: Epidemiology, Diagnosis and Clinical Management

Purpose of review

Endometriosis is a disease of adolescents and reproductive-aged women characterized by the presence of endometrial tissue outside the uterine cavity and commonly associated with chronic pelvic pain and infertility. Here we review the epidemiology of endometriosis as well as potential biomarkers for detection and with the goal of highlighting risk factors that could be used in combination with biomarkers to identify and treat women with endometriosis earlier..

Recent findings

Early age at menarche, shorter menstrual length, and taller height are associated with a higher risk of endometriosis while parity, higher body mass index (BMI) and smoking are associated with decreased risk. Endometriosis often presents as infertility or continued pelvic pain despite treatment with analgesics and cyclic oral contraceptive pills.

Summary

Despite a range of symptoms, diagnosis of endometriosis is often delayed due to lack of non-invasive, definitive and consistent biomarkers for diagnosis of endometriosis. Hormone therapy and analgesics are used for treatment of symptomatic endometriosis. However, the efficacy of these treatments are limited as endometriosis often recurs. In this review, we describe potential diagnostic biomarkers and risk factors that may be used as early non-invasive in vitro tools for identification of endometriosis to minimize diagnostic delay and improve reproductive health of patients.

Preconception perfluoroalkyl and polyfluoroalkyl substances and incident pregnancy loss, LIFE Study

Equivocal findings are reported for perfluoroalkyl and polyfluoroalkyl substances (PFASs) and self-reported pregnancy loss. We prospectively assessed PFASs and pregnancy loss in a cohort comprising 501 couples recruited preconception and followed daily through 7 post-conception weeks. Seven PFASs were quantified: 2-N-ethyl-perfluorooctane sulfonamide acetate (Et-PFOSA-AcOH); 2-N-methyl-perfluorooctane sulfonamido acetate (Me-PFOSA-AcOH); perfluorodecanoate (PFDeA); perfluorononanoate (PFNA); perfluorooctane sulfonamide (PFOSA); perfluorooctane sulfonate (PFOS); and perfluorooctanoate (PFOA). Women used home pregnancy test kits. Loss denoted conversion from a positive to a negative pregnancy test, onset of menses or clinical confirmation (n=98; 28%). Chemicals were log transformed and rescaled by their standard deviations to estimate adjusted hazard ratios (HRs) and 95% confidence intervals. No significantly elevated HRs were observed for any PFASs suggesting no association with loss: Et-PFOSA-AcOH (1.04; 0.87, 1.23), Me-PFOSA-AcOH (0.79; 0.61, 1.00; p<0.05), PFDeA (0.83; 0.66, 1.04), PFNA (0.86; 0.70, 1.06), PFOSA (0.74; 0.50, 1.09), PFOS (0.81; 0.65, 1.00), and PFOA (0.93; 0.75, 1.16).

Women's Reproductive History Before the Diagnosis of Incident Endometriosis

BACKGROUND

Endometriosis is a gynecologic disease reported to be associated with infertility and, possibly, adverse pregnancy outcomes. While considerable research focuses on pregnancy outcomes following diagnosis and/or treatment, few data actually describe women's reproductive history before diagnosis for a more complete understanding of endometriosis and reproduction.

MATERIALS AND METHODS

The study sample comprised 473 women (aged 18-44 years) undergoing laparoscopies or laparotomies, irrespective of surgical indication at 14 clinical sites, during the period 2007-2009. Upon enrollment and before surgery, women were queried about pregnancy intentions and the time required to become pregnant for planned pregnancies. Endometriosis was defined as surgically visualized disease. Using discrete time survival analysis, we estimated fecundability odds ratios (FORs) and 95% confidence intervals (CIs) to assess time to pregnancy (TTP) after adjusting for potential confounders (age, body composition, cigarette smoking, site). Generalized estimating equations accounted for multiple pregnancy attempts per woman. FORs <1.0 denote a longer TTP or diminished fecundity.

RESULTS

Approximately 66% and 69% of women with and without endometriosis, respectively, reported having a planned pregnancy before surgery, respectively. After adjustment, an endometriosis diagnosis was associated with ≈29% reduction in fecundity or a longer TTP across all pregnancy-trying attempts (adjusted FOR = 0.71; 95% CI 0.46-1.10). While FORs were consistently <1.0, irrespective of endometriosis staging, CIs included 1.

CONCLUSIONS

Women with endometriosis had a longer TTP than unaffected women, irrespective of disease severity, although the findings did not achieve significance. Prior reproductive history may be informative for predicting fecundity and pregnancy outcomes following diagnosis/treatment.

Evaluation of Risk Factors Associated with Endometriosis in Infertile Women

BACKGROUND

Endometriosis affects women's physical and mental wellbeing. Symptoms include dyspareunia, dysmenorrhea, pelvic pain, and infertility. The purpose of this study is to assess the correlation between some relevant factors and symptoms and risk of an endometriosis diagnosis in infertile women.

MATERIALS AND METHODS

A retrospective study of 1282 surgical patients in an infertility Institute, Iran between 2011 and 2013 were evaluated by laparoscopy. Of these, there were 341 infertile women with endometriosis (cases) and 332 infertile women with a normal pelvis (comparison group). Chi-square and t tests were used to compare these two groups. Logistic regression was done to build a prediction model for an endometriosis diagnosis.

RESULTS

Gravidity [odds ratio (OR): 0.8, confidence interval (CI): 0.6-0.9, P=0.01], parity (OR: 0.7, CI: 0.6-0.9, P=0.01), family history of endometriosis (OR: 4.9, CI: 2.1-11.3, P<0.001), history of galactorrhea (OR: 2.3, CI: 1.5-3.5, P=0.01), history of pelvic surgery (OR: 1.9, CI: 1.3-2.7, P<0.001), and shorter menstrual cycle length (OR: 0.9, CI: 0.9-0.9, P=0.04) were associated with endometriosis. Duration of natural menstruation and age of menarche were not correlated with subsequent risk of endometriosis (P>0.05). Fatigue, diarrhea, constipation, dysmenorrhea, dyspareunia, pelvic pain and premenstrual spotting were more significant among late-stage endometriosis patients than in those with early-stage endometriosis and more prevalent among patients with endometriosis than that of the comparison group. In the logistic regression model, gravidity, family history of endometriosis, history of galactorrhea, history of pelvic surgery, dysmenorrhoea, pelvic pain, dysparaunia, premenstrual spotting, fatigue, and diarrhea were significantly associated with endometriosis. However, the number of pregnancies was negatively related to endometriosis.

CONCLUSION

Endometriosis is a considerable public health issue because it affects many women and is associated with the significant morbidity. In this study, we built a prediction model which can be used to predict the risk of endometriosis in infertile women.

Surgical History and the Risk of Endometriosis: A Hospital-Based Case-Control Study

Women tend to receive more surgical procedures than men. Our mouse study shows that surgical stress promotes the development of endometriosis. This study was undertaken to test the hypothesis that surgery increases the risk of endometriosis. We recruited 208 patients with ovarian endometrioma and 212 age-matched patients with ovarian teratoma and retrieved information on the history of any surgical procedures after menarche, grouped by laparotomy, laparoscopy, gynecologically related procedures, cesarean section, and surgeries performed on torso and extremities was recorded. We then evaluated the association, if any, between endometriosis and history of surgical procedures. Cases and controls were comparable with respect to age, marital status, education level, and occupation. Eleven (5.3%) cases had laparotomy before the index surgery while 4 (1.9%) controls did. Sixty-six (31.7%) cases had Cesarean section while 53 (25.0%) controls did. Multivariate analysis identified age, at the index surgery laparotomy, and cesarean section as 3 factors positively associated with the risk of endometriosis while parity was found to be negatively associated with the risk. Laparotomy was associated with increased risk of endometriosis (odds ratio [OR] = 3.64, 95% confidence interval [CI] = 1.08-12.31), while cesarean section was associated with 2-fold increase in risk (OR = 2.16, 95% CI = 1.31-3.55). Both laparotomy and cesarean section may increase the risk of endometriosis probably by activation of adrenergic signaling, thus facilitating angiogenesis and accelerating the growth of endometriotic lesions that are already in existence. This finding may have important ramifications for the perioperative management of patients with increased risk or recurrence risk of endometriosis.

Functional Connectivity is Associated With Altered Brain Chemistry in Women With Endometriosis-Associated Chronic Pelvic Pain

In contrast to women with relatively asymptomatic endometriosis, women with endometriosis-associated chronic pelvic pain (CPP) exhibit nonpelvic hyperalgesia and decreased gray matter volume in key neural pain processing regions. Although these findings suggest central pain amplification in endometriosis-associated CPP, the underlying changes in brain chemistry and function associated with central pain amplification remain unknown. We performed proton spectroscopy and seed-based resting functional connectivity magnetic resonance imaging to determine whether women with endometriosis display differences in insula excitatory neurotransmitter concentrations or intrinsic brain connectivity to other pain-related brain regions. Relative to age-matched pain-free controls, women with endometriosis-associated CPP displayed increased levels of combined glutamine-glutamate (Glx) within the anterior insula and greater anterior insula connectivity to the medial prefrontal cortex (mPFC). Increased connectivity between these regions was positively correlated with anterior insula Glx concentrations (r = .87), as well as clinical anxiety (r = .61, P = .02), depression (r = .60, P = .03), and pain intensity (r = .55, P = .05). There were no significant differences in insula metabolite levels or resting-state connectivity in endometriosis patients without CPP versus controls. We conclude that enhanced anterior insula glutamatergic neurotransmission and connectivity with the mPFC, key regions of the salience and default mode networks, may play a role in the pathophysiology of CPP independent of the presence of endometriosis.

PERSPECTIVE

Similar to other chronic pain conditions, endometriosis-associated pelvic pain is associated with altered brain chemistry and function in pain processing regions. These findings support central pain amplification as a mechanism of chronic pelvic pain, and clinicians should consider the use of adjunctive therapies that target central pain dysfunction in these women.

Targeting oxidative stress to treat endometriosis

INTRODUCTION

Endometriosis affects 10% of women of reproductive age. It is defined as the presence of implanted active endometrial tissue outside the uterine cavity. The exact pathophysiology of endometriosis is still uncertain, although several optional etiological theories have been suggested. Being so common, a novel treatment for endometriosis is widely quested. Recent studies addressing the pathological characteristics of endometriosis have revealed a vicious cycle in which oxidative stress (OS) is generated, which in turn facilitates the implantation of the ectopic endometrium. At the same time, the generation of high amounts of reactive oxygen species further triggers a state of OS.

AREAS COVERED

The author examined the evidence associating OS and endometriosis. After establishing an association, a search for antioxidant agents that were investigated specifically on endometriosis patients are described including Vitamins C and E, melatonin, resveratrol, xanthohumol and epigallocatechin-3-gallate. A significant effect of all the reviewed antioxidants on endometriosis is reported.

EXPERT OPINION

Aiming for the reduction of OS as the treatment goal for endometriosis looks promising. However, since most of the studies are either in vitro or are animal based, further studies on human subjects are deemed necessary to elucidate the impact of OS reduction on patients with endometriosis.

Clinical diagnosis of pelvic endometriosis: a scoping review

BACKGROUND

Accurate and timely diagnosis of endometriosis is associated with confusion. Clinical manifestations, imaging techniques, biomarkers and surgical techniques are used as diagnostic approaches. This paper reviews current evidence on clinical manifestation in order to help practitioners and perhaps improve women's health.

METHODS

A review of the literature on clinical diagnosis of pelvic endometriosis that appeared in the English language biomedical journals was performed using PubMed, Science Direct and Google Scholar. The search strategy included the combination of key words 'endometriosis' and 'diagnosis' or 'clinical diagnosis' in the titles or abstracts of articles. The search included all papers published during the year 2000 to 2014. Then, the findings were classified in order to summarize the evidence.

RESULTS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, in all 51 papers were found relevant and included in this review. In general we found three categories of diagnostic approaches for clinical manifestation including: i) diagnosis via symptoms obtained from history taking, ii) diagnosis via signs obtained from physical examination and iii) diagnosis via risk factors obtained from history taking.

CONCLUSION

Diagnosis of endometriosis is a matter of concern. Since the disease is associated with diverse clinical symptoms and signs, deeper and more comprehensive consideration according to patient's history and clinical findings is recommended for early and more accurate detection in order to prioritize women for further investigation and contribute to its early management.

Chronic lymphocytic leukemia-associated refractory immune thrombocytopenia successfully treated with eltrombopag

Chronic lymphocytic leukemia (CLL) may be associated with immune thrombocytopenia (ITP). The standard treatment for CLL-associated ITP is steroids. For refractory cases, various treatment strategies such as rituximab, splenectomy, and thrombopoietic mimetics are available. We report a patient with CLL who developed recurrent ITP and life-threatening pulmonary hemorrhage. Platelet counts remained extremely low despite massive platelet transfusion and treatment including steroids, immunoglobulin, and single-dose rituximab infusion. The bleeding stopped and platelet counts were increased to normal range 13 days after treatment with eltrombopag 25 mg per day. Our experience suggests that eltrombopag is an effective treatment option in CLL-associated, refractory ITP, especially during major bleeding, which requires relatively rapid improvement of thrombocytopenia.

Risk profiles for endometriosis in Japanese women: results from a repeated survey of self-reports

Background

The prevalence and risk factors for endometriosis may differ according to diagnosis methodologies, such as study populations and diagnostic accuracy. We examined risk profiles in imaging-diagnosed endometriosis with and without surgical confirmation in a large population of Japanese women, as well as the differences in risk profiles of endometriosis based on history of infertility.

Methods

Questionnaires that included items on sites of endometriosis determined by imaging techniques and surgical procedure were mailed to 1025 women who self-reported endometriosis in a baseline survey of the Japan Nurses’ Health Study (n = 15 019).

Results

Two hundred and ten women had surgically confirmed endometriosis (Group A), 120 had imaging-diagnosed endometriosis without a surgical procedure (Group B), and 264 had adenomyosis (Group C). A short menstrual cycle at 18–22 years of age and cigarette smoking at 30 years of age were associated with significantly increased risk of endometriosis (Group A plus Group B), while older age was associated with risk of adenomyosis (Group C). In women with a history of infertility, a short menstrual cycle was associated with a significantly increased risk of endometriosis in both Group A and Group B, but risk profiles of endometriosis were different between Group A and Group B in women without a history of infertility.

Conclusions

Women with surgically confirmed endometriosis and those with imaging-diagnosed endometriosis without surgery have basically common risk profiles, but these risk profiles are different from those with adenomyosis. The presence of a history of infertility should be taken into consideration for evaluation of risk profiles.

Endometriosis and the Enigmatic Question of Progression

Aims

The aim of this study was to identify whether endometriosis is a progressive disease with age, and to review the literature on this topic.

Material and methods

The incidence of endometriosis in a cohort of 500 women who underwent laparoscopy between 2003 and 2013 in the Greenville Health System, in South Carolina, United States, was reviewed. The search of the world literature on progression of endometriosis was limited to 1980 and beyond.

Results

The correlation between stage of endometriosis and age was found to be small (r = −0.04; 95% CI, −0.13 to 0.04; p = 0.3; n = 471). The literature search identified 16 studies on adults. Progression of endometriosis findings at laparoscopy occurred in 31% of the cases with follow-up (n = 162).

Conclusions

Endometriosis of minimal or mild American Society for Reproductive Medicine (rASRM) classification stage is equally likely to be present in women of all ages; similarly, endometriosis in its severe form is not age-dependent.

Coexistence of Polycystic Ovary Syndrome and Endometriosis in Women with Infertility

Purpose

The aim of this study was to investigate if there is a higher incidence of endometriosis in patients with polycystic ovary syndrome (PCOS), compared with normal fertile controls.

Material and methods

Women with PCOS according to Rotterdam criteria, with infertility and/or pelvic pain, were identified (n = 104), and together with fertile women seeking bilateral tubal ligation (n = 111), they were submitted to laparoscopy at the Greenville Hospital System or the University of North Carolina at Chapel Hill. A biopsy was performed in 40 patients with PCOS to confirm or not endometriosis.

Results

Age was similar in both groups (control: 29.7 ± 0.5 years; PCOS: 29.6 ± 0.4). The incidence of suspected endometriotic lesions in controls and PCOS patients was 12.6% (95% confidence interval [95% CI], 7.6%-20%) and 74% (95% CI, 64.8%-81.5%), respectively; with an odds ratio of 19.7 (95% CI, 9.6-40.2) of finding endometriosis in PCOS (p<0.0001). Our results were similar when endometriosis was confirmed by pathology report. Of the PCOS patients with endometriosis, 76% had endometriosis stage I or II, according to the revised American Society for Reproductive Medicine criteria.

Conclusions

In this case-control study, a significant association between endometriosis and women with PCOS with pelvic pain and/or infertility was found. The majority of endometriotic lesions (76%) were stage I or II.

Severe teenage acne and risk of endometriosis

STUDY QUESTION

Is there a relationship between severe teenage acne and endometriosis?

SUMMARY ANSWER

Endometriosis is positively associated with severe teenage acne.

WHAT IS KNOWN ALREADY

No studies have specifically explored a possible association between severe acne in adolescence and risk of endometriosis.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study used data collected from 88 623 female nurses from September 1989 to June 2009 as part of the Nurses' Health Study II (NHS II) cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Regression models were used to calculate hazard ratios (HRs) and confidence intervals (CIs) for endometriosis among women with and without severe teenage acne. Multivariate models were adjusted for established risk factors of endometriosis.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 4 382 laparoscopically confirmed endometriosis cases were documented during 1 132 272 woman-years of follow-up. Compared with women without a history of severe teenage acne, women who had severe teenage acne had a 20% increased risk of endometriosis (HR = 1.20, 95% CI: 1.08-1.32). The association was not affected by adjusting for use of tetracycline or isotretinoin.

LIMITATIONS AND REASONS FOR CAUTION

The HR is likely to be underestimated since we only included endometriosis cases confirmed by laparoscopy. Although geographically diverse, the NHS II cohort is primarily Caucasian, which may limit generalization to more ethnically diverse populations.

WIDER IMPLICATIONS OF THE STUDY

The results of this study suggest that severe teenage acne is associated with an increased risk of endometriosis. As a visible and non-invasive clinical indicator, severe teenage acne may be useful for early detection of endometriosis. We bring this counter-intuitive association to the attention of clinicians for the benefit of the patient and an early diagnosis of endometriosis.

STUDY FUNDING/COMPETING INTEREST

This study was funded by research grant CA176726 from the National Institute of Health. M.K. is supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme (#PIOF-GA-2011-302078). The funding agencies had no role in the design of the study, in the analysis and interpretation of the data, in the writing of the report or in the decision to submit the paper for publication.

Cadmium and Reproductive Health in Women: A Systematic Review of the Epidemiologic Evidence

An evolving body of evidence supports that cadmium, a non-essential heavy metal, may be associated with multiple adverse women's reproductive health outcomes. Our objective was to conduct a systematic review of epidemiologic studies that evaluated cadmium exposure and the following reproductive health outcomes: puberty/menarche, fertility, time to pregnancy, pregnancy loss, preeclampsia, endometriosis, uterine leiomyoma, and menopause. Twenty-two studies were identified based upon our search criteria. Available evidence was inadequate to draw meaningful conclusions for most of the reproductive outcomes studied. The strongest evidence was for a possible association between cadmium and preeclampsia, which was limited to cross-sectional studies. Some evidence, although conflicting, was also observed for fertility related outcomes. This lack of evidence underscores the need for additional research on cadmium and women's reproductive health outcomes.

Trace elements and endometriosis: the ENDO study

There has been limited study of trace elements and endometriosis. Using a matched cohort design, 473 women aged 18-44 years were recruited into an operative cohort, along with 131 similarly aged women recruited into a population cohort. Endometriosis was defined as surgically visualized disease in the operative cohort, and magnetic resonance imaging diagnosed disease in the population cohort. Twenty trace elements in urine and three in blood were quantified using inductively coupled plasma mass spectrometry. Logistic regression estimated the adjusted odds (aOR) of endometriosis diagnosis for each element by cohort. No association was observed between any element and endometriosis in the population cohort. In the operative cohort, blood cadmium was associated with a reduced odds of diagnosis (aOR=0.55; 95% CI: 0.31, 0.98), while urinary chromium and copper reflected an increased odds (aOR=1.97; 95% CI: 1.21, 3.19; aOR=2.66; 95% CI: 1.26, 5.64, respectively). The varied associations underscore the need for continued research.