Insights from Mendelian randomization and genetic correlation analyses into the relationship between endometriosis and its comorbidities

Blood Pressure, Cardiometabolic Traits, and Cardiovascular Events in Women With Uterine Fibroids: A Genetic Correlation and Mendelian Randomization Study

BACKGROUND

Uterine fibroids (UFs) are understudied uterus neoplasms, mainly affecting women of reproductive age and often leading to hysterectomy. Clinical series suggest impaired cardiometabolic features in UFs. We investigated potential genetic links between blood pressure (BP), several cardiometabolic traits, and UFs.

METHODS AND RESULTS

We used summary statistics of genome-wide association studies for UFs and 18 traits related to BP, obesity, lipids, and main vascular diseases. We applied linkage disequilibrium score regression to estimate genetic correlations and Genome-Wide Complex Trait Analysis-multitrait-based conditional and joint analysis to perform adjusted correlations. Univariate and bidirectional Mendelian randomization verified potential causal associations with UFs. We found UFs to significantly correlate with systolic BP (genetic correlation coefficient [rg]=0.08, P=8.7×10-5) and diastolic BP (rg=0.12, P=8.2×10-8), including after adjustment for body mass index. UFs also positively corelated with body mass index (rg=0.11, P=4.1×10-4), waist-to-hip ratio (rg=0.09, P=7.3×10-3), type 2 diabetes (rg=0.15, P=1.9×10-5), and triglycerides (rg=0.17, P=7.6×10-7). We identified a negative correlation with sex hormone-binding globulin (rg=-0.16, P=3×10-4), a marker of bioavailability of sex steroids. No evidence for shared genetic basis with vascular diseases was observed, except with migraine (rg=0.08, P=5.8×10-7). Mendelian randomization analyses confirmed higher body mass index to increase UF risk (beta-per-kg/m2=0.033, P=6.1×10-5), as did waist-to-hip ratio (beta-per-unit=0.193, P=3.3×10-5) and triglycerides (bet-per-mmol/L=0.163, P=1.9×10-5). Higher sex hormone-binding globulin decreased UF risk (beta-per-nmol/L=0.005, P=2.5×10-3). No causal effect was found for BP.

CONCLUSIONS

Our study shows that UFs share substantial genetic basis with traits related to BP, obesity, diabetes, and migraine, a predominantly female vascular disease. We provide Mendelian randomization-based evidence for central obesity, visceral fat traits, and sex-steroid bioavailability as relevant risk factors for UFs.

25-hydroxyvitamin D and Endometriosis: A bidirectional Mendelian randomization study

Numerous studies have demonstrated a correlation between serum 25-hydroxyvitamin D (25OHD) and endometriosis. However, the precise nature of this association remains elusive. The causal connection between 25OHD and endometriosis remains uncertain, as it is yet to be determined whether one directly influences the other. The objective of our research was to investigate the cause-and-effect connection between 25OHD and endometriosis. The study employed Mendelian randomization (MR) in a bidirectional two-sample investigation to examine the causal relationship between 25OHD and endometriosis. The analysis utilized the most recent publicly accessible statistics from the genome-wide association study (GWAS) encompassing 25OHD, endometriosis, and its five subtypes. The primary analytical approach employed was Inverse-Variance Weighting (IVW), accompanied by supplementary analysis methods including weighted median, MR-Egger, simple mode, and weighted mode. Furthermore, sensitivity analyses were conducted to assess the potential influence of heterogeneity and pleiotropy on the MR outcomes. MR primary analysis showed no significant causal effect of 25OHD on endometriosis (OR = 0.892, 95%CI = 0.745 ~ 1.068, P = 0.213). Similarly, there was no evidence to support a causal relationship of endometriosis on 25OHD (IVW Beta = 0.005, 95%CI = 0.993 ~ 1.018, P = 0.406). However, when conducting MR analysis on different subtypes of endometriosis and 25OHD, we found a positive correlation between endometriosis of ovary and 25OHD level (IVW Beta = 0.012, 95%CI = 1.002 ~ 1.022, P = 0.024). This study indicates that there is no causal relationship between serum 25OHD and endometriosis. However, it is important to note that serum 25OHD levels will increase in patients with endometriosis of the ovary. Further observational studies and clinical trials are indispensable.

The independent and joint associations of hysterectomy and uterine fibroids or endometriosis with ovarian cancer incidence: results from a US-based cohort

Uterine fibroids and endometriosis may be associated with an increased risk of ovarian cancer. Less is known about the role of hysterectomy in these associations. We estimated the independent and joint associations of hysterectomy, fibroids, and endometriosis with ovarian cancer incidence in the prospective Sister Study cohort (2003-2009). We used time-varying Cox proportional hazards models to estimate covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). By the end of follow-up, 34% of 40 928 eligible participants had fibroids, 13% had endometriosis, and 7% had both. A total of 274 women developed ovarian cancer during follow-up (median = 12.3 years). In mutually adjusted models, fibroids (HR, 1.65; 95% CI, 1.28-2.12) and possibly endometriosis (HR, 1.16; 95% CI, 0.82-1.63) were positively associated with ovarian cancer. Hysterectomies (20% of participants) were also positively associated with ovarian cancer (HR, 1.29; 95% CI, 0.95-1.74). There was some evidence that hysterectomies may mitigate ovarian cancer risk among women with fibroids (HR, 0.83; 95% CI, 0.56-1.24) but not among women with endometriosis (HR, 1.20; 95% CI, 0.65-2.22). Identifying these joint associations adds to our understanding of ovarian cancer etiology and may help inform decisions about how women with fibroids, endometriosis, and hysterectomies are treated and surveilled for ovarian cancer. This article is part of a Special Collection on Gynecological Cancer.

Evaluating the association between lipidome and female reproductive diseases through comprehensive Mendelian randomization analyses

This study aimed to assess the causal relationship between lipidome and female reproductive diseases (FRDs) using an advanced series of Mendelian randomization (MR) methods. This study utilized genome-wide association study (GWAS) summary statistics encompassing 179 lipidomes and six prevalent FRDs, namely polycystic ovary syndrome (PCOS), endometriosis, uterine fibroid, female infertility, uterine endometrial cancer, and ovarian cancer. The two-sample MR (TSMR) approach was employed to investigate the causal relationships, with further validation using false discovery rate (FDR) and multivariable MR (MVMR) methods. Subsequently, a range of comprehensive evaluations were performed, including sensitivity analysis, mediation MR analysis, reverse MR analysis, and steiger test. Examining 179 lipidome traits as exposures and 6 FRDs as outcomes, this study identified significant causal effects of 56 lipids on FRDs. Following multiple testing correction and MVMR validation, sphingomyelin (d38:2) was found to have a protective effect against PCOS (β = -0.104, 95% CI: -0.199 ~ -0.010, P = 0.031). Phosphatidylcholine (18:0_22:6) was associated with a decreased risk of developing uterine fibroid (β = -0.111, 95% CI: -0.201~ -0.021, P = 0.016), and sterol ester (27:1/20:3) showed significance in uterine endometrial cancer (β = -0.248, 95% CI: -0.443 ~ -0.053, P = 0.013). Conversely, phosphatidylethanolamine (18:2_0:0) was associated with increased risk of endometriosis (β = 0.183, 95% CI: 0.015 ~ 0.350, P = 0.033), while sterol ester (27:1/18:1) posed a risk influence on uterine fibroid (β = 1.007, 95% CI: 0.925 ~ 1.089, P < 0.001), and phosphatidylcholine (16:0_22:6) on uterine endometrial cancer (β = 0.229, 95% CI: 0.039 ~ 0.420, P = 0.018). Furthermore, it was determined that the causal associations between these lipidome profiles and FRDs were independent of BMI, obesity, diabetes, smoking, alcohol use, physical activity, inflammation, depression, waist-hip ratio, vitamin D, dehydroepiandrosterone sulphate, sex hormone binding globulin, and testosterone levels. Most outcomes passed consistent tests without evidence of heterogeneity, pleiotropy, or reverse causality. The results indicated a close association between specific lipidomes, particularly sphingomyelin, lysophosphatidylethanolamine, cholesterol ester, and phosphatidylcholines, with FRDs. These lipid species may potentially serve as biomarkers and future drug targets for the treatment of FRDs.

Prostatitis, benign prostatic hyperplasia, and prostate cancer: a bidirectional Mendelian randomization study and clinical implications for these patients' populations

BACKGROUND

No authoritative books or guidelines are currently available for revealing the interrelationships of prostatitis, benign prostatic hyperplasia (BPH), and prostate cancer (PCa). Moreover, no consensus on this issue has been reached among previously published epidemiological studies or meta-analyses.

PURPOSE

We first took advantage of Mendelian randomization to clarify this issue and provide clinical implications for these patients' populations.

METHODS

Bidirectional two-sample and mediator Mendelian randomization were applied to explore the causal relationships among prostatitis, BPH, and PCa. Sensitivity analyses, including phenotype scanning, heterogeneity, pleiotropy, leave-one-out analysis, and the Steiger test, were conducted to evaluate the robustness and reliability of our results.

RESULTS

Our results revealed the interrelationships among prostatitis, BPH, and PCa via Mendelian randomization, confirming that genetic susceptibility to prostatitis or BPH could lead to increased risks of PCa directly or indirectly (P < 0.05). Moreover, mediator Mendelian randomization revealed four potential mediator pathways, including the prostatitis-BPH-PCa, the BPH-PCa-prostatitis, the PCa-prostatitis-BPH, and the PCa-BPH-prostatitis pathways. Based on these, we also provided clinical implications for prostatitis, BPH, and PCa patients' populations, respectively. Interestingly, a total of three vicious circles were revealed by us, including the prostatitis-BPH circle, the BPH-PCa circle, and the prostatitis-BPH-PCa circle. All of these three vicious circles contributed to the progression of benign prostate diseases to malignant diseases.

CONCLUSION

We successfully clarified the interrelationships among prostatitis, BPH, and PCa, providing clinical implications for these patients' populations. A total of three vicious circles were also revealed by us to provide novel ideas for future drug development and guide clinical decision-making.

Causal Relationship Between Endometriosis, Female Infertility, and Primary Ovarian Failure Through Bidirectional Mendelian Randomization

Background

Endometriosis and its associated gynecological diseases such as female infertility and primary ovarian failure (POF), impose a long-term disease burden on women. This study aims to explore the causal relationships between these conditions through a two-sample bidirectional Mendelian randomization (MR) study.

Methods

We utilized large-scale GWAS data and conducted bidirectional MR analyses using methods such as Inverse Variance Weighted (IVW) and MR-Egger to assess the causal relationships between endometriosis and female infertility, POF, amenorrhoea, and oligomenorrhoea.

Results

MR analysis revealed significant causal relationships between endometriosis and female infertility (OR=1.430, 95% CI 1.306-1.567, P<0.01) as well as POF (OR=1.348, 95% CI 1.050-1.731, P=0.019). Reverse MR analysis indicated causal relationships between amenorrhoea (OR=1.076, 95% CI 1.009-1.148, P=0.026) and female infertility (OR=1.340, 95% CI 1.092-1.645, P<0.01) with endometriosis. Sensitivity analyses confirmed the robustness of these findings (heterogeneity: Q_pval>0.05, pleiotropy: pval>0.05).

Conclusion

This study suggested that managing endometriosis may help prevent conditions such as female infertility and POF, and vice versa. Future research is needed to confirm these findings in more diverse populations.

The relationship between blood lipids and endometriosis: a cross-sectional study from NHANES (1999-2006) and a bidirectional Mendelian randomization study

OBJECTIVE

Observational studies suggest a link between blood lipid levels and endometriosis risk, but clinical evidence is limited and causality has not been established. This study aims to clarify this relationship using NHANES data (1999-2006) and bidirectional Mendelian Randomization (MR) analysis.

METHODS

We analyzed NHANES data to explore the relationship between blood lipids and endometriosis risk using multivariable logistic regression, nonlinear testing, and trend analysis. For causal inference, MR was performed using GWAS data from the UK Biobank (lipid levels) and the Finnish Endometriosis Database (endometriosis).

RESULTS

In NHANES (n=2,201), elevated triglycerides (TG) were significantly associated with increased endometriosis risk (OR, 2.10; 95% CI, 1.00-3.49; p < 0.05). MR analysis confirmed this association (OR, 1.19; 95% CI, 1.07-1.32; p < 0.006) and suggested HDL may protect against endometriosis (OR, 0.79; 95% CI, 0.63-0.99; p < 0.05). Additionally, bidirectional MR indicated that endometriosis may also contribute to TG dysregulation (OR, 1.02; 95% CI, 1.01-1.03; p < 0.006).

CONCLUSION

Our findings suggest that elevated TG levels may increase endometriosis risk, while HDL may provide a protective effect. These results offer new insights and may inform future management strategies for endometriosis. However, large-scale longitudinal studies are needed to further validate these associations.

The causal effect of serum amino acids on the risk of prostate cancer: a two-sample mendelian randomization study

Prostate cancer (PCa) is the second most common malignancy affecting men globally. Recent advances in metabolomics have highlighted significant alterations in specific amino acid (AA) metabolism linked to PCa, indicating their potential utility in diagnosis and therapy. However, no direct causal association between serum AA levels and PCa risk has been established. A total of 35 patients with PCa and 30 individuals with benign prostatic hyperplasia (BPH) were recruited for this study. Targeted metabolomic analysis was performed using ultra-high-performance liquid chromatography-tandem mass spectrometry on serum samples. Two-sample Mendelian randomization (MR) was applied to explore potential causal links between serum AA levels and PCa risk, including mediator effects using dual-phase MR and assessing reverse causality through reverse MR. Results Targeted metabolomic profiling identified six amino acids-glutamate (Glu), Ser, histidine (His), arginine (Arg), aspartic acid (Asp), and glycine (Gly)-that showed significant area under the ROC curve in differentiating between BPH and PCa cases. Notably, Glu demonstrated an inverse association with PCa risk, distinct from the other AAs identified. However, definitive evidence supporting a causal relationship between low Glu levels and increased PCa risk was not observed. Our results suggest a protective role of Glu against PCa development, which may have implications for disease prognosis. Increasing dietary Glu intake may present a potential preventive or therapeutic approach for PCa.

The causal role of gastroesophageal reflux disease in endometriosis: a bidirectional Mendelian randomization study

Observational studies have reported an association between gastroesophageal reflux disease (GERD) and endometriosis. We conducted a two-sample and bidirectional Mendelian randomization analysis to determine whether those associations are causal. Two-sample and bidirectional MR analyses were performed using summary statistics from the European Individual Genome-Wide Association Study (GWAS). The inverse variance weighting (IVW) method is used as the main analysis method to evaluate causality. Sensitivity analyses were performed to assess heterogeneity, horizontal versatility, and stability. The results showed no significant causal association between GERD in women with endometriosis in the UK Bank database [ratio (OR) ≈ 0, 95% adjusted interval (CI) 1.0007∼1.0044, P = 0.006] and Finn databases [ratio (OR) = 1.29, 95% adjusted interval (CI) 0.99∼1.67, P = 0.06]. However, when studying the Finn database only for endometriosis, which is confined to the uterus, a significant increase in GERD was limited to the risk of endometriosis in the uterus [ratio (OR) = 1.47, 95% adjusted interval (CI) 1.00∼2.17, P = 0.05]. Sensitivity analysis showed that the results were robust and did not detect multi efficacy or heterogeneity. Meanwhile, reverse MR analysis showed that endometriosis did not increase the risk of GERD. This MR study supports a causal relationship between GERD and an increased risk of endometriosis confined to the uterus. Therefore, patients with gastric esophageal reflux should be treated with gynecological examination to avoid and prevent the development of endometriosis.

A cause-effect relationship between uterine diseases and breast cancer: A bidirectional Mendelian randomization study

Objective

To explore the cause-effect relationship between uterine diseases (UDs) and breast cancer (BC) and underlying mechanism of the cause-effect relationship, enhance understanding of the association between BC and UDs.

Methods

A two-sample bidirectional Mendelian randomization (MR) analysis was conducted. We obtained summary statistics data from GWAS for BC, endometriosis, endometrial cancer (EC), uterine leiomyoma (UL), uterine polyps (UP), and cervical cancer (CC). Independent SNPs were selected as instrumental variables (IVs) for each disease. The inverse variance weighted (IVW) method was primary used for estimating the causal association between UDs and BC. To further evaluate the consistency and dependability of the results, we also utilized the weighted median, weighted mode, simple mode, and MR-Egger methods, along with sensitivity analyses. Furthermore, a supplementary analysis focusing on the variants linked to BC and UDs was conducted. This involved identifying corresponding genes and subsequently performing KEGG/GO analyses to investigate potential molecular mechanisms.

Results

The results indicated significant associations between genetic susceptibility to endometriosis, EC, and UL with BC risk. The odds ratios (ORs) were as follows: endometriosis at 0.963 (95 % CI, 0.942-0.984; p = 7.11e-5), EC at 1.056 (95 % CI, 1.033-1.081; p = 2.39e-6), and UL at 1.027 (95 % CI, 1.006-1.048; p = 0.010). Conversely, the predisposition to BC inferred from genetic factors was markedly correlated with an elevated risk of EC indicated by an OR of 1.066 (95 % CI, 1.019-1.116; p = 0.006), and was correlated with UP risk (OR, 1.001,95 % CI, 1.000-1.002; p = 0.001).Sensitivity analyses provided weak evidence for these effects, suggesting that the study's outcomes are consistent and trustworthy. Further analysis of the genetic variants associated with BC, and these related genes are enriched in Cellular senescence, GnRH secretion, Phosphatidylinositol signaling system, and so on.

Conclusion

This study corroborates the existence of a reciprocal causal relationship between BC and EC, as well as highlighting the substantial correlations between a genetic susceptibility to UL and endometriosis with BC. BC may exert their influence on EC and UP through Cellular senescence, GnRH secretion, and other pathways. These discoveries offer fresh perspectives on the genetic pathogenesis of BC and UDs, and can guide future experimental studies. Additionally, they lay down a groundwork for the development of tailored preventative and therapeutic strategies moving forward.

Association between endometriosis and arthritis: results from NHANES 1999-2006, genetic correlation analysis, and Mendelian randomization study

Background

Previous studies reported that endometriosis may have a higher risk of arthritis. However, it remains unclear whether the association between endometriosis and arthritis has genetic correlations, or the relationship is causal. Linkage Disequilibrium Score (LDSC) and Mendelian Randomization (MR) analyses use genetic variation as a natural experiment to explore genetic correlations and causal inferences from observational data, reducing unmeasured confounding factors.

Method

Participants (aged 20-54 years, n = 2,915) for the cross-sectional study were obtained from the National Health and Nutrition Examination Survey (NHANES). Endometriosis and arthritis were diagnosed based on self-reported by reproductive health and medical condition questionnaire. Weighted multivariable logistic regression was used to explore the relationship between endometriosis and arthritis. LDSC and MR analysis were performed using the genome-wide association study (GWAS) summary statistics to identify the causal association.

Result

A significant positive association between endometriosis and arthritis was found after multivariable adjustment (OR = 1.89; 95% CI: 1.33, 2.67). When exploring different types of arthritis, a positive association was revealed with rheumatoid arthritis (RA), other types of arthritis, and cases that the arthritis type were unknown, with an OR of 2.07 (95% CI: 1.03, 4.17), 2.78 (95% CI: 1.30, 5.95), and 2.06 (95% CI: 1.36, 3.11), respectively. However, genetic correlation analysis between endometriosis and RA did not reveal any significant findings (all P values > 0.05). Moreover, MR analysis also failed to identify a causal relationship between endometriosis and RA (all P values > 0.05).

Conclusion

Cross-sectional study identified a significant positive association between endometriosis and arthritis among US women, especially among RA, while findings based on LDSC and MR analysis did not support a genetic correlation or causal role. These findings suggest that clinicians should pay more attention to the coexistence of RA in endometriosis patients and explore the shared pathophysiological mechanisms of these two disorders, with a particular focus on extrinsic factors rather than intrinsic genetic inheritance.

The association of circulating lipoprotein lipids and apolipoproteins with risk of endometriosis: a Mendelian randomization study

BACKGROUND

Endometriosis is a poorly understood disease that affects up to 196 million women worldwide and imposes high costs in terms of economic burden and quality of life of women. Traits of circulating lipids have been related to the onset and progression of endometriosis in previous observational studies but the results have remained contradictory.

METHODS

We performed univariable and multivariable Mendelian randomization (MR) analyses using instrument variables to genetically predict the associations of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, triglycerides, and apolipoprotein (apo) A-I and B from the UK Biobank with endometriosis (consisting of 8288 cases and 68 969 controls from the FinnGen consortium). The inverse-variance weighted (IVW) method was used as the primary estimate, whereas MR-Egger and weighted median were conducted as complements to the IVW model.

RESULTS

Increased levels of triglycerides were associated with higher risk of endometriosis and endometriosis of the pelvic peritoneum in the univariable MR analyses. In multivariable MR analysis including apoB, LDL cholesterol, and triglycerides in the same model, triglycerides still retained a robust effect. Decreased levels of apoA-I and HDL cholesterol were associated with increased risk of endometriosis and endometriosis of the pelvic peritoneum in univariable MR analyses. After mutual adjustment, HDL cholesterol retained a robust effect whereas the association for apoA-I was attenuated.

CONCLUSIONS

This is the first MR-based evidence to suggest that triglycerides and HDL cholesterol are the predominant traits that account for the aetiological relationship of lipoprotein lipids with risk of endometriosis, in particular endometriosis of the pelvic peritoneum. Further well-designed randomized controlled trials are needed to address these results.

Genetic Mechanisms Driving Uterine Leiomyoma Pathobiology, Epidemiology, and Treatment

Uterine leiomyomas (ULs) are the most common benign tumor of the uterus. They can be associated with symptoms including abnormal uterine bleeding, pelvic pain, urinary frequency, and pregnancy complications. Despite the high prevalence of UL, its underlying pathophysiology mechanisms have historically been poorly understood. Several mechanisms of pathogenesis have been suggested, implicating various genes, growth factors, cytokines, chemokines, and microRNA aberrations. The purpose of this study is to summarize the current research on the relationship of genetics with UL. Specifically, we performed a literature review of published studies to identify how genetic aberrations drive pathophysiology, epidemiology, and therapeutic approaches of UL. With regards to pathophysiology, research has identified MED12 mutations, HMGA2 overexpression, fumarate hydratase deficiency, and cytogenetic abnormalities as contributors to the development of UL. Additionally, epigenetic modifications, such as histone acetylation and DNA methylation, have been identified as contributing to UL tumorigenesis. Specifically, UL stem cells have been found to contain a unique DNA methylation pattern compared to more differentiated UL cells, suggesting that DNA methylation has a role in tumorigenesis. On a population level, genome-wide association studies (GWASs) and epidemiologic analyses have identified 23 genetic loci associated with younger age at menarche and UL growth. Additionally, various GWASs have investigated genetic loci as potential drivers of racial disparities in UL incidence. For example, decreased expression of Cytohesin 4 in African Americans has been associated with increased UL risk. Recent studies have investigated various therapeutic options, including ten-eleven translocation proteins mediating DNA methylation, adenovirus vectors for drug delivery, and "suicide gene therapy" to induce apoptosis. Overall, improved understanding of the genetic and epigenetic drivers of UL on an individual and population level can propel the discovery of novel therapeutic options.

Epidemiologic and genetic associations of female reproductive disorders with depression or dysthymia: a Mendelian randomization study

Observational studies have previously reported an association between depression and certain female reproductive disorders. However, the causal relationships between depression and different types of female reproductive disorders remain unclear in terms of direction and magnitude. We conducted a comprehensive investigation using a two-sample bi-directional Mendelian randomization analysis, incorporating publicly available GWAS summary statistics. Our aim was to establish a causal relationship between genetically predicted depression and the risk of various female reproductive pathological conditions, such as ovarian dysfunction, polycystic ovary syndrome(PCOS), ovarian cysts, abnormal uterine and vaginal bleeding(AUB), endometriosis, leiomyoma of the uterus, female infertility, spontaneous abortion, eclampsia, pregnancy hypertension, gestational diabetes, excessive vomiting in pregnancy, cervical cancer, and uterine/endometrial cancer. We analyzed a substantial sample size, ranging from 111,831 to 210,870 individuals, and employed robust statistical methods, including inverse variance weighted, MR-Egger, weighted median, and MR-PRESSO, to estimate causal effects. Sensitivity analyses, such as Cochran's Q test, MR-Egger intercept test, MR-PRESSO, leave-one-out analysis, and funnel plots, were also conducted to ensure the validity of our results. Furthermore, risk factor analyses were performed to investigate potential mediators associated with these observed relationships. Our results demonstrated that genetic predisposition to depression or dysthymia was associated with an increased risk of developing PCOS (OR = 1.43, 95% CI 1.28-1.59; P = 6.66 × 10-11), ovarian cysts (OR = 1.36, 95% CI 1.20-1.55; P = 1.57 × 10-6), AUB (OR = 1.41, 95% CI 1.20-1.66; P = 3.01 × 10-5), and endometriosis (OR = 1.43, 95% CI 1.27-1.70; P = 2.21 × 10-7) after Bonferroni correction, but no evidence for reverse causality. Our study did not find any evidence supporting a causal or reverse causal relationship between depression/dysthymia and other types of female reproductive disorders. In summary, our study provides evidence for a causal relationship between genetically predicted depression and specific types of female reproductive disorders. Our findings emphasize the importance of depression management in the prevention and treatment of female reproductive disorders, notably including PCOS, ovarian cysts, AUB, and endometriosis.

Identification of miR-30c-5p microRNA in Serum as a Candidate Biomarker to Diagnose Endometriosis

The diagnosis of endometriosis by laparoscopy is delayed until advanced stages. In recent years, microRNAs have emerged as novel biomarkers for different diseases. These molecules are small non-coding RNA sequences involved in the regulation of gene expression and can be detected in peripheral blood. Our aim was to identify candidate serum microRNAs associated with endometriosis and their role as minimally invasive biomarkers. Serum samples were obtained from 159 women, of whom 77 were diagnosed with endometriosis by laparoscopy and 82 were healthy women. First, a preliminary study identified 29 differentially expressed microRNAs between the two study groups. Next, nine of the differentially expressed microRNAs in the preliminary analysis were evaluated in a new cohort of 67 women with endometriosis and 72 healthy women. Upon validation by quantitative real-time PCR technique, the circulating level of miR-30c-5p was significantly higher in the endometriosis group compared with the healthy women group. The area under the curve value of miR-30c-5p was 0.8437, demonstrating its diagnostic potential even when serum samples registered an acceptable limit of hemolysis. Dysregulation of this microRNA was associated with molecular pathways related to cancer and neuronal processes. We concluded that miR-30c-5p is a potential minimally invasive biomarker of endometriosis, with higher expression in the group of women with endometriosis diagnosed by laparoscopy.

Polygenic risk score phenome-wide association study reveals an association between endometriosis and testosterone

BACKGROUND

Endometriosis affects 1 in 9 women, yet it is poorly understood with long diagnostic delays, invasive diagnoses, and poor treatment outcomes. Characterised by the presence of endometrial-like tissue outside of the uterus, its main symptoms are pain and infertility. Endometriosis often co-occurs with other conditions, which may provide insights into the origins of endometriosis.

METHODS

Here a polygenic risk score phenome-wide association study of endometriosis was conducted in the UK Biobank to investigate the pleiotropic effects of a genetic liability to endometriosis. The relationship between the polygenic risk score for endometriosis and health conditions, blood and urine biomarkers and reproductive factors were investigated separately in females, males and females without an endometriosis diagnosis. The relationship between endometriosis and the blood and urine biomarkers was further investigated using genetic correlation and Mendelian randomisation approaches to identify causal relationships.

RESULTS

Multiple health conditions, blood and urine biomarkers and reproductive factors were associated with genetic liability to endometriosis in each group, indicating many endometriosis comorbidities are not dependent on the physical manifestation of endometriosis. Differences in the associated traits between males and females highlighted the importance of sex-specific pathways in the overlap of endometriosis with many other traits. Notably, an association of genetic liability to endometriosis with lower testosterone levels was identified. Follow-up analysis utilising Mendelian randomisation approaches suggested lower testosterone may be causal for both endometriosis and clear cell ovarian cancer.

CONCLUSIONS

This study highlights the diversity of the pleiotropic effects of genetic risk to endometriosis irrespective of a diagnosis of endometriosis. A key finding was the identification of a causal effect of the genetic liability to lower testosterone on endometriosis using Mendelian randomisation.

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.