Correlation of low serum vitamin-D with uterine leiomyoma: a systematic review and meta-analysis

Modifiable prognostic factors in uterine fibroid development: a systematic review of literature

BACKGROUND

Many risk factors in uterine fibroid development have been identified, but women and their physicians are less aware of the influence of lifestyle on uterine fibroid development. The objective of this systematic review is to investigate and summarize modifiable prognostic factors associated with uterine fibroid development.

METHODS

Pubmed and Embase were searched for relevant articles according to PRISMA guidelines. References from included articles were screened and when relevant also included. Human in vivo studies on modifiable factors in fibroid development were included. Studies on non-modifiable factors and treatment, in vitro studies and animal studies were excluded. 607 articles were screened and 33 articles were included. Two independent investigators collected data from the report.

RESULTS

The strongest risk factor for fibroid development was a high BMI, while the strongest protective factors were a high fruit and vegetable intake and high vitamin D intake.

CONCLUSION

More high-quality studies are necessary to better understand the impact of the abovementioned factors as well as the role they play in the growth of already existing fibroids.

The Association of Vitamin D with Uterine Fibroids in Premenopausal Patients: a Systematic Review and Meta-Analysis

OBJECTIVE

This study aims to consolidate existing literature regarding the association between vitamin D and uterine fibroid presence and growth.

DATA SOURCES

A comprehensive search across databases including MEDLINE, Embase, CINAHL, Web of Science, ClinicalTrials.gov, and grey literature was conducted from inception to February 2023, using relevant keywords. Authors were contacted for unpublished data.

STUDY SELECTION

From 9931 studies screened based on title and abstract, those evaluating serum vitamin D levels or vitamin D treatment effects, using ultrasonography for diagnosis, and involving at least 25 pre-menopausal participants were included. Case reports, case series, and reviews were excluded.

DATA EXTRACTION AND SYNTHESIS

Data were extracted using a predefined form. Methodological quality was assessed through the Newcastle-Ottawa Scale and the Risk of Bias-2 tools. Evidence quality was evaluated using Grading of Recommendations Assessment, Development, and Evaluation. Data from three randomized controlled trials (n = 328) and 23 observational studies (n = 5650) were meta-analyzed via random effects modeling. Patients receiving oral vitamin D supplementation had a significantly different change in fibroid size (SMD -5.7%, CI -10.63 to -0.76, P = 0.02, I2 = 99%), as measured by percentage change in diameter or volume, compared to controls, over the span of 2-6 months. Those receiving supplementation had vitamin D insufficiency; regimens varied between 50 000 IU weekly for 12 weeks, 50 000 IU weekly for 8 weeks, and 50 000 IU biweekly for 10 weeks. Patients with fibroids exhibited lower serum vitamin D concentrations (MD -5.50 ng/mL, CI 6.99 to -4.01, P < 0.001, I2 = 87%) and higher odds of vitamin D deficiency (OR 3.71, CI 1.90-7.24, P < 0.001, I2 = 80%).

CONCLUSION

This review underscores the potential of vitamin D in mitigating fibroid development and growth. While promising, further research is warranted to optimize dosage and treatment duration, potentially offering a non-invasive solution for at-risk patients. Continued exploration of vitamin D's role in fibroid treatment is encouraged.

OBJECTIF

Cette étude vise à consolider la littérature existante concernant l'association entre la vitamine D et la présence et la croissance des fibromes utérins. SOURCE DES DONNéES: Une recherche exhaustive a été réalisée dans les bases de données MEDLINE, Embase, CINAHL, Web of Science et ClinicalTrials.gov et dans la littérature à l'aide de mots-clés pertinents pour la période allant de leur création à février 2023. Les auteurs ont été contactés pour obtenir des données non publiées. SéLECTION DES éTUDES: Dans les 9 931 études sélectionnées d'après leurs titre et résumé, seules celles ayant évalué les taux sériques de vitamine D ou les effets d'un traitement à la vitamine D, utilisé l'échographie pour le diagnostic et comptant au moins 25 participantes non ménopausées ont été retenues. Les études de cas, les études de série de cas et les revues n'ont pas été retenues. EXTRACTION DES DONNéES ET SYNTHèSE: Les données ont été extraites au moyen d'un formulaire prédéfini. La qualité méthodologique a été évaluée au moyen de l'échelle de Newcastle-Ottawa et de l'outil d'évaluation du risque de biais RoB-2. La qualité des données a été évaluée à l'aide de la méthodologie GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Les données de trois essais cliniques randomisés (n = 328) et de 23 études observationnelles (n = 5650) ont été méta-analysées à l'aide d'une modélisation à effets aléatoires. Les patientes recevant une supplémentation orale en vitamine D ont présenté un changement significativement différent de la taille des fibromes (différence des moyennes standardisées : -5,7 %; IC : -10,63 à -0,76; P = 0,02; I2 = 99 %), tel que mesuré par le changement en pourcentage du diamètre ou du volume, par rapport aux témoins, sur une période de 2 à 6 mois. Les personnes recevant une supplémentation présentaient une insuffisance en vitamine D; les schémas posologiques étaient de 50 000 UI par semaine pendant 12 semaines, 50 000 UI par semaine pendant 8 semaines ou 50 000 UI toutes les deux semaines pendant 10 semaines. Les patientes atteintes de fibromes avaient des concentrations sériques de vitamine D plus faibles (différence moyenne : -5,50 ng/mL; IC : 6,99 à -4,01; P < 0,001; I2 = 87 %) et un risque plus élevé de carence en vitamine D (RC : 3,71; IC : 1,90-7,24; P < 0,001; I2 = 80 %).

CONCLUSION

Cette étude souligne le potentiel de la vitamine D dans l'atténuation du développement et de la croissance des fibromes. Bien que ces conclusions soient prometteuses, la recherche doit se poursuivre afin d'optimiser le dosage et la durée du traitement, ce qui pourrait constituer une solution non invasive pour les patientes à risque. La poursuite de l'étude du rôle de la vitamine D dans le traitement des fibromes est encouragée.

Currently Available Treatment Modalities for Uterine Fibroids

Uterine fibroids (leiomyomas and myomas) are the most common benign gynecological condition in patients presenting with abnormal uterine bleeding, pelvic masses causing pressure or pain, infertility and obstetric complications. Almost a third of women with fibroids need treatment due to symptoms.

OBJECTIVES

In this review we present all currently available treatment modalities for uterine fibroids.

METHODS

An extensive search for the available data regarding surgical, medical and other treatment options for uterine fibroids was conducted.

REVIEW

Nowadays, treatment for fibroids is intended to control symptoms while preserving future fertility. The choice of treatment depends on the patient's age and fertility and the number, size and location of the fibroids. Current management strategies mainly involve surgical interventions (hysterectomy and myomectomy hysteroscopy, laparoscopy or laparotomy). Other surgical and non-surgical minimally invasive techniques include interventions performed under radiologic or ultrasound guidance (uterine artery embolization and occlusion, myolysis, magnetic resonance-guided focused ultrasound surgery, radiofrequency ablation of fibroids and endometrial ablation). Medical treatment options for fibroids are still restricted and available medications (progestogens, combined oral contraceptives andgonadotropin-releasing hormone agonists and antagonists) are generally used for short-term treatment of fibroid-induced bleeding. Recently, it was shown that SPRMs could be administered intermittently long-term with good results on bleeding and fibroid size reduction. Novel medical treatments are still under investigation but with promising results.

CONCLUSIONS

Treatment of fibroids must be individualized based on the presence and severity of symptoms and the patient's desire for definitive treatment or fertility preservation.

Vitamin D and its binding protein in patients with leiomyomas

AIM

This study examined the levels of VitD, VitD binding protein (DBP), and free VitD in leiomyomas patients and their association with the quantity, dimensions, and site of fibroid growths. Additionally, we evaluated the potentiality of employing these factors as a biomarker tool for the diagnosis and assessment of uterine fibroid progression.

METHODS

This study involved the participation of 55 women with leiomyomas and 50 healthy women. We utilized commercial ELISA kits to measure the levels of total VitD and DBP in their serum. Additionally, we calculated the levels of free VitD and the ratio of VitD to DBP. Moreover, we determined the number, size, and location of the leiomyomas in the patients.

RESULTS

There were no significant differences in the levels of total VitD between the groups. However, patients had significantly lower levels of free VitD and higher levels of DBP compared to the control group. The size of the largest leiomyomas showed a negative relationship with free VitD and a positive relationship with DBP. Receiver operating characteristic analyses, showed that the cut-off value for free VitD was 4.47 pg/mL, with a sensitivity of 75.6% and a specificity of 74.4%. The cut-off value for DBP was 256.2 μg/mL, with a sensitivity of 86% and a specificity of 70.3%.

CONCLUSIONS

Free VitD and DBP potentially contribute to the development of leiomyomas and are linked to the size of these tumors. The measurement of serum levels of these factors could serve as additional biomarkers for the diagnosis of leiomyomas.

Epigallocatechin Gallate for the Treatment of Benign and Malignant Gynecological Diseases-Focus on Epigenetic Mechanisms

The most common malignant gynecologic diseases are cervical, uterine, ovarian, vaginal, and vulvar cancer. Among them, ovarian cancer causes more deaths than any other cancer of the female reproductive system. A great number of women suffer from endometriosis, uterine fibroids (UFs), adenomyosis, dysmenorrhea, and polycystic ovary syndrome (PCOS), which are widespread benign health problems causing troublesome and painful symptoms and significantly impairing the quality of life of affected women, and they are some of the main causes of infertility. In addition to the available surgical and pharmacological options, the effects of supporting standard treatment with naturally occurring compounds, mainly polyphenols, are being studied. Catechins are responsible for the majority of potential health benefits attributed to green tea consumption. Epigallocatechin gallate (EGCG) is considered a non-toxic, natural compound with potential anticancer properties. Antioxidant action is its most common function, but attention is also drawn to its participation in cell division inhibition, apoptosis stimulation and epigenetic regulation. In this narrative review, we describe the role of EGCG consumption in preventing the development of benign reproductive disorders such as UF, endometriosis, and PCOS, as well as malignant gynecologic conditions. We discuss possible epigenetic mechanisms that may be related to the action of EGCG.

Effect of Oral Consumption of Vitamin D on Uterine Fibroids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Impaired vitamin D status is highly prevalent among women with UFs. The objective of this first-ever systematic review and meta-analysis was to summarize the effect of vitamin D supplementation on the size of uterine fibroids (UFs). We performed a comprehensive literature search for published randomized controlled trials (RCTs) in Medline, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials from inception to September 2022. Five trials including 511 participants (256 cases and 255 controls) were included. Pooling results from five trials, which compared size of UFs between experimental and placebo groups, revealed that vitamin D supplementation could significantly decrease the size of UFs (standardized mean difference [SMD]: -0.48, 95% confidence interval [CI]: -0.66, -0.31) and cause improvement in serum level of vitamin D compared to placebo group (SMD: 3.1, 95% CI: 0.66, 5.55). A significant effect was observed in the subset of trials administering vitamin D supplementation for >8 wk (SMD: -0.62, 95% CI: -0.88, -0.37). In conclusion, vitamin D supplementation significantly increases serum levels of vitamin D and reduces the size of UFs. However, larger, well-designed RCTs are still needed to determine the effect of vitamin D on other parameters of UFs.

Evidence-Based Approach for Secondary Prevention of Uterine Fibroids (The ESCAPE Approach)

Uterine fibroids (UFs) are common tumors in women of reproductive age. It is imperative to comprehend UFs' associated risk factors to facilitate early detection and prevention. Simple relying on surgical/pharmacological treatment of advanced disease is not only highly expensive, but it also deprives patients of good quality of life (QOL). Unfortunately, even if the disease is discovered early, no medical intervention is traditionally initiated until the disease burden becomes high, and only then is surgical intervention performed. Furthermore, after myomectomy, the recurrence rate of UFs is extremely high with the need for additional surgeries and other interventions. This confused approach is invasive and extremely costly with an overall negative impact on women's health. Secondary prevention is the management of early disease to slow down its progression or even halt it completely. The current approach of watchful observation for early disease is considered a major missed opportunity in the literature. The aim of this article is to present an approach named the ESCAPE (Evidence-Based Approach for Secondary Prevention) of UF management. It comprises simple, inexpensive, and safe steps that can arrest the development of UFs, promote overall reproductive health, decrease the number of unnecessary surgeries, and save billions of health care systems' dollars worldwide.

Vitamin D and infertility

PURPOSE OF REVIEW

Vitamin D deficiency has been implicated as a contributing factor to a spectrum of reproductive health burden, including difficulty conceiving, pathogenesis of gynaecological disorders such as uterine fibroids and endometriosis, to metabolic and endocrine burden of polycystic ovarian syndrome (PCOS).

RECENT FINDINGS

There have been recent publications showing that in infertile women who are supplemented with vitamin D, there are higher pregnancy rates; there are improved ovarian reserve parameters in women with diminished ovarian reserve; curtailed fibroid growth in those with uterine myomas; lessened dysmenorrhea in endometriosis patients; and improved menstrual regularity, lowered testosterone, AMH and insulin levels in women with PCOS. In infertile men, sperm parameters, especially motility, are positively correlated with vitamin D serum levels.

SUMMARY

Vitamin D status appears to be relevant to reproductive physiology, and to physiological processes underlying common gynaecological disorders as well as for reproductive success.

A Systematic Review of Vitamin D and Fibroids: Pathophysiology, Prevention, and Treatment

Uterine fibroids are the most common tumor of reproductive-age women worldwide and cause significant morbidity in affected women. Vitamin D has emerged as a potential therapy for uterine fibroids based on experimental and epidemiologic evidence. The objective of this systematic review was to evaluate the role of vitamin D in the pathophysiology of uterine fibroids and its efficacy for prevention and treatment of fibroids. A comprehensive search was conducted of Cochrane Library, Embase, PubMed, Scopus, and Web of Science from inception to March 2022. English-language publications that evaluated vitamin D and uterine fibroids in humans, whether experimental or clinical, were considered. The search yielded 960 publications, and 89 publications met inclusion criteria: 23 preclinical studies, 25 clinical studies, and 41 review articles. Preclinical studies indicated that the vitamin D receptor was decreased in fibroid cells. Vitamin D treatment of fibroid cells decreased proliferation, extracellular matrix protein expression, and Wnt/β-catenin signaling. Fourteen clinical studies (n = 3535 participants) assessed serum vitamin D level in women with ultrasound-proven fibroids, and all found an inverse correlation between serum vitamin D level and presence of fibroids. Five clinical studies (n = 472 patients) evaluated treatment of fibroids with vitamin D. Four of five studies showed vitamin D significantly inhibited fibroid growth. One pilot study (n = 109 patients) of vitamin D for secondary prevention of fibroids demonstrated smaller recurrent fibroids in the treated group. These studies provide evidence for vitamin D as a therapy for uterine fibroids and underscore the need for well-designed, randomized, placebo-controlled clinical trials.

Update on the Role and Regulatory Mechanism of Extracellular Matrix in the Pathogenesis of Uterine Fibroids

Uterine fibroids (UFs), also known as leiomyomas, are benign tumors of the myometrium affecting over 70% of women worldwide, particularly women of color. Although benign, UFs are associated with significant morbidity; they are the primary indication for hysterectomy and a major source of gynecologic and reproductive dysfunction, ranging from menorrhagia and pelvic pain to infertility, recurrent miscarriage, and preterm labor. So far, the molecular mechanisms underlying the pathogenesis of UFs are still quite limited. A knowledge gap needs to be filled to help develop novel strategies that will ultimately facilitate the development of therapies and improve UF patient outcomes. Excessive ECM accumulation and aberrant remodeling are crucial for fibrotic diseases and excessive ECM deposition is the central characteristics of UFs. This review summarizes the recent progress of ascertaining the biological functions and regulatory mechanisms in UFs, from the perspective of factors regulating ECM production, ECM-mediated signaling, and pharmacological drugs targeting ECM accumulation. In addition, we provide the current state of knowledge by discussing the molecular mechanisms underlying the regulation and emerging role of the extracellular matrix in the pathogenesis of UFs and in applications. Comprehensive and deeper insights into ECM-mediated alterations and interactions in cellular events will help develop novel strategies to treat patients with this common tumor.

Vitamin D and uterine fibroid growth, incidence, and loss: a prospective ultrasound study

OBJECTIVE

Fibroid treatments that have few side-effects and can preserve fertility are a clinical priority. We studied the association between serum vitamin D and uterine fibroid growth, incidence, and loss.

DESIGN

A prospective community cohort study (enrollment 2010-2012) with 4 study visits over 5 years to conduct standardized ultrasounds, measure 25-hydroxyvitamin D (25(OH)D), and update covariates.

SETTING

Detroit, Michigan area.

PATIENTS

Self-identified African American or Black women aged 23-35 at enrollment without previous clinical diagnosis of fibroids.

INTERVENTION(S)

Serum 25(OH)D measured using immunoassay or liquid chromatography-tandem mass spectrometry.

MAIN OUTCOME MEASURE(S)

The primary outcomes were fibroid growth, as measured by change in log volume per 18 months, and fibroid incidence (first detection of fibroid in previously fibroid-free uterus). Adjusted growth estimates from linear mixed models were converted to estimated difference in volume for high vs. low 25(OH)D. Incidence differences were estimated as hazard ratios from age-specific Cox regression. A secondary outcome fibroid loss (reduction in fibroid number between visits), was modeled using Poisson regression. Covariates (reproductive and hormonal variables, demographics, body mass index, current smoking) and 25(OH)D were modeled as time-varying factors.

RESULT(S)

At enrollment among 1,610 participants with ≥1 follow-up ultrasound, mean age was 29.2 years, 73% had deficient vitamin D (<20ng/mL), and only 7% had sufficient vitamin D (≥30ng/mL). Serum 25(OH)D ≥20ng/mL compared with <20ng/mL was associated with an estimated 9.7% reduction in fibroid growth (95% confidence interval [CI]: -17.3%, -1.3%), similar to the minimally adjusted estimate -8.4% (95% CI: -16.4, 0.3). Serum 25(OH)D ≥30ng/mL compared with <30ng/mL was associated with an imprecise 22% reduction in incidence (adjusted hazard ratio=0.78; 95% CI: 0.47, 1.30), similar to the unadjusted estimate of 0.84 (95% CI: 0.51, 1.39). The >30ng/mL group also had a 32% increase in fibroid loss (adjusted risk ratio=1.32; 95% CI: 0.95, 1.83).

CONCLUSION(S)

Our data support the hypothesis that high concentrations of vitamin D decrease fibroid development but are limited by the few participants with serum 25(OH)D ≥30ng/mL. Interventional trials that raise and maintain 25(OH)D concentrations >30ng/mL and then prospectively monitor fibroid development are needed to further assess supplemental vitamin D efficacy and determine optimal treatment protocols.

Immunohistochemical Expression of Vitamin D Receptor in Uterine Fibroids

One of the many factors involved in the development of uterine fibroids is vitamin D deficiency. One aspect of this deficiency is decreased serum concentration of calcidiol-25(OH)D, a metabolite of D3 vitamin. The active form of vitamin D3, which arises after numerous enzymatic reactions, is calcitriol-1,25(OH)2D3; this compound is transported to various body tissues. Vitamin D possesses extra-genomic effects due to its influence on various signaling pathways, i.e., through activating tyrosine kinases and by genomic effects via binding to a specific nuclear receptor, vitamin D receptor (VDR). The vitamin D/VDR complex regulates the expression of genes and is involved in the pathogenesis of fibroids. Numerous studies have shown that vitamin D supplementation reduces fibroid size. It has also been shown that the expression of VDR in myoma tissue is significantly lower than in the uterine muscle tissue at the tumor periphery. However, the expression of VDR in non-myoma uterine muscle has not previously been investigated. Our VDR expression studies were performed immunohistochemically with tissue microarrays (TMA) in three tissue groups: 98 uterine myoma tissues, 98 uterine tissues (tumor margin), and 12 tissues of normal uterine muscle (i.e., without fibroids). A statistical analysis showed significantly lower VDR expression in uterine muscle at the periphery of the fibroid than in healthy uterine muscle. Lower expression of VDR at the periphery of the myoma compared to that in normal uterine muscle may indicate potential for new myomas. This observation and the described reduction in the size of fibroids after vitamin D supplementation supports the hypothesis of causal development of uterine fibroids and may be useful for the prevention of re-development in the event of their excision from the uterus.

Comprehensive Review of Uterine Fibroids: Developmental Origin, Pathogenesis, and Treatment

Uterine fibroids are benign monoclonal neoplasms of the myometrium, representing the most common tumors in women worldwide. To date, no long-term or noninvasive treatment option exists for hormone-dependent uterine fibroids, due to the limited knowledge about the molecular mechanisms underlying the initiation and development of uterine fibroids. This paper comprehensively summarizes the recent research advances on uterine fibroids, focusing on risk factors, development origin, pathogenetic mechanisms, and treatment options. Additionally, we describe the current treatment interventions for uterine fibroids. Finally, future perspectives on uterine fibroids studies are summarized. Deeper mechanistic insights into tumor etiology and the complexity of uterine fibroids can contribute to the progress of newer targeted therapies.

Relation between vitamin D and uterine fibroid

Background; Uterine fibroids (UFs) are benign tumors that develop from the uterus' smooth muscle cells and are mostly found in the pelvic. Aim of the work; we aimed to compare serum vitamin D level between patients, have uterine fibroids and those without. Subjects and methods; our current study included 90 females and was conducted as a case control study; 50 were diagnosed with uterine fibroid and 40 were healthy volunteers (control) during the period from July 2019 to July 2020.  they were recruited from Al Zahra’a University Hospital. Serum vitamin D level was measured by ELISA. Results; Vitamin D serum concentrations were significantly lower in the studied females with UFs compared to healthy controls (mean 19.24 ±16.0 vs. 33.83 ±17.5) ng/mL in cases and controls, respectively, with a statistically significant p-value <0.001. Serum vitamin D levels have a significant, linear, negative, moderate association with uterine fibroids size. Conclusion; in our study group, reduced serum vitamin D levels were found to be inversely related to UF burden. A lack of vitamin D may be a risk factor for the incidence of uterine fibroids.

The Effect of Estrogen-Related Genetic Variants on the Development of Uterine Leiomyoma: Meta-analysis

Uterine leiomyoma is the most common benign gynecological tumor in women of reproductive age. It has been diagnosed approximately in 5 to 69% of women and was symptomatic in 30% of them. The underlying pathobiology of uterine leiomyoma is not well understood yet, but it can be defined as an estrogen-dependent tumor. Thus, this meta-analysis aimed to investigate ESR1rs9340799 (XbaI, A351G), ESR1rs2234693 (Pvull, T397C), and COMT rs4680 (Val158Met) polymorphisms, which affect estrogen functioning and metabolism, in association with UL risk. According to PRISMA protocol, systematic searching of databases resulted 24 included studies. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were used to evaluate associations of the three targeted polymorphisms with uterine leiomyoma risk in dominant model of inheritance. Meta-analysis included 4969 women diagnosed with uterine leiomyoma and 4934 controls. ESR1 (XbaI, A351G) polymorphism showed no significant association with uterine myeloma risk (OR = 1.19, 95% CI 0.98-1.45, P = 0.07). ESR1 (Pvull, T397C) was associated with a higher risk of uterine leiomyoma, but only in Asian (OR = 1.78, 95% CI 1.30-2.45, P = 0.0004) and COMT (Val158Met) according to our data is significantly associated with a lower risk of leiomyoma (OR = 0.83, 95% CI 0.71-0.97, P = 0.02). Our updated meta-analysis provided statistical evidence for the protective role of COMT (Val158Met) in association with the susceptibility to uterine leiomyoma and the possible role of ESR1 (Pvull, T397C) as a risk factor of this tumor.

Epigenomic and enhancer dysregulation in uterine leiomyomas

BACKGROUND

Uterine leiomyomas, also known as uterine fibroids or myomas, are the most common benign gynecological tumors and are found in women of reproductive and postmenopausal age. There is an exceptionally high prevalence of this tumor in women by the age of 50 years. Black women are particularly affected, with an increased incidence, earlier age of onset, larger and faster growing fibroids and greater severity of symptoms as compared to White women. Although advances in identifying genetic and environmental factors to delineate these fibroids have already been made, only recently has the role of epigenomics in the pathogenesis of this disease been considered.

OBJECTIVE AND RATIONALE

Over recent years, studies have identified multiple epigenomic aberrations that may contribute to leiomyoma development and growth. This review will focus on the most recent discoveries in three categories of epigenomic changes found in uterine fibroids, namely aberrant DNA methylation, histone tail modifications and histone variant exchange, and their translation into altered target gene architecture and transcriptional outcome. The findings demonstrating how the altered 3D shape of the enhancer can regulate gene expression from millions of base pairs away will be discussed. Additionally, translational implications of these discoveries and potential roadblocks in leiomyoma treatment will be addressed.

SEARCH METHODS

A comprehensive PubMed search was performed to identify published articles containing keywords relevant to the focus of the review, such as: uterine leiomyoma, uterine fibroids, epigenetic alterations, epigenomics, stem cells, chromatin modifications, extracellular matrix [ECM] organization, DNA methylation, enhancer, histone post-translational modifications and dysregulated gene expression. Articles until September 2021 were explored and evaluated to identify relevant updates in the field. Most of the articles focused on in the discussion were published between 2015 and 2021, although some key discoveries made before 2015 were included for background information and foundational purposes. We apologize to the authors whose work was not included because of space restrictions or inadvertent omission.

OUTCOMES

Chemical alterations to the DNA structure and of nucleosomal histones, without changing the underlying DNA sequence, have now been implicated in the phenotypic manifestation of uterine leiomyomas. Genome-wide DNA methylation analysis has revealed subsets of either suppressed or overexpressed genes accompanied by aberrant promoter methylation. Furthermore, differential promoter access resulting from altered 3D chromatin structure and histone modifications plays a role in regulating transcription of key genes thought to be involved in leiomyoma etiology. The dysregulated genes function in tumor suppression, apoptosis, angiogenesis, ECM formation, a variety of cancer-related signaling pathways and stem cell differentiation. Aberrant DNA methylation or histone modification is also observed in altering enhancer architecture, which leads to changes in enhancer-promoter contact strength, producing novel explanations for the overexpression of high mobility group AT-hook 2 and gene dysregulation found in mediator complex subunit 12 mutant fibroids. While many molecular mechanisms and epigenomic features have been investigated, the basis for the racial disparity observed among those in the Black population remains unclear.

WIDER IMPLICATIONS

A comprehensive understanding of the exact pathogenesis of uterine leiomyoma is lacking and requires attention as it can provide clues for prevention and viable non-surgical treatment. These findings will widen our knowledge of the role epigenomics plays in the mechanisms related to uterine leiomyoma development and highlight novel approaches for the prevention and identification of epigenome targets for long-term non-invasive treatment options of this significantly common disease.

Body mass index and vitamin D as risk factors for the development of uterine leiomyomas in Mexican women

Objective:

The objective of the present study was to determine if body mass index and vitamin D levels are risk factors for the development of uterine leiomyomas in Mexican women.

Methods:

A cross-sectional study was designed. Inclusion criteria were women between 20 and 55 years with a suspect of uterine leiomyomas. Transvaginal ultrasonography was made to confirm the diagnosis and clinical variables were collected. Vitamin D levels were measured in serum by chemiluminescence immunoassay. Binary linear regression analysis was conducted to assess the predictors of uterine leiomyomas.

Results:

A total of 106 patients were evaluated, the mean age was 41.4 ± 8.0 years. The serum levels of vitamin D were insufficient in 94 (88.7%) and 82 (77.3%) has overweight or obesity. However, only 50 (47.2%) of participants have a diagnostic of uterine leiomyomas. BMI not increased the probability of having insufficient levels of vitamin D or uterine leiomyomas. Only, age (> 45 years) and levels of vitamin D (<30 ng/mL) were predictors of uterine leiomyomas (OR 10.345, 95% CI 2.737–39.095; p = 0.001; and OR 2.26, 95% CI 1.011–5.073; p = 0.014), respectively.

Conclusions:

Insufficient levels of vitamin D are common in Mexican women. Age and hypovitaminosis D are possible risk factors in the development of uterine leiomyomas in Mexican women.

A prospective cohort study of ambient air pollution exposure and risk of uterine leiomyomata

STUDY QUESTION

To what extent are ambient concentrations of particulate matter <2.5 microns (PM2.5), nitrogen dioxide (NO2) and ozone (O3) associated with risk of self-reported physician-diagnosed uterine leiomyomata (UL)?

SUMMARY ANSWER

In this large prospective cohort study of Black women, ambient concentrations of O3, but not PM2.5 or NO2, were associated with increased risk of UL.

WHAT IS KNOWN ALREADY

UL are benign tumors of the myometrium that are the leading cause of gynecologic inpatient care among reproductive-aged women. Black women are clinically diagnosed at two to three times the rate of white women and tend to exhibit earlier onset and more severe disease. Two epidemiologic studies have found positive associations between air pollution exposure and UL risk, but neither included large numbers of Black women.

STUDY DESIGN, SIZE, DURATION

We conducted a prospective cohort study of 21 998 premenopausal Black women residing in 56 US metropolitan areas from 1997 to 2011.

PARTICIPANTS/MATERIAL, SETTING, METHODS

Women reported incident UL diagnosis and method of confirmation (i.e. ultrasound, surgery) on biennial follow-up questionnaires. We modeled annual residential concentrations of PM2.5, NO2 and O3 throughout the study period. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for a one-interquartile range (IQR) increase in air pollutant concentrations, adjusting for confounders and co-pollutants.

MAIN RESULTS AND THE ROLE OF CHANCE

During 196 685 person-years of follow-up, 6238 participants (28.4%) reported physician-diagnosed UL confirmed by ultrasound or surgery. Although concentrations of PM2.5 and NO2 were not appreciably associated with UL (HRs for a one-IQR increase: 1.01 (95% CI: 0.93, 1.10) and 1.05 (95% CI: 0.95, 1.16), respectively), O3 concentrations were associated with increased UL risk (HR for a one-IQR increase: 1.19, 95% CI: 1.07, 1.32). The association was stronger among women age <35 years (HR: 1.26, 95% CI: 0.98, 1.62) and parous women (HR: 1.28, 95% CI: 1.11, 1.48).

LIMITATIONS, REASONS FOR CAUTION

Our measurement of air pollution is subject to misclassification, as monitoring data are not equally spatially distributed and we did not account for time-activity patterns. Our outcome measure was based on self-report of a physician diagnosis, likely resulting in under-ascertainment of UL. Although we controlled for several individual- and neighborhood-level confounding variables, residual confounding remains a possibility.

WIDER IMPLICATIONS OF THE FINDINGS

Inequitable burden of air pollution exposure has important implications for racial health disparities, and may be related to disparities in UL. Our results emphasize the need for additional research focused on environmental causes of UL.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the National Cancer Institute (U01-CAA164974) and the National Institute of Environmental Health Sciences (R01-ES019573). L.A.W. is a fibroid consultant for AbbVie, Inc. and accepts in-kind donations from Swiss Precision Diagnostics, Sandstone Diagnostics, FertilityFriend.com and Kindara.com for primary data collection in Pregnancy Study Online (PRESTO). M.J. declares consultancy fees from the Health Effects Institute (as a member of the review committee). The remaining authors declare they have no actual or potential competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

A-kinase anchoring protein 13 interacts with the vitamin D receptor to alter vitamin D-dependent gene activation in uterine leiomyoma cells

OBJECTIVE

To determine if A-kinase anchoring protein 13 (AKAP13) interacts with the vitamin D receptor (VDR) to alter vitamin D-dependent signaling in fibroid cells. Uterine leiomyomas (fibroids) are characterized by a fibrotic extracellular matrix and are associated with vitamin D deficiency. Treatment with vitamin D (1,25-dihydroxyvitamin D₃) reduces fibroid growth and extracellular matrix gene expression. A-kinase anchoring protein 13 is overexpressed in fibroids and interacts with nuclear hormone receptors, but it is not known whether AKAP13 may interact with the VDR to affect vitamin D signaling in fibroids.

DESIGN

Laboratory studies.

SETTING

Translational science laboratory.

INTERVENTION(S)

Human immortalized fibroid or myometrial cells were treated with 1,25-hydroxyvitamin D₃ (1,25(OH)₂D₃) and transfected using expression constructs for AKAP13 or AKAP13 mutants, RhoQL, C3 transferase, or small interfering ribonucleic acids (RNAs).

MAIN OUTCOME MEASURE(S)

Messenger ribonucleic acid (mRNA) levels of AKAP13, fibromodulin, and versican as measured by quantitative real-time polymerase chain reaction. Glutathione S-transferase-binding assays. Vitamin D-dependent gene activation as measured by luciferase assays.

RESULT(S)

1,25(OH)₂D₃ resulted in a significant reduction in mRNA levels encoding AKAP13, versican, and fibromodulin. Small interfering RNA silencing of AKAP13 decreased both fibromodulin and versican mRNA levels. Glutathione S-transferase-binding assays revealed that AKAP13 bound to the VDR through its nuclear receptor interacting region. Cotransfection of AKAP13 and VDR significantly reduced vitamin D-dependent gene activation. RhoA pathway inhibition partially relieved repression of vitamin D-dependent gene activation by AKAP13.

CONCLUSION(S)

These data suggest that AKAP13 inhibited the vitamin D receptor activation by a mechanism that required, at least in part, RhoA activation.

Evaluation of vitamin D receptor expression in uterine leiomyoma and nonneoplastic myometrial tissue: a cross-sectional controlled study

BACKGROUND

Uterine myomas are the most frequent benign solid pelvic tumors in women of reproductive age. At present, uterine myomas are the most common indication for hysterectomy because of the morbidity they cause, including intense bleeding, compression of adjacent organs, pain, and infertility. Some studies show that vitamin D receptor (VDR) expression is correlated with the etiology of uterine leiomyomas. This study aimed to assess the expression of VDR in uterine leiomyoma and nonneoplastic myometrial tissue.

METHODS

A controlled cross-sectional study involving 40 women who underwent abdominal hysterectomy the Department of Gynecology of the Getúlio Vargas Hospital of Federal University of Piauí, Brazil, was performed to compare the immunohistochemical expression of VDR in samples of uterine leiomyoma tissue with adjacent nonneoplastic myometrial tissue. The mean percetages of stained nuclei in the two groups was compared by Student's t teste, with significance established at p < 0.05.

RESULTS

The percentage of cells with nuclei stained by anti-VDR in the myometrial and leiomyoma tissue was 79.52 % (± 4.32) and 60.22 % (± 7.24), respectively (p < 0.0001).

CONCLUSIONS

The mean percentage of nuclei expressing VDR was significantly lower in the uterine leiomyoma than in nonneoplastic myometrial tissue.

Vitamin D as a risk factor for the presence of asymptomatic uterine fibroids in premenopausal Han Chinese women

OBJECTIVES

To investigate the relationship between vitamin D deficiency and the risk of asymptomatic uterine fibroids (UFs).

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENT(S)

The present analysis recruited 133 asymptomatic patients with UFs and 80 normal control subjects from October 2017 to June 2020. Age matching created 61 pairs.

INTERVENTION(S)

Medical history, transvaginal or transabdominal genital ultrasound scan, blood sampling, and measurement of vitamin D concentrations.

MAIN OUTCOME MEASURE(S)

Evaluation of the impact of vitamin D level on the risk of newly diagnosed asymptomatic UFs in premenopausal Han Chinese women.

RESULT(S)

Vitamin D levels of UF-positive patients were lower than those of healthy control subjects in unmatched samples (12.1 ng/mL vs. 16.8 ng/mL) and in matched samples (11.4 vs. 17.5 ng/mL). Younger patients (≤40 years) had a lower vitamin D level than older subjects in healthy control group (15.1 ng/mL vs. 19.0 ng/mL). We did not observe any age-vitamin D interactive effect in unmatched samples. Multivariate logistic regression revealed that asymptomatic patients presented a lower level of vitamin D than did normal groups in both unmatched and matched sample. In addition, the optimal threshold vitamin D level for having asymptomatic UFs was 14.34 ng/mL.

CONCLUSION(S)

Vitamin D deficiency may be associated with increased risk of asymptomatic UFs in premenopausal Han Chinese women.

Vitamin D: Mechanism of Action and Biological Effects in Uterine Fibroids

Uterine fibroids (UFs) are the most common benign gynecological tumors. It was estimated that fifty percent of women presenting with UFs has symptomatology that negatively influences their quality of life. Pharmacological and/or surgical treatments are frequently required, depending on the woman's desire to preserve fertility, with a high impact on healthcare costs. Generally, the use of currently available pharmacological treatments may lead to side effects. Therefore, there is a growing interest in a natural and safe approach for UFs. In recent years, epidemiological studies reported a vitamin D deficiency in patients with UFs raised interest in the potential biological effects of vitamin D supplementation. In vitro studies proved vitamin D efficacy in inhibiting UFs growth by targeting pathways involved in the regulation of various biological processes, including proliferation, extracellular matrix (ECM) remodeling, DNA repair, signaling and apoptosis. However, clinical studies supported only in part the beneficial effects of vitamin D supplementation in reducing UFs growth and tumor volume. Randomized controlled trials and large population studies are mandatory as the potential clinical benefits are likely to be substantial.