Levels of circulating insulin cell-free DNA in women with polycystic ovary syndrome - a longitudinal cohort study

Role of genomic DNA methylation in PCOS pathogenesis: a systematic review and meta-analysis involving case controlled clinical studies

PCOS is often associated with aberrant DNA methylation. Despite the advances in diagnostics and treatment of PCOS, the pathophysiological mechanism remain unknown. Several genes are epigenetically dysregulated in PCOS and associated with pathological consequences of PCOS and metabolic comorbidities, however the methylation status of specific genes and to what extent the genes are deregulated in terms of methylation pattern are unknown. This review aimed to analyse the existing data for specific genes and find conclusive evidence of their involvement in PCOS and associated risks. A comprehensive literature search was conducted in five electronic databases. The case-controlled clinical studies using both PCOS and healthy women and evaluating the methylation pattern without any treatment or intervention were included in the study. A random-effect model was used to extract the data for meta-analysis, and outcomes were expressed as standardized mean difference with a 95% CI. From 541 screened records, 41 studies were included in the review and 21 of them were used for meta-analysis of 20 genes. Meta-analysis revealed a significant global DNA hypomethylation in different tissues and peripheral blood of patients with PCOS compared to healthy controls. Specific gene methylation assessment revealed that genes associated with several functions were significantly hypomethylated and hypermethylated in patients with PCOS. This review provides conclusive evidence of epigenetic deregulation of specific genes in PCOS. These genes can potentially be used to develop diagnostic biomarkers or as targets for personalised therapy.

Natural history of polycystic ovary syndrome: A systematic review of cardiometabolic outcomes from longitudinal cohort studies

OBJECTIVE

Women with polycystic ovary syndrome (PCOS) have a worsened metabolic profile but the progression of cardiometabolic features over time is unclear. Understanding this natural history is a key priority in PCOS research and vital for guiding the prevention and management of this common condition. We explored cardiometabolic changes that are observed in women with PCOS compared to those without PCOS across the life course.

DESIGN, PATIENTS AND MEASUREMENTS

A systematic review of longitudinal cohort studies was conducted across MEDLINE, EMBASE, Ovid PsycInfo, CINAHL PLUS and EBM reviews between 15 January 2020 and 11 February 2021. Eligible studies included participants with or without PCOS diagnosed according to the 2003 Rotterdam or the 1990 National Institutes of Health (NIH) criteria. We included studies that were published from the year 1990 to 2021 with data on cardiometabolic outcomes as per the PCOS core outcomes set.

RESULTS

There were 31 longitudinal studies with 28,316 participants from four continents. At the start of follow up, participants were aged between 1 year and 49 years with a follow-up period ranging from 2 to 32 years. Changes in BMI and the risk of coronary heart disease were similar in adult women with and without PCOS. Women with PCOS had a higher risk of Type 2 diabetes than their non-PCOS counterparts. Evidence for the majority of all other outcomes was conflicting and with inadequate data.

CONCLUSION

Understanding the natural history of PCOS and particularly changes in cardiometabolic features remains challenging. Existing literature is extensive but heterogeneous and inconsistent. Longitudinal studies in unselected populations are needed to provide high-quality data in this area.

Computational challenges in detection of cancer using cell-free DNA methylation

Cell-free DNA(cfDNA) methylation profiling is considered promising and potentially reliable for liquid biopsy to study progress of diseases and develop reliable and consistent diagnostic and prognostic biomarkers. There are several different mechanisms responsible for the release of cfDNA in blood plasma, and henceforth it can provide information regarding dynamic changes in the human body. Due to the fragmented nature, low concentration of cfDNA, and high background noise, there are several challenges in its analysis for regular use in diagnosis of cancer. Such challenges in the analysis of the methylation profile of cfDNA are further aggravated due to heterogeneity, biomarker sensitivity, platform biases, and batch effects. This review delineates the origin of cfDNA methylation, its profiling, and associated computational problems in analysis for diagnosis. Here we also contemplate upon the multi-marker approach to handle the scenario of cancer heterogeneity and explore the utility of markers for 5hmC based cfDNA methylation pattern. Further, we provide a critical overview of deconvolution and machine learning methods for cfDNA methylation analysis. Our review of current methods reveals the potential for further improvement in analysis strategies for detecting early cancer using cfDNA methylation.

OUP accepted manuscript

STUDY QUESTION

What is the natural history of reproductive, psychological and oncological features in women with polycystic ovary syndrome (PCOS) in comparison to those without PCOS across the life course?

SUMMARY ANSWER

Existing longitudinal data on changes in reproductive, psychological and oncological features in PCOS are inadequate and conflicting, but the limited evidence suggests that total testosterone (T) and dehydroepiandrosterone sulphate (DHEAS) levels decline more significantly in women with PCOS than in those without PCOS, and the risk of gestational diabetes is higher in pregnant women with PCOS compared to their counterparts without PCOS.

WHAT IS KNOWN ALREADY

The progression of reproductive, psychological and oncological features in PCOS remains unclear, which limits prevention and early diagnosis strategies across the lifespan. Understanding the natural history of PCOS is one of the overarching priorities in PCOS research.

STUDY DESIGN, SIZE, DURATION

This is a systematic review of longitudinal cohort studies with a narrative presentation of findings. Databases MEDLINE, EMBASE, Ovid PsycInfo, CINAHL PLUS and EBM reviews were searched between 15 January 2020 and 11 February 2021 with no language restrictions. Only studies published from the year 1990 to February 2021 were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In line with current guidelines for the assessment and management of PCOS, we included studies where participants were females with PCOS diagnosed according to the 2003 Rotterdam or the 1990 National Institutes of Health (NIH) consensus criteria.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 21 longitudinal studies including 62 123 participants over four continents reported reproductive, psychological and/or oncological outcomes. Participants were females aged between 15 and 49 years at baseline, with follow-up periods ranging from 4 weeks to 32 years. Consistent evidence based on limited studies suggests that total T and DHEAS levels decline to a greater degree in women with PCOS compared to those without PCOS, and the risk gestational diabetes is higher in women with PCOS than in those without PCOS. Evidence reporting changes over time in the majority of the remaining outcomes was unclear due to conflicting and/or insufficient information.

LIMITATIONS, REASONS FOR CAUTION

There was extreme heterogeneity between studies in terms of study setting, population characteristics, follow-up period, effect measures used and laboratory testing approaches.

WIDER IMPLICATIONS OF THE FINDINGS

Understanding the natural history of PCOS and changes in diagnostic, reproductive, psychological and oncological features of PCOS across the lifespan is still a challenge and the existing literature is both limited and conflicting. It is important that future long-term prospective longitudinal studies are conducted in unselected and well-characterized populations.

STUDY FUNDING/COMPETING INTEREST(S)

This specific study was not funded. S.K. is supported by scholarships from the Research Training Program of the Commonwealth of Australia and Monash University; H.J.T. is supported by an Australian National Health and Medical Research Council fellowship; and A.E.J. is supported by the Australian National Health and Medical Research Council's Centre for Research Excellence in Women’s Health in Reproductive Life. R.A. was employed by the American Society for Reproductive Medicine and is a consultant to Spruce Biosciences and Fortress Biotech. The other authors have no conflicts of interest to declare.

REGISTRATION NUMBER

Prospero registration number: CRD42020165546.

Natural History of Polycystic Ovary Syndrome and New Advances in the Epidemiology

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women, affecting up to 15% of the female population. The natural history of the syndrome is complex, including both androgen exposure in early life and adiposity-driven dysfunction involving also dysregulated, also involving altered hypothalamus-ovarian crosstalk. The manifestations can arise as early as childhood or puberty onward, suggesting that genetic susceptibility is an important etiological factor. In adulthood, women with PCOS present with reproductive, metabolic, and psychological health issues at a population-based level. Epidemiological studies on large datasets offer an excellent opportunity to evaluate health effects and costs related to the syndrome. Hospital or insurance-based datasets are also available; however, the results are not representative of the female population in the community. More longitudinal studies spanning from early childhood to late adulthood are needed to assess the long-term health impact and early manifestations of PCOS. Moreover, the identification of women with PCOS from large datasets can be expensive. Self-reported symptoms or PCOS diagnosis may offer a feasible approach.

Long-term cardiometabolic disease risk in women with PCOS: a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with cardiometabolic disease, but recent systematic reviews and meta-analyses of longitudinal studies that quantify these associations are lacking.

OBJECTIVE AND RATIONALE

Is PCOS a risk factor for cardiometabolic disease?

SEARCH METHODS

We searched from inception to September 2019 in MEDLINE and EMBASE using controlled terms (e.g. MESH) and text words for PCOS and cardiometabolic outcomes, including cardiovascular disease (CVD), stroke, myocardial infarction, hypertension (HT), type 2 diabetes (T2D), metabolic syndrome and dyslipidaemia. Cohort studies and case–control studies comparing the prevalence of T2D, HT, fatal or non-fatal CVD and/or lipid concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) between women with and without PCOS of ≥18 years of age were eligible for this systematic review and meta-analysis. Studies were eligible regardless of the degree to which they adjusted for confounders including obesity. Articles had to be written in English, German or Dutch. Intervention studies, animal studies, conference abstracts, studies with a follow-up duration less than 3 years and studies with less than 10 PCOS cases were excluded. Study selection, quality assessment (Newcastle–Ottawa Scale) and data extraction were performed by two independent researchers.

OUTCOMES

Of the 5971 identified records, 23 cohort studies were included in the current systematic review. Women with PCOS had increased risks of HT (risk ratio (RR): 1.75, 95% CI 1.42 to 2.15), T2D (RR: 3.00, 95% CI 2.56 to 3.51), a higher serum concentration of TC (mean difference (MD): 7.14 95% CI 1.58 to 12.70 mg/dl), a lower serum concentration of HDL-C (MD: −2.45 95% CI −4.51 to −0.38 mg/dl) and increased risks of non-fatal cerebrovascular disease events (RR: 1.41, 95% CI 1.02 to 1.94) compared to women without PCOS. No differences were found for LDL-C (MD: 3.32 95% CI −4.11 to 10.75 mg/dl), TG (MD 18.53 95% CI −0.58 to 37.64 mg/dl) or coronary disease events (RR: 1.78, 95% CI 0.99 to 3.23). No meta-analyses could be performed for fatal CVD events due to the paucity of mortality data.

WIDER IMPLICATIONS

Women with PCOS are at increased risk of cardiometabolic disease. This review quantifies this risk, which is important for clinicians to inform patients and to take into account in the cardiovascular risk assessment of women with PCOS. Future clinical trials are needed to assess the ability of cardiometabolic screening and management in women with PCOS to reduce future CVD morbidity.

Cell-free DNA discoveries in human reproductive medicine: providing a new tool for biomarker and genetic assays in ART

Cell-free DNAs (cfDNAs) are fragmented forms of DNA that are released into extracellular environments. Analyzing them, regarding either concentration or genetic/epigenetic status can provide helpful information about disorders, response to treatments, estimation of success rates, etc. Moreover, since they are presented in body fluids, evaluation of the aforementioned items would be achieved by less/non-invasive methods. In human reproduction field, it is required to have biomarkers for prediction of assisted reproduction techniques (ART) outcome, as well as some non-invasive procedures for genetic/epigenetic assessments. cfDNA is an appropriate candidate for providing the both approaches in ART. Recently, scientists attempted to investigate its application in distinct fields of reproductive medicine that resulted in discovering its applicability for biomarker and genetic/epigenetic analyses. However, due to some limitations, it has not reached to clinical administration yet. In this article, we have reviewed the current reported data with respect to advantages and limitations of cfDNA utilization in three fields of ART, reproduction of male and female, as well as in vitro developed embryos.