Polycystic ovary syndrome (PCOS) is a heterogeneous and complex disorder that has both adverse reproductive and metabolic implications for affected women. However, there is generally poor ...understanding of its etiology. Varying expert-based diagnostic criteria utilize some combination of oligo-ovulation, hyperandrogenism, and the presence of polycystic ovaries. Criteria that require hyperandrogenism tend to identify a more severe reproductive and metabolic phenotype. The phenotype can vary by race and ethnicity, is difficult to define in the perimenarchal and perimenopausal period, and is exacerbated by obesity. The pathophysiology involves abnormal gonadotropin secretion from a reduced hypothalamic feedback response to circulating sex steroids, altered ovarian morphology and functional changes, and disordered insulin action in a variety of target tissues. PCOS clusters in families and both female and male relatives can show stigmata of the syndrome, including metabolic abnormalities. Genome-wide association studies have identified a number of candidate regions, although their role in contributing to PCOS is still largely unknown.
This introduction is to a Views and Reviews series of articles outlining best practices in the design and analysis of reproductive medicine articles. The investigators are experienced researchers and ...biostatisticians who highlight key points with illustrative examples from both published and theoretical clinical studies. This series is meant not only to educate readers in the interpretation of clinical research studies but also to inspire better-designed studies in the future.
Abstract
There appears to be an epidemic of both obesity and polycystic ovary syndrome (PCOS) in the world today. However, obesity per se is not a part of the phenotype in many parts of the world. ...Obesity is likely not a cause of PCOS, as the high prevalence of PCOS among relatively thin populations demonstrates. However, obesity does exacerbate many aspects of the phenotype, especially cardiovascular risk factors such as glucose intolerance and dyslipidemia. It is also associated with a poor response to infertility treatment and likely an increased risk for pregnancy complications in those women who do conceive. Although most treatments of obesity, with the exception of bariatric surgery, achieve modest reductions in weight and improvements in the PCOS phenotype, encouraging weight loss in the obese patient remains one of the front-line therapies. However, further studies are needed to identify the best treatments, and the role of lifestyle therapies in women of normal weight with PCOS is uncertain.
Polycystic ovary syndrome (PCOS) is a common, complex genetic disorder affecting up to 15% of reproductive-age women worldwide, depending on the diagnostic criteria applied. These diagnostic criteria ...are based on expert opinion and have been the subject of considerable controversy. The phenotypic variation observed in PCOS is suggestive of an underlying genetic heterogeneity, but a recent meta-analysis of European ancestry PCOS cases found that the genetic architecture of PCOS defined by different diagnostic criteria was generally similar, suggesting that the criteria do not identify biologically distinct disease subtypes. We performed this study to test the hypothesis that there are biologically relevant subtypes of PCOS.
Using biochemical and genotype data from a previously published PCOS genome-wide association study (GWAS), we investigated whether there were reproducible phenotypic subtypes of PCOS with subtype-specific genetic associations. Unsupervised hierarchical cluster analysis was performed on quantitative anthropometric, reproductive, and metabolic traits in a genotyped cohort of 893 PCOS cases (median and interquartile range IQR: age = 28 25-32, body mass index BMI = 35.4 28.2-41.5). The clusters were replicated in an independent, ungenotyped cohort of 263 PCOS cases (median and IQR: age = 28 24-33, BMI = 35.7 28.4-42.3). The clustering revealed 2 distinct PCOS subtypes: a "reproductive" group (21%-23%), characterized by higher luteinizing hormone (LH) and sex hormone binding globulin (SHBG) levels with relatively low BMI and insulin levels, and a "metabolic" group (37%-39%), characterized by higher BMI, glucose, and insulin levels with lower SHBG and LH levels. We performed a GWAS on the genotyped cohort, limiting the cases to either the reproductive or metabolic subtypes. We identified alleles in 4 loci that were associated with the reproductive subtype at genome-wide significance (PRDM2/KAZN, P = 2.2 × 10-10; IQCA1, P = 2.8 × 10-9; BMPR1B/UNC5C, P = 9.7 × 10-9; CDH10, P = 1.2 × 10-8) and one locus that was significantly associated with the metabolic subtype (KCNH7/FIGN, P = 1.0 × 10-8). We developed a predictive model to classify a separate, family-based cohort of 73 women with PCOS (median and IQR: age = 28 25-33, BMI = 34.3 27.8-42.3) and found that the subtypes tended to cluster in families and that carriers of previously reported rare variants in DENND1A, a gene that regulates androgen biosynthesis, were significantly more likely to have the reproductive subtype of PCOS. Limitations of our study were that only PCOS cases of European ancestry diagnosed by National Institutes of Health (NIH) criteria were included, the sample sizes for the subtype GWAS were small, and the GWAS findings were not replicated.
In conclusion, we have found reproducible reproductive and metabolic subtypes of PCOS. Furthermore, these subtypes were associated with novel, to our knowledge, susceptibility loci. Our results suggest that these subtypes are biologically relevant because they appear to have distinct genetic architecture. This study demonstrates how phenotypic subtyping can be used to gain additional insights from GWAS data.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
There are a variety of effective treatment options to induce ovulation in women with polycystic ovary syndrome (PCOS). The most effective treatments are primarily reproductive and target the ...hypothalamic–pituitary–ovarian (HPO) axis. Letrozole, an aromatase inhibitor, is headed toward replacing clomiphene, a selective estrogen receptor modulator, as the first-choice option. Metabolic treatments likely work indirectly through the HPO axis. Many metabolic treatments have shown initial promise and later failed (troglitozone or d-chiro-inositol) or disappointed (metformin); further studies are needed of newer agents to treat type 2 diabetes. Weight loss interventions, both lifestyle related, through obesity drugs or through bariatric surgery have shown mixed results on pregnancy outcomes. With both reproductive and metabolic treatments, combination therapies (such as metformin and clomiphene together) may offer greater benefit to distinct subgroups of patients.
The adverse effects of obesity of female reproduction have been extensively documented. However, there are few prospective studies that have examined preconception weight loss interventions. There is ...a need to develop successful interventions with significant weight loss and compliance and most importantly document the effects of preconception interventions on important perinatal outcomes such as live birth and the health of the infant and mother. The existing data from randomized trials that come closest to meeting these criteria have failed to document improved live-birth rates after the intervention compared with control groups. There is a tendency to equate favorable weight change both before and during pregnancy with a direct qualitative improvement in all perinatal outcomes, yet the results from the most successful treatment of morbid obesity, that is, bariatric surgery, with on average 40% weight loss, suggest a mixed risk-benefit ratio on perinatal outcomes. Although interventions to control gestational weight gain have been more completely studied than preconception ones, and have documented successful interventions to achieve appropriate weight gain, there is no clear evidence that controlling gestational weight gain actually improves any important perinatal outcome. Future studies must develop more successful and effective interventions, capture perinatal outcomes instead of weight change as the primary outcomes, use, at least preconception, new antiobesity drugs (in combination with other therapies), and study bariatric surgery in prospective trials to improve our understanding of the effectiveness of obesity treatment before pregnancy.
Objective:
The aim was to formulate practice guidelines for the diagnosis and treatment of polycystic ovary syndrome (PCOS).
Participants:
An Endocrine Society-appointed Task Force of experts, a ...methodologist, and a medical writer developed the guideline.
Evidence:
This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence.
Consensus Process:
One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of The Endocrine Society and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines. Two systematic reviews were conducted to summarize supporting evidence.
Conclusions:
We suggest using the Rotterdam criteria for diagnosing PCOS (presence of two of the following criteria: androgen excess, ovulatory dysfunction, or polycystic ovaries). Establishing a diagnosis of PCOS is problematic in adolescents and menopausal women. Hyperandrogenism is central to the presentation in adolescents, whereas there is no consistent phenotype in postmenopausal women. Evaluation of women with PCOS should exclude alternate androgen-excess disorders and risk factors for endometrial cancer, mood disorders, obstructive sleep apnea, diabetes, and cardiovascular disease. Hormonal contraceptives are the first-line management for menstrual abnormalities and hirsutism/acne in PCOS. Clomiphene is currently the first-line therapy for infertility; metformin is beneficial for metabolic/glycemic abnormalities and for improving menstrual irregularities, but it has limited or no benefit in treating hirsutism, acne, or infertility. Hormonal contraceptives and metformin are the treatment options in adolescents with PCOS. The role of weight loss in improving PCOS status per se is uncertain, but lifestyle intervention is beneficial in overweight/obese patients for other health benefits. Thiazolidinediones have an unfavorable risk-benefit ratio overall, and statins require further study.
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