Endometrial blood flow is impaired in women with polycystic ovarian syndrome who are clinically hyperandrogenic

Metabolic disparities between obese and non-obese patients with polycystic ovary syndrome: implications for endometrial receptivity indicators

OBJECTIVE

To investigate the differences in the metabolic indicators and sex hormones between obese and non-obese patients with polycystic ovary syndrome (PCOS), and their impacts on endometrial receptivity (ER).

METHODS

We selected 255 individuals with PCOS, and categorized them into the obese groups, including the OP group (obese patients with PCOS) and the ON group (obese patients without PCOS), and selected 64 individuals who were categorized in the non-obese groups, namely, the control groups, which comprise the NP group (non-obese patients with PCOS) and the NN group(non-obese patients without PCOS). The one-way analysis of variance (ANOVA) and Mann-Whitney U tests were used to compare the metabolic indicators, and sex hormone-associated and ER-associated indicators between the groups. The correlation between the aforementioned clinical markers and ER was analyzed using the Pearson's correlation coefficient.

RESULTS

(1) In comparison with the NP group, the OP group exhibited higher levels (p < .01) of free androgen index (FAI), anti-müllerian hormone (AMH), fasting insulin (FINS), insulin level within 60 min, 120 min, and 180 min-60minINS, 120minINS, and 180minINS, respectively, fasting blood glucose (FBG), blood glucose level within two hours (2hGlu), homeostatic model assessment for insulin resistance (HOMA-IR), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), waist-to-hip ratio (WHR), waist circumference, hip circumference, the ratio of the maximum blood flow velocity of the uterine artery during systole to the blood flow velocity of the uterine artery at the end of diastole (uterine artery S/D), and blood flow resistance index (RI) of the uterine artery. In comparison with the NP group, the OP group exhibited lower levels (p < .01) of sex hormone binding globulin (SHBG), dehydroepiandrosterone (DHEA), high molecular weight adiponectin (HMWA), and high-density lipoprotein cholesterol (HDL-C). (2) In the PCOS group, RI was significantly positively correlated with FAI, FINS, 120minINS, HOMA-IR, and WHR (p < .01), and significantly negatively correlated with SHBG, HDL-C, and HMWA (p < .01); uterine artery S/D was significantly positively correlated with FAI, FINS, 2hGlu, HOMA-IR, LDL-C, and WHR (p < .01), significantly positively correlated with 120minINS and FBG (p < .05), and significantly negatively correlated with SHBG and HMWA (p < .01).

CONCLUSION

(1) The OP group exhibited obvious metabolic disorders and poor ER, which was manifested as low levels of SHBG and HMWA, and high levels of FAI, HOMA-IR, WHR, uterine artery S/D, and RI. (2) In patients with PCOS, there was a substantial correlation between ER-associated indicators RI and uterine artery S/D and FAI, FINS, 120minINS, HOMA-IR, WHR, SHBG, and HMWA.

Effects of combined metformin and cabergoline versus metformin alone on ovarian and hormonal activities in Iraqi patients with PCOS and hyperprolactinemia: a randomized clinical trial

Polycystic ovary syndrome (PCOS) is one of the most prevalent metabolic diseases during female reproductive life, often associated with insulin resistance and hyperprolactinemia. The efficacy of metformin and cabergoline for managing PCOS remains debated in the literature. This three-arm interventional study in Iraq assessed the effects of these drugs on body mass index (BMI), hormonal balance, and uterine artery blood flow in 75 women with PCOS and hyperprolactinemia. Participants were randomized into three groups: metformin (500 mg twice daily), cabergoline (0.5 mg weekly), and a combination of both, with 25 patients in each group. Baseline and 90-day follow-up characteristics included BMI, serum hormonal levels, and ultrasound features. Metformin resulted in significant weight reduction (p=0.038); however, the addition of cabergoline caused a more significant reduction in body mass index (p=0.001). The combined treatment significantly lowered testosterone levels (p=0.008). In addition, this combination significantly reduced the level of LH (p=0.043) and increased the level of FSH (p=0.047). The results suggest that metformin and cabergoline when used together, act synergistically and safely to reduce BMI, testosterone, and LH levels while increasing FSH levels. Furthermore, this combination improved endometrial blood flow and ovulation in women with PCOS.

Hyperandrogenism and Its Possible Effects on Endometrial Receptivity: A Review

Endometrial receptivity is a state of the endometrium defined by its readiness for embryo implantation. When the receptivity of the endometrium is impaired due to hyperandrogenism or androgen excess, this condition can lead to pregnancy loss or infertility. Hyperandrogenism encompasses a wide range of clinical manifestations, including polycystic ovary syndrome (PCOS), idiopathic hirsutism, hirsutism and hyperandrogaenemia, non-classical congenital adrenal hyperplasia, hyperandrogenism, insulin resistance, acanthosis nigricans (HAIR-AN), ovarian or adrenal androgen-secreting neoplasms, Cushing's syndrome, and hyperprolactinaemia. Recurrent miscarriages have been shown to be closely related to elevated testosterone levels, which alter the endometrial milieu so that it is less favourable for embryo implantation. There are mechanisms for endometrial receptivity that are affected by excess androgen. The HOXA gene, aVβ3 integrin, CDK signalling pathway, MECA-79, and MAGEA-11 were the genes and proteins affect endometrial receptivity in the presence of a hyperandrogenic state. In this review, we would like to explore the other manifestations of androgen excess focusing on causes other than PCOS and learn possible mechanisms of endometrial receptivity behind androgen excess leading to pregnancy loss or infertility.

Cardiovascular disease risk in offspring of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder affecting women at reproductive age. PCOS diagnosis (Rotterdam criteria) is based on the presence of two out of three criteria; clinical and/or biochemical hyperandrogenism, oligo- or an-ovulation and polycystic ovaries. PCOS women suffer from a constellation of reproductive and metabolic abnormalities including obesity and insulin resistance. PCOS women also have increased blood pressure and increased risk of cardiovascular diseases (CVD). In-utero, offspring of PCOS women are exposed to altered maternal hormonal environment and maternal obesity (for most of PCOS women). Offspring of PCOS women could also be subject to genetic susceptibility, the transgenerational transmission of some of the PCOS traits or epigenetic changes. Offspring of PCOS women are commonly reported to have an abnormal birth weight, which is also a risk factor for developing CVD and hypertension later in life. Although studies have focused on the growth pattern, reproductive and metabolic health of children of PCOS women, very limited number of studies have addressed the risk of hypertension and CVD in those offspring particularly as they age. The current narrative review is designed to summarize the available literature (both human studies and experimental animal studies) and highlight the gaps in addressing hypertension and CVD risks in offspring of PCOS women or hyperandrogenemic female animal models.

Transcriptomic Analysis Reveals Endometrial Dynamics in Normoweight and Overweight/Obese Polycystic Ovary Syndrome Women

The aim of this work was to identify the transcriptomic characteristics of the endometrium in normoweight and overweight/obese polycystic ovary syndrome (PCOS) potentially underlying the pathogenesis. This study included 38 patients undergoing in vitro fertilization: 22 women with PCOS and 16 matched controls. Each of the groups was subdivided into normoweight (body mass index (BMI) < 25 kg/m²) and overweight/obese (BMI ≥25 kg/m²) subgroups. Endometrium samples were collected in the secretory phase from controls or in a modeled secretory phase using daily administration of progesterone from women with PCOS before in vitro fertilization treatment. Transcriptome profiles were assessed by high-throughput RNA sequencing to investigate distinct endometrial gene expression patterns in PCOS. Bioinformatics analyses revealed that the endometrium from PCOS expresses significantly different transcripts encoding endometrial receptivity, inflammatory response, angiogenesis, and energy metabolism. Additionally, our study demonstrated that the differentially expressed genes between normoweight and overweight/obese PCOS are involved in fatty acid metabolism, endometrial decidualization, and immune response. For the first time, we have described the transcriptome characteristics of normoweight and overweight/obese PCOS endometria. Our results indicate different endometrial gene expressions between different subtypes of PCOS and non-PCOS women, which might affect endometrial functions in PCOS patients.

Effects of N-acetylcysteine and metformin treatment on the stereopathological characteristics of uterus and ovary

In this study, the stereo-pathological effect of metformin and N-acetyl cysteine is evaluated on the uterus and ovary of polycystic ovary syndrome (PCOS) mice. 96 mature females (8-weekold, weight of 20–30 gr) BALB/c mice were classified into 6 groups including the control group (n= 16), letrozole-induced PCOS group (n=16), PCOS + metformin (n=16), PCOS+NAC (n=16) and a separate control group for NAC (n=16). Another PCOS group was maintained for a month to make sure that features remain till the end of the study. Testosterone level, vaginal cytology and stereological evaluations were assessed. Vaginal cytology in letrozole-receiving mice showed a diestrus phase continuity. Testosterone level, body weight, uterine weight, endometrial volume, myometrial volume, gland volume, stromal volume, epithelial volume, vessel volume, daughter and conglomerate glands, endometrial thickness, and myometrial thickness exhibited an increasing trend in the uterus of PCOS mice. While normal gland and vessel length decreased in the PCOS group. Ovarian volume, corticomedullary volume, primary follicles, secondary follicles, and ovarian cysts were increased in PCOS ovaries. While corpus luteum, primordial, graafian, and atretic follicles showed a decline in the PCOS group. NAC and metformin, however, managed to restore the condition to normal. Given the prevalence of PCOS and its impact on fertility, the use of noninvasive methods is of crucial significance. NAC can control and treat pathological parameters and help as a harmless drug in the treatment of women with PCOS.

Association between hyperandrogenism and adverse pregnancy outcomes in patients with different polycystic ovary syndrome phenotypes undergoing in vitro fertilization/intracytoplasmic sperm injection: a systematic review and meta-analysis

OBJECTIVE

To study the association between hyperandrogenism (HA) and adverse pregnancy outcomes in patients with different polycystic ovary syndrome phenotypes undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

METHODS

We reviewed all eligible articles published up to October 2020 after searching in PubMed, Embase, Cochrane Library, Web of Science, Wanfang Data, and CNKI databases. The primary outcomes were the clinical pregnancy rate (CPR), miscarriage rate (MR), and live birth rate (LBR), whereas the secondary outcomes were the number of retrieved oocytes and endometrial thickness. Risk ratios (RRs) or mean differences with 95% confidence intervals (CIs) were calculated to estimate the HA impact on IVF/ICSI outcomes in patients with polycystic ovary syndrome (PCOS) phenotypes.

RESULTS

Of the 789 trials identified, nine retrospective studies involving 3037 patients with PCOS were included. Compared to the PCOS group with normal androgen levels, the PCOS group with HA exhibited increased MR (RR: 1.56, 95% CI: 1.13, 2.16); the CPR (RR: 0.88, 95% CI: 0.77, 1.01) and LBR (RR: 0.79, 95% CI: 0.55, 1.11) were not significantly different between these groups. Subgroup analysis revealed that the CPR was lower in the polycystic ovarian (PCO)-morphology + HA + oligo-anovulation (AO) group than in the PCO + AO group (RR: 0.81, 95% CI: 0.67, 0.99). Among Asians, the PCOS/HA group had increased MR (RR: 1.56, 95% CI: 1.06, 2.31) and showed thinner endometrial thickness. However, among Caucasians, no differences were observed between the two groups.

CONCLUSIONS

HA may have adverse effects on clinical pregnancy and miscarriage outcomes in different PCOS phenotypes, particularly among Asians.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Effect of amlodipine on blood flow of preovulatory follicle in women with clomiphene resistant polycystic ovaries: a randomized controlled trial

OBJECTIVE

To detect whether amlodipine could increase pre-ovulatory follicular blood flow, thus enhancing ovulation and creating a better chance of conception in women with PCOS.

METHODS

165 women were screened of which 124 were qualified and women were equally randomized to 62 receiving clomiphene citrate and amlodipine and 62 receiving clomiphene citrate and placebo. The primary outcome was to detect if amlodipine can improve pre-ovulatory follicle blood flow studied by colour and power Doppler Pulsatility index of ovarian arteries, with drug administration. The secondary outcomes were endometrial thickness and clinical pregnancy.

RESULTS

The mean value of the ovarian arteries Pulsatility Index was significantly lower in the amlodipine group when compared to those of the placebo group (1.36 and 1.82, respectively, with P value 0.002). Mean endometrial thickness, for all women in both groups, on the day of detecting a mature follicle was significantly higher in the amlodipine group compared to the placebo group (8.99 and 7.0, respectively, with P value 0.003), and clinical pregnancy increased from 11% to 37% in the amlodipine group compared to the placebo group.

CONCLUSION

Amlodipine improves ovarian blood flow and increases the chances of conception.

TRIAL REGISTRATION

Pan African Clinical Trial Registry (http://www.pactr.org). Trial No: PAC TR201708002485292.

Effects of hypoxia‑inducible factor‑1α on endometrial receptivity of women with polycystic ovary syndrome

Embryo implantation is associated with an hypoxic endometrial microenvironment. Hypoxia‑inducible factor‑1α (HIF‑1α) is activated under hypoxic conditions. In the present study, the expression pattern of HIF‑1α in endometrial tissue was investigated and its effects on endometrial receptivity in patients with polycystic ovary syndrome (PCOS) were examined. A total of 81 patients were enrolled for in vitro fertilization and embryo transfer. They were divided into PCOS (n=40) and Control groups (n=41); both groups were further divided based on body weight (overweight and normal weight subgroups). The expressions of HIF‑1α, vascular endothelial growth factor (VEGF) and glucose transporter protein (GLUT)‑1 and GLUT4 were determined by reverse transcription‑quantitative polymerase chain reaction and immunohistochemistry. The results demonstrated that mRNA and protein expression levels of HIF‑1α and VEGF in the PCOS group were significantly lower compared with expression levels in the Control group. However, there were no statistically significant differences in the expression levels of GLUT1 and GLUT4 between groups. In patients with PCOS, GLUT1 and GLUT4 were mainly localized in the nuclei and cytoplasm, but not in the cell membrane. Overweight patients had the lowest expression levels of HIF‑1α, VEGF and GLUT1 expression compared with normal weight patients. In conclusion, HIF‑1α may be involved in the molecular mechanisms of endometrial dysfunction in women with PCOS, particularly in those who are overweight. HIF‑1α might therefore be a novel target for improving the endometrial receptivity and successful embryo implantation in PCOS women.

Effects of Cabergoline administration on uterine perfusion in women with polycystic ovary syndrome

Objectives: The aim of this study was to determine the effects of Cabergoline administration on uterine blood flow in women suffering from polycystic ovary syndrome (PCOS).

Methods: This study is a randomized, controlled, triple-blind trial which is tested on 40 women who were randomly divided into two groups of 20 people and using a randomized block design during which the subjects were assessed and included. They were suffering from polycystic ovarian syndrome. Inclusion criteria were classically defined PCOS criteria including: oligomenorrhea or amenorrhea, clinical or Laboratory findings based on increase in blood level androgen (testosterone) and ultrasound confirmation of PCOS. Exclusion criteria were Pregnancy, lactation, Dopamine Agonist Therapy. After selection of intervention and placebo groups, primary control Doppler ultrasound was done for both groups. Then a weekly dose of Cabergoline 0.5 mg was administered to intervention group for duration of 12 weeks. Placebo group were administered placebo in the same fashion. At the end of 12 weeks, Doppler ultrasound was performed and the results were recorded in the check lists.

Results: No significant difference was noticed in both groups with respect to their age, employment, level of education, type of infertility, duration of marriage, and results of RI and PI before intervention. Later PCOS patients under the treatment of Cabergoline showed a significant increase in uterine blood flow Pulsatility Index (PI) before 2.65±0.52 and after 1.98±0.52 and RI before 0.85 and after intervention 0.77), yet no significant difference were found in PCOS patient under the treatment of placebo.

Conclusion: PCOS patients were shown to have more resistance in uterine blood flow than healthy people; however, Cabergoline administration proved to increase uterine blood perfusion and regulate menstruation cycle.

Uterine volume and endometrial thickness in the early follicular phase in patients with polycystic ovary syndrome

OBJECTIVE

We aimed to evaluate uterine volume and endometrial thickness during the early follicular phase in patients with polycystic ovary syndrome (PCOS) and healthy controls.

METHODS

We studied 1,016 PCOS patients and 182 healthy controls. The anthropometric, endocrine, and metabolic characteristics of PCOS were determined. Uterine volume and endometrial thickness were also recorded.

RESULTS

Uterine volume progressively increased with age both in PCOS patients and controls. Patients with PCOS and body mass index (BMI) ≥25 kg/m2 had greater uterine volumes than PCOS patients with BMI <25 kg/m2 (P<.001). Patients with the classic PCOS phenotypes (i.e., with oligo-ovulation and/or anovulation [ANOV] and hyperandrogenemia [HA] with or without polycystic ovaries [PCO]) had smaller uterine volume than PCOS patients with the additional phenotypes introduced by the Rotterdam criteria (i.e., with PCO and either ANOV or HA; P = .033) and controls (P = .045).

CONCLUSION

Uterine volume increases progressively with age and obesity in PCOS patients. The smaller uterine volumes and endometrial thicknesses in the classic PCOS phenotypes might be attributed to the more severe HA of these patients.

Effect of metformin treatment on endometrial vascular indices in anovulatory obese/overweight women with polycystic ovarian syndrome using three-dimensional power doppler ultrasonography

PURPOSE

Metformin has been shown to be an effective treatment for anovulatory polycystic ovary syndrome (PCOS) patients in terms of menstrual cyclicity, ovulation, and pregnancy, as well as reduction of early miscarriage rate. The aim of the study is to assess the effect of metformin on the endometrial vascular indices in anovulatory obese PCOS women using three-dimensional power Doppler sonography (3DPDUS).

METHODS

A prospective study was set to determine the beneficial effects of metformin on PCOS patients. Fifty anovulatory obese PCOS patients were compared with another 50 healthy volunteers who were age- and body mass index-matched (control group). PCOS patients were treated with metformin (Glucophage; MerckSerono) 850 mg 3 times a day for 6 months. Assessment of the endometrial thickness and volume, uterine Doppler indices, and Doppler vascular indices of the endometrium and subendometrium in the periovulatory and midluteal phases were performed with 3DPDUS.

RESULTS

There was a significant increase in the endometrial thickness, endometrial volume, and endometrial and subendometrial vascularity indices (vascularization index, flow index, vascularization flow index) after 6 months of metformin treatment in PCOS women, whereas there was no change in the resistance index and the pulsatility index of the uterine artery in both periovulatory and midluteal phases.

CONCLUSIONS

Metformin, owing to its metabolic, endocrine, vascular, and anti-inflammatory effects, improves markers of endometrial receptivity.