Serum X-box-binding protein 1 levels in PCOS patients

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.

Prolidase activity in women with polycystic ovarian syndrome undergoing assisted conception

Background: Prolidase is a manganese (Mn)-dependent cytosolic exopeptidase that degrades imidodipeptides with C-terminal proline or hydroxyproline. Prolidase recycling from imidodipeptides plays a critical role in collagen resynthesis and extracellular matrix (ECM) remodelling. Following an increase in gonadotropins, ovarian and follicular collagen undergo substantial degradation. Abnormal ovarian ECM composition is associated with polycystic ovary syndrome (PCOS). This study aimed to examine prolidase activity in the serum and follicular fluid (FF) of women undergoing in vitro fertilisation/intracytoplasmic sperm injection (IVF/ICSI) treatment, comparing those with PCOS to those with normal ovarian function.Methods: This prospective study enrolled 50 participants, of whom 44 were included. PCOS diagnosis followed the Rotterdam consensus criteria, with 20 patients constituting the study group. The control group comprised 24 individuals with mild-to-moderate male infertility. Prolidase enzyme activity in serum and FF was measured using the Chinard reagent via spectrophotometric analysis and compared between the groups.Results: Serum and FF prolidase levels were significantly lower in patients with PCOS (p < 0.05). A direct correlation was observed between serum and FF prolidase levels (p < 0.05). Although blastocyst quality scoring (BQS) significantly decreased in PCOS patients, no statistical difference was observed in the clinical pregnancy rate between the groups (p < 0.05) (p > 0.05). A negative correlation existed between serum prolidase levels and total antral follicle (AF) count (p < 0.05). Conversely, both serum and FF prolidase levels positively correlated with BQS (r = 0.574)(p < 0.05) (r = 0.650)(p < 0.05).Conclusions: Patients with PCOS showed lower serum and FF prolidase levels, indicating abnormal degradation of ovarian and follicular collagen, potentially causing anovulation.

Body mass index stratified meta-analysis of genome-wide association studies of polycystic ovary syndrome in women of European ancestry

BACKGROUND

Polycystic ovary syndrome (PCOS) is a complex multifactorial disorder with a substantial genetic component. However, the clinical manifestations of PCOS are heterogeneous with notable differences between lean and obese women, implying a different pathophysiology manifesting in differential body mass index (BMI). We performed a meta-analysis of genome-wide association study (GWAS) data from six well-characterised cohorts, using a case-control study design stratified by BMI, aiming to identify genetic variants associated with lean and overweight/obese PCOS subtypes.

RESULTS

The study comprised 254,588 women (5,937 cases and 248,651 controls) from individual studies performed in Australia, Estonia, Finland, the Netherlands and United States of America, and separated according to three BMI stratifications (lean, overweight and obese). Genome-wide association analyses were performed for each stratification within each cohort, with the data for each BMI group meta-analysed using METAL software. Almost half of the total study population (47%, n = 119,584) were of lean BMI (≤ 25 kg/m2). Two genome-wide significant loci were identified for lean PCOS, led by rs12000707 within DENND1A (P = 1.55 × 10-12) and rs2228260 within XBP1 (P = 3.68 × 10-8). One additional locus, LINC02905, was highlighted as significantly associated with lean PCOS through gene-based analyses (P = 1.76 × 10-6). There were no significant loci observed for the overweight or obese sub-strata when analysed separately, however, when these strata were combined, an association signal led by rs569675099 within DENND1A reached genome-wide significance (P = 3.22 × 10-9) and a gene-based association was identified with ERBB4 (P = 1.59 × 10-6). Nineteen of 28 signals identified in previous GWAS, were replicated with consistent allelic effect in the lean stratum. There were less replicated signals in the overweight and obese groups, and only 4 SNPs were replicated in each of the three BMI strata.

CONCLUSIONS

Genetic variation at the XBP1, LINC02905 and ERBB4 loci were associated with PCOS within unique BMI strata, while DENND1A demonstrated associations across multiple strata, providing evidence of both distinct and shared genetic features between lean and overweight/obese PCOS-affected women. This study demonstrated that PCOS-affected women with contrasting body weight are not only phenotypically distinct but also show variation in genetic architecture; lean PCOS women typically display elevated gonadotrophin ratios, lower insulin resistance, higher androgen levels, including adrenal androgens, and more favourable lipid profiles. Overall, these findings add to the growing body of evidence supporting a genetic basis for PCOS as well as differences in genetic patterns relevant to PCOS BMI-subtype.