Serum Fetuin-A levels, insulin resistance and oxidative stress in women with polycystic ovary syndrome

YKL-40 Knockdown Decreases Oxidative Stress Damage in Ovarian Granulosa Cells

Background: Oxidative stress has been implicated in the pathogenesis of polycystic ovarian syndrome (PCOS). To develop novel antioxidant drugs, it is necessary to explore the key regulatory molecules involved in oxidative stress in PCOS. Plasma YKL-40 levels are elevated in patients with PCOS; however, its role remains unclear. Methods: The follicular fluids of 20 women with PCOS and 12 control subjects with normal ovarian function were collected, and YKL-40 in follicular fluids was measured by enzyme-linked immunosorbent assay. A letrozole-induced PCOS rat model was established and the expression level of YKL-40 in the ovaries was detected by immunohistochemistry. KGN cells were treated with H2O2 to generate an ovarian granulosa cell (OGC) model of oxidative stress. The siRNA was transfected into the cells for knockdown. The effect of YKL-40 knockdown on H2O2-treated KGN cells was evaluated by measuring proliferation, apoptosis, activities of T-SOD, GSH-Px, and CAT, levels of MDA, IL-1β, IL-6, IL-8, and TNF-α, and the PI3K/AKT/NF-κB signaling pathway. Results: YKL-40 levels were elevated in the follicular fluids of women with PCOS compared with control subjects with normal ovarian function. The expression level of YKL-40 in the ovaries of rats with PCOS is obviously higher than that in the ovaries of the control group rats. H2O2 treatment enhanced YKL-40 mRNA expression and protein secretion. YKL-40 knockdown enhanced cell proliferation and antioxidant capacity while decreasing apoptosis and inflammatory factor levels in KGN cells following H2O2 treatment. The knockdown activated the PI3K/AKT signaling pathway and suppressed NF-κB nuclear translocation from the cytoplasm. Conclusion: YKL-40 levels were elevated in the follicular fluids of women with PCOS and the ovaries of rats with PCOS. YKL-40 expression can be induced by oxidative stress, and YKL-40 knockdown can decrease oxidative stress damage in OGCs.

Sex hormone-binding globulin (SHBG) mitigates ER stress and improves viability and insulin sensitivity in adipose-derived mesenchymal stem cells (ASC) of equine metabolic syndrome (EMS)-affected horses

BACKGROUND

Equine metabolic syndrome (EMS), which encompasses insulin resistance, low-grade inflammation and predisposition to laminitis is a critical endocrine disorder among the most prevalent conditions affecting horses from different breeds. According to the most recent research, low human sex hormone-binding globulin (SHBG) serum levels correlate with an increased risk of obesity, insulin resistance and diabetes, and may contribute to overall metabolic dysregulations. This study aimed to test whether exogenous SHBG could protect EMS affected adipose-derived stromal stem cells (EqASCEMS) from apoptosis, oxidative stress, ER stress and thus improve insulin sensitivity.

METHODS

EqASCEMS wells were treated with two different concentrations (50 and 100 nM) of exogenous SHBG, whose biocompatibility was tested after 24, 48 and 72 h of incubation. Several parameters including cell viability, apoptosis, cell cycle, reactive oxygen species levels, ER stress, Pi3K/MAPK activation and insulin transducers expression were analysed.

RESULTS

Obtained data demonstrated that exogenous SHBG treatment significantly promoted ASCs cells proliferation, cell cycle and survival with reduced expression of p53 and p21 pro-apoptotic mediators. Furthermore, SHBG alleviated the oxidative stress caused by EMS and reduced the overaccumulation of intracellular ROS, by reducing ROS + cell percentage and regulating gene expression of endogenous antioxidant enzymes (Sod 1, Cat, GPx), SHBG treatment exhibited antioxidant activity by modulating total nitric oxide (NO) levels in EMS cells as well. SHBG treatment dampened the activation of ER stress sensors and effectors in EqASCEMS cells via the upregulation of MiR-7a-5p, the decrease in the expression levels of ATF-6, CHOP and eiF2A and the restoration of PDIA3 chaperone protein levels. As a consequence, SHBG application substantially improved insulin sensitivity through the modulation of Pi3K/Akt/Glut4 insulin signalling cascades.

CONCLUSION

Our results suggest that the SHBG is endowed with crucial beneficial effects on ASCs metabolic activities and could serve as a valuable therapeutic target for the development of efficient EMS treatment protocols. Video Abstract.

Hepatokine Profile in Adolescents with Polycystic Ovary Syndrome: A Case-Control Study

The current guidelines suggest routine screening for non-alcoholic fatty liver disease (NAFLD) in patients with polycystic ovary syndrome (PCOS). Hepatokines seem to be promising surrogate endpoints for the diagnosis and severity of NAFLD. PCOS has its onset in adolescence and its metabolic sequalae begin during the same period. There are scarce data on the hepatokine profile of adolescent PCOS patients. This case-control study examined the serum profile of the hepatokines sex hormone-binding globulin (SHBG), selenoprotein P, fibroblast growth factor 21 (FGF21), and fetuin A in a sample of adolescent PCOS patients, and their association to metabolic and hormonal parameters. The selenoprotein P and SHBG serum concentrations were significantly decreased in PCOS patients vs. the controls (median (IQR), 2.47 (0.40) vs. 2.66 (0.36) μg/mL, p = 0.025; mean ± SD, 41.71 ± 19.41 vs. 54.94 ± 22.12 nmol/L, p = 0.011, respectively), whereas selenoprotein P was significantly and positively associated with testosterone (r = 0.325, p = 0.007) and the free androgen index (r = 0.361, p = 0.002). The SHBG demonstrated multiple significant negative correlations with adverse metabolic parameters. Among the PCOS patients, the FGF21 concentrations were significantly higher in those with NAFLD, whereas a 1 pg/mL increase in the FGF21 concentration increased the odds of NAFLD diagnosis by liver ultrasound by 1%, suggesting FGF21 as a potential biomarker for hepatic disease in females with PCOS in adolescence. Fetuin A was the least differentiated hepatokine between the PCOS patients and controls with the least associations with metabolic and hormonal parameters.

Fetuin-A and Its Association with Anthropometric, Atherogenic, and Biochemical Parameters and Indices among Women with Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) contributes to metabolic and endocrine complications for women of reproductive age. We set out to assess the relationship between fetuin-A and anthropometric parameters, anthropometric indices, body composition, and atherogenic indices, as well as carbohydrate and lipid profile in women with polycystic ovary syndrome (PCOS). Methods. The study included 49 women with PCOS, aged between 18 and 39 years. All patients were tested for fetuin-A, fasting glucose and insulin, and lipid parameters, after oral-glucose administration were done. All of them underwent anthropometric measurements and body composition analyses such as BMI (Body Mass Index), WHR (Waist to Hip Ratio), WHtR (Waist to Height Ratio), BAI (Body Adiposity Index), VAI (Visceral Adiposity Index), LAP (Lipid Accumulation Product), BRI (Body Roundness Index), ABSI (A Body Shape Index), ABSI z-core (ABSI with added mortality risk in correlation with age and gender), AIP (Atherogenic Risk of Plasma), AC (Atherogenic Coefficient), Castelli risk index-I, and Castelli risk index-II. Results: Obesity was diagnosed in 18 patients (36.7%) based on BMI index and 7 patients (14.3%) based on BAI index. Significantly increased risk of metabolic complications was observed among 26 patients (53.1%) based on waist circumferences. Based on VAI index, risk of metabolic disease was observed among 17 women (34.7%). Dyslipidemia such as hypercholesterolemia, hypertriglyceridemia, and mixed hyperlipidemia was detected among 14 patients (28.6%), and insulin resistance was observed among 29 (59.2%). There was a positive correlation between fetuin-A and total cholesterol (r = 0.30, p = 0.0034). There was no statistically significant correlation between fetuin-A and all of the anthropometric measurements and anthropometric indices, atherogenic indices, and other biochemical parameters. Conclusion: Fetuin-A correlates with hypercholesterolemia. It is necessary to conduct further research regarding the relationship between fetuin-A concentrations and body composition, anthropometric indices, and metabolic disorders in women with PCOS. Surprisingly, the effects of concentration of fetuin-A and anthropometric indices (BAI, VAI, LAP, ABSI, ABSI z-core) in woman with PCOS have not been closely examined. Future studies that take these variables into account will need to be undertaken. More information on the relationship between fetuin-A concentrations and anthropometric indices would aid us in establishing a greater degree of accuracy on this matter.

Abnormal Endometrial Receptivity and Oxidative Stress in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women of childbearing age. Individual heterogeneity is evident, and the prevalence rate ranges between 6 and 15% globally. The prevalence rate of PCOS in Chinese women of childbearing age is 5.6%. The main manifestations are infertility, sparse menstruation, irregular vaginal bleeding, long-term endometrial hyperplasia, and endometrial cancer. PCOS is often associated with hyperandrogenemia, insulin resistance, hyperinsulinemia, obesity, metabolic syndrome, and intestinal flora disorder. Although there have been many studies in the past, the underlying pathophysiological mechanism of the disease is still unclear. Studies have shown that PCOS diseases and related complications are closely related to local oxidative stress imbalance in the endometrium, leading to poor endometrial receptivity and effects on pregnancy. Previous reviews have mainly focused on the abnormal mechanism of ovarian oxidative stress in women with PCOS, while reviews on endometrial receptivity and oxidative stress are relatively insufficient. This study reviews the abnormal cellular and molecular mechanisms of oxidative stress due to comorbidities in women with PCOS, leading to a downregulation of endometrial receptivity.

Investigating Fetuin-A and Paraoxonase-1 Activity as Markers in Polycystic Ovary Syndrome Based on Body Mass Index: A Prospective Case-Control Study

Introduction Polycystic ovary syndrome (PCOS) may have an increased risk for the development of systemic and metabolic pathogenesis such as cardiovascular diseases, insulin resistance (IR), diabetes mellitus (DM) and dyslipidemia. However, there is no reliable marker to show the relation. Fetuin-A is an adipokine whereas paraoxonase-1 (PON-1) is a high-density lipoprotein-linked enzyme to demonstrate oxidative stress. This study aimed to evaluate serum fetuin-A and PON-1 levels in infertile PCOS women based on body mass index (BMI). Methods A prospective case-control study in a university setting was designed. A total of 88 patients admitted to the Giresun University Faculty of Medicine Gynecology Clinic between February and April 2021 were included in the study. The subjects were divided as follows: PCOS-low-BMI (BMI≤25) vs. Controls-low-BMI (BMI≤25) and PCOS-high-BMI (BMI>25) vs. Controls-high-BMI (BMI>25). Those who had at least two criteria of the 2003 Rotterdam Consensus were diagnosed with PCOS. Serum fetuin-A and PON-1 levels were compared. Results The mean levels of fetuin-A were not significantly different in the groups (p=0.955). Serum PON-1 levels were lower in the PCOS group (109.1±61.4 vs. 140.1±80.0; p=0.040), but it lost significance with adjusted values for covariants as age and BMI. Although PON-1 was not significantly different in the PCOS group of BMI<25 kg/m² subgroup, it was significantly lower in the PCOS group of BMI≥25 kg/m² subgroup (p=0.820 vs. p=0.048). Conclusion Serum fetuin-A activity did not differ with PCOS. Serum PON-1 might be a promising and research-worthy marker, especially for obese PCOS patients.

Evaluation of the pathophysiological role of Fetuin A levels in adolescents with polycystic ovary syndrome

OBJECTIVES

Polycystic ovary syndrome (PCOS) is an endocrinopathy, in which hyperandrogenism and hyperinsulinism have both occurred. Fetuin-A, a natural inhibitor of tyrosine kinase, leads to insulin resistance. The aim was to evaluate the relationship between fetuin-A and hyperandrogenism and hyperinsulinism and the role of fetuin-A in the pathophysiology of PCOS.

METHODS

Thirty-eight cases with PCOS and 40 healthy adolescents were included in the study. PCOS and controls were divided into obese/non-obese subgroups. LH, FSH, total and free testosterone (TT, FT), SHBG, androstenedione, DHEAS were measured in patients with PCOS. Fasting glucose, insulin, lipid profile, AST, ALT, HsCRP, and fetuin levels of PCOS patients and healthy controls were also measured.

RESULTS

Fetuin-A levels were higher in PCOS patients than in controls. In the obese-PCOS group, when compared to non-obese PCOS patients; the levels of SHBG and HDL were low while cholesterol, LDL, triglyceride, HOMA-IR, FT, FAI, and HSCRP levels were high, but Fetuin-A levels were similar. In the obese-PCOS group, fetuin-A levels were higher than in obese-controls. HOMA-IR and fetuin-A levels were higher in non-obese PCOS patients than in non-obese controls. In the PCOS group, fetuin-A was positively correlated with TT, FT, FAI and androstenedione and negatively correlated with SHBG. Regression analysis demonstrated that FT, SHBG, and androstenedione significantly predicted fetuin-A levels (R2=54%). In non-obese PCOS patients and controls, fetuin-A was positively correlated with insulin and HOMA-IR.

CONCLUSIONS

These results suggest a relationship between androgen levels and fetuin-A in PCOS cases, independent of insulin resistance, and may shed light on further studies.

Serum Fetuin-A levels are increased and associated with insulin resistance in women with polycystic ovary syndrome

BACKGROUND

Insulin resistance (IR) is a common characteristic of women with polycystic ovary syndrome (PCOS). It has been reported that circulating Fetuin-A levels were associated with IR and type 2 diabetes mellitus (T2DM). However, previous reports were inconsistent.

METHODS

Two hundred seven subjects were screened for PCOS according to the diagnostic guideline of the Rotterdam consensus criterion. Serum Fetuin-A levels were measured using an ELISA kit. An independent t-test or Nonparametric test was used to detect differences between PCOS and control groups. Spearman's correlation analysis was used to examine the association of the serum Fetuin-A with other parameters.

RESULTS

Our findings showed that circulating Fetuin-A concentration ranged from 196.6 to 418.2 μg/L for most women without PCOS (95%). Women with PCOS had higher circulating Fetuin-A levels than healthy women (437.9 ± 119.3 vs. 313.8 ± 60.5 μg/L; p <  0.01). Serum Fetuin-A was positively correlated with BMI, WHR, TG, TC, LDL-C, HOMA-IR, LH, T, and DHEA-S. Multivariate regression analysis showed that WHR, TG, HOMA-IR, and DHEA-S were independent predictors of the levels of circulating Fetuin-A. Binary logistic regression revealed that serum Fetuin-A was associated with the occurrence of PCOS. In addition, our ROC curve analysis found that the cutoff values for Fetuin-A to predict PCOS and IR were 366.3 and 412.6 μg/L.

CONCLUSION

Blood Fetuin-A may be a useful biomarker for screening women for PCOS and IR.

Fetuin-A – Alpha2-Heremans-Schmid Glycoprotein: From Structure to a Novel Marker of Chronic Diseases Part 2. Fetuin-A – A Marker of Insulin Resistance and Related Chronic Diseases

Fetuin-A is a secretory liver glycoprotein with multiple physiological functions such as regulation of insulin resistance, tissue calcification, bone metabolism, cellular proteolytic activity, and self-proliferative signaling.

Fetuin-A is a unique molecule which binds to the insulin receptor, modulating its sensitivity, and transducing “the physiological conditions” (serum levels of the metabolites like glucose, free fatty acids, inflammatory signals) from outside into inside the cells. Plasma fetuin-A levels correlate with reduced glucose tolerance and insulin resistance. Impaired insulin sensitivity leads to the development of metabolic syndrome, an increased risk for type 2 diabetes (T2DM), dyslipidaemias and cardiovascular diseases (CVDs). Furthermore, fetuin-A inversely correlates with inflammatory and activation biomarkers, e.g. in patients with T2DM. Thus, circulatory fetuin-A levels may have plausible predictive importance as a biomarker of risk of diabetes and negative acute phase protein. Dysregulated, it plays a crucial role in the pathogenesis of some metabolic disorders and clinical inflammatory conditions like metabolic syndrome, T2DM, CVDs, polycystic ovary syndrome (PCOS), etc.

Emerging Topics in Cardiometabolic and Psychologic Sequelae, Pathogenesis, and Treatment of Polycystic Ovarian Syndrome: A Review

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder, affecting 6–10% of reproductive age women and influences the reproductive, metabolic, dermatologic, and psychiatric health of affected girls and women. Despite its prevalence, the pathogenesis of the disease is largely unknown, and treatment options are limited. Thus, PCOS has been a ripe area for research in recent years, and novel etiologic pathways, diagnostic parameters, and treatment options are being explored. This review focuses on recent data suggesting pathogenic and therapeutic considerations, as well as the psychiatric and metabolic sequelae of PCOS.

Plasma level of peroxiredoxin 3 in patients with polycystic ovarian syndrome

BACKGROUND

As a member of peroxiredoxin (PRX) family, PRX3 is predominantly located in mitochondria and plays an important role of free radical scavenging. Since a body of evidence demonstrated the involvement of PRX3 in insulin secretion, insulin sensitivity, and glucose metabolism, the present study was conducted to investigate the role of PRX3 in the pathogenesis of polycystic ovarian syndrome (PCOS) featured in insulin resistance.

METHODS

Enzyme-linked immunosorbent assay was performed to detect plasma PRX3 in PCOS patients and control subjects. Levels of reactive oxygen species (ROS) and oxidized PRXs were detected in mouse islet cells treated with gradient glucose.

RESULTS

We did not find significant difference of fasting plasma PRX3 between PCOS patients and controls. No association was noticed between fasting plasma PRX3 and fasting plasma glucose or insulin. After oral glucose tolerance test (OGTT), PCOS patients showed higher levels of both glucose and insulin as compared to controls. The plasma level of PRX3 was significantly increased at 2 h and began to fall back at 3 h of OGTT. There was a one-hour time lag of peak values between plasma PRX3 and insulin, and the plasma PRX3 at 2 h was positively correlated with the insulin level at 1 h of OGTT of PCOS patients. In addition, the level of ROS was significantly elevated at 1 h and oxidized PRX3 was increased dramatically at 2 h of 16.7mM glucose stimulation in mouse islet cells.

CONCLUSION

It seems that PRX3 does not show its antioxidant function under baseline conditions. Instead, PRX3 responds to oxidative stress induced by rapid increase of insulin and glucose in patients with PCOS.

Associations of serum fetuin-A and oxidative stress parameters with polycystic ovary syndrome

Objective

The aim of this study was to compare serum fetuin-A levels and oxidative stress markers, as indicators of insulin resistance, in women with polycystic ovary syndrome (PCOS) and in healthy controls.

Methods

This prospective case-control study included 46 patients with PCOS and 48 age- and body mass index–matched control women. Levels of serum hormones, fetuin-A, and oxidative stress markers were measured in blood samples taken during the early follicular period from each participant.

Results

Follicle-stimulating hormone (FSH), luteinising hormone (LH), total testosterone levels, and the LH/FSH ratio were found to be significantly higher in women with PCOS than in controls. Serum total antioxidant status, total oxidant status, and oxidative stress index parameters all indicated significantly higher levels of oxidative stress in PCOS patients than in controls. Serum fetuin-A levels, which were analyzed as an indicator of insulin resistance, were higher in the PCOS group than in the control group (210.26±65.06 µg/mL and 182.68±51.20 µg/mL, respectively; p=0.024).

Conclusion

The data obtained from the present study suggest that higher levels of both serum fetuin-A and oxidative stress markers might be related with PCOS.

Low-Dose Spironolactone-Pioglitazone-Metformin Normalizes Circulating Fetuin-A Concentrations in Adolescent Girls with Polycystic Ovary Syndrome

BACKGROUND

Fetuin-A is a glycoprotein produced in the liver and related to metabolic syndrome; fetuin-A secretion is divergently regulated in different pathological conditions. In girls with polycystic ovary syndrome (PCOS), insulin sensitization results in a more favorable endocrine-metabolic outcome than oral contraception; we assessed whether those differences are underscored by changes in circulating fetuin-A.

METHODS

Fetuin-A concentration endocrine-metabolic markers and hepatovisceral fat were measured longitudinally in 35 PCOS girls [age, 16 yr; body mass index (BMI), 23 kg/m²] randomized to receive either oral contraception [ethinylestradiol-levonorgestrel (n = 18)] or a low-dose combination of spironolactone, pioglitazone, and metformin (SPIOMET, n = 17) over 12 months. Healthy adolescent girls (age- and BMI-matched) were used as controls (n = 25).

RESULTS

Pretreatment fetuin-A serum levels in PCOS girls were lower than those in controls. After 12 months on treatment, fetuin-A raised to control levels only in the SPIOMET subgroup (P = 0.009, versus oral contraception); this increase was paralleled by a healthier metabolic profile with less hepatic fat (by MRI); baseline serum fetuin-A as well as the changes over 12 months was inversely related to hepatic adiposity.

CONCLUSIONS

A low-dose combination of insulin sensitizers and an antiandrogen-but not oral contraception-normalizes fetuin-A levels in adolescent girls with PCOS. This trial is registered with ISRCTN29234515.

Roles of Oxidative Stress in Polycystic Ovary Syndrome and Cancers

Oxidative stress (OS) has received extensive attention in the last two decades, because of the discovery that abnormal oxidation status was related to patients with chronic diseases, such as diabetes, cardiovascular, polycystic ovary syndrome (PCOS), cancer, and neurological diseases. OS is considered as a potential inducing factor in the pathogenesis of PCOS, which is one of the most common complex endocrine disorders and a leading cause of female infertility, affecting 4%–12% of women in the world, as OS has close interactions with PCOS characteristics, just as insulin resistance (IR), hyperandrogenemia, and chronic inflammation. It has also been shown that DNA mutations and alterations induced by OS are involved in cancer pathogenesis, tumor cell survival, proliferation, invasion, angiogenesis, and so on. Furthermore, recent studies show that the females with PCOS are reported to have an increasing risk of cancers. As a result, the more serious OS in PCOS is regarded as an important potential incentive for the increasing risk of cancers, and this study aims to analyze the possibility and potential pathogenic mechanism of the above process, providing insightful thoughts and evidences for preventing cancer potentially caused by PCOS in clinic.

Proteinuria as the Most Relevant Parameter Affecting Fetuin-A Levels in Preeclampsia

The present study aimed to examine the factors affecting the possible changes in serum fetuin-A in patients with preeclampsia (PE). The examined factors included the parameters of insulin resistance (IR) [(insulin sensitivity (HOMA%S), insulin resistance (HOMA2IR), and beta-cell functions (HOMA%B)], which were calculated using the HOMA2 calculator, and total and ionized calcium and magnesium levels.

Sixty PE patients and thirty healthy pregnant women, which comprised the study group and control group, respectively participated in the present study. Fetuin-A, estradiol, insulin, glucose, total and ionized calcium and magnesium, total protein, albumin, and globulins were measured in their sera.

The results of the present study showed that serum total and ionized magnesium and the I.Ca/Mg ratio decreased in PE women. Although the fasting insulin level and HOMA2IR were higher and HOMA2%S was lower in PE compared with the control women, PE did not appear as an overt insulin-resistant state. Serum fetuin-A was low in PE patients compared with the control group because PE women had proteinuria. Fetuin-A levels were not correlated with the characteristics and IR parameters, cations, and estradiol levels, but it was correlated with the severity of proteinuria.

These results confirmed the hypothesis that proteinuria results in the loss of fetuin-A because it has a low molecular weight.

Association of abdominal obesity, insulin resistance, and oxidative stress in adipose tissue in women with polycystic ovary syndrome

OBJECTIVE

To study the expression of insulin signaling-related genes and oxidative stress markers in the visceral adipose tissue obtained from polycystic ovary syndrome (PCOS) patients and healthy control subjects and to investigate the relationships among abdominal obesity, insulin resistance, and oxidative stress at the tissue level.

DESIGN

Case-control study.

SETTING

University teaching hospital.

PATIENT(S)

In total, 30 PCOS patients and 30 healthy control subjects, who underwent laparoscopic surgery, were included in the study.

INTERVENTION(S)

Abdominal obesity was defined based on waist circumference (WC). The homeostasis model index was used to assess insulin resistance (HOMA-IR).

MAIN OUTCOME MEASURE(S)

Gene expression of glucose transporter 4 (GLUT4) and insulin receptor substrate 1 (IRS1) in visceral adipose tissue (VAT) and the parameters of oxidative stress, such as superoxide dismutase, enzyme glutathione reductase, and dimethylarginine, were measured, and the expression of protein oxidative damage product 3-nitro-tyrosine residues (nitrotyrosine) in VAT was identified with the use of immunohistochemistry.

RESULT(S)

PCOS was associated with lower expression of GLUT4 and IRS1 and a higher level of oxidative stress in VAT, which was strongly correlated with WC and HOMA-IR. Presence of abdominal obesity further intensified the correlations observed in our measurements. The nitrotyrosine expression in VAT was stronger in PCOS patients.

CONCLUSION(S)

The strong correlation of insulin resistance with oxidative stress at the VAT level suggests that local oxidative stress and abnormalities of insulin signaling in adipose tissue play critical roles in the pathogenesis of PCOS.