Decreased total antioxidant status and increased oxidative stress in women with polycystic ovary syndrome may contribute to the risk of cardiovascular disease

Role of isoprenylation in simvastatin-induced inhibition of ovarian theca-interstitial growth in the rat

Statins are competitive inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, a rate-limiting step of the mevalonate pathway. The pleiotropic effects of statins may be due to inhibition of cholesterol synthesis, as well as decreased availability of several biologically important intermediate components of the mevalonate pathway, including two substrates for isoprenylation (farnesyl pyrophosphate [FPP] and geranylgeranyl pyrophosphate [GGPP]). Recently, we demonstrated statin-induced inhibition of ovarian theca-interstitial cell proliferation in vitro, as well as reduction of testosterone levels in women with polycystic ovary syndrome (PCOS). This study evaluates the relative contribution of inhibition of isoprenylation and/or cholesterol availability to the modulation of theca-interstitial proliferation. Rat theca-interstitial cells were cultured in chemically defined media with or without simvastatin, FPP, GGPP, squalene, and/or two membrane-permeable forms of cholesterol (25-hydroxycholesterol and 22-hydroxycholesterol). Simvastatin inhibited DNA synthesis and the count of viable cells. The effects of simvastatin were partly abrogated by FPP and GGPP but not by squalene or cholesterol. Inhibition of farnesyl transferase and geranylgeranyl transferase reduced cell proliferation. The present findings indicate that simvastatin inhibits proliferation of theca-interstitial cells, at least in part, by reduction of isoprenylation. These observations provide likely mechanisms explaining clinically observed improvement of ovarian hyperandrogenism in women with PCOS.

Effects of grape seed extract in Type 2 diabetic subjects at high cardiovascular risk: a double blind randomized placebo controlled trial examining metabolic markers, vascular tone, inflammation, oxidative stress and insulin sensitivity

OBJECTIVE

Current research has focused upon the potential links between novel markers of vascular risk such as endothelial dysfunction, oxidative stress, inflammation and insulin resistance in the pathogenesis of Type 2 diabetes and its complications. Grape seed extract (GSE), a flavonoid-rich product, is a potential moderator of these markers. This study aimed to test the hypothesis that GSE may improve these markers in high-risk cardiovascular subjects with Type 2 diabetes.

RESEARCH DESIGN AND METHODS

Thirty-two Type 2 diabetes mellitus patients, prescribed diet or oral glucose-lowering agents, received GSE (600 mg/day) or placebo for 4 weeks in a double-blinded randomized crossover trial. Markers of endothelial function (measured by photoplethysmography), oxidative stress [total antioxidant status (TAOS), reduced glutathione (GSH)/oxidized glutathione (GSSG)], inflammation [highly sensitive C-reactive protein (hsCRP), urinary albumin : creatinine ratio), insulin resistance [homeostasis model assessment-insulin resistance (HOMA-IR)] and metabolism (fructosamine, lipid profile) was measured at baseline and after intervention with GSE or placebo.

RESULTS

Baseline characteristics (16 male and 16 female): age 61.8 +/- 6.36 years; body mass index 30.2 +/- 5.92 kg/m2; diabetes duration 5.9 +/- 2.14 years. Following GSE (but not placebo), significant changes were noted in fructosamine (282 +/- 40.9 vs. 273 +/- 50.2 mmol/l; P = 0.0004); whole blood GSH (2359 +/- 823 vs. 3595 +/- 1051 mmol/l; P < 0.01) and hsCRP (3.2 +/- 3.65 vs. 2.0 +/- 2.2 mg/l; P = 0.0006). Total cholesterol concentration also decreased (4.5 +/- 0.96 vs. 4.3 +/- 0.99 mmol/l; P = 0.05). No statistically significant changes were shown in endothelial function, HOMA-IR or TAOS.

CONCLUSION

GSE significantly improved markers of inflammation and glycaemia and a sole marker of oxidative stress in obese Type 2 diabetic subjects at high risk of cardiovascular events over a 4-week period, which suggests it may have a therapeutic role in decreasing cardiovascular risk.

Anti-mullerian hormone is associated with advanced glycosylated end products in lean women with polycystic ovary syndrome

OBJECTIVE

Oocyte maturation process characterizes polycystic ovary syndrome (PCOS). The mechanisms of this abnormality leading to chronic anovulation are under investigation. Advanced glycosylated end products (AGEs), a marker of oxidative stress linked with oocyte maturation are localized in granulosa cells and are increased in sera, in women with PCOS. The aim of this study was to investigate the relationship, whether there is an association between the anti-mullerian hormone (AMH), a hormone produced by granulosa cells and AGEs in ovulatory and anovulatory PCOS (PCOS-Anov), as well as in non-PCOS anovulatory (Non-PCOS Anov) women. Design Cross-sectional study.

METHODS

Data from sixty women with PCOS (37 anovulatory and 23 regularly ovulating) were compared with eleven Non-PCOS Anov women and 25 normal women. In each subject biochemical, hormonal, and ultrasonographic parameters were studied.

RESULTS

AMH values were statistically significantly higher in PCOS-Anov (7.63+/-3.12) in comparison with ovulatory PCOS (PCOS-Ov; 4.92+/-2.50), Non-PCOS Anov (3.66+/-1.4), and controls (4.02+/-1.27 ng/ml). AGEs demonstrated a similar pattern: 8.70+/-1.65 in PCOS-Anov, 7.43+/-1.79, PCOS-Ov, 5.21+/-0.09, Non-PCOS Anov, and 5.85+/-0.89 U/ml in controls (P<0.005 for all comparison respectively). Follicle number was significantly higher in PCOS-Anov in comparison with other groups. A significant positive correlation between AMH and AGEs was observed (r: 0.326, P<0.01), and with the estimated AMH/AGEs ratio to follicle number (r: 0.42, P: 0.0001) and the presence of anovulation.

CONCLUSIONS

These data suggest that an oxidative marker, AGEs, and AMH, may interact in the anovulatory mechanisms in women with PCOS.

Elevated coagulation and inflammatory markers in adolescents with a history of premature adrenarche

Females with a history of premature adrenarche are at high risk of developing polycystic ovary syndrome (PCOS) and features of the metabolic syndrome later in life. Coagulation disorders, subclinical inflammation, and oxidative stress have been reported in patients with PCOS and metabolic syndrome. These factors were studied in a group of adolescents with a history of premature adrenarche. This is a cross-sectional study that determined the biochemical-hormonal profile and indices of inflammation, coagulation, and oxidative stress in 45 adolescent girls with a history of premature adrenarche and 19 age- and body mass index-matched controls. Girls with premature adrenarche had hyperandrogenism and higher indices of insulin resistance than controls. They also had significantly higher C-reactive protein (0.76 +/- 0.65 vs 0.41 +/- 0.31 mg/L, P = .0001) and plasminogen activator inhibitor 1 (37.6 +/- 24.7 vs 24.47 +/- 4.6 ng/mL, P = .034), and lower tissue plasminogen activator values in comparison with controls (3.5 +/- 1.5 vs 5.2 +/- 2.12 ng/mL, P = .0019). Both C-reactive protein(r = 0.545, P = .0001) and plasminogen activator inhibitor 1 (r = 0.36, P = .04) were positively correlated with oxidative stress, whereas tissue plasminogen activator was positively correlated (r = 0.37, P = .02) with total antioxidant status. None of these factors was correlated with androgens or indices of insulin resistance. Adolescent girls with a history of premature adrenarche display metabolic deviations usually encountered in subjects with PCOS and metabolic syndrome, such as subclinical inflammation and fibrinolytic abnormalities.

Role of androgen excess on metabolic aberrations and cardiovascular risk in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with a clustering of metabolic and cardiovascular risk factors. Insulin resistance is implicated as the major player in the metabolic abnormalities and contributes to the increased cardiovascular risk associated with the syndrome. However, androgen excess appears to participate as an independent parameter, which further aggravates the cardiovascular and metabolic aberrations in affected women with PCOS. The resultant impact of hyperandrogenemia possibly acquires clinical significance for women's health in the context of PCOS, particularly since recent data support an increased incidence of coronary artery disease and of cardiovascular events directly related to androgen levels in women with the syndrome.

Mild ovarian stimulation for IVF

BACKGROUND

Mild ovarian stimulation for in vitro fertilization (IVF) aims to achieve cost-effective, patient-friendly regimens which optimize the balance between outcomes and risks of treatment.

METHODS

Pubmed and Medline were searched up to end of January 2008 for papers on ovarian stimulation protocols for IVF. Additionally, references to related studies were selected wherever possible.

RESULTS

Studies show that mild interference with the decrease in follicle-stimulating hormone levels in the mid-follicular phase was sufficient to override the selection of a single dominant follicle. Gonadotrophin-releasing hormone antagonists compared with agonists reduce length and dosage of gonadotrophin treatment without a significant reduction in the probability of live birth (OR 0.86, 95% CI 0.72-1.02). Mild ovarian stimulation may be achieved with limited gonadotrophins or with alternatives such as anti-estrogens or aromatase inhibitors. Another option is luteinizing hormone or human chorionic gonadotrophin administration during the late follicular phase. Studies regarding these approaches are discussed individually; small sample size of single studies along with heterogeneity in patient inclusion criteria as well as outcomes analysed does not allow a meta-analysis to be performed. Additionally, the implications of mild ovarian stimulation for embryo quality, endometrial receptivity, cost and the psychological impact of IVF treatment are discussed.

CONCLUSIONS

Evidence in favour of mild ovarian stimulation for IVF is accumulating in recent literature. However, further, sufficiently powered prospective studies applying novel mild treatment regimens are required and structured reporting of the incidence and severity of complications, the number of treatment days, medication used, cost, patient discomfort and number of patient drop-outs in studies on IVF is encouraged.

Oxidant stress in healthy normal-weight, overweight, and obese individuals

This study was undertaken to investigate the association among BMI and lipid hydroperoxide (LH), total antioxidant status (TAS), superoxide dismutase (SOD), and reduced glutathione (GSH). Ninety (n = 90) healthy males and females (n = 23/67) (29 normal weight (BMI: 22.74 +/- 0.25 kg/m(2)), 36 overweight (BMI: 27.18 +/- 0.23 kg/m(2)), and 25 obese (33.78 +/- 0.48 kg/m(2))) participated in the study. Data collected included anthropometric measures, fasting blood glucose, lipid profile, LH, TAS, and enzymatic antioxidants (SOD, and reduced GSH). The results of the study showed that obese individuals had significantly increased LH levels compared to normal-weight individuals (obese vs. normal weight (0.88 +/- 0.05 vs. 0.67 +/- 0.03 micromol/l, P < 0.01)) but the increased levels were not significantly different when compared to the overweight group (obese vs. overweight (0.88 +/- 0.05 vs. 0.79 +/- 0.05 micromol/l)). No other consistent significant differences in TAS, SOD, and GSH were identified between groups. This study concluded that only obesity and not moderate overweight elevates LH levels. Furthermore, the levels of TAS, SOD, and GSH in obesity do not explain the increased LH levels observed in obesity.

The effects of insulin sensitizers on the cardiovascular risk factors in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in pre-menopausal women characterized by menstrual cycle disturbances, chronic anovulation, and clinical and/or biochemical hyperandrogenism. Although, the primary etiology of PCOS remains unknown, insulin resistance/hyperinsulinemia plays a pivotal role in the pathogenesis of the syndrome. A growing body of recent data support that women with PCOS have displayed an increased prevelance of cardiovascular disease (CVD) risk factors putting potentially at a hight risk for heart disease. Most of these CVD risk factors are etiologically correlated with insulin resistance/hyperinsulinemia, highlighting the role of insulin sensitizers in the therapeutic quiver for the chronic treatment of PCOS. In this review, we discuss the current literature on the CVD risk factors in PCOS and the influence of insulin sensitizers upon these risk factors.

Increased serum advanced glycation end-products is a distinct finding in lean women with polycystic ovary syndrome (PCOS)

BACKGROUND

Nonenzymatic advanced glycation and oxidation end-products, advanced glycation end-products (AGEs), impart a potent impact on vessels and other tissues in diabetic state and in euglycaemic conditions with increased oxidative stress. Insulin resistant (IR) polycystic ovary syndrome (PCOS) women, have elevated serum AGEs, increased receptor (RAGE) expression, and increased deposition with differential localization in the polycystic ovarian tissue (theca and granulosa) compared to normal.

OBJECTIVE

To determine whether the raised AGE levels in noninsulin resistant women with PCOS is a distinct finding compared with those presenting the isolated components of the syndrome and among PCOS subphenotypes. Noninsulin resistant women were selected in order to show that serum AGEs are elevated in PCOS independently of the presence of IR.

DESIGN

Clinical trial.

PATIENTS

One hundred and ninety-three age- and BMI-matched young lean noninsulin resistant women were studied. Among them, 100 women were diagnosed with PCOS according to Rotterdam criteria, and divided to subphenotypes (hyperandrogenaemia with or without PCO morphology and with or without anovulation). Sixty-eight women with the isolated components of the PCOS phenotype were also studied along with 25 healthy women.

MEASUREMENTS

Serum AGE levels, metabolic, hormonal profiles and intravaginal ultrasound were determined in all subjects.

RESULTS

The studied population did not differ in BMI, fasting insulin concentration, waist : hip and glucose : insulin ratios. PCOS women exhibited statistically higher AGEs levels (7.96 +/- 1.87 U/ml, P < 0.001) compared with those with isolated hyperandrogenaemia (5.61 +/- 0.61 U/ml), anovulation (5.53 +/- 1.06 U/ml), US-PCO morphology (5.26 +/- 0.25 U/ml) and controls (5.86 +/- 0.89 U/ml).

CONCLUSIONS

In PCOS, serum AGEs are distinctly elevated compared with women having the isolated characteristics of the syndrome. No difference was observed between PCOS subphenotypes. As chronic inflammation and increased oxidant stress have been incriminated in the pathophysiology of PCOS, the role of AGEs as inflammatory and oxidant mediators, may be linked with the metabolic and reproductive abnormalities of the syndrome.

Evaluation of antioxidant systems (coenzyme Q10 and total antioxidant capacity) in morbid obesity before and after biliopancreatic diversion

Biliopancreatic diversion (BPD) is a surgical procedure performed in patients with untreatable obesity and insulin resistance. The demonstrated metabolic and hormonal results of this procedure include the reversal of insulin resistance; an increase in diet-induced thermogenesis; and modifications of gut hormones, such as gastrin, enteroglucagon, neurotensin, and cholecystokinin. On the other hand, obesity is a condition of increased oxidative stress; however, few studies have investigated antioxidant systems in obese persons with BPD. To evaluate the metabolic status and antioxidant systems in such patients, we studied a group of 11 morbidly obese patients, aged 28 to 62 years, with a mean body mass index (BMI) of 54.71 +/- 2.52 kg/m(2), before and after successful BPD (mean post-BPD BMI, 44.68 +/- 1.51 kg/m(2)). A control group composed of 10 slightly overweight women, with a mean BMI of 28.5 +/- 0.72 kg/m(2), was also studied. Coenzyme Q(10) (CoQ(10)) levels (also normalized for cholesterol levels) and total antioxidant capacity in blood plasma were assessed in these populations. The most striking datum was the extremely low level of CoQ(10) in postoperative period (0.34 +/- 0.16 vs 0.66 +/- 0.09 mug/mL, P = .04); also, the data corrected for cholesterol levels presented the same pattern, with a more marked significance (152.46 +/- 11.13 vs 186.4 +/- 17.98 nmol/mmol, P = .001). This could be due to lipid malabsorption after surgery. In fact, the pre-BPD data present all the metabolic and hormonal characteristics of severe obesity; and after BPD, there was a net improvement in the metabolic parameters. The first pathophysiologic phenomenon seems to be lipid malabsorption that has been argued to be the cause of insulin resistance reversion. This metabolic interpretation is also confirmed by the absence of significant variations of total antioxidant capacity (57.5 +/- 5.3 vs 66 +/- 5.3). The mechanisms of these phenomena remain to be established. These data suggest the importance of correcting postsurgical metabolic complications, in these clinical populations, with CoQ(10) supplementation.

Plasma cytokines in obese women with polycystic ovary syndrome, before and after metformin treatment

OBJECTIVES

Most research confirms that metformin therapy has a positive influence on cardiovascular risk factors (CVRF) such as dyslipidemia, insulin resistance and hyperandrogenism in polycystic ovary syndrome (PCOS). The aims of the present study were to establish other CVRF, such as plasma adiponectin, tumor necrosis factor-alpha (TNFalpha), interleukin-6 (IL-6) and C-reactive protein (CRP) levels, in obese premenopausal women with PCOS and to investigate the effect of metformin treatment on these factors.

MATERIALS AND METHODS

The study group consisted of 29 PCOS woman with body mass index (BMI) >25 kg/m(2). They were treated over 6 months with 500 mg metformin twice daily. Twenty-nine healthy individuals matched for age and BMI were controls. Adiponectin, TNFalpha, IL-6 and CRP levels were examined in all PCOS (before and after treatment) and control women.

RESULTS

In the PCOS group significantly lower plasma adiponectin and TNFalpha levels were observed, whereas there were no differences in plasma IL-6 and CRP levels between PCOS and control groups. Plasma adiponectin increased significantly after metformin treatment, but levels of inflammatory factors did not change.

Oxidative stress and antioxidants: exposure and impact on female fertility

BACKGROUND

Reproductive failure is a significant public health concern. Although relatively little is known about factors affecting fertility and early pregnancy loss, a growing body of literature suggests that environmental and lifestyle factors play an important role. There is sufficient evidence to hypothesize that diet, particularly its constituent antioxidants, and oxidative stress (OS) may influence the timing and maintenance of a viable pregnancy. We hypothesize that conditions leading to OS in the female affect time-to-pregnancy and early pregnancy loss.

METHODS

We review the epidemiology of female infertility related to antioxidant defenses and oxidation and examine potential sources of OS from the ovarian germ cell through the stages of human pregnancy and pregnancy complications related to infertility. Articles were identified through a search of the PubMed database.

RESULTS

Female OS is a likely mediator of conception and threshold levels for OS exist, dependent on anatomic location and stage of preconception.

CONCLUSIONS

Prospective pregnancy studies with dietary assessment and collection of biological samples prior to conception with endpoints of time-to-pregnancy and early pregnancy loss are needed.

Genome instability is increased in lymphocytes of women with polycystic ovary syndrome and is correlated with insulin resistance

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with insulin resistance and reproductive and metabolic abnormalities. The potential genetic contributors to PCOS are unclear. We tested the hypothesis that genomic instability (chromosome malsegregation and DNA damage) is increased in PCOS.

METHODS

Overweight age, weight and BMI-matched women with (n=14) and without (n=16) PCOS (age 34.2+/-6.0 years, weight 90.7+/-14.5 kg, BMI 34.0+/-5.6 kg/m(2), mean+/-S.D.) were assessed for chromosome malsegregation (assessed by X chromosome chromogenic in situ hybridisation) and micronucleus frequency (assessed by the cytokinesis block micronucleus index) in lymphocytes.

RESULTS

Women with PCOS had significantly elevated genomic instability as demonstrated by a significantly higher number of binucleated lymphocytes containing micronuclei, total number of micronuclei, a higher proportion of aneuploid X chromosome signals (2:1 X and 3:1 X) and a lower proportion of normal X chromosome segregation signals (2:2 X) in binucleated lymphocytes than women without PCOS. Surrogate measures of insulin resistance positively correlated with the proportion of aneuploid cells (2:1; 3:1 X chromosome signals) and inversely with the proportion of normal cells (2:2 X chromosome signals).

CONCLUSION

Women with PCOS display increased genomic instability (higher micronuclei and chromosome malsegregation) compared to women without PCOS and this increase may be related to the insulin resistance phenotype.

Oxidative stress and potential interventions to reduce oxidative stress in overweight and obesity

PURPOSE

Obesity may be a state of chronic oxidative stress. Oxidative stress may be the mechanism underlying the development of co-morbidities in obesity. This review provides a summary of the available evidence regarding systemic oxidative stress in young, older and clinical obese populations.

METHODS

Medline was searched for all available articles published between 1975 and 2006 that evaluated oxidative stress biomarkers in resting conditions or following various interventions in overweight and obese humans.

RESULTS

Obesity elevates oxidative stress in young, old and clinical populations as shown by elevations in lipid peroxidation (malondialdehyde, hydroperoxides, 4-hydroxynonenal, isoprostanes, conjugated dienes) or protein oxidation (8-hydroxy-deoxyguanosine). Lipid peroxidation is associated with several indices of adiposity and a low systemic antioxidant defence (i.e. antioxidant enzymes, tissue dietary antioxidants, glutathione). Oxidative stress may be exacerbated with acute exercise, advancing age or co-existing clinical conditions and may be corrected by improving antioxidant defences through fat volume reduction via surgery, pharmacological agents, exercise and/or dietary modification.

CONCLUSION

Oxidative stress is related to chronic disease in obesity, but is reversible with one or more interventions described above.

Abdominal adiposity and the polycystic ovary syndrome

Abdominal adiposity, overweightness and obesity are frequently present in patients with polycystic ovary syndrome (PCOS). A large body of evidence suggests that abdominal adiposity and the resulting insulin resistance contribute to ovarian and, possibly, adrenal hyperandrogenism. However, androgen excess itself might also contribute to abdominal fat deposition in hyperandrogenic women. Recent genomic and proteomic analyses of visceral fat from PCOS patients have detected differences in gene expression and protein content compared with those of non-hyperandrogenic women. Here we review the existing evidence for a vicious circle whereby androgen excess favoring the abdominal deposition of fat further facilitates androgen secretion by the ovaries and adrenals in PCOS patients.

Increased body iron stores of obese women with polycystic ovary syndrome are a consequence of insulin resistance and hyperinsulinism and are not a result of reduced menstrual losses

OBJECTIVE

Increased serum ferritin levels, indicating increased body iron stores, have been found in overweight and obese women with polycystic ovary syndrome (PCOS). This finding might result from reduced menstrual losses secondary to oligo- or amenorrhea or from hyperinsulinism secondary to insulin resistance, because insulin favors the intestinal absorption and the tissue deposition of iron. To explore which of these mechanisms is responsible for the increase in body iron stores in women with PCOS, we have monitored the changes in serum ferritin levels during treatment with an antiandrogenic oral contraceptive or an insulin sensitizer.

RESEARCH DESIGN AND METHODS

Thirty-four consecutive PCOS patients were randomized to an oral contraceptive containing 35 microg ethinyl-estradiol plus 2 mg cyproterone acetate (Diane(35) Diario) or metformin (850 mg twice daily), and their serum ferritin levels were evaluated at baseline and after 12 and 24 weeks of treatment.

RESULTS

Despite the fact that treatment with Diane(35) Diario restored regular menstrual cycles in all the patients, whereas metformin only did so in 50% of them, serum ferritin levels decreased at 12 and 24 weeks of treatment only with metformin, in association with a marked increase in insulin sensitivity. On the contrary, no changes in ferritin and insulin sensitivity were observed with Diane(35) Diario.

CONCLUSIONS

Our present results suggest that insulin resistance and hyperinsulinism, and not the reduced menstrual losses secondary to from oligo- or amenorrhea, are responsible of the increased ferritin levels and body iron stores found in overweight and obese women with PCOS.

Polycystic ovary syndrome and pregnancy outcome: red herring or red flag?

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women, associated with a characteristic ovarian appearance at ultrasound scan, hyperandrogenism, and ovulatory disorders. The pathogenesis appears to be mainly related to reduced insulin sensitivity in peripheral tissues, leading to hyperinsulinaemia. There is a wide variation in the severity of PCOS symptoms. Women with PCOS are believed to be predisposed to a variety of complications in pregnancy. We present a summary of the evidence surrounding these claims and discuss the weaknesses of the available to date studies.

Alterations in lipoprotein defense against oxidative stress in metabolic syndrome

Metabolic syndrome (MetS) is a high-risk condition for premature atherosclerotic vascular disease. Patients with MetS display a lipoprotein profile in which dense low-density lipoproteins (LDL), which are more susceptible to oxidation, predominate. Oxidation of lipoproteins can be attenuated in vivo by enzymatic and nonenzymatic antioxidant defenses, but high-density lipoproteins (HDL) play a key role in the protection of LDL from oxidation. Such activity depends on the presence of apolipoproteins (apoA-I, apoA-II, apoA-IV, apoE) and enzymes (paraoxonase 1, platelet activating factor-acetylhydrolase, lecithin:cholesterol acyltransferase, glutathione peroxidase). The impairment of HDL antioxidative activity in MetS is partly related to an enrichment of small HDL in triglycerides and their depletion in cholesteryl esters, to the replacement of apoA-I by serum amyloid A, and to glycation and oxidation of apoA-I. Therapeutic normalization of the quantity and the quality of HDL particles may constitute a novel approach to attenuate atherosclerosis and cardiovascular risk in MetS.

Reduction of perifollicular arterial blood flow resistance after hCG administration is a good indicator of the recovery of mature oocytes in ART treatment

PURPOSE

To demonstrate our hypothesis that a correlation exists between oocyte maturity and a decrease in intraovarian blood flow resistance in assisted reproductive technology (ART) treatment cycles, oocyte maturity and total antioxidant status (TAOS) in follicular fluid was examined.

METHODS

A total of 59 cycles involving 51 infertile patients undergoing ART treatment in our hospital were recruited in this study. The ART cycles were divided into two groups: deeply decreased (DD) group and not-deeply decreased (NDD) group, according to the pulsatility index (PI) values for perifollicular arterial blood flow before and after hCG administration. The PI values that showed a decrease in their PI after hCG administration of 10% or more were defined "deeply decreased" and showed a decrease of less than 10% were considered "not-deeply decreased." The recovery rates of mature and immature oocytes and TAOS in follicular fluid were compared between the two groups.

RESULTS

Mature and immature oocyte recovery rates in the DD group (62.5% and 17.2%) were significantly higher and lower, respectively, than those in the NDD group (41.7% and 38.3%, p < 0.05). The TAOS (1.55 +/- 0.44 mmol/L) of the DD group was significantly lower than that in the NDD group (1.68 +/- 0.47 mmol/L, p < 0.05).

CONCLUSIONS

The decrease in intraovarian arterial blood flow resistance measured after hCG administration may be a good indicator of retrieving mature oocyte.

Indices of Low-Grade Inflammation in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is probably the most common endocrinopathy of reproductive age. PCOS represents a disorder that not only enhances the risk for type 2 diabetes (T2D) but is also associated with an increased number of cardiovascular risk factors known to facilitate atherogenesis. On the other hand, inflammation is thought to play an important role in the progression and development of complications of atherosclerosis. Evidence of low-grade chronic inflammation in PCOS is indicated by the presence of elevated C-reactive protein (CRP) levels, inflammatory cytokines (i.e., IL-6 and IL-18), and increased leucocyte count. CRP, a nonspecific marker of inflammation, has been proven to be one of the strongest predictors of the risk of cardiovascular events in patients with or without cardiovascular disease. The levels of the adhesion molecules (AM), sIVAM-1, sVCAM-1, and sE-selectin in serum reflect low-grade chronic inflammation of the endothelium and independently predict coronary heart disease (CHD) and T2D. In a recent study in a large number of PCOS women we demonstrated elevated levels of sIVAM-1 and sE-selectin and we further substantiated the existence of a low-grade chronic inflammatory process in PCOS. However, it remains to be assessed with long-term studies whether the early presence of markers of chronic inflammation in young women with this syndrome has clinical significance.

The presence of antibodies to oxidative modified proteins in serum from polycystic ovary syndrome patients

Polycystic ovary syndrome (PCOS) affects 5-10% of women of reproductive age. Free radicals, as a product of oxidative stress, impair cells and tissue properties related to human fertility. These free radicals, together with the oxidized molecules, may have a cytotoxic or deleterious effects on sperm and oocytes, on early embryo development or on the endometrium. Aldehyde-modified proteins are highly immunogenic and circulating autoantibodies to new epitopes, such as malondialdehyde (MDA), may affect the reproductive system. Autoantibodies or elevated reactive oxygen species (ROS) in serum are often associated with inflammatory response. The purpose of this work is to investigate whether PCOS women show increased levels of oxidized proteins (protein-MDA) and anti-endometrial antibodies (AEA) in their sera, compared with control patients, and to determine whether AEA specificity is related to oxidized protein derivatives. Sera from 31 women [10 patients with PCOS (PCOS group) and 21 women with male factor of infertility (control group)] were chosen from patients attending for infertility. Anti-endometrial antibodies were determined by enzyme-linked immunosorbent assay (ELISA) with an endometrial cell line (RL-95). Antibodies against MDA modified human serum albumin (HSA-MDA) were also determined by ELISA. Oxidized proteins (protein-MDA) in serum were determined by a colorimetric assay. Patients with PCOS have significantly higher levels of AEA and anti-HSA-MDA, as well as oxidized proteins (protein-MDA) in serum than control patients. For the first time, we describe an autoimmune response in PCOS patients, in terms of AEA. The evidence of protein-MDA in the serum of these patients, together with the increased antibody reactivity to MDA-modified proteins (HSA-MDA) in vitro, supports the conclusion that oxidative stress may be one of the important causes for abnormal endometrial environment with poor embryo receptivity in PCOS patients.

Are polycystic ovaries associated with cardiovascular disease risk as polycystic ovary syndrome?

AIM

Our aim was to assess C-reactive protein (CRP) levels and insulin resistance in women with polycystic ovary syndrome (PCOS) or polycystic ovaries (PCO).

METHODS

The study population included 30 women with PCOS, 30 with PCO and 30 healthy controls. CRP and insulin resistance index (IRI) (fasting glucose/insulin) were measured. A receiver-operator characteristic (ROC) curve was constructed to determine the cut-off value of CRP to predict increased cardiovascular risk.

RESULTS

There were no statistically significant differences between the three groups with regard to age and body mass index. IRI was significantly lower in the PCOS group than in the PCO and control groups. No difference existed between the PCO and control groups. Median CRP levels in the control, PCO and PCOS groups were 0.75, 1.3 and 1.5 mg/l, respectively (p = 0.005). CRP could differentiate between women with and without increased cardiovascular risk at a cut-off value of 2.42 mg/l, with a sensitivity of 79% and a specificity of 81%.

CONCLUSION

As in PCOS patients, women with PCO have higher serum CRP levels than healthy control women. This may contribute to increased cardiovascular disease risk in patients with PCO.

Biomarkers and potential mechanisms of obesity-induced oxidant stress in humans

OBJECTIVE

Oxidative stress may be the unifying mechanism underlying the development of comorbidities in obesity. Evidence suggests that a clustering of sources of oxidative stress exists in obesity: hyperglycemia, hyperleptinemia, increased tissue lipid levels, inadequate antioxidant defenses, increased rates of free radical formation, enzymatic sources within the endothelium, and chronic inflammation.

METHOD

This review provides a summary of the available evidence on systemic oxidative stress in humans and specific metabolic pathways by which obesity may elevate systemic oxidant stress. The authors suggest possible methods of reducing oxidative stress such as antioxidant supplementation, caloric restriction and/or physical activity and surgical intervention to combat free radicals and reduce adipose tissue.

RESULTS

Obesity is associated with oxidative stress and can be reduced with weight loss (regardless of exercise or surgery induced weight loss), caloric restriction or antioxidant rich diets.

CONCLUSION

Oxidative stress levels are elevated in human obesity, and these levels are modifiable with various lifestyle modifications and surgical interventions.

Beneficial effect of metformin on pregnancy outcome in women with polycystic ovary syndrome is not associated with major changes in C-reactive protein levels or indices of coagulation

In women with polycystic ovary syndrome, C-reactive protein levels and D-dimer, antithrombin III, activated protein C resistance, and activated partial thromboplastin time were unaffected by metformin treatment throughout pregnancy. Protein C levels increased slightly in the metformin group compared with the placebo group.

The optimal diet for women with polycystic ovary syndrome?

An optimal diet is one that not only prevents nutrient deficiencies by providing sufficient nutrients and energy for human growth and reproduction, but that also promotes health and longevity and reduces the risk of diet-related chronic diseases. The composition of the optimal diet for women with polycystic ovary syndrome (PCOS) is not yet known, but such a diet must not only assist short term with weight management, symptoms and fertility, but also specifically target the long-term risks of type 2 diabetes, CVD and certain cancers. With insulin resistance and compensatory hyperinsulinaemia now recognised as a key factor in the pathogenesis of PCOS, it has become clear that reducing insulin levels and improving insulin sensitivity are an essential part of management. Diet plays a significant role in the regulation of blood glucose and insulin levels, yet research into the dietary management of PCOS is lacking and most studies have focused on energy restriction rather than dietary composition per se. On the balance of evidence to date, a diet low in saturated fat and high in fibre from predominantly low-glycaemic-index-carbohydrate foods is recommended. Because PCOS carries significant metabolic risks, more research is clearly needed.

Decreased serum paraoxonase 1 (PON1) activity: an additional risk factor for atherosclerotic heart disease in patients with PCOS?

BACKGROUND

Patients with polycystic ovary syndrome (PCOS) may have an increased risk for the development of hypertension and atherosclerotic heart disease (AHD), the pathophysiological mechanisms of which are not clear. Paraoxonase1 (PON1) is a high-density lipoprotein-associated enzyme that prevents oxidative modification of low-density lipoprotein. The aim of this study was to measure the serum levels of PON1 activity in patients with PCOS and to compare with those of regularly cycling controls.

METHODS

Serum lipid parameters, malondialdehyde (MDA) levels and PON1 activity, were measured in PCOS patients (n = 23) and regularly cycling, age-, body mass index- and smoking status-matched controls (n = 23). All patients had normal glucose tolerance test as assessed by a 75 g oral glucose tolerance test. None of the patients had clinically evident hypertension or AHD.

RESULTS

Apart from the mean serum PON1 activity, all parameters in the lipid profile including serum MDA levels were comparable between the two groups. There were no significant differences in respect to fasting glucose (4.64 +/- 0.5 versus 4.43 +/- 0.83 mmol/l) and fasting glucose insulin ratio (11.06 +/- 8.26 versus 11.49 +/- 4.90) among the two groups (P > 0.05). However, HOMA insulin resistance index was significantly higher in patients with PCOS compared with the controls (2.06 +/- 0.86 versus 1.51 +/- 0.49; P = 0.01). Also, mean serum PON1 activity was significantly lower in the PCOS group compared with the controls (151.2 +/- 90.8 versus 217.7 +/- 101.6, respectively; P = 0.027).

CONCLUSIONS

Reduced serum PON1 activity might contribute to the increased susceptibility for the development of AHD in women with PCOS.

The effects of rosiglitazone and metformin on oxidative stress and homocysteine levels in lean patients with polycystic ovary syndrome

BACKGROUND

Oxidative stress and hyperhomocysteinaemia are risk factors for cardiovascular diseases. The aim of this study was to assess the effects of rosiglitazone and metformin on cardiovascular disease risk factors such as insulin resistance, oxidative stress and homocysteine levels in lean patients with polycystic ovary syndrome (PCOS).

METHODS

Fifty lean patients (BMI <25 kg/m2) with PCOS and 35 healthy subjects were included this study. Serum homocysteine, sex steroids, fasting insulin, fasting glucose and lipid levels were measured. Total antioxidant status (TAS; combines concentrations of individual antioxidants) and malonyldialdehyde concentration (MDA) were determined. Insulin resistance was evaluated by using the homeostasis model insulin resistance index (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), Area under the curve insulin (AUCI) and the insulin sensitivity index (ISI). Patients were divided into two groups. One group was treated with metformin (n = 25) and the other received rosiglitazone (n = 25) for 12 weeks. All measurements were repeated at the end of 12 weeks.

RESULTS

Compared with healthy women, those with PCOS had significantly elevated serum MDA, homocysteine, HOMA-IR, AUCI and lipoprotein a levels, and significantly decreased serum TAS, QUICKI and ISI. Serum free testosterone levels showed a significant positive correlation with MDA, AUCI and HOMA-IR, and a negative correlation with TAS, ISI and QUICKI in PCOS patients. HOMA-IR and AUCI significantly decreased, while QUICKI and ISI significantly increased after treatment in both groups. Serum TAS level increased and serum MDA level decreased after the rosiglitazone treatment, but these parameters did not change after the metformin treatment. Serum homocysteine and lipid levels did not change in either group, while serum androgen levels and LH/FSH ratio significantly decreased after the treatment period in only the rosiglitazone-treated group.

CONCLUSION

Elevated insulin resistance, oxidative stress and plasma homocysteine levels and changes in serum lipid profile (risk factors for cardiovascular disease) were observed in lean PCOS patients. Rosiglitazone seemed to decrease elevated oxidative stress when compared with metformin treatment in lean PCOS patients.

The molecular basis for oxidative stress-induced insulin resistance

Reactive oxygen and nitrogen molecules have been typically viewed as the toxic by-products of metabolism. However, accumulating evidence has revealed that reactive species, including hydrogen peroxide, serve as signaling molecules that are involved in the regulation of cellular function. The chronic and/or increased production of these reactive molecules or a reduced capacity for their elimination, termed oxidative stress, can lead to abnormal changes in intracellular signaling and result in chronic inflammation and insulin resistance. Inflammation and oxidative stress have been linked to insulin resistance in vivo. Recent studies have found that this association is not restricted to insulin resistance in type 2 diabetes, but is also evident in obese, nondiabetic individuals, and in those patients with the metabolic syndrome. An increased concentration of reactive molecules triggers the activation of serine/threonine kinase cascades such as c-Jun N-terminal kinase, nuclear factor-kappaB, and others that in turn phosphorylate multiple targets, including the insulin receptor and the insulin receptor substrate (IRS) proteins. Increased serine phosphorylation of IRS reduces its ability to undergo tyrosine phosphorylation and may accelerate the degradation of IRS-1, offering an attractive explanation for the molecular basis of oxidative stress-induced insulin resistance. Consistent with this idea, studies with antioxidants such as vitamin E, alpha-lipoic acid, and N-acetylcysteine indicate a beneficial impact on insulin sensitivity, and offer the possibility for new treatment approaches for insulin resistance.

The molecular-genetic basis of functional hyperandrogenism and the polycystic ovary syndrome

The genetic mechanisms underlying functional hyperandrogenism and the polycystic ovary syndrome (PCOS) remain largely unknown. Given the large number of genetic variants found in association with these disorders, the emerging picture is that of a complex multigenic trait in which environmental influences play an important role in the expression of the hyperandrogenic phenotype. Among others, genomic variants in genes related to the regulation of androgen biosynthesis and function, insulin resistance, and the metabolic syndrome, and proinflammatory genotypes may be involved in the genetic predisposition to functional hyperandrogenism and PCOS. The elucidation of the molecular genetic basis of these disorders has been burdened by the heterogeneity in the diagnostic criteria used to define PCOS, the limited sample size of the studies conducted to date, and the lack of precision in the identification of ethnic and environmental factors that trigger the development of hyperandrogenic disorders. Progress in this area requires adequately sized multicenter collaborative studies after standardization of the diagnostic criteria used to classify hyperandrogenic patients, in whom modifying environmental factors such as ethnicity, diet, and lifestyle are identified with precision. In addition to classic molecular genetic techniques such as linkage analysis in the form of a whole-genome scan and large case-control studies, promising genomic and proteomic approaches will be paramount to our understanding of the pathogenesis of functional hyperandrogenism and PCOS, allowing a more precise prevention, diagnosis, and treatment of these prevalent disorders.

Long-term metabolic, cardiovascular and neoplastic risks with polycystic ovary syndrome

Metabolic abnormalities and obesity have long been associated with the development of cardiovascular disease in the general population. These same features are also associated with polycystic ovary syndrome (PCOS). An increased prevalence of hypertension, dyslipidaemia, obesity and hyperinsulinaemia, as well as changes in coagulation and blood vessel function, provide an explanation as to why women with PCOS are at an increased risk of developing cardiovascular disease over the long term.

Insulin resistance in patients with polycystic ovary syndrome

With a prevalence of 5%-10% the polycystic ovary syndrome (PCOS) is an exceptionally common disorder of premenopausal women. According to prospective studies, women with PCOS present abnormal glucose tolerance and diabetes mellitus in 31%-35% and 7.5%-10%, respectively. PCOS patients have a higher prevalence of cardiovascular risk factors such as hypertension, type 2 diabetes and dyslipidaemia. The rate of spontaneous abortions as well as the risk to develop gestational or type 2 diabetes is increased in PCOS. Therefore, PCOS is not only a reproductive problem but a complex endocrine disease with important health implications. The role of the glucose metabolism in PCOS, the health consequences and possible interventions are reviewed in this article.