Differential effects of insulin sensitivity on androgens in obese women with polycystic ovary syndrome or normal ovulation

Decreased Serum Level of Gamma-amino Butyric Acid in Egyptian Infertile Females with Polycystic Ovary Syndrome is Correlated with Dyslipidemia, Total Testosterone and 25(OH) Vitamin D Levels

Background

Polycystic ovary syndrome (PCOS) is one of the most common female endocrine disorders around the world. Increasing evidence suggests that neurotransmitter Gamma-aminobutyric acid (GABA) is involved in the pathogenesis of PCOS through its central role in the hypothalamus. However, the peripheral role of GABA in PCOS has not been sufficiently investigated in spite of its existence in peripheral organs. First, the aim of this study is to, investigate serum GABA level in Egyptian PCOS patients. Second, to explore the correlation between serum GABA level with Body Mass Index (BMI), dyslipidemia, totaltestosterone and 25 (OH) vitamin D.

Methods

Eighty PCOS patients and eighty age-matched healthy females were included in this study. All parameters were assessed colourimetrically or with ELISA.

Results

PCOS patients exhibited significantly decreased serum GABA level compared to controls (p < 0.001). There was a significant positive correlation between serum GABA and 25(OH) vitamin D levels (r = 0.26, p = 0.018), and a significant negative correlation with total testosterone (r = - 0.3, p = 0.02), total cholesterol (TC) (r = - 0.31, p = 0.01) and LDL-Cholesterol (LDL-C) (r = - 0.23, p = 0.045), respectively.

Conclusions

The findings of this study suggest that disrupted GABA level in the peripheral circulation is an additional contributing factor to PCOS manifestations. GABA deficiency was correlated with 25 (OH) vitamin D deficiency, dyslipidemia, and total testosterone. Further investigations for GABA adjustment might provide a promising means for better management of PCOS symptoms.

The Relation Between Free Testosterone and Components of Metabolic Syndrome in Women With Polycystic Ovary Syndrome

Objective: To assess the relationship between free testosterone level and components of MS in women with PCOS. Materials and methods: This is a cross-sectional study which was conducted on 215 women with PCOS. PCOS was diagnosed based on the Rotterdam criteria. Patients were divided into two subgroups of patients with and without MS based on ATP III criteria. In each subgroup, the association between individual components of MS with free testosterone was measured. Data were analyzed using SPSS software. Results: The prevalence of MS was 28.8% (n = 62). The mean level of free testosterone in patients with blood pressure ≥ 130/85 was significantly higher than those with blood pressure < 130/85 mm/hg. (p = 0.029) Also, in patients with diastolic blood pressure ≥ 85, the level of free testosterone was significantly higher than patients with diastolic blood pressure < 85. (p = 0.026). Results showed significant positive correlation between the level of free testosterone and cholesterol (p = 0.024). But no significant correlation was noted between levels of free testosterone and other variables. Conclusion: Regarding the relationship between blood pressure and high levels of free testosterone, it seems that regular blood pressure screening has a higher priority of concern comparing other complications for preventing cardiovascular adverse effects in women with PCOS and hyperandrogenism.

Role of androgen ratios in the prediction of the metabolic phenotype in polycystic ovary syndrome

OBJECTIVE

To identify the androgen ratio that best predicts insulin resistance and metabolic syndrome among women with polycystic ovary syndrome (PCOS).

METHODS

Data for 180 women with PCOS and 180 healthy controls were extracted from two previous studies in Iran (conducted during 2008-2010 and 2011-2013). The diagnosis of PCOS was based on the Rotterdam criteria. The serum concentration of different androgens was measured. Receiver operating characteristic curve analysis was used to assess the ability of various androgen ratios to predict insulin resistance and metabolic syndrome.

RESULTS

Among women with PCOS, the testosterone-to-androstenedione ratio was the best predictor of insulin resistance (sensitivity 0.83, specificity 0.42) and metabolic syndrome (sensitivity 0.85, specificity 0.70). Among healthy controls, the ratio of free androgen index to testosterone was the best predictor of insulin resistance (sensitivity 0.84, specificity 0.33) and metabolic syndrome (sensitivity 0.91, specificity 0.17).

CONCLUSION

The prediction of insulin resistance and metabolic syndrome among women with PCOS was best accomplished with the testosterone-to-androstenedione ratio.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS, AMERICAN COLLEGE OF ENDOCRINOLOGY, AND ANDROGEN EXCESS AND PCOS SOCIETY DISEASE STATE CLINICAL REVIEW: GUIDE TO THE BEST PRACTICES IN THE EVALUATION AND TREATMENT OF POLYCYSTIC OVARY SYNDROME - PART 2

Polycystic ovary syndrome (PCOS) is recognized as the most common endocrine disorder of reproductive-aged women around the world. This document, produced by the collaboration of the American Association of Clinical Endocrinologists and the Androgen Excess Society aims to highlight the most important clinical issues confronting physicians and their patients with PCOS. It is a summary of current best practices in 2014. Insulin resistance is believed to play an intrinsic role in the pathogenesis of PCOS. The mechanism by which insulin resistance or insulin give rise to oligomenorrhea and hyperandrogenemia, however, is unclear. Hyperinsulinemic-euglycemic clamp studies have shown that both obese and lean women with PCOS have some degree of insulin resistance. Insulin resistance is implicated in the ovulatory dysfunction of PCOS by disrupting the hypothalamic-pituitary-ovarian axis. Given the association with insulin resistance, all women with PCOS require evaluation for the risk of metabolic syndrome (MetS) and its components, including type 2 diabetes, hypertension, hyperlipidemia, and the possible risk of clinical events, including acute myocardial infarction and stroke. Obese women with PCOS are at increased risk for MetS with impaired glucose tolerance (IGT; 31 to 35%) and type 2 diabetes mellitus (T2DM; 7.5 to 10%). Rates of progression from normal glucose tolerance to IGT, and in turn to T2DM, may be as high as 5 to 15% within 3 years. Data suggest the need for baseline oral glucose tolerance test every 1 to 2 years based on family history of T2DM as well as body mass index (BMI) and yearly in women with IGT. Compared with BMI- and age-matched controls, young, lean PCOS women have lower high-density lipoprotein (HDL) size, higher very-low-density lipoprotein particle number, higher low-density lipoprotein (LDL) particle number, and borderline lower LDL size. Statins have been shown to lower testosterone levels either alone or in combination with oral contraceptives (OCPs) but have not shown improvement in menses, spontaneous ovulation, hirsutism, or acne. Statins reduce total and LDL cholesterol but have no effect on HDL, C-reactive protein, fasting insulin, or homeostasis model assessment of insulin resistance in PCOS women, in contrast to the general population. There have been no long-term studies of statins on clinical cardiac outcomes in women with PCOS. Coronary calcification is more prevalent and more severe in PCOS than in controls. In women under 60 years of age undergoing coronary angiography, the presence of polycystic ovaries on sonography has been associated with more arterial segments with >50% stenosis, but the relationship between PCOS and actual cardiovascular events remains unclear. Therapies for PCOS are varied in their effects and targets and include both nonpharmacologic as well as pharmacologic approaches. Weight loss is the primary therapy in PCOS--reduction in weight of as little as 5% can restore regular menses and improve response to ovulation- inducing and fertility medications. Metformin in premenopausal PCOS women has been associated with a reduction in features of MetS. Clamp studies using ethinyl estradiol/drosperinone combination failed to reveal evidence of an increase in either peripheral or hepatic insulin resistance. Subjects with PCOS have a 1.5-times higher baseline risk of venous thromboembolic disease and a 3.7-fold greater effect with OCP use compared with non-PCOS subjects. There is currently no genetic test to screen for or diagnose PCOS, and there is no test to assist in the choice of treatment strategies. Persistent bleeding should always be investigated for pregnancy and/or uterine pathology--including transvaginal ultrasound exam and endometrial biopsy--in women with PCOS. PCOS women can have difficulty conceiving. Those who become pregnant are at risk for gestational diabetes (which should be evaluated and managed appropriately) and the microvascular complications of diabetes. Assessment of a woman with PCOS for infertility involves evaluating for preconceptional issues that may affect response to therapy or lead to adverse pregnancy outcomes and evaluating the couple for other common infertility issues that may affect the choice of therapy, such as a semen analysis. Women with PCOS have multiple factors that may lead to an elevated risk of pregnancy, including a high prevalence of IGT--a clear risk factor for gestational diabetes--and MetS with hypertension, which increases the risk for pre-eclampsia and placental abruption. Women should be screened and treated for hypertension and diabetes prior to attempting conception. Women should be counseled about weight loss prior to attempting conception, although there are limited clinical trial data demonstrating a benefit to this recommendation. Treatment for women with PCOS and anovulatory infertility should begin with an oral agent such as clomiphene citrate or letrozole, an aromatase inhibitor.

Fasting Glucose Changes in Adolescents with Polycystic Ovary Syndrome Compared with Obese Controls: A Retrospective Cohort Study

STUDY OBJECTIVE

To compare changes in fasting glucose among adolescents with polycystic ovary syndrome (PCOS) with those in obese adolescents without PCOS.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of 310 adolescents with PCOS and 250 obese adolescents (age range 13 to 18 years) seen at Mayo Clinic, Rochester, MN, from 1996 to 2012.

METHODS

Included for analysis were 98 adolescents with PCOS and 150 obese adolescents who had 2 or more fasting glucose measurements separated by at least 6 months. Adolescents with impaired fasting glucose (IFG) or diabetes were excluded. Multivariate models were used to assess predictors of change in fasting glucose.

RESULTS

At diagnosis, adolescents with PCOS had lower body mass index (BMI) (kg/m(2)) and older age than obese adolescents (P < .001). Adolescents with PCOS had shorter follow-up (P = .02). Baseline fasting glucose was not different between groups. Mean change in fasting glucose was 2.4 ± 9.4 mg/dL per year for PCOS and 2.2 ± 6.2 mg/dL per year for obese adolescents (P = .83). Significant predictors for change in fasting glucose were BMI and fasting glucose at diagnosis (P < .01). Within the PCOS cohort, BMI was a significant predictor for development of IFG (P = .003). Prevalence of hypertension increased in the PCOS cohort from baseline to follow-up (P = .02). PCOS and BMI were significantly associated with development of HTN in the entire cohort.

CONCLUSION

Adolescent girls with PCOS do not show a significant change in fasting glucose or an increased risk for the development of IFG compared with obese adolescents. BMI, not PCOS status, was the strongest predictor for changes in fasting glucose and development of IFG over time.

Hyperandrogenemia in polycystic ovary syndrome: exploration of the role of free testosterone and androstenedione in metabolic phenotype

Objective

To evaluate the association between androstenedione, testosterone, and free testosterone and metabolic disturbances in polycystic ovary syndrome.

Methods

We analyzed the association between androstenedione, testosterone, and free testosterone and metabolic parameters in a cross-sectional study including 706 polycystic ovary syndrome and 140 BMI-matched healthy women. Polycystic ovary syndrome women were categorized into 4 groups: normal androstenedione and normal free testosterone (NA/NFT), elevated androstenedione and normal free testosterone (HA/NFT), normal androstenedione and elevated free testosterone (NA/HFT), elevated androstenedione and free testosterone (HA/HFT).

Results

Polycystic ovary syndrome women with elevated free testosterone levels (HA/HFT and NA/HFT) have an adverse metabolic profile including 2 h glucose, HbA1c, fasting and 2 h insulin, area under the insulin response curve, insulin resistance, insulin sensitivity index (Matsuda), triglycerides, total and high density lipoprotein cholesterol levels compared to NA/NFT (p<0.05 for all age- and BMI-adjusted analyses). In binary logistic regression analysis adjusted for age and BMI, odds ratio for insulin resistance was 2.78 (1.34–5.75, p = 0.006) for polycystic ovary syndrome women with HA/HFT compared to NA/NFT. We found no significantly increased risk of metabolic disorders in polycystic ovary syndrome women with HA/NFT. In multiple linear regression analyses (age- and BMI-adjusted), we found a significant negative association between androstenedione/free testosterone-ratio and area under the insulin response curve, insulin resistance, and total cholesterol/high density lipoprotein cholesterol-ratio and a positive association with Matsuda-index, and high density lipoprotein cholesterol (p<0.05 for all).

Conclusions

Polycystic ovary syndrome women with elevated free testosterone levels but not with isolated androstenedione elevation have an adverse metabolic phenotype. Further, a higher androstenedione/free testosterone-ratio was independently associated with a beneficial metabolic profile.

Cardiovascular and metabolic risks associated with PCOS

Polycystic ovary syndrome, the most common endocrine disorder of reproductive age women, is often associated with insulin resistance and associated disorders. The frequency of type 2 diabetes, hyperlipidemia, cardiac risk markers, structural vascular disease, and clinical disease events are increased in this population of women. PCOS, however, represents a broad spectrum of clinical presentations, as defined by different criteria proposed in Europe and the United States. The role of insulin resistance and hence the risk of cardiometabolic disorders may in part be determined by the definition of PCOS used. Epidemiologic studies and clinical trials support the need to identify women with PCOS to determine their risk of cardiometabolic disorders to prevent and/or treat their serious consequences.

Berberine reduces insulin resistance induced by dexamethasone in theca cells in vitro

Theca cells with dexamethasone-induced insulin resistance showed defective glucose uptake and excessive testosterone production, both of which were effectively antagonized by berberine. Therefore, insulin-resistant theca cells may contribute to the pathogenesis of hyperandrogenism in polycystic ovary syndrome.

Metabolic syndrome and polycystic ovary syndrome... and vice versa

The metabolic syndrome (MS) and the polycystic ovary syndrome (PCOS) appear to be interrelated, although they are distinct entities. Women with PCOS appear to be commonly affected by MS, while women with MS may display reproductive or endocrine features of PCOS. These clinical observations appear to be only partly attributable to the association of both syndromes with obesity and imply a reciprocal pathophysiologic relationship between PCOS and MS with potentially significant clinical sequelae. Adult women with MS are at a greater risk of developing cardiovascular disease; women with PCOS also appear to carry such an increased risk in their postmenopausal life. Conversely, women with MS may experience reproductive disturbances, reminiscent of PCOS, more commonly than their counterparts from the general population. This review presented the current epidemiology of MS in adults and adolescents with PCOS, as well as the limited amount of data on the prevalence of features of PCOS among women with MS or MS features. We also discuss the potential pathophysiologic mechanisms underlying the relationship between these interweaving, but distinct, syndromes.

Endocrine factors associated with non-alcoholic fatty liver disease in women with polycystic ovary syndrome: do androgens play a role?

OBJECTIVE

To characterise the metabolic profile of women with polycystic ovary syndrome (PCOS) and non-alcoholic fatty liver disease (NAFLD) and to determine whether circulating androgens differ in PCOS women with NAFLD compared to PCOS subjects without NAFLD.

METHODS

Retrospective study of 21 women with PCOS, elevated liver enzymes and ultrasound evidence of hepatic steatosis matched with 32 PCOS women with normal liver enzymes. Extensive demographic, endocrine and metabolic data were compared. Pearson's correlation coefficients were calculated to assess for potential relationships between the free androgen index (FAI) and other dependent variables.

RESULTS

PCOS subjects with NAFLD demonstrate greater insulin resistance but have similar circulating androgen levels.

CONCLUSION

In this pilot study, insulin resistance was the most prominent feature characterising NAFLD complicating PCOS. Total testosterone, FAI, DHEAS and 17-hydroxyprogesterone levels were similar between patients with PCOS and without NAFLD.

Androgens and polycystic ovary syndrome

PURPOSE OF REVIEW

Polycystic ovary syndrome (PCOS) is a common complex endocrine genetic disorder, which involves overproduction of androgens, leading to heterogeneous range of symptoms and associated with increased metabolic and cardiovascular morbidity. This review focuses on androgen biosynthesis, use, metabolism in PCOS and clinical consequences of hyperandrogenism.

RECENT FINDINGS

Controversial definition of the disorder and different phenotypic subgroups present a challenge for clinical and basic research. Further investigation of different phenotypes highlights the fact that PCOS probably represents a group of disorders with different etiologies. Prenatal androgen exposure and adolescent studies suggest early in life androgen excess as initiating factor of PCOS, but insufficient evidence available to confirm this hypothesis. Various intracellular signaling pathways implicated in PCOS steroidogenesis and in androgen action have been studied, however, PCOS pathogenesis remains obscure. Growing evidence links androgens with pathophysiology of PCOS and metabolic derangements.

SUMMARY

Despite intensive investigation, etiology and underlying mechanisms of PCOS remain unclear, warranting further investigation. Better understanding of molecular and genetic basis might lead to invention of novel therapeutic approaches. Long-term interventional studies that lower androgen levels in women with hyperandrogenism might protect against metabolic and cardiovascular comorbidities are needed.

Insulin sensitizers for women with polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is the most frequent endocrine disorder and most common cause of anovulation in women of reproductive age. It is a heterogeneous disorder, characterized by excess androgen, ovulatory dysfunction and/or polycystic ovaries. The syndrome is known for its association with several reproductive problems, including infertility and obstetric adverse effects. In addition, significant long-term health problems have been strongly linked to PCOS, with women suffering from the disorder having a significantly higher risk of diabetes, cardiovascular risk and some types of cancer, such as endometrial cancer. Although its etiology is unknown, insulin resistance is believed to play a pivotal role in its pathophysiology, with insulin sensitizers found to provide an exciting option in managing health problems associated with PCOS. Almost a decade ago, we proposed a non-insulin-sensitizing mechanism of action for insulin sensitizers through their effect on steroidogenesis. Accumulating evidence supported such an assumption, with solid evidence for a modulating effect on steroidogenesis by metformin and glitazones in the ovaries, adrenal glands and fat cells. Furthermore, other exciting positive roles for insulin sensitizers, in particular glitazones, have been reported at the level of endothelial function. Studying the value of insulin sensitizers in preventing long-term health problems in women with PCOS is still in the stage of infancy.

Polycystic ovary syndrome is associated with tissue-specific differences in insulin resistance

OBJECTIVE

The potential differential contributions of skeletal muscle and adipose tissue to whole body insulin resistance were evaluated in subjects with polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

Forty-two PCOS subjects and 15 body mass index-matched control subjects were studied. Insulin action was evaluated by the hyperinsulinemic/euglycemic clamp procedure. Isolated adipocytes and cultured muscle cells were analyzed for glucose transport activity; adipocytes, muscle tissue, and myotubes were analyzed for the expression and phosphorylation of insulin-signaling proteins.

RESULTS

Fifty-seven per cent of the PCOS subjects had impaired glucose tolerance and the lowest rate of maximal insulin-stimulated whole body glucose disposal compared to controls (P < 0.01). PCOS subjects with normal glucose tolerance had intermediate reduction in glucose disposal rate (P < 0.05 vs. both control and impaired glucose tolerance subjects). However, rates of maximal insulin-stimulated glucose transport (insulin responsiveness) into isolated adipocytes were comparable between all three groups, whereas PCOS subjects displayed impaired insulin sensitivity. In contrast, myotubes from PCOS subjects displayed reduced insulin responsiveness for glucose uptake and normal sensitivity. There were no differences between groups in the expression of glucose transporter 4 or insulin-signaling proteins or maximal insulin stimulation of phosphorylation of Akt in skeletal muscle, myotubes, or adipocytes.

CONCLUSIONS

Individuals with PCOS display impaired insulin responsiveness in skeletal muscle and myotubes, whereas isolated adipocytes display impaired insulin sensitivity but normal responsiveness. Skeletal muscle and adipose tissue contribute differently to insulin resistance in PCOS. Insulin resistance in PCOS cannot be accounted for by differences in the expression of selected signaling molecules or maximal phosphorylation of Akt.