THE EFFECTS OF ENDOCRINE DISRUPTORS ON FEMALE GONADAL AXIS: AN UPDATE.

Endocrine disruptors (EDs) are considered to have an impact on the function of reproductive axis at different levels as well on reproductive organs in both sexes. Complexity of female reproductive system influenced with various stressors including EDs lead to morphological and functional alterations. This is resulting in modulation of neuroendocrine regulation with consequent developmental irregularities and derangements, causative infertility, endometriosis as well as premature ovarian insufficiency or polycystic ovary syndrome. A number of experimental clues was obtained on female animal models using various EDs such as synthetic estrogens and phytoestrogens, neurotransmitters, pesticides or various chemicals. These substances lead towards consequent derangement of the neuroendocrine control of reproduction from early phases of reproductive development towards different phases of adult reproductive period. This text will address some novel insights into the effects of EDs on neuroendocrine regulation of gonadal axis, effects on ovaries as well on endometrium during implantation period.

THE EFFECT OF THERAPY WITH INSULIN ANALOGUES (ASPART AND GLARGINE) ON OXIDATIVE STRESS PARAMETERS IN PATIENTS WITH TYPE 1 DIABETES MELLITUS.

Context: There are evidences that excessive production of reactive oxygen species is one of important abnormalities that contribute to development of chronic diabetic complications. Objective: To test the effect of intensive insulin therapy with analogues through the examining the level of oxidative stress parameters. Subjects and Methods: Comparison of data obtained by prospective analysis in 49 patients with T1DM was used, before and after six months of intensive insulin analog therapy. Results: The values of all three investigated parameters of oxidative stress malondialdehyde (MDA); xanthine oxidase (XO) and nitrates and nitrites (NOx) in our population with T1DM compared to the control (group of 42 voluntary blood donors) are statistically higher. The levels of antioxidant protection parameters compared to the control group also differ; the activities of catalase and glutathione peroxidase (GPx) are statistically higher in our population of T1DM patients compared to the control and superoxide dismutase (SOD) activities are statistically lower.The values of all three examined parameters of oxidative stress decrease after six months of intensive insulin analog therapy and were statistically lower after the therapy: for MDA p<0.001, for XO p<0.01 and for NOx p<0.05. The activities of catalase (p<0.001) and GPx (p<0.01) both decrease with therapy, while the activity of SOD is highest after the sixth month of therapy (p<0.001). Conclusion: In our patients with T1DM compared to the control the level of oxidative stress is significantly higher. Intensive insulin analog therapy with aspart and glargine promotes predominantly the improvement of oxidative stress, and in a less degree antioxidant protection.

The effect of metformin and myoinositol on metabolic outcomes in women with polycystic ovary syndrome: role of body mass and adiponectin in a randomized controlled trial.

PURPOSE: To compare the effects of insulin sensitizers metformin (MET) and myo-inositol (MI) on adiponectin levels and metabolic characteristics in women with polycystic ovary syndrome (PCOS) with respect to their body mass index (BMI). METHODS: In this open label, parallel randomized clinical trial, 66 women with PCOS (33 normal-weight and 33 overweight/obese) were randomized to either MI (4 g/day) or MET (1500 mg/day) for a period of 6 months. Serum concentration of adiponectin, hormonal and metabolic laboratory outcomes and clinical assessment of BMI, body composition and Ferriman-Gallwey score (FG score) were evaluated before and after treatment. RESULTS: After the 6-month intervention, comparison between MET and MI in time to treatment analysis showed no significant differences between the two treatments for all analyzed parameters. Only borderline significantly lower AUC glucose was found in the MET group in comparison to the MI group (p = 0.071). The main effect of treatment was shown for glucose concentration at 120 min OGTT (p = 0.032) and testosterone (p = 0.002). The main effect of time was shown for body mass (p = 0.004), waist circumference (p < 0.001), BMI (p = 0.003), body fat mass (p = 0.001), adiponectin (p = 0.020), fasting glucose (p = 0.001), testosterone (p = 0.015), SHBG (p = 0.013), 17OH progesterone (p = 0.008), LH (p = 0.004) and estradiol (p = 0.014). CONCLUSION: Our study showed similar effects of MET and MI on BMI, body composition, hormonal profile, metabolism of glucose and insulin, and adiponectin level. The two insulin sensitizers, MET and MI, were useful in reducing BMI and improving body composition without significant differences between the two treatments in PCOS women. TRIAL REGISTRATION: ISRCTN13199265. Trial registration date: 14.04.2021. (ISRCTN Registry), retrospectively registered.

THE EFFECT OF MYOINOSITOL AND METFORMIN ON CARDIOVASCULAR RISK FACTORS IN WOMEN WITH POLYCYSTIC OVARY SYNDROME: A RANDOMIZED CONTROLLED TRIAL.

CONTEXT: Cardiovascular risk is increased in women with polycystic ovary syndrome (PCOS). Do insulin sensitizing agents such as metformin (MET) and myoinositol (MI) ameliorate biomarkers of cardiovascular risk? OBJECTIVE: To compare the effects of MET and MI on blood pressure, lipid profile and high sensitive C-reactive protein (hs-CRP) in women with PCOS in respect to their body mass index (BMI). DESIGN: Open label, parallel randomized, single center study. SUBJECTS AND METHODS: Sixty six women with PCOS (33 normal-weight and 33 overweight/obese) were randomized to either MI (4 g/day) or MET (1500 mg/day) for a period of 6 months. Serum concentration of hormones, lipid profile, oxidized LDL (ox-LDL), hs-CRP, blood pressure measurement and clinical assessment of BMI, waist circumference (WC) and Ferriman Gallwey score (FG score) were performed before and after treatment. RESULTS: Thirty patients in each group completed the trial. Compared with MET, MI significantly decreased diastolic blood pressure (DBP) (p=0.036) and significantly increased serum hs-CRP (p=0.043). No differences between groups in total cholesterol (TC), HDL-cholesterol, LDL-cholesterol, ox-LDL and triglycerides were reported after 6 months. Treatment with MI reduced BMI (p=0.037), WC (p=0.005), DBP (p=0.021) and TC (p=0.008). During MET treatment a significant decrease in BMI (p=0.005), WC (p=0.004), FG score (p=0.001), testosterone (p=0.013) and free androgen index (FAI) (p=0.006) was observed. CONCLUSIONS: Our study showed an advantage of MI in reduction of DBP and TC thus predicting favorable metabolic and cardiovascular outcomes in PCOS women. MET more effectively decrease indices of hyperandrogenism.

Insulin resistance, androgens, and lipids are gradually improved in an age-dependent manner in lean women with polycystic ovary syndrome: insights from a large Caucasian cohort.

PURPOSE: Polycystic ovary syndrome (PCOS), considered a lifelong condition, manifests mainly as a cluster of hyperandrogenic symptoms during the early reproductive years, with the affected woman gradually developing an adverse cardiometabolic profile over the years. However, some data point to the possibility of differences in the evolution of PCOS according to a woman's weight. The aim of the present study was to evaluate the metabolic and hormonal profiles of women with PCOS over time. METHODS: A total of 763 lean women with PCOS (BMI 20-25 kg/m2) and 376 controls were included. The study group was further divided into three age groups representing women post-adolescence, of reproductive age, and of late reproductive age. All subjects were assessed clinically, biochemically, and hormonally. RESULTS: Waist circumference, lipids, androgens, and insulin resistance index (homeostasis model assessment of IR index (HOMA-IR)) were significantly higher in the PCOS group compared with controls. Age subgroup analysis showed a progressive decrease of HOMA-IR and waist circumference, and lipid levels were comparable between PCOS and controls in all age groups. Androgens remained significantly higher in PCOS, but they gradually decreased through time. A significant negative association of age with waist circumference, androgens, insulin, and HOMA-IR was revealed. Univariate and multivariate regression analysis disclosed a strong correlation of HOMA-IR with age (p = 0.014, ß - 0.19, SE coefficient 0.008) as a single parameter or in combination with total cholesterol (TC) (p < 0.001, age: ß - 0.023, SE 0.10; TC: ß 0.084, SE 0.027). CONCLUSION: Insulin resistance, androgens, and lipids are gradually improved in an age-dependent manner in lean PCOS women. We hypothesize that if these women do not gain weight with the passage of time, there is a high probability that their cardiometabolic risk will be attenuated.

Non-alcoholic fatty liver disease is associated with insulin resistance and lipid accumulation product in women with polycystic ovary syndrome.

STUDY QUESTION: What are the most relevant factors associated with non-alcoholic fatty liver disease (NAFLD) in women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Insulin resistance (IR) and lipid accumulation product (LAP) are independently associated with NAFLD in PCOS. WHAT IS KNOWN ALREADY: Obesity and IR are frequently present in both women with PCOS and subjects having NAFLD. The coexistence of PCOS and NAFLD might synergistically increase the risk for both type 2 diabetes (T2DM) and cardiovascular disease (CVD). LAP, calculated from waist circumference (WC) and triglycerides (TGs) concentrations [(WC-58) × TGs], has been shown to represent an integrated marker of cardiometabolic risk in women with PCOS. STUDY DESIGN, SIZE, DURATION: This cross-sectional study included 600 Caucasian women diagnosed with PCOS by the Rotterdam criteria between May 2008 and May 2013. PARTICIPANTS, SETTINGS, METHODS: The study was done at the university hospitals in Belgrade, Serbia and Thessaloniki, Greece. All subjects underwent anthropometric measurements and analyses of fasting blood glucose, insulin, lipids, total testosterone and SHBG, as well as liver tests (transaminases, γ-glutamyltransaminase, total bilirubin and alkaline phosphatase). Calculations for a NAFLD liver fat score (NAFLD-LFS) (with, accordingly, determination of metabolic syndrome and testing for T2DM) as well as homeostasis model assessment of IR (HOMA-IR), LAP as a marker of visceral adiposity, and free androgen index (FAI) were performed. We evaluated the prevance of NAFLD and analyzed associations of the above variables with NAFLD. MAIN RESULTS AND THE ROLE OF CHANCE: NAFLD was more prevalent in patients with PCOS than in controls (50.6 versus 34.0%, respectively). Women with PCOS had higher readings for WC, LAP, insulin and HOMA-IR, total cholesterol and TGs than controls (P < 0.001). In PCOS women, the NAFLD-LFS significantly (P < 0.001) correlated with WC, BMI, glucose, HOMA-IR, TGs, LAP and FAI. In multivariate logistic regression, HOMA-IR and LAP were independently associated with NAFLD (P ≤ 0.001). LIMITATIONS, REASONS FOR CAUTION: A possible weakness of the study may be the absence of structural confirmation of liver status. Hovewer, liver biopsy is invasive, difficult to perform in large populations and carries some risk of complications while magnetic resonance spectroscopy does not provide any information regarding the presence of fibrosis and is not routinely available. Another possible limitation could be the measurement of total testosterone by radioimmunoassay, which can be inaccurate when determining low levels of testosterone. Finally, fewer controls than subjects in the study group could have affected the significance of the results. WIDER IMPLICATIONS OF THE FINDINGS: There is a debate on the most accurate clinical method for diagnosing liver disease as an early predictor of T2DM and CVD in general population and in PCOS women. There current study provided data on this issue from a cohort of Caucasian women with PCOS. STUDY FUNDING/COMPETING INTERESTS: The study was supported by a research grant by the Serbian Ministry of Science and Education (grant nos 41009 and 175032). All authors have no competing interests.

Cardiac Nitric Oxide Synthases and Na⁺/K⁺-ATPase in the Rat Model of Polycystic Ovary Syndrome Induced by Dihydrotestosterone.

Nitric oxide synthases (NOSs) and Na(+)/K(+)-ATPase are enzymes essential for regular functioning of the heart. Since both enzymes are under insulin and androgen regulation and since insulin action and androgen level were disturbed in polycystic ovary syndrome (PCOS), we hypothesized that cardiac nitric oxide (NO) production and sodium/potassium transport would be deteriorated in PCOS. To test our hypothesis we introduced animal model of PCOS based on dihydrotestosterone (DHT) treatment of female Wistar rats and analyzed protein expression, phosphorylation or subcellular localization of endothelial NOS (eNOS), inducible NOS (iNOS) and alpha subunits of Na(+)/K(+)-ATPase in the heart. Obtained results indicate that DHT treatment significantly decreased cardiac eNOS protein level and activating phosphorylation at serine 1,177, while inhibitory phosphorylation at threonine 495 was increased. In contrast to expression of eNOS, iNOS protein level in the heart of DHT-treated rats was significantly elevated. Furthermore, cardiac protein level of alpha 1 subunit of the ATPase, as well as its plasma membrane content, were decreased in rats with PCOS. In line with this, alpha 2 subunit protein level in fraction of plasma membranes was also significantly below control level. In conclusion, DHT treatment impaired effectiveness of NOSs and Na(+)/K(+)-ATPase in the female rat heart. Regarding the importance of NO production and sodium/potassium transport in the cardiac contraction and blood flow regulation, it implicates strong consequences of PCOS for heart functioning.

Cardiovascular risk factors and events in women with androgen excess.

Androgen excess (AE) was approximated to be present in 7% of the adult population of women. Polycystic ovary syndrome (PCOS) is the most prevalent among them, followed by idiopathic hirsutism (IH), congenital adrenal hyperplasia (CAH), hyperandrogenic insulin-resistant acanthosis nigricans (HAIRAN) syndrome, and androgen-secreting neoplasms (ASNs). Increased cardiovascular risk was implicated in women with AE. Serum testosterone independently increases risk for cardiovascular disease (CVD), and correlates even with indices of subclinical atherosclerosis in various populations of postmenopausal women. Hyperandrogenism in PCOS is closely related to the aggravation of abdominal obesity, and together with insulin resistance forming the metabolic core for the development of CVD. However, phenotypic variability of PCOS generates significant influence on the cardiometabolic risks. Numerous risk factors in PCOS lead to 5-7 times higher risk for CVD and over 2-fold higher risk for coronary heart disease and stroke. However, issue on the cardiometabolic risk in postmenopausal women with hyperandrogenic history is still challenging. There is a significant overlapping in the CVD characteristics of women with PCOS and variants of CAH. Relevant clinical data on the prevalence and cardiometabolic risk and events in women with IH, HAIRAN syndrome or ASNs are scarce. The effects of various oral contraceptives (OCs) and antiandrogenic compounds on metabolic profile are varying, and could be related to the selected populations and different therapy regiments mainly conducted in women with PCOS. It is assumed relation of OCs containing antiandrogenic progestins to the increased risk of cardiovascular and thromboembolic events.

Insulin resistance in non-obese women with polycystic ovary syndrome: relation to byproducts of oxidative stress.

To get more insight into molecular mechanisms underlying oxidative stress and its link with insulin resistance, oxidative stress parameters, as well as, antioxidant enzyme activities were studied in young, non-obese women with polycystic ovary syndrome (PCOS). Study was performed in 34 PCOS women and 23 age and body mass index (BMI)-matched healthy controls. Plasma nitrotyrosine and malondialdehyde (MDA), representative byproducts of protein and lipid oxidative damage, were determined by enzyme immunoassay. Antioxidant enzyme activities, superoxide dismutase (SOD) and glutathione peroxidase (GPX) were studied spectrophotometrically. Insulin resistance was calculated using homeostasis assessment model (HOMA-IR). Plasma nitrotyrosine and MDA were increased, but only nitrotyrosine was significantly higher (p < 0.05) in PCOS women compared to controls. Uric acid (surrogate marker of × antine oxidase) was also significantly elevated in PCOS (p < 0.05). Both plasma SOD and GPX activity showed no statistically significant difference between PCOS and controls. Indices of insulin resistance (insulin and HOMAIR) were significantly higher in PCOS group and positively correlated with level of MDA (r = 0.397 and r = 0.523, respectively; p < 0.05) as well as GPX activity (r = 0.531 and r = 0.358, respectively; p < 0.05). Our results indicate that insulin resistance could be responsible for the existence of subtle form of oxidative stress in young, nonobese PCOS women. Hence, presence of insulin resistance, hyperinsulinemia and oxidative damage are likely to accelerate slow development of cardiovascular disease in PCOS.