Insulin sensitivity in women with polycystic ovary syndrome: relationship to hyperandrogenemia

An Ovarian Steroid Metabolomic Pathway Analysis in Basal and Polycystic Ovary Syndrome (PCOS)-like Gonadotropin Conditions Reveals a Hyperandrogenic Phenotype Measured by Mass Spectrometry

Prior work has demonstrated that murine ovarian explants and isolated ovarian follicles can recapitulate human-like 28-day cycles in vitro with normal patterns of estradiol and progesterone secretion in response to gonadotropin stimulation. The objective of this study was to manipulate the gonadotropin stimulation protocol to mimic polycystic ovary syndrome (PCOS) and assess the resulting changes in ovarian steroidogenesis. A secondary aim of the study was to develop a high-throughput, sensitive, and specific liquid chromatography with tandem mass spectrometry (LC-MS/MS) assay to measure seven steroid hormones (estrone, estradiol, progesterone, testosterone, androstenedione, dehydroepiandrosterone, and dihydrotestosterone) in conditioned culture media. Ovaries were harvested from 12-day-old CD-1 mice and cultured for 28 days, with ovulation induction on culture day 14. Media were supplemented human chorionic gonadotropin (hCG, a luteinizing hormone analog) and follicle stimulating hormone (FSH) at ratios of 1:0 (standard media), 1:1 (physiologic ratio), and 3:1 (PCOS-like ratio). Ovaries cultured in PCOS-like media displayed hyperandrogenism and impaired ovulation, two key features of a PCOS-like phenotype. Taken together, this first-of-its-kind presentation of hormone levels from single tissues creates a map of the enzymatic steps most acutely affected by gonadotropin dysregulation and may provide opportunities for assessing other potential insults in PCOS pathogenesis.

Polycystic Ovary Syndrome in Insulin-Resistant Adolescents with Obesity: The Role of Nutrition Therapy and Food Supplements as a Strategy to Protect Fertility

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in young reproductive-aged women. PCOS is often associated with obesity and impairs reproductive health. Even though several theories have been proposed to explain the pathogenic mechanism of PCOS, the role of insulin resistance (IR) as a key etiological component, independently of (but amplified by) obesity, is well recognized. The consequent hyperinsulinemia activates excessive ovarian androgen production, leading to PCOS. Additionally, the state of chronic inflammation related to obesity impacts ovarian physiology due to insulin sensitivity impairment. The first-line treatment for adolescents with obesity and PCOS includes lifestyle changes; personalized dietary interventions; and, when needed, weight loss. Medical nutrition therapy (MNT) and the use of specific food supplements in these patients aim at improving symptoms and signs, including insulin resistance and metabolic and reproductive functions. The purpose of this narrative review is to present and discuss PCOS in adolescents with obesity, its relationship with IR and the role of MNT and food supplements in treatment. Appropriate early dietary intervention for the management of adolescents with obesity and PCOS should be considered as the recommended approach to restore ovulation and to protect fertility.

Very low dose spironolactone protects experimentally-induced polycystic ovarian syndrome from insulin-resistant metabolic disturbances by suppressing elevated circulating testosterone

Polycystic ovarian syndrome (PCOS) is the most common endocrinological disorder in women of reproductive age and hyperandrogenism is a prominent feature of PCOS resulting in infertility and increased risk of developing metabolic disorders including insulin resistance (IR), abdominal adiposity, glucose intolerance and cardiovascular diseases. Spironolactone (SPL), a non-selective mineralocorticoid receptor (MR) antagonist, has been in wide clinical use for several decades. In this study, we investigated the effects of SPL on IR and metabolic disturbances in letrozole-induced PCOS rats. Eighteen adults female Wistar rats were randomly divided into 3 groups and treated with vehicle, letrozole (LET; 1 mg/kg) and LET + SPL (SPL; 0.25 mg/kg), p.o. once daily for 21 consecutive days. Results showed that LET treatment induced PCOS characterised by elevated plasma testosterone and luteinizing hormone (LH) accompanied with increased body weight and visceral adiposity, IR, glucose intolerance, dyslipidemia and altered histomorphological ovaries. Treatment with SPL however attenuated the elevated testosterone in LET-induced PCOS model accompanied with a reversal in all the observed alterations. Taken together, analysis of the physical, biochemical and histological evidences shows that the protective effect of this very low dose spironolactone may be through its anti-androgenic mechanism.

Low-dose spironolactone ameliorates insulin resistance and suppresses elevated plasminogen activator inhibitor-1 during gestational testosterone exposure

CONTEXT

Elevated gestational circulating testosterone has been associated with pathological pregnancies that increase the risk of development of cardiometabolic disorder in later life.

OBJECTIVE

We hypothesised that gestational testosterone exposure, in late pregnancy, causes glucose deregulation and atherogenic dyslipidaemia that would be accompanied by high plasminogen activator inhibitor-1 (PAI-1). The study also hypothesise that low-dose spironolactone treatment would ameliorate these effects.

METHODS

Pregnant Wistar rats received vehicle, testosterone (0.5 mg/kg; sc), spironolactone (0.5 mg/kg, po) or testosterone and spironolactone daily between gestational days 15 and 19.

RESULTS

Gestational testosterone exposure led to increased HOMA-IR, circulating insulin, testosterone, 1-h post-load glucose, atherogenic dyslipidaemia, PLR, PAI-1 and MDA. However, all these effects, except that of circulating testosterone, were ameliorated by spironolactone.

CONCLUSIONS

These results demonstrate that low-dose spironolactone ameliorates glucose deregulation and atherogenic dyslipidaemia during elevated gestational testosterone exposure, at least in part, by suppressing elevated PAI-1.

Insulin Resistance: Any Role in the Changing Epidemiology of Thyroid Cancer?

In the past few decades, the incidence of thyroid cancer (TC), namely of its papillary hystotype (PTC), has shown a steady increase worldwide, which has been attributed at least in part to the increasing diagnosis of early stage tumors. However, some evidence suggests that environmental and lifestyle factors can also play a role. Among the potential risk factors involved in the changing epidemiology of TC, particular attention has been drawn to insulin-resistance and related metabolic disorders, such as obesity, type 2 diabetes, and metabolic syndrome, which have been also rapidly increasing worldwide due to widespread dietary and lifestyle changes. In accordance with this possibility, various epidemiological studies have indeed gathered substantial evidence that insulin resistance-related metabolic disorders might be associated with an increased TC risk either through hyperinsulinemia or by affecting other TC risk factors including iodine deficiency, elevated thyroid stimulating hormone, estrogen-dependent signaling, chronic autoimmune thyroiditis, and others. This review summarizes the current literature evaluating the relationship between metabolic disorders characterized by insulin resistance and the risk for TC as well as the possible underlying mechanisms. The potential implications of such association in TC prevention and therapy are discussed.

Prenatal Exposure to Endocrine Disruptors: A Developmental Etiology for Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most common and complex endocrinopathies among reproductive-age women. Polycystic ovary syndrome is characterized by symptomatology of oligomenorrhea and androgen excess, with or without presence of polycystic ovarian morphology. The etiology of PCOS is multifactorial, including genetic and environmental components. It has been previously established that prenatal androgen exposure results in a PCOS phenotype in experimental animal models and epidemiologic human studies. Investigators hypothesize that prenatal exposure to endocrine-disrupting chemicals (EDCs) may contribute to PCOS development. This review examines the emerging research investigating prenatal exposure to 3 major classes of EDCs-bisphenol A (BPA), phthalates, and androgenic EDCs-and the development of PCOS and/or PCOS-related abnormalities in humans and animal models. Highlights of this review are as follows: (1) In rodent studies, maternal BPA exposure alters postnatal development and sexual maturation;, (2) gestational exposure to dibutyl phthalate and di(2-ethylhexyl)phthalate results in polycystic ovaries and a hormonal profile similar to PCOS; and (3) androgenic EDCs, nicotine and 3,4,4'-trichlorocarbanilide, create a hyperandrogenic fetal environment and may pose a potential concern. In summary, prenatal exposure to EDCs may contribute to the altered fetal programming hypothesis and explain the significant variability in severity and presentation.

Low vitamin D3 and high anti-Müllerian hormone serum levels in the polycystic ovary syndrome (PCOS): Is there a link?

OBJECTIVES

Low vitamin D serum level has been reported in women with polycystic ovary syndrome (PCOS) compared to controls. A few in vitro studies showed that the bioactive form of vitamin D is able to modulate the expression of the anti-Müllerian hormone (AMH) gene. However, in vivo studies failed to demonstrate clearly whether low vitamin D3 serum level is involved in the AMH excess of PCOS. This prospective study evaluates serum vitamin D3 and AMH levels in women with PCOS and in controls, before and after vitamin D supplementation.

MATERIALS AND METHODS

Among vitamin D deficient patients, 23 patients with PCOS were compared to 27 women with normal ovarian reserve (NOR). The vitamin D deficient patients received a vitamin D supplementation according to the depth of their insufficiency. For the 23 patients with PCOS and the 27 controls, serum AMH assay and serum calciotropic hormone assays [25-hydroxyvitamin D (25[OH]D), 1,25 dihydroxyvitamin D (1,25[OH]₂D) and parathyroid hormone (PTH)] were performed before and after supplementation.

RESULTS

Serum 25(OH)D levels before treatment were statistically lower in PCOS women than in NOR patients (P<0.05), even after adjustment for BMI, age and AMH level, but not after adjustment for waist circumference measurement. No difference in the serum AMH levels before and after treatment was observed neither in PCOS patients nor in NOR patients. In both groups, 25(OH)D serum levels were not related to serum AMH levels, serum 1,25(OH)₂D and serum PTH levels, before and after treatment.

CONCLUSION

We found no evidence that serum calciotropic hormones are linked to circulating AMH levels, particularly in PCOS.

Polycystic ovary syndrome, diabetes and cardiovascular disease: risks and risk factors

Polycystic ovary syndrome is one of the most common endocrine disorders in the human, affecting approximately 10% of women of reproductive age. Although originally considered a gynaecological disorder, the syndrome is associated with a wide range of endocrine and metabolic abnormalities, including insulin resistance. Affected women are at an increased risk of developing gestational and non-insulin dependent diabetes and there is an association with cardiovascular risk factors including obesity, hypertension, dyslipidaemia, hyperhomocysteinaemia, increased intima media thickness and impaired vascular elasticity. The effect on cardiovascular mortality is currently unclear. However, in view of the proven links with diabetes and the cardiovascular risk markers, this condition should be considered within the province of physicians as well as gynaecologists.

Insulin resistance in polycystic ovary syndrome is associated with defective regulation of ERK1/2 by insulin in skeletal muscle in vivo

Insulin resistance is a recognized feature of PCOS (polycystic ovary syndrome). However, the molecular reason(s) underlying this reduced cellular insulin sensitivity is not clear. The present study compares the major insulin signalling pathways in skeletal muscle isolated from PCOS and controls. We measured whole-body insulin sensitivity and insulin signalling in skeletal muscle biopsies taken before and after acute exposure to hyperinsulinaemia in nine women diagnosed with PCOS and seven controls. We examined the expression, basal activity and response to in vivo insulin stimulation of three signalling molecules within these human muscle samples, namely IRS-1 (insulin receptor substrate-1), PKB (protein kinase B) and ERK (extracellular-signal-regulated kinase) 1/2. There was no significant difference in the expression, basal activity or activation of IRS-1 or PKB between PCOS and control subjects. However, there was a severe attenuation of insulin stimulation of the ERK pathway in muscle from all but two of the women with PCOS (the two most obese), and an accompanying trend towards higher basal phosphorylation of ERK1/2 in PCOS. These results are striking in that the metabolic actions of insulin are widely believed to require the IRS-1/PKB pathway rather than ERK, and the former has been reported as defective in some previous PCOS studies. Most importantly, the molecular defect identified was independent of adiposity. The altered response of ERK to insulin in PCOS was the most obvious signalling defect associated with insulin resistance in muscle from these patients.

Testosterone deficiency impairs glucose oxidation through defective insulin and its receptor gene expression in target tissues of adult male rats

Testosterone and insulin interact in their actions on target tissues. Most of the studies that address this issue have focused on the physiological concentration of testosterone, which maintains normal insulin sensitivity but has deleterious effects on the same when the concentration of testosterone is out of this range. However, molecular basis of the action of testosterone in the early step of insulin action is not known. The present study has been designed to assess the impact of testosterone on insulin receptor gene expression and glucose oxidation in target tissues of adult male rat. Adult male albino rats were orchidectomized and supplemented with testosterone (100 microg/100 g b. wt., twice daily) for 15 days from the 11th day of post orchidectomy. On the day after the last treatment, animals were euthanized and blood was collected for the assay of plasma glucose, serum testosterone and insulin. Skeletal muscles, such as gracilis and quadriceps, liver and adipose tissue were dissected out and used for the assay of various parameters such as insulin receptor concentration, insulin receptor mRNA level and glucose oxidation. Testosterone deprivation due to orchidectomy decreased serum insulin concentration. In addition to this, insulin receptor number and its mRNA level and glucose oxidation in target tissues were significantly decreased (p<0.05) when compared to control. However, testosterone replacement in orchidectomized rats restored all these parameters to control level. It is concluded from this study that testosterone deficiency-induced defective glucose oxidation in skeletal muscles, liver and adipose tissue is mediated through impaired expression of insulin and its receptor gene.

The ESHRE/ASRM consensus on polycystic ovary syndrome (PCOS) – an extended critical analysis

The 'ESHRE/ASRM consensus on diagnosis, nomenclature and long-term health risks of polycystic ovarian syndrome (PCOS)' (conference in Rotterdam, Netherlands, March, 2003), which was criticized shortly after its oral presentation in 2003, is still being debated following its publication in 2004. Therefore, an extended, intensive analysis of all parameters and their combinations has been performed, differentiating between inclusion and exclusion criteria. By doing this, the profound significance of the endocrinological part of the syndrome is highlighted. The nomenclature, semantic meaning of terms, definitions, structural balancing, specificity, practicability, flexibility, limitations and reproducibility for both individualization, as well as grouping from the clinical and scientific perspective, have been examined in detail. This analysis supports previous critical comments, and reaches the conclusion that the recommendations of the consensus lack accuracy and specificity, a weakness that results in the risk of overdiagnosis and in a lack of reproducibility. Altogether, they fail to fulfil the criteria of universal guidelines on several levels. Instead, a profound paradigm shift is demanded, from an inconsistent perception to a more systematic, balanced and comprehensive view. A short indication on an alternative sweeping concept of a strictly defined, therapy-targeted classification and diagnostic procedure of female functional androgenization is presented.

Flow-mediated dilatation in overweight and obese women with polycystic ovary syndrome

OBJECTIVE

There remains a large degree of disagreement about the association of polycystic ovary syndrome (PCOS) with impaired endothelial dysfunction and cardiovascular disease (CVD) risk. The purpose of this study was to determine whether overweight and obese women with PCOS have impaired endothelial function compared with weight-matched controls without PCOS and whether endothelial function is associated with cardiovascular risk markers and hormonal parameters.

DESIGN

Cross-sectional analysis.

SETTING

An outpatient trial at the Commonwealth Scientific Industrial Research Organisation Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n= 12) and weight-matched controls without PCOS (n= 10).

METHODS

Endothelial function, cardiovascular risk markers and hormonal parameters were assessed in the patients.

MAIN OUTCOME MEASURES

Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery using high-resolution ultrasound. Lipid profile, fasting insulin level, glucose level, insulin resistance, C-reactive protein level, folate level, Vitamin B(12) level and hormonal parameters.

RESULTS

Women with PCOS had significantly higher testosterone levels (P < 0.001) and free androgen index (P= 0.006) compared with the controls without PCOS. Both groups were normoinsulinaemic, and there were no significant differences in any of the markers of CVD between women with and without PCOS. Furthermore, FMD was similar in both groups (PCOS 6.1 +/- 1.2% versus control 5.6 +/- 1.0%, P= 0.77).

CONCLUSIONS

Compared with a group of weight-matched women with similar metabolic profiles, normoinsulinemic, overweight and obese women with PCOS did not show any greater impairment in endothelial function assessed by FMD. A normoinsulinemic phenotype of PCOS with low metabolic risk factors may reduce the risk of endothelial dysfunction in overweight and obese women with this syndrome. Further studies are required that directly compare FMD in normoinsulinemic and hyperinsulinaemic women with PCOS.

Upregulation of adiponectin receptor 1 and 2 mRNA and protein in adipose tissue and adipocytes in insulin-resistant women with polycystic ovary syndrome

AIMS/HYPOTHESIS

Polycystic ovary syndrome (PCOS) is a multifaceted metabolic disease linked with insulin resistance (IR) and obesity. Adiponectin, which is lower in IR states, exerts its glucose-lowering and anti-inflammatory effects by activating two receptors, ADIPOR1 and ADIPOR2. There are no data on the relative expression of these receptors in adipose tissue of PCOS women.

METHODS

We investigated the expression of adiponectin receptors from corresponding s.c. and omental (o.m.) adipose tissue in women with PCOS compared with matched non-PCOS women. As there is a disturbance in the steroid milieu in PCOS women, we also assessed the effects of testosterone and oestradiol on adiponectin receptors using adipocytes and adipocyte explants. Real-time RT-PCR and western blotting were used to assess the relative adiponectin receptor mRNA expression and protein production, respectively. Biochemical measurements were performed in our hospital's laboratory.

RESULTS

We are the first to describe adiponectin receptor expression and production, in corresponding s.c. and o.m. human adipose tissues at the mRNA and protein level. We demonstrate the upregulation of mRNA expression and protein production of adiponectin receptors in women with PCOS, in s.c. and o.m. adipose tissue. Treatment of adipose tissue explants and adipocytes with testosterone and oestradiol induced the expression of adiponectin receptor mRNA and protein. There was a significant positive association between ADIPOR1/R2 expression and homeostasis model assessment, testosterone, oestradiol and triglycerides and a negative relationship with sex hormone-binding globulin.

CONCLUSIONS/INTERPRETATION

The precise reason for the upregulation of adiponectin receptors seen in PCOS women, a pro-diabetic state, is unknown, but it appears that sex steroids may play a role in their regulation in adipose tissue.

Is the PCOS diagnosis solved by ESHRE/ASRM 2003 consensus or could it include ultrasound examination of the ovarian stroma?

BACKGROUND

The clinical heterogeneity of polycystic ovary syndrome (PCOS) is mirrored by the unceasing debate on the most appropriate diagnostic criteria.

METHODS AND RESULTS

To highlight differences and inconsistencies between NIH and ESHRE/ASRM criteria, we applied them to 375 patients with oligo/amenorrhoea and signs of hyperandrogenism. Among them, we identified 273 women with PCOS according to NIH, whereas up to 345 patients fulfilled ESHRE/ASRM criteria. The 72 patients, constituting the gap between the two classifications, exhibited a lower expression of clinical signs compared with the 273 patients matching both criteria. To the whole group, we then applied the ESHRE/ASRM criteria modified to include an easily reproducible ultrasound examination of the ovarian stroma (UCSC criteria). In this way, we identified 30 women who were healthy according to all criteria, 37 affected by PCOS according only to the ESHRE/ASRM Consensus, 35 affected according only to the UCSC and ESHRE/ASRM criteria and 273 who were considered to have PCOS by all criteria. These groups showed a progressively increasing expression of PCOS features.

CONCLUSION

In the grey area between NIH and ESHRE/ASRM classifications, UCSC criteria could identify a subgroup of women, missed by NIH criteria, with more pronounced stigmas than those identified by ESHRE/ASRM criteria alone, and who may profit more from a targeted therapy.

Genomic variants in polycystic ovary syndrome

The polycystic ovary syndrome (PCOS) is a common disorder in premenopausal women, characterized by the presence, among other traits, of hyperandrogenism, insulin resistance, and hyperinsulinism. The familial aggregation of PCOS lead the interest to the molecular genetic basis of this syndrome, especially to the genes encoding proteins involved in androgen synthesis and the regulation of insulin synthesis and action. Considering the relationship between insulin resistance and chronic inflammation, and the clustering of inflammatory markers in PCOS patients, recent studies focused on the involvement of proinflammatory genotypes on the pathogenesis of PCOS. Mounting evidence suggest at present a complex model of inheritance for PCOS, in which predisposing and protecting genomic variants interact with environmental factors such as obesity and a sedentary lifestyle, finally leading to the classic phenotype of this syndrome. Moreover, the association of hyperandrogenism, insulin resistance and chronic inflammation raised the possibility of an increase risk of cardiovascular disease in women suffering from PCOS. In the present review we will summarize the most important findings published to date regarding the molecular genetic mechanisms underlying the association of PCOS with insulin resistance and chronic inflammation, and the possible interaction of these mechanisms with environmental factors.

Acarbose in obese patients with polycystic ovarian syndrome: a double-blind, randomized, placebo-controlled study

BACKGROUND

The present study assessed the effects of low-dose acarbose on obese patients with polycystic ovarian syndrome (PCOS).

METHODS

A double-blind placebo-controlled study was conducted on 30 obese hyperinsulinaemic women with PCOS treated with 150 mg/day acarbose or placebo for 6 months. The women were evaluated for hirsutism, menstrual regularity, body mass index (BMI), insulin resistance and glucose tolerance, sex hormone-binding globulin (SHBG), LH, FSH, testosterone and androstenedione, and side-effects.

RESULTS

The patients in the acarbose group showed a reduction in BMI (35.87 +/- 2.60 versus 33.10 +/- 2.94 kg/m(2)) and in the Ferriman-Gallwey index (8.85 +/- 2.31 versus 8 +/- 1.82), and an increased chance of menstrual regularity (rate = 2.67). SHBG concentration increased (21.01 +/- 7.9 versus 23.85 +/- 7.77 nmol/l) and the free androgen index was reduced (14.81 +/- 9.06 versus 11.48 +/- 6.18). None of these parameters were modified in the placebo group. Mild side-effects occurred in 84% of the patients in the acarbose group and disappeared after the first 3 months.

CONCLUSION

A low dose of acarbose administered to obese patients with PCOS promotes a reduction in free androgen index and BMI and an increase in SHBG, with improvement of hirsutism and of the menstrual pattern, and is well tolerated by patients.

Adiponectin and resistin serum levels in women with polycystic ovary syndrome during oral glucose tolerance test: a significant reciprocal correlation between adiponectin and resistin independent of insulin resistance indices

Polycystic ovary syndrome (PCOS) is associated with an increased incidence of insulin resistance (IR), obesity, and type 2 diabetes. Resistin, an adipocytokine, may represent a link between obesity, and these metabolic disorders. There is also evidence that inflammation is a hyperresistinemic state in humans, and cytokine induction of resistin may contribute to insulin resistance in endotoxemia, obesity, and other inflammatory states. In contrast, adiponectin, increases insulin sensitivity, improves glucose tolerance, inhibits inflammatory pathways, while adenovirus-expressed adiponectin reduces atherosclerotic lesions in a mouse model of atherosclerosis. We aimed to assess, in women with PCOS, whether there is a relationship between adiponectin and resistin and the indices of IR, and whether serum levels of these adipocytokines are altered by glucose-induced hyperinsulinaemia. Serum levels of resistin and adiponectin were measured at 0, 60, and 120 min during 75 g oral glucose tolerance test (OGTT), in 19 women with PCOS, age 36.3+/-11.4 years (mean+/-SD), body mass index (BMI) 29.3+/-7.7 kg/m2, and correlated with the indices of IR, such as HOMA-IR, QUICKI, and the insulin resistance index calculated from glucose and insulin levels obtained during OGTT. There was no change in resistin concentrations (7.31+/-4.58, 7.47+/-5.40, 7.22+/-5.12 pg/ml, at 0, 60, and 120 min of OGTT, respectively, P = 0.77), but there was an increase in adiponectin from 11.32+/-4.64 microg/ml at baseline to 14.78+/-7.41 microg/ml, at 120 min of OGTT (P < 0.01). The magnitude of the overall rise in adiponectin was greater from 60 to 120 min (from 12.31+/-5.72 to 14.78+/-7.41 microg/ml, P < 0.006). Neither resistin, nor adiponectin correlated with the indices of IR, lipids, or other hormonal parameters of the PCOS. There was, however, a significant negative correlation between serum resistin and adiponectin (P = 0.001). In conclusion, we observed a strong negative correlation between serum adiponectin and resistin, despite the lack of direct correlation with the indices of IR. Given the opposite effects of resistin and adiponectin on the inflammatory process, we speculate that relative proportion of adiponectin-to-resistin might potentially influence cardiometabolic risk in women with the PCOS independently of IR parameters. The observed increase in adiponectin during OGTT requires further study.

Administration of B-group vitamins reduces circulating homocysteine in polycystic ovarian syndrome patients treated with metformin: a randomized trial

BACKGROUND

The aim of the current study was to assess the effects of B-group vitamins and folic acid administration on serum levels of homocysteine (Hcy) in patients with polycystic ovarian syndrome (PCOS) on short-term metformin treatment.

METHODS

Patients were randomly assigned to one of three treatment groups. Group 1 patients (n = 20) received metformin (850 mg twice daily); group 2 patients (n = 20) received metformin (850 mg twice daily) and B-group vitamins (vitamin B1, 250 mg; vitamin B6, 250 mg; vitamin B12, 1000 microg twice daily); and group 3 patients (n = 20) received metformin (850 mg twice daily) and folic acid (174 microg twice daily). In all groups, lipid profiles and plasma total Hcy, vitamin B12, folic acid and glucose levels were recorded at baseline and at 3 months.

RESULTS

A 26.5% increase in Hcy levels was seen after 12 weeks of metformin therapy, while 21.17 and 8.33% decreases in Hcy levels were detected when B-group vitamins or folic acid plus metformin were given respectively. There were no statistically significant differences recorded in insulin sensitivity using homeostasis model assessment in the three groups.

CONCLUSION

These findings suggest that B-group vitamins and folic acid administration counteract the Hcy-increasing effect seen with metformin therapy.

The effect of obesity on the outcome of infertility management in women with polycystic ovary syndrome

INTRODUCTION

Obesity has become a worldwide epidemic with ever increasing incidence and public health problems in both developing and developed countries.

OBJECTIVE

The objective of the study is to investigate the incidence of obesity among patients with polycystic ovarian syndrome attending infertility clinic and the effect on treatment outcome.

METHODOLOGY

Two hundred and seventy women with polycystic ovarian syndrome attending the infertility clinic were evaluated clinically, biochemically, and laparoscopically. They were stratified according to their body mass index (BMI) as follows: normal weight: 18-24; overweight: 25-29, obese:30-34, and grossly obese: > or = 35. Therapy included induction of ovulation with clomiphene citrate and gonadotrophins. The patients were followed up through during induction of ovulation and pregnancy.

RESULTS

There were ethnic differences in mean BMI. Significantly more obese women had oligomenorrhoea (p<0.01) and anovulation (p<0.01) than women with normal weight. Obesity adversely affected the outcome of ovulation induction with clomiphene citrate and gonadotrophins; 79% of women with BMI 18-24 ovulated at 6 months compared to 15.3% in those with BMI 30-34 (p<0.001) and 11.8% in women with BMI > or = 35 (p<0.001). The pregnancy rate and outcome were also adversely affected by obesity.

CONCLUSION

Obesity has a negative impact on the outcome of treatment of infertility. Weight reduction programme should be an essential component of infertility management.

Reduction of dehydroepiandrosterone sulfate synthesis in women with polycystic ovary syndrome by human menopausal gonadotropin but not purified urinary follicle stimulating hormone: a comparative pilot study

We aimed to compare the effects of two different gonadotropins on steroid production in patients with polycystic ovary syndrome (PCOS). The study group comprised 20 infertile patients diagnosed with PCOS who were accepted into in vitro fertilization-embryo transfer and gamete intra-Fallopian transfer programs. Ten patients were consecutively allocated to a purified urinary follicle stimulating hormone (FSH) administration group while the other ten received human menopausal gonadotropin (hMG). All patients were pretreated with a gonadotropin releasing hormone-agonist. The patients were followed by daily vaginal ultrasonography until at least two follicles reached a diameter of 17 mm or an estradiol value of at least 100 pg/ml per follicle. To induce ovulation, human chorionic gonadotropin was given. On the 3rd day of menstruation, serum estradiol, luteinizing hormone (LH), FSH, total testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), insulin-like growth factor-I and insulin were measured. These same parameters were measured again on the day of follicle aspiration in both serum and follicular fluid. In both groups, the serum levels of estradiol and androstenedione were raised significantly, and on aspiration day the serum level of DHEAS was significantly raised in the FSH group but not in the hMG group. Our findings suggest that in PCOS patients exogenous hMG induces a different steroid synthesis pattern compared to pure FSH, hypothetically by reduction of the delta-5 steroid synthesis pathway in the adrenals and/or in the ovary.

Insulin resistance and lipid profile in women with polycystic appearing ovaries: implications with regard to polycystic ovary syndrome

The aim of this study was to investigate carbohydrate and lipid profiles in women with polycystic appearing ovaries (PCO) on ultrasound examination who did not fulfill the criteria for polycystic ovary syndrome (PCOS). We sonographically evaluated and biochemically diagnosed 35 patients with PCO, 31 women with PCOS and 23 healthy controls. We performed oral glucose tolerance tests (OGTT) and calculated the quantitative insulin sensitivity check index (QUICKI) and the homeostatic model assessment (HOMAIR) scores. Serum fasting insulin levels, 1-h insulin response, HOMAIR and QUICKI scores were significantly higher in the PCO and PCOS groups than in the controls. However, serum fasting glucose levels, fasting insulin levels, HOMAIR and QUICKI scores were similar in women with PCO and PCOS. In women with PCO, high-density lipoprotein (HDL) levels were higher, and very-low-density lipoprotein (VLDL) and triglyceride levels were lower compared with women with PCOS. Furthermore, insulin responses to OGTT, HOMAIR and QUICKI scores and lipid values correlated with serum androgen levels and body mass index (BMI) in PCO patients. In conclusion, women with PCO who do not fulfill the criteria for PCOS have abnormal insulin sensitivity and insulin resistance. The finding of similar insulin abnormalities in women with PCO to those in women with PCOS confirms that women with PCO have similar metabolic characteristics to those with PCOS.

Polycystic ovary syndrome--a systemic disorder?

Polycystic ovary syndrome (PCOS) is the commonest endocrine disturbance affecting women. There is considerable heterogeneity of symptoms and signs amongst women with PCOS and for an individual these may change over time. PCOS is familial and genetics appear to be associated with disturbances of insulin secretion. Polycystic ovaries can exist without clinical signs of the syndrome, which may then become expressed over time. There are a number of interlinking factors that affect expression of PCOS. A gain in weight is associated with a worsening of symptoms whilst weight loss will ameliorate the endocrine and metabolic profile and symptomatology. Women with PCOS are characterized by the presence of insulin resistance, central obesity and dyslipidaemia, which appears to place them at a higher risk of developing diabetes as well as cardiovascular disease. A number of studies have confirmed the higher incidence of diabetes, although they have not shown a higher risk of mortality from ischaemic heart disease (IHD). Cross-sectional studies have demonstrated a significant association between PCOS and IHD. Prospective, long-term longitudinal studies confirming this risk are still awaited. Weight loss remains the most effective first line therapeutic intervention in women with PCOS and recently the use of insulin sensitizing agents has demonstrated benefit.

Relationship between polycystic ovaries, body mass index and insulin resistance

BACKGROUND

To investigate insulin levels in lean and overweight women with and without polycystic ovaries. An observational, cross-sectional study at The Northem General Hospital, Sheffield, UK.

METHODS

Sixty-eight women born at Jessop Hospital, Sheffield, between 1952 and 1953 were divided into four groups according to the status of their polycystic ovaries and body mass index: either > or approximately 25. Therefore, this was an unselected sample, unlike previous studies that have recruited from endocrine clinics or similar. Subjects underwent pelvic ultrasonography to visualize their ovaries in order to diagnose or exclude polycystic ovaries. They all underwent a short insulin tolerance test.

RESULTS

Women with a body mass index > 25 and with polycystic ovaries were the most insulin resistant. Women with a body mass index of < or = ?25 and with normal ovaries were the most insulin sensitive. Women with a body mass index < or = ?25 and polycystic ovaries were the more resistant than those with a body mass index > 25 and with normal ovaries.

CONCLUSION

Obesity increases insulin resistance, and the presence of polycystic ovaries increases insulin resistance. The presence of polycystic ovaries appears to have a stronger influence than obesity on insulin resistance. This is the first study to demonstrate these relationships using unselected volunteers.

N-acetyl-cysteine treatment improves insulin sensitivity in women with polycystic ovary syndrome

OBJECTIVE

To evaluate the effect of N-acetyl-cysteine (NAC) on insulin secretion and peripheral insulin resistance in subjects with polycystic ovary syndrome (PCOS).

DESIGN

Prospective data analysis.

SETTING

Volunteer women in an academic research environment.

PATIENT(S)

Six lean and 31 obese subjects, aged 19-33 years.

INTERVENTION(S)

Patients were treated for 5-6 weeks with NAC at a dose of 1.8 g/day orally. A dose of 3 g/day was arbitrarily chosen for massively obese subjects. Six of 31 obese patients with PCOS were treated with placebo and served as controls.

MAIN OUTCOME MEASURE(S)

Before and after the treatment period, the hormonal and lipid blood profile and insulin sensitivity, assessed by an hyperinsulinemic euglycemic clamp, were evaluated and an oral glucose tolerance test (OGTT) was performed.

RESULT(S)

Fasting glucose, fasting insulin, and glucose area under curve (AUC) were unchanged after treatment. Insulin AUC after OGTT was significantly reduced, and the peripheral insulin sensitivity increased after NAC administration, whereas the hepatic insulin extraction was unaffected. The NAC treatment induced a significant fall in T levels and in free androgen index values (P<.05). In analyzing patients according to their insulinemic response to OGTT, normoinsulinemic subjects and placebo-treated patients did not show any modification of the above parameters, whereas a significant improvement was observed in hyperinsulinemic subjects.

CONCLUSION(S)

NAC may be a new treatment for the improvement of insulin circulating levels and insulin sensitivity in hyperinsulinemic patients with polycystic ovary syndrome.

Long-term consequences of polycystic ovary syndrome: results of a 31 year follow-up study

A cohort of 786 women who received a diagnosis of polycystic ovary syndrome (PCOS) in the United Kingdom before 1979 was traced to investigate the long-term consequences of the syndrome. Data were obtained from death certificates for 70 women. Morbidity data were collected from general practice records and questionnaires for 319 women diagnosed with PCOS an average of 31 years previously and for 1060 age-matched control women. The proportion of women with involuntary infertility was 17.5% in the PCOS group compared with 1.3% in the control group. All-cause mortality in the cohort did not differ from that of the general population of women. Women with PCOS were not at significantly increased risk of mortality or morbidity from breast cancer but were at increased risk of endometrial cancer. Women with a history of PCOS had higher levels of several cardiovascular risk factors including diabetes, hypertension, raised plasma cholesterol and body mass index > 30 kg m(minus sign2). Mortality and morbidity from coronary heart disease did not differ significantly between the women with PCOS and comparison groups. Control of obesity is likely to be particularly important for women with a history of PCOS.

A new ultrasound criterion for the diagnosis of polycystic ovary syndrome: the ovarian stroma/total area ratio

OBJECTIVE

To evaluate whether some ultrasound parameters of ovarian morphology can discriminate between control women and patients with polycystic ovary syndrome (PCOS).

DESIGN

Retrospective data analysis.

SETTING

Volunteers women in an academic research environment.

PATIENT(S)

Eighty amenorrheic or oligomenorrheic women and 30 normal ovulatory control participants.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

We evaluated ovarian volume, area, stroma, and the stroma/total area (S/A) ratio by use of transvaginal pelvic ultrasound; and we assayed serum levels of gonadotropin, androgen, and estradiol during the early follicular phase (days 2 to 5) of the menstrual cycle in regularly cycling controls and on a random day in amenorrheic patients.

RESULT(S)

Patients with PCOS showed significantly higher ovarian volume, area, stroma, and mean S/A ratio when compared to multifollicular and control groups. Cut-off values have been defined for ovarian volume (13.21 mL), area (7.00 cm2), stroma (1.95 cm2), and S/A ratio (0.34). The sensitivity for PCOS diagnosis was 21%, 4%, 62%, and 100%, respectively. The S/A ratio showed the most significant correlation with the androgen levels.

CONCLUSION(S)

The evaluation of the S/A ratio can differentiate between PCOS and control or multifollicular women with both a sensitivity and a specificity of 100%. Furthermore, this ultrasound parameter is strictly related to hormonal milieu and to anthropometric characteristics.

Resistência à insulina na pubarca precoce - Relação com os androgênios

O objetivo deste estudo foi descrever o perfil da insulina e determinar sua relação com o hiperandrogenismo na pubarca precoce (PP). Avaliamos 23 meninas com PP devido à adrenarca precoce e 5 controles (C) pré-puberais normais (7,3±1,1 x 7,1±1,8 anos). Os níveis de sulfato de deidroepiandrosterona (SDHEA), testosterona (T) e globulina ligadora dos hormônios sexuais (SHBG) foram medidos. O índice de massa corporal (IMC) e o índice do androgênio livre (IAL) foram calculados. O teste oral de tolerância à glicose (G) foi realizado; sendo calculadas a relação de jejum da insulina (I) pela G (FIGR= I/G) e as áreas abaixo das curvas da G e I (AACG e AACI). A FIGR > 22 foi considerada como sugestiva de resistência a I (RI). O IMC foi maior na PP do que nos C: 18,8±3,0 x 15,5±1,6, p= 0,03. Os níveis de SDHEA (71,7±40,6 x 34,2±6,9µg/dl, p= 0,02), T (0,41±0,4 x 0,17±0,1nmol/L, p= 0,02) e IAL (0,73±0,7 x 0,17±0,04, p= 0,001) foram maiores na PP, enquanto a SHBG (63,7±23,1 x 110,2±23,9nmol/L, p= 0,0006) foi menor. A FIGR foi sugestiva de RI em 44% dos casos de PP, mas os níveis de G, I, a AACG, a AACI e a FIGR foram semelhantes aos C. Na PP foi observada correlação inversa entre SDHEA e I (r = -0,43, p= 0,04) e entre SHBG e IMC (r = -0,74, p = 0,0001) e AACI (r=-0,36, p= 0,09). A AACI mostrou uma correlação positiva com o IMC (r=0,56, p= 0,006) e a FIGR (r= 0,86, p= 0,0001). Embora o hiperandrogenismo adrenal possa não ter um efeito adverso sobre a sensibilidade à I na infância, como demonstrado pela correlação inversa entre o SDHEA e a I em meninas com PP, a presença da FIGR sugestiva de RI foi relativamente comum, permanecendo incerta a relação entre os níveis dos androgênios adrenais e a sensibilidade à insulina.

[Plasma insulin, IGF-I and breast cancer]

Several recent epidemiological studies have shown an increase in breast cancer risk among women who have elevated plasma levels of testosterone, reduced levels of sex hormone-binding globulin (SHBG), and hence elevated levels of bioavailable androgens and estrogens not bound to SHBG. This endocrine profile is generally associated with obesity and chronic hyperinsulinemia, of which it is most likely a result. Lack of physical activity, obesity, and a diet rich in rapidly digestible carbohydrates and poor in fibre favour the development of insulin resistance and hyperinsulinemia. The elevated insulin levels, in turn are related to decreases in plasma and tissue levels of IGFBP-1 and IGFBP-2 (insulin-like growth factor-binding proteins), and this may increase the availability of insulin-like growth factor-I (IGF-I) to its receptors. Like insulin, IGF-I also inhibits the hepatic synthesis of SHBG, whereas both hormones stimulate the ovarian synthesis of sex steroids. Moreover, insulin and IGF-I can both enhance the development of breast tumours, through their cognate receptors within the mammary tissue. Taken together, these observations lead to the hypothesis that breast cancer risk may be increased in women with elevated plasma insulin levels, and/or with elevated levels of bioactive IGF-I. Hyperinsulinemia and an increased IGF-I bioactivity could thus be an important physiological link between a western lifestyle, overnutrition, a hyperandrogenic sex steroid profile, and increased breast cancer risk. Prospective cohort studies will be needed to test this hypothesis, and to study in greater detail the possible relationships of breast cancer risk with plasma levels of IGF-I and IGFBPs. Confirmation of a relationship of breast cancer risk with plasma insulin levels, on the one hand, or with total plasma IGF-I, on the other hand, could open up new perspectives for breast cancer prevention, either by changes in dietary intake patterns and physical activity, or by the use of certain chemopreventive drugs.

Impaired insulin action on granulosa-lutein cells in women with polycystic ovary syndrome and insulin resistance

We studied the in vitro response to insulin of granulosa-lutein cells derived from patients with polycystic ovary syndrome (PCOS) and clinically defined insulin resistance. Insulin sensitivity was assessed by continuous infusion of glucose with model assessment test (CIGMA). Insulin resistant (PCOS-IR; n = 8), noninsulin resistant (PCOS-NIR; n = 9) patients with PCOS, and women with tubal factor infertility (TF; n = 8) underwent controlled ovarian stimulation with long-term gonadotropin-releasing hormone (GnRH) agonist, recombinant follicle stimulating hormone (FSH), and in vitro fertilization. Primary cultures of granulosa-lutein cells were incubated with insulin (10, 100, 500 ng/ml) and/or luteinizing hormone (LH) (10, 100 ng/ml) in the presence of low density lipoprotein (100 micrograms/ml). The progesterone and lactate accumulation were measured in the culture medium. LH potently stimulated the progesterone secretion in all groups. Insulin alone had no effect on progesterone release in any of the groups, but stimulated lactate formation in the PCOS-NIR and TF groups. Insulin augmented the effect of LH on progesterone secretion selectively in the PCOS-NIR group. The expression of the insulin receptor was determined by Western blotting in separate cultures of granulosa-lutein cells, and showed receptor down-regulation in the PCOS-IR patients. We infer that the in vitro effect of insulin on progesterone and lactate release by granulosa-lutein cells is impaired in insulin resistant PCOS patients.

Insulin, androgens, and obesity in women with and without polycystic ovary syndrome: a heterogeneous group of disorders

OBJECTIVE

To analyze the correlations among insulin, androgens, body mass index (BMI), and other related metabolic anomalies in women with and without polycystic ovary syndrome (PCOS).

DESIGN

Retrospective study of normal and obese women with and without PCOS.

SETTING

Gynecologic endocrinology units of Elche, San Juan, and Alicante Hospitals and Hormone Laboratory at Alicante University Hospital ("Miguel Hernández" University).

PATIENT(S)

A total of 212 women were studied: 137 with PCOS and 75 without PCOS.

INTERVENTION(S)

BMI, gonadotropins, insulin, androgens (T, androstenedione, DHEAS), 17alpha-hydroxyprogesterone, sex hormone-binding globulin, and triglycerides were studied. Glycemia and insulin response to the tolerance test (GTT) with a 100-g oral glucose load were also assessed in 103 women.

RESULT(S)

A good correlation between insulin and BMI was found in normal and obese women without hormonal dysfunction and in patients with or without PCOS. Good correlations, although lower, between insulin and T, and BMI, insulin, and T with triglycerides were also found in patients with PCOS. These patients fell into clearly distinct categories: with or without insulin resistance and with or without obesity, but slim women with PCOS had insulin and metabolic variables similar to those without PCOS, and most obese women with PCOS were insulin-resistant and more hyperandrogenic and hypertriglyceridemic.

CONCLUSION(S)

Insulin, androgens, and BMI are related in women both with PCOS and without PCOS, especially in obese ones. Insulin and metabolic indices are similar in lean women with PCOS and those without PCOS, but obese women with PCOS are more insulin-resistant, hyperandrogenic, and hypertriglyceridemic. Three types of disorders can be distinguished: simple nonhyperandrogenic obesity, typical nonhyperinsulinemic PCOS, and insulin-resistant PCOS.

Impact of insulin and body mass index on metabolic and endocrine variables in polycystic ovary syndrome

To assess the differential impact of the insulin secretory pattern and obesity on the endocrinometabolic features of the polycystic ovary syndrome (PCOS), we studied 110 PCOS women. Patients underwent a gonadotropin-releasing hormone (GnRH) test, an oral glucose tolerance test (OGTT), and basal evaluation of hormonal and biochemical parameters. Basal androgens and lipids, basal and stimulated gonadotropins, insulin, and glucose levels were measured. Patients were classified into four groups according to the body mass index (BMI) and insulin secretion: normoinsulinemic-lean ([NL] n = 24), normoinsulinemic obese ([NO] n = 24), hyperinsulinemic lean ([HL] n = 17), hyperinsulinemic obese ([HO] n = 45). HL patients showed a higher luteinizing hormone (LH) area under curve (AUC) after GnRH stimulus compared with NL patients (HL v NL, 4,285 +/- 348 v 3,377 +/- 314 IU/L x 120 min, P < .05), whereas we failed to find a statistically significant difference in a similar comparison among obese subjects (HO v NO, 3,606 +/- 302 v 3,129 +/- 602 IU/L x 120 min). A trend toward increased plasma testosterone and decreased sex hormone-binding globulin (SHBG) was found in relation to hyperinsulinemia and obesity, thus resulting in a higher free androgen index (FAI) in groups HL and NO versus NL (HL, 5.54 +/- 0.51; NO, 5.64 +/- 0.49; NL, 4.13 +/- 0.33; P < .05 and P < .01, respectively). The presence of both exaggerated insulin secretion and obesity resulted in a synergistic additive effect on the FAI in the HO group (6.81 +/- 0.34). Concerning the lipoprotein lipid profile, the NL group showed lower plasma triglyceride levels compared with the other three groups, whereas no significant differences were found for nonesterified fatty acid (NEFA) concentrations. Higher low-density lipoprotein cholesterol (LDL-C) and very-low-density lipoprotein cholesterol (VLDL-C) and lower high-density lipoprotein cholesterol (HDL-C) levels were found in the obese groups compared with the lean counterparts, whereas the same parameters did not significantly differ in a comparison between normoinsulinemic and hyperinsulinemic groups. In conclusion, our data suggest an important role of hyperinsulinemia in the LH response to a GnRH stimulus and an independent and synergistic additive effect of obesity and hyperinsulinemia on the FAI in PCOS.

Endocrine methods of ovulation induction

The rationale of ovulation induction is to achieve the development of a single follicle and ultimately a singleton healthy baby. Problems faced by women with anovulatory polycystic ovary syndrome are the sensitivity of the ovary to stimulation and health issues such as obesity. This chapter will discuss medical management including strategies to lose weight, address hyperinsulinaemia with insulin-sensitizing agents, such as metformin, and outline methods of ovulation induction from the usual first-line therapy of clomiphene citrate and the subsequent use of gonadotrophin therapy in clomiphene-resistant patients. Appropriately directed surgical ovulation induction with laparoscopic ovarian diathermy appears to be as efficacious as gonadotrophin therapy but will not be discussed in the context of this chapter.

The pathogenesis of polycystic ovary syndrome: lessons from ovarian stimulation studies

In polycystic ovary syndrome (PCOS) the ovary produces markedly increased amounts of both androgens and estrogens in response to gonadotropin stimulation. Distinctive responses of 17-hydroxyprogesterone and androstenedione to ovarian stimulation testing suggest that ovarian hyperandrogenism is a result of dysregulation of theca cell androgen production which is intrinsic to the ovary. The occurrence of hyperestrogenism together with hyperandrogenism in PCOS suggests that whatever the abnormality of local regulatory factors of steroidogenesis, it affects granulosa as well as theca cells. Dysregulation is often associated with an increase in the number of follicles which evade atresia and reach the 2-8 mm stage of development. Autocrine/paracrine factors, especially those which are FSH-dependent, likely play an important role in the pathogenesis of the ovarian abnormality. Both LH and insulin hypersecretion probably play a secondary role in PCOS by amplifying the preexisting ovarian dysregulation. Because FSH secretion is under tight long-loop negative-feedback control and LH is not, hyperandrogenism is the primary clinical manifestation of dysregulation of steroid production in PCOS. However, anovulation in PCOS is most likely a result of excessive estrogen and inhibin production by multiple, small follicles which inhibit FSH secretory dynamics sufficiently to prevent selection of a dominant follicle.

Involvement of ovarian steroids in the opioid-mediated reduction of insulin secretion in hyperinsulinemic patients with polycystic ovary syndrome

To evaluate the possible involvement of ovarian steroids on the opioid-mediated disorders of insulin in patients affected by polycystic ovary syndrome (PCOS), we studied 40 PCOS women. All patients underwent an oral glucose tolerance test (OGTT; 75 g) and basal hormone assay; based on the insulin response to OGTT, 26 women were classified as hyperinsulinemic and continued the study protocol. Patients were randomly divided into three groups characterized by different treatments: group A (nine patients) was treated with GnRH analog (one ampule every 28 days for 2 months), group B (eight patients) was treated with naltrexone (an oral opioid antagonist, 50 mg/day, orally) for 8 weeks, and group C (nine patients) was treated with GnRH analog plus naltrexone for 2 months. After continuation of treatment, all patients repeated the basal study in a second hospitalization. Naltrexone treatment significantly reduced the insulin response to OGTT, whereas GnRH analogue administration did not significantly change the insulin secretion after the glucose load. The GnRH analog/ naltrexone cotreatment was not able to influence the insulin secretory pattern; in fact, the insulin area under the curve was superimposable before and after therapy. These data could lead to the hypothesis that the opioidergic regulation of insulin secretion requires a normal steroidogenic pattern, thus suggesting that ovarian steroids modulate opioid activity also at peripheric districts.

Current concepts of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) may be loosely defined as unexplained hyperandrogenism, with variable degrees of cutaneous symptoms, anovulatory symptoms, and obesity. The vast majority of patients with the full-blown Stein-Leventhal syndrome have functional ovarian hyperandrogenism (FOH). However, FOH often occurs without the LH excess or polycystic ovaries of classic PCOS. Functional adrenal hyperandrogenism (FAH) is often found in the syndrome, but it is less closely associated with anovulatory symptoms than is FOH. The vast majority of FOH seems to arise from abnormal regulation (dysregulation) of ovarian androgen secretion. This typically is due to escape from desensitization to luteinizing hormone (LH); this appears to occur because of a breakdown in the processes that normally coordinate ovarian androgen and oestrogen secretion so as to prevent hyperoestrogenism. Similar dysregulation of adrenal androgen secretion in response to ACTH seems to account for most FAH. Dysregulation of androgen secretion may affect the ovary alone (isolated FOH), the adrenal alone (isolated FAH), or both together. Modest insulin resistance is common in PCOS/FOH, and the resultant hyperinsulinaemia is a major candidate as the cause of the dysregulation. The hyperinsulinaemia may arise from either 'nature' (genetic defects) or 'nurture' (exogenous obesity). Although hyperinsulinaemia alone does not have an obvious effect on steroidogenesis, it may act in genetically predisposed women as a 'second hit' to unmask latent abnormalities in steroidogenesis. The ovary, the adrenal cortex, and several other organs paradoxically function as if responding to the hyperinsulinaemic state in spite of resistance to the effects of insulin on glucose metabolism. PCOS should be viewed as an early manifestation of a hyperinsulinaemic condition that will predispose to cardiovascular and metabolic complications later in life. A subset of PCOS patients appear to have not only insulin resistance but also beta-cell secretory dysfunction, which may indicate a relationship of the disorder to NIDDM. The fundamental genetic defects remain to be elucidated.

Nutrition, hormones, and breast cancer: is insulin the missing link?

Breast cancer incidence rates are high in societies with a Western lifestyle characterized by low levels of physical activity, and by an energy-dense diet rich in total and saturated fat and refined carbohydrates. Epidemiologic studies, so far mostly on postmenopausal women, have shown that breast cancer risk is increased in hyperandrogenic women, with decreased levels of plasma sex-hormone binding globulin, and with increased levels of testosterone and of free estrogens. This paper describes the role of hyperinsulinemia as a physiologic link between nutritional lifestyle factors, obesity, and the development of a hyperandrogenic endocrine profile, and reviews evidence that may or may not support the theory that chronic hyperinsulinemia is an underlying cause of breast cancer. An hypothesis is presented, stipulating that breast cancer risk is increased not only in hyperandrogenic postmenopausal women, but also in premenopausal women with mild hyperandrogenism and normal (ovulatory) menstrual cycles. The author suggests further investigation as to whether there is a positive association between risk of breast cancer before menopause and subclinical forms of the polycystic ovary syndrome (PCOS), and to what extent diet and physical activity during childhood, by modulating the degree of insulin resistance during adolescence, may or may not be determinants of a PCO-like hyperandrogenic endocrine profile persisting into adulthood.

Seasonal changes in circulating serum concentration and in vitro testicular secretion of testosterone and androstenedione in the male vespertilionid bat (Scotophilus heathi)

Seasonal changes in the testicular activity were studied in the male Greater Yellow bat, Scotophilus heathi, in Varanasi, India (25 degrees N, 83 degrees E). The seasonal pattern of body weight of male bats was also recorded and compared with circulating androstenedione (A) and testosterone (T) concentration. There was a gradual increase in the body weight of the bat from September onward mainly due to accumulation of adipose tissue. Finally, body weight reached a peak level in November. Two periods of peak testicular weight and serum T concentration but only one peak of serum A concentration were observed. The first peak of T coincided closely with the peak A concentration and increased body weight. The first peak of T occurs several months before the time of mating and ovulation. The second peak of T correlated closely with the period of mating. In vitro study showed seasonal variation of the testicular responsiveness to LH stimulation. In vitro study also showed two peaks in the T but only one peak in the A production by testes in response to LH during different phases. Preliminary study showed that IGF-I but not insulin augmented hCG induced T production by testes in vitro. Our observation of an increase in serum A concentration during the period of overfeeding and weight gain and decline in A during the period of weight loss in S. heathi adds strength to the concept that nutritional status can influence hormonal function. This may be the reason for asynchrony between male and female gametic cycle found among vespertilionid bats.

Disturbances in insulin secretion and sensitivity in women with the polycystic ovary syndrome

Insulin resistance, defined as a diminished effect of a given dose of insulin on glucose homeostasis, is a highly prevalent feature of women with PCOS. Insulin resistance in PCOS is closely associated with an increase in truncal-abdominal fat mass, elevated free fatty acid levels, increased androgens, particularly free testosterone through reduced SHBG levels, and anovulation. The causes for insulin resistance in PCOS are still unknown. One line of evidence suggests that an increase in truncal-abdominal fat mass and subsequently increased free fatty acid levels induce insulin resistance in women with PCOS. Increased effects of corticosteroids and a relative reduction in oestrogen and progesterone seem to be involved in the aberrant body fat distribution. Conversely, there are also results supporting primary, genetic target cell defects as a cause of insulin resistance in PCOS. An explanation for these seemingly contradictory results could be that the group of women with PCOS is heterogeneous with respect to the primary event in carbohydrate/insulin disturbances. Also insulin secretion in PCOS is characterized by heterogeneity. At one end of the spectrum is a large subgroup of mainly obese women with reduced insulin secretion, which appears to result from failure of the beta cells to compensate for insulin resistance in susceptible women, resulting in glucose intolerance and NIDDM. In the insulin-resistant patients with normal glucose tolerance, most of the hyperinsulinaemia is probably due to secondarily increased insulin secretion and decreased insulin degradation. However, a component of the increased first-phase insulin release is not due to measurable insulin resistance. Notably, this is also found in lean women with normal insulin sensitivity, and is not reversed after weight reduction, in contrast to the findings for insulin resistance. The implications of this enhanced insulin release are not fully clear, but it may tentatively be associated with carbohydrate craving and subsequently increased risks for development of obesity and insulin resistance. It may represent a primary disturbance of insulin secretion in PCOS or may be associated with the perturbed steroid balance in anovulation. The insulin-androgen connection in PCOS appears to be amplified by several different mechanisms, notably in both directions, the initiating event probably varying between individuals. Thus insulin increases the biological availability of potent steroids, primarily testosterone, through the suppression of SHBG synthesis. Insulin is also involved as a progonadotrophin in ovarian steroidogenesis, with the possible net result of interfering with ovulation and/or increasing ovarian androgen production in states of hyperinsulinaemia. Conversely, testosterone may indirectly contribute to insulin resistance through facilitating free fatty acid release from abdominal fat, but perhaps also through direct muscular effects at higher serum levels. It seems likely that this constitution, presumably genetic, would provide evolutionary advantages in times of limited nutrition, given the energy-saving effects of insulin resistance. Hypothetically, hyperinsulinaemia (primary) could provide a stimulus to ensure intake of nourishment, but unlimited food supplies could in some cases initiate a vicious 'anabolic' circle, in which several of the proposed amplifying mechanisms between insulin and androgens--in both directions--could take part.

Ovarian morphology and insulin sensitivity in women with bulimia nervosa

OBJECTIVE

Hyperinsulinaemia has a role in the development of hyperandrogenism and polycystic ovary syndrome in women of normal weight. Polycystic ovaries are common in women with bulimia nervosa and this study aimed to determine whether women with bulimia nervosa are insulin resistant and to examine the relation between insulin sensitivity and ovarian morphology.

DESIGN

A short intravenous insulin tolerance test was used as a direct measure of insulin sensitivity in a group of women with bulimia nervosa and a control group.

PATIENTS

A series of 12 women with bulimia nervosa and normal weight was compared with a control group of 9 healthy women who had no clinical signs of eating disorder or hyperandrogenism and did not have polycystic ovaries.

MEASUREMENTS

Bulimic behaviour was assessed using the BITE (Bulimia Investigation Test, Edinburgh) questionnaire and clinical interviews. Ovarian morphology was assessed using transabdominal ultrasonography. Insulin sensitivity and serum insulin, fasting glucose, LH, FSH, prolactin, testosterone, androstenedione and sex hormone binding globulin (SHBG) were measured and compared between the two groups.

RESULTS

Ten of the 12 women with bulimia nervosa underwent ovarian ultrasound examination and they all had polycystic ovaries. There was no difference in serum LH, FSH, testosterone, androstenedione of SHBG concentrations between the women with bulimia nervosa and the non-bulimic control group. Fasting blood glucose concentrations were normal in all the women studied and did not differ between the women with bulimia nervosa and the control women. There was also no difference in fasting serum insulin or insulin sensitivity between the women with bulimia nervosa and the nonbulimic women.

CONCLUSIONS

Bulimia nervosa is not associated with insulin resistance and chronic hyperinsulinaemia.

Prevalence of an immunological LH beta-subunit variant in a UK population of healthy women and women with polycystic ovary syndrome

OBJECTIVE

An immunological LH beta-subunit variant has been described, which is undetectable using monoclonal antibodies directed to the intact LH molecule alone. Subjects have been found homozygous or heterozygous for nucleotide mutations within codons 8 and 15 in the LH beta-subunit gene. The prevalence of the variant LH beta-subunit has been estimated in a healthy UK population of women of reproductive age and in women with polycystic ovary syndrome (PCOS). The relationship of the variant molecule to the clinical and hormonal parameters of the subjects has been evaluated.

DESIGN

The control and PCOS subjects were screened for the presence of the mutation by using a ratio of two immunofluorometric assays using monoclonal antibodies (Mab). One assay, not detecting the LH variant, uses a Mab directed to the intact LH molecule and a beta-specific Mab. The other assay, detecting both the variant and wild-type LH, uses two beta-subunit specific Mabs. The mutations in the LH beta-subunit gene were confirmed by restriction fragment length polymorphism. The relationship of the presence of the variant to the clinical and hormonal parameters was assessed by ANOVA.

PATIENTS

Two hundred and twelve normal ovulatory women, of whom 66 (31%) were obese (body mass index > 25) and 146 (69%) non-obese, and 153 women with PCOS, 115 (75%) obese and 38 (25%) non-obese participated in the study.

RESULTS

The variant LH was detected in 31 (15%) controls and 32 (21%) PCOS subjects (P = 0.124) using specific Mab. Obese PCOS had a higher incidence of the heterozygous LH variant compared to obese controls (odds ratio 2.5, P = 0.03), and compared to non-obese PCOS (odds ratio 6.3, P = 0.01). The previously described two mutations in codon 8 and codon 15 were present in all subjects detected to be mutant hetero of homo-zygous by RFLP. There was no relationship between the presence of the variant LH and the clinical and hormonal parameter in the PCOS subjects; however, in the controls the presence of the variant LH was associated with a higher serum total testosterone (P = 0.046), oestradiol (P = 0.03) and SHBG (P = 0.002).

CONCLUSIONS

The results of this study show that the variant LH beta-subunit is a common polymorphism occurring in 15% of a healthy UK population of women. The prevalence was not higher in women with PCOS, though it was over represented in obese women with PCOS. The presence of the variant did not alter the clinical or hormonal expression of the disorder in women with PCOS. Its presence in the controls was however associated with higher serum oestradiol and probably secondary elevation of SHBG and testosterone, suggesting that the variant form of LH may be associated with subtle changes in the function of the hypothalamic-pituitary-gonadal axis.

Reproductive health and polycystic ovary syndrome

Women with hyperandrogenic disorders represent a unique group among those with infertility due to anovulation. Although antiestrogens are effective in restoring ovulation in most women, it remains unclear whether these treatments restore fecundability per ovulatory cycle and the ability to maintain pregnancy in these individuals. Moreover, antiestrogens are ineffective in restoring ovulation in some hyperandrogenic anovulatory women, whose condition poses unique and vexing challenges for the infertility therapist. Gonadotropin treatment in antiestrogen-resistant women often leads to ovarian hyperstimulation syndrome, which has been addressed by modification of dosing schedules (e.g., low-dose administration), pretreatment with gonadotropin-releasing hormone (GnRH) analogs, and elimination of luteinizing hormone from the administered gonadotropins. Surgical reduction in ovarian volume has met with some success, although there may be a risk of inducing surgical adhesions of the adnexa. The second major reproductive adversity facing these patients is their elevated risk of endometrial cancer. Unopposed estrogen exposure probably contributes to this risk, but hyperandrogenicity and hyperinsulinism may act independently or in concert with estrogen to amplify the risk in these women. While the risks and strategies for preventive care in these women need to be better defined, reproductive health specialists are urged to continue using presently accepted measures, including education, to maintain these women's reproductive health.