Indices of insulin sensitivity, beta cell function and serum proinsulin levels in the polycystic ovary syndrome

Association of Insulin Resistance and Elevated Androgen Levels with Polycystic Ovarian Syndrome (PCOS): A Review of Literature

The polycystic ovary syndrome (PCOS) is the disease featured by elevated levels of androgens, ovulatory dysfunction, and morphological abnormalities. At reproductive stage of women, the rate of PCOS occurrence is measured as 6–10% and the prevalence rate may be double. There are different pathophysiological factors involved in PCOS, and they play a major role in various abnormalities in individual patient. It is clear that there is noteworthy elevation of androgen in PCOS, causing substantial misery and infertility problems. The overexposure of androgen is directly linked with insulin resistance and hyperinsulinaemia. It has been reported previously that PCOS is related to cardiac metabolic miseries and potently increases the risk of heart diseases. Endometrial cancer is also a serious concern which is reported with exceedingly high incidence in women with PCOS. However, the overexposure of androgen has direct and specific influence on the development of insulin resistance. Although many factors are involved, resistance to the insulin and enhanced level of androgen are considered the major causes of PCOS. In the present review, we have focused on the pathophysiology and major revolutions of insulin resistance and excessive levels of androgen in females with PCOS.

Prevalence of ocular anomalies is increased in women with polycystic ovary syndrome-exploration of association with PAX6 genotype

BACKGROUND

Polycystic Ovarian Syndrome (PCOS), the most common reproductive endocrine disorder affecting premenopausal women, is frequently associated with central obesity and pancreatic β-cell dysfunction. Aniridia, a rare congenital eye disorder with haploinsufficiency of the PAX6 gene, was observed to co-occur with PCOS in a proband. This study investigates eye health and PAX6 genotypes of women with PCOS and controls.

MATERIALS AND METHODS

This is a cross-sectional study of 203 premenopausal women (100 healthy controls, 103 with PCOS) conducted at an academic medical center in Vancouver, Canada. Ophthalmological exams and detailed medical histories were obtained from each participant. DNA extracted from saliva was Sanger-sequenced for the exons, intron-exon boundaries, and untranslated regions of PAX6.

RESULTS

Women with PCOS had eye abnormalities, including abnormalities of the anterior segment, optic nerve, and retina, that were not observed in controls (p = 0.0002). Myopia prevalence was similar in both groups. Dry eye syndrome, by history, was markedly more prevalent in women with PCOS (22.3%) than controls (5%), p = 0.004. PAX6 genotype did not significantly differ between the two groups, nor was it associated with the greater prevalence of eye anomalies observed in women with PCOS.

CONCLUSION

This is the first study to systematically perform an ophthalmological examination in women with PCOS, who were found to have a higher prevalence of potentially serious eye health problems compared with controls. These data suggest that ophthalmological-metabolic-genetic connections in women with PCOS require further investigation. Confirmation of these data and increased attention to eye health in women with PCOS appears warranted.

Associations Between Asthma and Polycystic Ovary Syndrome: Current Perspectives

A potential correlation between polycystic ovary syndrome (PCOS) and asthma, used to be identified as diseases originating from two independent systems, has been supported by increasing evidence. From an epidemiological perspective, mounting studies have confirmed that women suffering from PCOS exhibit increased susceptibility to asthma. Meanwhile, PCOS and asthma seem to share several mutual pathological conditions, such as metabolic disorders, hormonal fluctuation, proinflammatory state, etc. Here, we further elucidate the correlation between asthma and PCOS by focusing on the internal common pathophysiology and adverse influences on women's health. Understanding the internal connection between PCOS and asthma may shed light on developing new prevention and control strategies to fight against these conditions.

Inositol in Polycystic Ovary Syndrome: Restoring Fertility through a Pathophysiology-Based Approach

Myo-inositol (MI) and D-chiro-inositol (DCI) are insulin second messengers, and MI is involved in follicular gonadotropin pathways which orchestrate ovulation. The tissue-specific MI/DCI ratio is modulated by insulin through aromatase and is altered in insulin resistance (IR), with reduced epimerization of MI to DCI in insulin-sensitive tissues. In ovaries, the MI/DCI ratio is 100:1, but is dramatically reduced by insulin-stimulated epimerase in hyperinsulinemic women with polycystic ovary syndrome (PCOS). Inositols have proved to be effective in PCOS, improving metabolic and hormonal state, and restoring spontaneous ovulation. In assisted reproductive technology, inositol improved ovarian stimulation parameters, although data concerning fertility outcomes are conflicting. Given their functions, inositols are an attractive treatment option for PCOS, although well-designed studies on spontaneous and non-spontaneous fertility are needed.

Insulin and the polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most prevalent endocrinopathy among women during reproductive age. PCOS is characterised by hyperandrogenaemia, hyperinsulinaemia, and deranged adipokines secretion from the adipose tissue. In addition to the reduced insulin sensitivity, PCOS women exhibit β-cell dysfunction as well. Low birth weight and foetal exposure to androgens may contribute to the development of the PCOS phenotype during life. Further metabolic complications lead to dyslipidaemia, worsening obesity and glucose tolerance, high prevalence of metabolic syndrome, and greater susceptibility to diabetes. PCOS women show age-related existence of hypertension, and subtle endothelial and vascular changes. Adverse reproductive outcomes include anovulatory infertility, and unrecognised potentiation of the hormone-dependent endometrial cancer. The main therapeutic approach is lifestyle modification. Metformin is the primary insulin-sensitising drug to be used as an adjuvant therapy to lifestyle modification in patients with insulin resistance and impaired glucose tolerance, as well as in those referred to infertility treatment. Thiazolidinediones should be reserved for women intolerant of or refractory to metformin, while glucagon-like peptide 1 analogues has a potential therapeutic use in obese PCOS women. Randomised clinical trials and repetitive studies on different PCOS phenotypes for the preventive actions and therapeutic options are still lacking, though.

The incretin effect and secretion in obese and lean women with polycystic ovary syndrome: a pilot study

BACKGROUND

Insulin resistance is considered to play an important role in the pathogenesis of polycystic ovary syndrome (PCOS) and in the progression to type 2 diabetes. Recent reports concentrate on a possible relationship between incretin secretion and beta-cell function in PCOS. The aim of the present study is to investigate the incretin effect in obese and lean women with PCOS.

METHODS

Twenty women with PCOS and ten age-matched healthy women were recruited in the study. The oral glucose tolerance test (OGTT) and isoglycemic test were carried out on each participant after an overnight fast at 2-weeks interval. Plasma levels of insulin, glucose, C-peptide, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) were assayed.

RESULTS

Obese women with PCOS demonstrated lower GIP concentrations (area under the curve [AUC]) in response to OGTT compared to the control group. The incretin effect was found significantly augmented in the obese women with PCOS compared to controls. This finding remained robust in the subgroup analysis including only body mass index (BMI)-matched healthy women.

CONCLUSIONS

Increased insulinotropic effect could counteract the blunted GIP response to OGTT in obese women with PCOS. It is suggested that the pathology of PCOS may also include impaired activity of the enteroinsular axis.

Predictors of pregnancy in women with polycystic ovary syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. The selection of first-line therapies for ovulation induction is empiric.

OBJECTIVE

The aim of the study was to develop a clinically useful predictive model of live birth with varying ovulation induction methods.

DESIGN, SETTING, AND PARTICIPANTS

We built four prognostic models from a large multicenter randomized controlled infertility trial of 626 women with PCOS performed at academic health centers in the United States to predict success of ovulation, conception, pregnancy, and live birth, evaluating the influence of patients' baseline characteristics.

INTERVENTIONS

Ovulation was induced with clomiphene, metformin, or the combination of both for up to six cycles or conception.

MAIN OUTCOME MEASURE

The primary outcome of the trial was the rate of live births.

RESULTS

Baseline free androgen index, baseline proinsulin level, interaction of treatment arm with body mass index, and duration of attempting conception were significant predictors in all four models. History of a prior loss predicted ovulation and conception, but not pregnancy or live birth. A modified Ferriman Gallwey hirsutism score of less than 8 was predictive of conception, pregnancy, and live birth (although it did not predict ovulation success). Age was a divergent predictor based on outcome; age greater than 34 predicted ovulation, whereas age less than 35 was a predictive factor for a successful pregnancy and live birth. Smoking history had no predictive value.

CONCLUSIONS

A live birth prediction chart developed from basic clinical parameters (body mass index, age, hirsutism score, and duration of attempting conception) may help physicians counsel and select infertility treatments for women with PCOS.

Anti-Mullerian hormone levels reflect severity of PCOS but are negatively influenced by obesity: relationship with increased luteinizing hormone levels

The objective of the study was the comparison of anti-Müllerian hormone (AMH) levels among obese or overweight and normal-weight women with the four different polycystic ovary syndrome (PCOS) phenotypes and healthy control subjects. AMH levels were evaluated in four age- and body mass index (BMI)-matched groups of 25 normal-weight and 25 obese or overweight women each, belonging to the four main subsets of the syndrome resulting from combinations of the three diagnostic criteria [group 1: oligo- and/or anovulation (ANOV), hyperandrogenemia (HA), and polycystic ovaries (PCO) on ultrasonographic evaluation; group 2: ANOV and HA; group 3: HA and PCO, group 4: ANOV and PCO], and in 50 (25 obese or overweight and 25 normal weight) age- and BMI-matched healthy control subjects. Age, BMI, waist circumference, FSH, LH, prolactin, testosterone, Delta(4)-androstenedione, dehydroepiandrosterone-sulfate, 17alpha-OH-progesterone, fasting insulin, glucose, AMH, free androgen index, and homeostasis model assessment for insulin resistance index were analyzed. AMH levels were significantly higher in PCOS groups 1 and 2 compared with groups 3 and 4 and the control group and higher in PCOS groups 3 and 4 compared with the control group. AMH levels were significantly increased in normal-weight compared with obese and overweight women. AMH concentrations were independently predicted, in order of significance, by LH and testosterone levels, BMI (negatively), and the total number of follicles 2-9 mm in diameter. The differences in circulating AMH levels between the main phenotypic groups of PCOS women appear to reflect the severity of the syndrome, but are negatively affected by obesity. Increased LH levels might be the most significant independent link between PCOS-associated disorders of ovulation and the observed increase in circulating AMH concentration.

Plasma visfatin levels in normal weight women with polycystic ovary syndrome

BACKGROUND

The present study was designed to measure plasma visfatin levels in normal weight women with polycystic ovary syndrome (PCOS) and to assess possible correlations between visfatin and the hormonal or metabolic parameters of the syndrome.

METHODS

Twenty-five normal weight [body mass index (BMI)<25 kg/m(2)] women with PCOS, 24 obese and overweight (BMI>25 kg/m(2)) controls (ovulating women without clinical or biochemical hyperandrogenism), and 24 normal weight controls were studied. Blood samples were collected between the 3rd and the 7th days of a menstrual cycle in the control groups and during a spontaneous bleeding episode in the PCOS groups at 9:00 A.M., after an overnight fast. Circulating levels of LH, FSH, prolactin (PRL), testosterone (T), Delta(4)-androstenedione (Delta(4)-Alpha), dehydroepiandrosterone sulfate (DHEA-S), 17alpha-OH-progesterone (17OH-P), sex hormone-binding globulin (SHBG), insulin, glucose, and visfatin were measured.

RESULTS

Plasma visfatin levels and the visfatin-to-insulin ratio were significantly lower in normal weight controls than in both normal weight women with PCOS and overweight or obese controls. The visfatin-to-insulin ratio was significantly higher in normal weight women with PCOS than in overweight or obese controls. Plasma visfatin levels were found to be positively correlated with LH and Delta(4)A levels, as well as with free androgen index (FAI) values, and negatively correlated with SHBG. LH and SHBG levels were found to be the only independent significant determinants of circulating visfatin. In the control groups, plasma visfatin levels were significantly correlated with BMI, waist (W) measurement, and waist-to-hip ratio (WHR).

CONCLUSIONS

Visfatin levels are positively associated with obesity in healthy women of reproductive age. Moreover, the present study indicates, for the first time, a possible involvement of increased visfatin levels in PCOS-associated metabolic and hormonal disturbances.

Obesity, weight loss, and the polycystic ovary syndrome: effect of treatment with diet and orlistat for 24 weeks on insulin resistance and androgen levels

OBJECTIVE

To investigate the combined effect of diet and orlistat, for 24 weeks, on anthropometric features, hormonal parameters, and indices of insulin resistance in obese women with polycystic ovary syndrome (PCOS) and in obese women without the syndrome.

DESIGN

Prospective clinical study.

SETTING

Department of obstetrics and gynecology in a major university in Greece.

PATIENT(S)

Eighteen selected women with PCOS were matched for age and body mass index with 14 obese control women.

INTERVENTION(S)

Subjects were prescribed an energy-restricted diet, and orlistat (120 mg, 3 times per d) was administered to all subjects for 24 weeks.

MAIN OUTCOME MEASURE(S)

At baseline, week 12, and week 24, after an overnight fast, blood samples were collected, and serum levels of FSH, LH, PRL, T, Delta(4)A, DHEAS, 17 alpha-hydroxyprogesterone, sex hormone-binding globulin, glucose, and insulin were measured.

RESULT(S)

Testosterone levels were significantly decreased with treatment in women with PCOS; this decrease was attributed to the first trimester, whereas T levels did not change during the second 12-week period. In women with PCOS, insulin levels and HOMA-IR values were decreased during the first 12 weeks, whereas no significant change was observed during the second trimester.

CONCLUSION(S)

Orlistat administration, combined with diet, for 24 weeks, resulted in significant weight loss and improvement of insulin resistance in obese women, with or without PCOS. Moreover, T levels were significantly decreased in women with PCOS. There appears to be a trend during the first 12-week period for greater improvement of metabolic and hormonal parameters in women with PCOS.