Insulin Resistance In Polycystic Ovary Syndrome Women Research Articles

Accurate screening for insulin resistance in PCOS women using fasting insulin concentrations

The aims of this cross-sectional study were to evaluate the relative agreement of both static and dynamic methods of diagnosing IR in women with polycystic ovary syndrome (PCOS) and to suggest a simple screening method for IR. All participants underwent serial blood draws for hormonal profiling and lipid assessment, a 3 h, 75 g load oral glucose tolerance test (OGTT) with every 15 min measurements of glucose and insulin, and an ACTH stimulation test. The prevalence of IR ranged from 12.2% to 60.5%, depending on the IR index used. Based on largest area under the curve on receiver operating curve (ROC) analyses, the dynamic indices outperformed the static indices with glucose to insulin ratio and fasting insulin (fInsulin) demonstrating the best diagnostic properties. Applying two cut-offs representing fInsulin extremes (<7 and >13 mIU/l, respectively) gave the diagnosis in 70% of the patients with high accuracy. Currently utilized indices for assessing IR give highly variable results in women with PCOS. The most accurate indices based on dynamic testing can be time-consuming and labor-intensive. We suggest the use of fInsulin as a simple screening test, which can reduce the number of OGTTs needed to routinely assess insulin resistance in women with PCOS.

Expression of the CD11c gene in subcutaneous adipose tissue is associated with cytokine level and insulin resistance in women with polycystic ovary syndrome

Alterations in the phenotypes of macrophages in adipose tissue play a key role in inflammation and insulin resistance (IR). The phenotypes of macrophages in subcutaneous adipose tissue (SAT) and the relationship between proinflammation markers and IR in women with polycystic ovary syndrome (PCOS) remain unclear. The objectives of this study are to characterize the gene expression of macrophage markers and cytokines in the SAT of PCOS women and to estimate their relationships with circulating levels of cytokines and IR. The cross-sectional study involves 16 PCOS women and 18 normal control women. Cytokines and macrophage markers in the circulation and SAT were determined using ELISA, quantitative PCR, or immunofluorescence staining. IR was estimated using the homeostasis model assessment (HOMA-IR). The gene expression levels of CD11c along with TNF α and leptin in SAT remained significantly higher in PCOS women than in normal women (P<0.05). However, no significant differences were found in CD68 mRNA expression in SAT between women with and without PCOS (P>0.05). Furthermore, CD11c mRNA abundance provided a stronger contribution to models predicting serum levels of TNFα (sTNFα) than did CD68 mRNA abundance. Lastly, increased sTNFα was associated with increased HOMA-IR in PCOS women, and this association was independent of both overall and visceral adiposity. The high expression level of CD11c mRNA in SAT was proved to be an important feature in PCOS women. Furthermore, CD11c mRNA abundance made a stronger contribution to models predicting sTNFα in which existing proinflammatory properties might significantly contribute to the pathogenesis of IR in PCOS women.

Androgen levels and metabolic parameters are associated with a genetic variant of F13A1 in women with polycystic ovary syndrome

The polycystic ovary syndrome (PCOS), characterized by hyperandrogenism, is one of the most common hormonal disorders among premenopausal women and is associated with infertility, obesity, and insulin resistance. Accumulating evidence suggests a role of the blood coagulation factor gene F13A1 in obesity (GeneBank ID: NM_000129.3). The aim of this study was to investigate the association of intronic allelic variants of the F13A1 gene with PCOS susceptibility and metabolic parameters in lean and obese PCOS women.In a case–control study, we determined an intronic F13A1 single nucleotide polymorphism (SNP) (dbSNP ID: rs7766109) in 585 PCOS and 171 control women and tested for PCOS susceptibility and associations with anthropometric, metabolic and hormonal parameters.Genotype frequencies of the F13A1 SNP rs7766109 were equivalent in PCOS and control women. In PCOS women, F13A1 gene variants were significantly associated with body mass index (BMI) (p=0.013), systolic blood pressure (p=0.042), insulin response (AUCins) (p=0.015), triglycerides (TG) (p=0.001), and high density lipoprotein cholesterol (HDL) (p=0.012). In the subgroup of obese PCOS women free androgen index (FAI), free testosterone and sex hormone binding globulin (SHBG) as well as glucose measurements showed a significantly different pattern across F13A1 gene variants (p=0.043; p=0.039 and p=0.013, respectively).We report for the first time an association of the F13A1 SNP rs7766109 with BMI, androgens, and insulin resistance in PCOS women. Further studies are needed to confirm our findings and to evaluate whether F13A1 is causally involved in the pathogenesis of PCOS related metabolic and hormonal disturbances.

The impact of intensified exercise training on insulin resistance and fitness in overweight and obese women with and without polycystic ovary syndrome

To evaluate mechanisms of insulin resistance (IR) in overweight and obese women with and without polycystic ovary syndrome (PCOS) and explore relationships between IR, fitness and body mass index (BMI) at baseline and following exercise intervention. Prospective controlled intensified exercise intervention study. A total of 20 overweight (BMI > 25 kg/m(2) ) and obese (>30 kg/m(2) ), reproductive-aged PCOS women and 13 non-PCOS overweight, healthy controls of comparable BMI and age were studied at baseline. Measures were repeated in 13 PCOS and eight control women following three 1-h exercise sessions per week over 12 weeks. Insulin resistance was measured by glucose infusion rate on euglycaemic hyperinsulinaemic clamp, and fitness was assessed by VO(2max) . At baseline, PCOS women were 46% more insulin resistant than controls (175·6 vs 257·2 mg/m(2) /min, P < 0·05) with IR independently associated with VO(2max) and BMI in the PCOS group only (P < 0·01). Postexercise IR improved across both groups (P < 0·01). In PCOS women, IR improved by 16% (P < 0·05) but was not restored to the same level as controls (P < 0·05). Improvement in IR and in VO(2max) was related to the PCOS group (r(2) = 0·85, P < 0·05), yet change in IR and in fitness was not related. No associations were found in controls. While intensified exercise improves IR in PCOS women, a higher IR persisted following exercise in PCOS women, and a clear relationship between improved IR and improved fitness was not found. Therefore, other mechanisms of, and therapies for, IR must be explored in PCOS as IR remains higher than observed in non-PCOS controls.

Functional neuroimaging of emotional processing in women with polycystic ovary syndrome

Polycystic Ovary Syndrome (PCOS) is associated with increased risk of depression. Other metabolic disorders are also associated with depression, with glycemic control improving symptoms. Our goal was to evaluate emotional processing in insulin resistant PCOS women (IR-PCOS) and to assess the impact of improved insulin regulation.

Pretreatment with oral contraceptives in infertile anovulatory patients with polycystic ovary syndrome who receive gonadotropins for controlled ovarian stimulation

This study was intended to assess the effects of oral contraceptives given before treatment in infertile anovulatory patients with polycystic ovary syndrome who receive gonadotropins for controlled ovarian stimulation. Pretreatment with oral contraceptives increased the mono-ovulatory cycles, the duration of stimulation for noncanceled cycles, and the number of vials of gonadotropins used. It also reduced the number of dominant follicles and the peak E(2) levels for dominant follicles. No effect was observed in rates of cycle cancellation, pregnancy, abortion, live birth, multiple pregnancies, and ovarian hyperstimulation syndrome.

FABP-A correlates with body fat mass in PCOS women

Objectives: Many women with the polycystic ovary syndrome (PCOS) are obese and insulin resistant. Adiopse-tissue derived factors might link obesity with insulin resistance. One of these factors might be the adipocyte-specific fatty acid-binding protein (FABP-A), which has been shown to correlate with obesity in humans. We therefore investigated a potential association of FABP-A to anthropometric parameters and insulin resistance in PCOS women.

Agreement among insulin sensitivity indexes on the diagnosis of insulin resistance in polycystic ovary syndrome and ovulatory women

Objective The objective was to compare agreement on the diagnosis of insulin resistance (IR) among insulin sensitivity indexes in both ovulatory women and those with polycystic ovary syndrome (PCOS). Study design In an observational study, the 75-g oral glucose tolerance test was performed in 105 women with PCOS and 51 ovulatory women. The insulin sensitivity indexes used were insulin quantitative sensitivity check index (QUICKI), 1/homeostasis model assessment-insulin resistance (1/HOMA-IR), area under curve for insulin (AUC-I), and the Matsuda insulin sensitivity index (COMP). For the IR diagnosis we used cut-off values described in recent publications (insulin >12 μIU/ml, 1/HOMA-IR <0.47, QUICKI ≤0.333, AUC-I ≥7000 μIU/ml 120 min, and COMP <4.75. Results Excellent agreement was assessed among insulin, QUICKI, and 1/HOMA-IR. However, the rate of IR detected by these indexes in the PCOS group (44.8–51.4%) was lower than expected. New cut-offs were then determined based on COMP results. Using these values, 1/HOMA-IR and QUICKI showed excellent agreement ( κ = 0.83) with COMP. Conclusion The observed agreements among insulin, QUICKI and 1/HOMA-IR were higher than 93%. Therefore, clinicians may choose any of those obtaining similar results. For clinicians who prefer COMP, but are looking for a simpler test to detect IR in PCOS women, the use of QUICKI and 1/HOMA-IR with the new cut-offs seems reasonable.

Abnormal glucose tolerance and insulin resistance in polycystic ovary syndrome amongst the Taiwanese population- not correlated with insulin receptor substrate-1 Gly972Arg/Ala513Pro polymorphism

BackgroundInsulin resistance and glucose dysmetabolism in polycystic ovary syndrome (PCOS) are related with the polymorphisms in the genes encoding the insulin receptor substrate (IRS) proteins, especially Gly972Arg/Ala513Pro polymorphism being reported to be associated with type-2 diabetes and PCOS. We intended to assess the prevalence of abnormal glucose tolerance (AGT) and insulin resistance in Taiwanese PCOS women. We also tried to assess whether the particular identity of Gly972Arg/Ala513Pro polymorphic alleles of the IRS-1 gene mutation can be used as an appropriate diagnostic indicator for PCOS.MethodsWe designed a prospective clinical study. Forty-seven Taiwanese Hoklo and Hakka women, diagnosed with PCOS were enrolled in this study as were forty-five healthy Hoklo and Hakka women as the control group. Insulin resistance was evaluated with fasting insulin, fasting glucose/insulin ratio, and homeostasis model assessment index for insulin resistance (HOMAIR). The genomic DNA of the subjects was amplified by PCR and digested by restriction fragmented length polymorphism (RFLP) with Bst N1 used for codon 972 and Dra III for codon 513.ResultsAGT was found in 46.8% of these PCOS patients and was significantly related to high insulin resistance rather than the low insulin resistance. Those patients with either insulin resistance or AGT comprised the majority of PCOS affected patients (AGT + fasting insulin ≥17: 83%, AGT + glucose/insulin ratio ≥6.5: 85.1%, AGT + HOMAIR ≥ 2: 87.2%, and AGT + HOMAIR ≥ 3.8: 72.3%). None of the tested samples revealed any polymorphism due to the absence of any Dra III recognition site or any Bst N1 recognition site in the amplified PCR fragment digested by restriction fragmented length polymorphism.ConclusionThere is significantly high prevalence of AGT and insulin resistance in PCOS women, but Gly972Arg and Ala513Pro polymorphic alleles of IRS-1 are rare and are not associated with the elevated risk of PCOS amongst Taiwanese subjects. This is quite different from the similar study in phylogenetically diverged Caucasian subjects.

Elevated Serum Levels of Interleukin-18 Are Associated with Insulin Resistance in Women with Polycystic Ovary Syndrome

Overproduction of proinflammatory factors is associated with obesity and diabetes. Interleukin (IL)-18 as a member of IL-1 cytokine family is increased in obese, in diabetic, and even in polycystic ovary syndrome (PCOS) patients. In the present study we evaluated the association of serum IL-18 levels with insulin resistance in PCOS women. Forty-two PCOS women and 38 control subjects were enrolled in this study and matched with respect to age and body mass index (BMI). Serum IL-18 levels and hormones were measured for all subjects. Furthermore, euglycemic hyperinsulinemic clamp test was performed in selected 30 PCOS women and 11 control subjects. Serum IL-18 levels were elevated in PCOS women compared with the control (p = 0.033). IL-18 levels were positively correlated with homeostasis model assessment index (HOMA) beta index, which assesses beta cell function (p = 0.035), but were inversely correlated with clamp indices, which best represent insulin resistance status: M, Clamp ISI*100, and MCRg values (p = 0.006, 0.010, and 0.009 respectively). No correlation was found between IL-18 and age, BMI, waist-to-hip ratio (WHR), lipid profile, dehydroepiandrosterone-sulfate (DHEAS), sex hormone- binding globulin (SHBG), or fasting insulin levels. In conclusion, in the present study, serum IL-18 levels were significantly increased in PCOS women and firmly associated with insulin resistance displayed by euglycemic hyperinsulinemic clamp test. It indicates that IL-18 may be a contributing factor linking inflammation and insulin resistance in PCOS women.

Adiponectin is independently associated with insulin sensitivity in women with polycystic ovary syndrome

The polycystic ovary syndrome (PCOS) is associated with obesity and insulin resistance predisposing to diabetes mellitus type 2 and atherosclerosis. Adiponectin is a recently discovered adipocytokine with insulin-sensitizing and putative antiatherosclerotic properties. The aim of the study was to elucidate determinants of circulating adiponectin levels and to investigate the potential role of adiponectin in insulin resistance in PCOS women. Plasma adiponectin and parameters of obesity, insulin resistance and hyperandrogenism were measured In 62 women with PCOS and in 35 healthy female controls. Both in PCOS and controls, adiponectin levels were lower in overweight or obese women than in normal-weight women, without any difference between PCOS and controls after adjustment for body mass index (BMI). In PCOS and in controls there was a significant correlation of adiponectin with BMI (r = -0.516, P < 0.001), fasting insulin (r = -0.404, P < 0.001), homeostasis model sensitivity (HOMA %S) (r = -0.424, P < 0.001) and testosterone (r = -0.279, P < 0.01), but no correlation with androstenedione (r = -0.112, P = 0.325), 17-OH-progesterone (r =-0.031, P = 0.784) or the LH/FSH ratio (r =-0.033, P = 0.753). Multiple linear regression analysis revealed that BMI and HOMA %S but not testosterone were independently associated with adiponectin plasma levels, explaining 16% (BMI) and 13% (HOMA %S) of the variability of adiponectin, respectively. In PCOS patients insulin sensitivity, as indicated by continuous infusion of glucose with model assessment (CIGMA %S) was significantly correlated with adiponectin (r = 0.55; P < 0.001), BMI (r =-0.575; P < 0.001), waist-to-hip ratio (WHR) (r =-0.48; P = 0.001), body fat mass assessed by dual-energy X-ray-absorptiometry (DEXA) [Dexa-fat (total) (r = -0.61; P < 0.001) and Dexa-fat (trunk) (r = -0.59; P < 0.001)] and with testosterone (r = -0.42; P = 0.001). Multiple linear regression analysis demonstrated that markers of obesity such as BMI, total or truncal fat mass, age and adiponectin were independently associated with CIGMA %S, and that circulating adiponectin accounted for about 18% of the degree of insulin resistance in PCOS. By contrast, testosterone was not a significant factor, suggesting that PCOS per se did not affect insulin sensitivity independent from obesity, age and adiponectin. Metformin treatment for 6 months in insulin-resistant PCOS women (n = 9) had no effect on plasma adiponectin (P = 0.59) despite significant loss of weight and fat mass and improvement in hyperandrogenaemia. PCOS per se is not associated with decreased levels of plasma adiponectin. However, circulating adiponectin is independently associated with the degree of insulin resistance in PCOS women and may contribute to the development and/or maintenance of insulin resistance independent from adiposity.

The impact of insulin resistance on the outcome of laparoscopic ovarian electrocautery in infertile women with the polycystic ovary syndrome

In this study we assessed how insulin resistance affects pregnancy rates in infertile women with the polycystic ovary syndrome (PCOS) treated with laparoscopic ovarian electrocautery. Sixty-four PCOS women were included in the study in a consecutive fashion. Following the CIGMA (continuous infusion of glucose with model assessment) test, 28 women were classified as insulin resistant and 36 women as non-insulin resistant. After the ovarian electrocautery patients were observed for 12-18 months. If pregnancy did not ensue, they were referred for one or more cycles of in vitro fertilization (IVF). Following ovarian electrocautery the non-insulin-resistant women more frequently achieved a regular menstrual cycle and ovulation than the insulin-resistant PCOS women. Consequently 18 (50%) of the non-insulin-resistant PCOS women achieved a pregnancy versus only five (18%) of women in the insulin-resistant PCOS group. Following treatment with both ovarian electrocautery and IVF, 27 (75%) of the non-insulin resistant PCOS women achieved a successful pregnancy, while 13 (46%) of the insulin-resistant PCOS group achieved this. In conclusion, insulin resistance may be an important marker of a poor outcome of treatment in PCOS infertility. Further studies are needed to evaluate the possible effect of treatment alternatives to alleviate the unfavorable influences of insulin resistance and hyperinsulinemia on ovulation induction in PCOS women.

Impact of Insulin Resistance on Pregnancy Complications and Outcome in Women with Polycystic Ovary Syndrome

The aim of the study was to determine the risk of developing gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH)/pre-eclampsia in a cohort of pregnant women with the polycystic ovary syndrome (PCOS) and known insulin sensitivity status. Pregnancies and neonatal outcome were recorded in a prospective cohort study comprising 29 non-insulin-resistant PCOS women, 23 insulin-resistant PCOS women and a control group of 355 women who had conceived after assisted reproduction. Hypertension, pre-eclampsia and GDM were recorded as well as pregnancy duration, method of delivery and birth weight. The frequency of hypertension was significantly elevated in PCOS women (11.5%) compared to controls (0.3%), p < 0.01. However, the frequency of pre-eclampsia was significantly elevated only in the insulin resistant PCOS women (13.5%) compared to controls (7.0%), p < 0.02. GDM was significantly more frequent in PCOS women (7.7%) than controls (0.6%), p < 0.01. Insulin resistance prior to pregnancy, determined by continuous infusion of glucose with model assessment (CIGMA) test, did not further increase the frequency of GDM. Newborns from PCOS pregnancies were significantly more often delivered by Caesarean section than controls (40.3 vs. 27.3%, p < 0.05) and transferred to neonatal intensive care unit more often than controls (19.2 vs. 9.0%, p < 0.01). Thus we show that the frequencies of pre-eclampsia and GDM are increased in PCOS pregnancies.

The impact of insulin resistance on the outcome of ovulation induction with low-dose follicle stimulating hormone in women with polycystic ovary syndrome.

In this study we examined the possible correlation between insulin metabolism and outcome of gonadotrophin stimulation in infertile clomiphene citrate resistant women with polycystic ovary syndrome (PCOS). The patient group comprised 42 women who were entered into the study in a consecutive fashion. Following performance of the CIGMA (continuous infusion of glucose with model assessment) test, 17 women were classified as insulin resistant and 25 women as non-insulin resistant. Each woman received up to two cycles of low-dose follicle stimulating hormone (FSH) stimulation starting with 75 IU of FSH for 1 week, giving a total of 70 cycles performed. The insulin resistant PCOS women required more gonadotrophin and a longer time to achieve follicular maturation. By multiple regression gonadotrophin consumption correlated best with CIGMA value but not with fasting insulin concentration or body mass index. In the insulin resistant PCOS women 10 out of 29 cycles were cancelled due to a multifollicular response, while only one of 41 cycles was cancelled in the non-insulin resistant PCOS women. Although ovulation rate in completed cycles was similar between the groups, the conception rate was significantly better in the non-insulin resistant PCOS women. In conclusion, in PCOS women insulin resistance seems to be an unfavourable condition resulting in an elevated cancellation rate and a low conception rate following low-dose FSH stimulation.

Serum immunoreactive leptin concentrations in women with polycystic ovary syndrome.

Recent data in the mouse demonstrate that leptin, a protein hormone produced by fat cells, is required for fertility. In the absence of leptin the mice become obese, diabetic and infertile. Polycystic ovary syndrome (PCOS), a common cause of infertility in women, is associated with obesity and insulin resistance. Because of the increased frequency of PCOS in obese women we tested the hypothesis that alterations in serum leptin concentrations might be associated with PCOS. Immunoreactive leptin concentrations were measured in 58 women with PCOS and 70 regularly menstruating (control) women. As has previously been shown there was a positive correlation between leptin levels and body mass index (BMI). Although the leptin levels in the majority of women with PCOS fell within the control range, 29% of PCOS women had leptin levels above the 99% prediction interval for their BMI and none had low leptin levels. There were also positive correlations of leptin levels with free testosterone and insulin sensitivity in control women. In women with PCOS, 13% and 9.5% exhibited higher than expected leptin concentrations with respect to free testosterone and insulin sensitivity, respectively. Insulin resistant PCOS women had higher leptin levels than controls. The data demonstrate that a substantial proportion of women with PCOS have leptin levels that are higher than expected for their BMI, free testosterone and insulin sensitivity. These results suggest that abnormalities in leptin signaling to the reproductive system may be involved in certain cases of PCOS.