Insulin and insulin-like growth factor-I responsiveness in polycystic ovarian syndrome**Presented in part at the 36th Annual Meeting of the Society for Gynecologic Investigation, San Diego, California, March 15 to 18, 1989.††Supported in part by the United States Public Health Service grants RR00865, CA30388, and CC32737, Bethesda, Maryland, to the Clinical Research Center, University of California at Los Angeles, Los Angeles, California

Correlation of Clinical, Hormonal, Biochemical and Ultrasound Parameters Between Adult and Adolescent Polycystic Ovarian Syndrome

Purpose

To correlate the clinical, hormonal, biochemical and ultrasound parameters in adolescent patients with polycystic ovarian syndrome (PCOS) and to compare them with adult patients.

Methods

This was a prospective, correlational study. 50 adult (20-35 years) and 50 adolescent patients (15-19 years) who had features of PCOS (Rotterdam Criteria, 2003) were selected. The control group comprised of 50 women of same age in each group with normal parameters. Pelvic ultrasound was done in early follicular phase (3-5th day of menstrual cycle). Assessment of hormonal and biochemical parameters (LH/FSH ratio, free testosterone level, lipid profile and fasting glucose/insulin ratio) and grey-scale ultrasound was done.

Results

No significant difference was observed in menstrual pattern in adults and adolescents with PCOS. The mean values of serum LH/FSH ratio and free testosterone were significantly higher in both adult and adolescent PCOS patients as compared to their controls (p < 0.001). The mean value of serum insulin was significantly higher (p < 0.001) with positive correlation (adult: r = 0.655, p < 0.01; adolescent: r = 0.451, p < 0.01) of serum insulin with free testosterone. Hyperandrogenemia without hyperinsulinemia was found in 56% adolescent and 60% adult PCOS patients. 82% adolescent and 88% adult PCOS patients showed multiple follicles (> 5) on ultrasound. The ovarian morphology had positive correlation with serum LH and free testosterone. The mean ovarian volume was significantly higher in adult (10.48 ± 4.38 vs. 4.17 ± 0.91) and adolescent (11.08 ± 5.82 vs. 4.23 ± 0.89) PCOS patients, when compared with controls, respectively.

Conclusion

No statistically significant difference was noted in PCOS between adults and adolescents.

Nitric oxide (NO) levels in patients with polycystic ovary syndrome (PCOS): a meta-analysis

Objective

The pathogenesis of polycystic ovarian syndrome (PCOS) remains unclear, but is known to be related to increased insulin resistance, diabetes, obesity, oxidative stress, inflammation, and cardiovascular disease. No meta-analyses have examined whether PCOS is associated with nitric oxide (NO). Therefore, we aimed to evaluate the association between serum/plasma nitrite levels and PCOS.

Methods

We performed a meta-analysis. To identify eligible original articles, we searched online computerized databases, including EMBASE, Medline, and Web of Science. The characteristics of each single study, as well as the standard mean difference (SMD) with corresponding confidence intervals (CIs), were calculated and subgroup analysis was performed to examine heterogeneity.

Results

We included 12 articles with 16 studies and a total of 895 patients were included in the meta-analysis. We found a significant association between PCOS and serum or plasma nitrite levels, with a pooled SMD of −0.61 (95% CI: −1.05 to −0.16). The final pooled data were determined by the random effects model because significant high heterogeneity (I² = 89%) was found.

Conclusions

Our meta-analysis shows that decreased serum or plasma nitrite levels are associated with PCOS. The pathogenesis of PCOS may be due to endothelial dysfunction; however, further research to confirm this possibility is required.

Evaluation of ovarian functionality after a dietary treatment in obese women with polycystic ovary syndrome

In women with polycystic ovary syndrome (PCOS) weight loss is associated with an improvement in insulin sensitivity and a reduction of the insulin concentration in the plasma. It is clear, then, that the first therapeutic approach that can be considered in obese PCOS patients for restoration of the menstrual cycle should be a diet. The aim of our study was to examine the effect of long-term caloric restriction on the clinical and biochemical abnormalities in obese PCOS women. The results obtained make it clear that caloric restriction for 4 weeks causes an increase in SHBG and decreases of free testosterone and insulin, with consequent improvement of the clinical picture.

Insulin resistance: the link between metabolic disorders and cystic ovarian disease in high yielding dairy cows?

A preliminary investigation was performed to examine whether insulin resistance is a factor in the pathogenesis of cystic ovarian disease (COD) in high-yielding dairy cows. In total 30 cows, of which 15 were diagnosed as suffering from COD based on the anamnesis and clinical examination, and the other 15 served as matched controls, were subjected to an intravenous glucose tolerance test (IVGTT). The aim of the study was to investigate whether insulin activity was altered in COD cows. Differences in glucose clearance between the COD cows and their controls were analyzed comparing the fractional turnover rate (k), the glucose half-time (T1/2), and the area under the curve (AUC) 60 and 120 min after infusion. Differences in insulin response were analyzed comparing the insulin increment, the insulin peak concentration, and the AUC 60 and 120 min after glucose infusion. Although insulin resistance, attended by a secondary hyperinsulinemia, is stated to directly contribute to the ovarian abnormalities that characterize the polycystic ovary syndrome (PCOS) in human medicine, this was not observed in COD cows. On the contrary, COD cows appeared to have a low insulin response following an intravenous glucose load as compared with their matched controls. This was illustrated by significantly lower insulin increments (P = 0.04) and lower insulin peak concentrations (P = 0.04). As COD cows had a significantly lower insulin response to a standard glucose load, it was concluded that insulin could be a factor in the pathogenesis of COD in dairy cows.

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.

Polycystic ovary syndrome: pathophysiology and outcome with in vitro fertilization

OBJECTIVE

To assess the efficacy of IVP-ET in infertile women with the polycystic ovary syndrome (PCOS) and to provide a comprehensive review of contemporary therapeutic options and their complications as reflected in the current literature.

DESIGN

Pertinent studies in medical literature identified through computerized bibliographic search and via manual review of relevant scientific publications.

RESULTS

In vitro fertilization and ET is an effective therapy for PCOS patients who are refractory to ovulation induction in vivo or who have coexisting infertility factors. The use of GnRH agonist (GnRH-a) is associated with significant reductions in the incidence of pregnancy loss and may improve fertilization and cleavage rates. In the PCOS patient, the use of purified FSH preparations does not appear to improve pregnancy rates nor other clinical parameters when compared with hMG. Severe ovarian hyperstimulation syndrome (OHSS) is an important consideration when PCOS patients undergo superovulation protocols. Strategies for OHSS prevention include the use of intravenous albumin immediately after oocyte retrieval, triggering of ovulation with a GnRH-a, or withholding menotropin therapy for several days before hCG administration. Cryopreservation of all embryos for future transfer in an artificial cycle has also proven to be an effective alternative in PCOS patients at high risk for severe OHSS.

CONCLUSIONS

Pregnancy rates for PCOS patients undergoing IVF-ET are comparable with those for women with tubal factor infertility. Therefore, IVF-ET should be offered to patients with PCOS who are refractory to conventional infertility modalities.

Chronic hyperinsulinemia and the adrenal androgen response to acute corticotropin-(1-24) stimulation in hyperandrogenic women

OBJECTIVE

Many women with androgen excess demonstrate elevated circulating insulin levels independent of obesity. In addition, in these women some investigators have demonstrated a negative correlation between the circulating levels of the adrenal androgens, dehydroepiandrosterone or dehydroepiandrosterone sulfate and insulin. The mechanism by which insulin decreases adrenal androgens is unclear. The objective of this study was to determine whether chronic hyperinsulinemia in hyperandrogenic women results in an alteration in the adrenocortical response to corticotropin, resulting in decreased androgen secretion.

STUDY DESIGN

We studied seven hyperandrogenic women with severe chronic hyperinsulinemia and eight hyperandrogenic normoinsulinemic patients. Nine healthy women served as controls for the basal hormonal levels and the response to a 3-hour, 100 gm oral glucose tolerance test. In all subjects insulin and glucose were measured hourly during the oral glucose tolerance test and the baseline sample was assayed for total testosterone, dehydroepiandrosterone sulfate, dehydroepiandrosterone, androstenedione, sex hormone-binding globulin, and free testosterone. In hyperandrogenic women cortisol, dehydroepiandrosterone, and androstenedione were also measured, before and 60 minutes, after acute intravenous administration of 0.25 mg corticotropin (1-24).

RESULTS

There was no difference in the response of cortisol, dehydroepiandrosterone, or androstenedione to corticotropin-(1-24) stimulation between normoinsulinemic and hyperinsulinemic hyperandrogenic patients. As defined, the hyperinsulinemic patients had higher basal and peak insulin levels and areas under the insulin response curve compared with the normoinsulinemic patients or controls. Total testosterone and dehydroepiandrosterone did not differ among study groups. As expected, hyperandrogenic patients demonstrated lower sex hormone-binding globulin activity and higher free testosterone, androstenedione, and dehydroepiandrosterone sulfate basal levels compared with controls.

CONCLUSIONS

The results of this study do not support the hypothesis that chronic hyperinsulinemia in hyperandrogenic patients significantly inhibits the andrenocortical secretion of dehydroepiandrosterone or androstenedione in response to corticotropin stimulation or the basal circulating adrenal androgen levels. Additional studies, including a greater number of patients, may be needed to fully establish these conclusions.

The relationship between circulating androgens, obesity, and hyperinsulinemia on serum insulin-like growth factor binding protein-1 in the polycystic ovarian syndrome

OBJECTIVE

Our purpose was to evaluate the relationship of obesity, hyperinsulinemia, and hyperandrogenemia on serum insulin-like growth factor binding protein-1 levels in women with the polycystic ovarian syndrome.

STUDY DESIGN

Insulin-like growth factor binding protein-1, insulin, and androgen levels were studied during a 3-hour intravenous glucose tolerance test in 16 women with polycystic ovarian syndrome (nine obese and seven nonobese) and 20 healthy control women (10 obese and 10 nonobese).

RESULTS

Positive correlations were observed between basal (r = 0.77, p = 0.04) and area under curve (r = 0.86, p < 0.001) insulin-like growth factor binding protein-1 with basal androstenedione in the nonobese women with polycystic ovarian syndrome but not in other groups of women examined or between other androgens and insulin-like growth factor binding protein-1. An inverse relationship was observed between log area under curve insulin-like growth factor binding protein-1 levels and log body mass index in polycystic ovarian syndrome (r = -0.54, p = 0.03) and in normal women (r = -0.43, p = 0.06). The log area under curve insulin-like growth factor binding protein-1 level was approximately an inverse linear function of log area under curve insulin response for both women with polycystic ovarian syndrome (r = -0.70, p < 0.001) and control women (r = -0.72, p < 0.001). Additionally, after the area under curve insulin response during intravenous glucose tolerance testing was controlled for, the decline in area under curve insulin-like growth factor binding protein-1 responses was on average 66% less in both obese and nonobese women with polycystic ovarian syndrome compared with same-weight controls (95% confidence interval 110% to 270%, p = 0.04).

CONCLUSION

These data indicate that insulin and body mass index are the major determinants of circulating insulin-like growth factor binding protein-1 and that chronic hyperandrogenemia does not appear to further reduce serum insulin-like growth factor binding protein-1 levels in obese or normal-weight women with polycystic ovarian syndrome.

Insulin-like growth factors: clinical experience in ovarian function

Insulin, insulin-like growth factor, and insulin-like growth factor binding proteins have been shown to play major roles in the modulation of both normal and disturbed ovarian physiology. Identification of many of the actions of these peptides was initially characterized using animal models. However, an increasing body of evidence has emerged to clarify their contributions in human reproductive function. It is clear that at various stages of folliculogenesis, local steroid production acts in concert with intraovarian peptides to promote dominant follicle development. This review will discuss the physiologic role(s) of the insulin-insulin-like growth factor-insulin-like growth factor binding protein family in reproductive function and disorders of androgen excess.

Laparoscopic surgery of chronic hyperandrogenic anovulation

The review describes briefly the clinical and endocrinological characteristics of chronic hyperandrogenic anovulation (CHA), as well as ovulation induction by hormone therapy (therapy of first choice) and by classical wedge resection. The main purpose of this study, however, is to compare different laparoscopic treatments of CHA, with emphasis on laser treatments by argon, CO2, Nd:YAG, and frequency-doubled Nd:YAG laser. The overall results of laparoscopic treatments in hormone-therapy-resistant patients with CHA are encouraging and the results are comparable. In the studies considered in this review, ovulation was induced for longer or shorter periods in 21 out of 31 patients (68%) after ovarian biopsy, in 57 out of 73 patients (78%) after electrosurgery, and in 82 out of 118 patients (70%) after laser treatment. Subsequent conception occurred in 44%, 40%, and in 41% of the patients, respectively. Of interest is the fact that some hormone-therapy-resistant patients become sensitive to Clomiphene after laparoscopic treatment, giving an overall percentage of ovulation and an overall pregnancy rate of 89% and 54%, respectively, for electrosurgery, and of 88% and 50%, respectively, for laser treatment. Unfortunately, adhesion formation, a serious complication of surgical treatment of the ovaries, is still a drawback using laparoscopic surgical techniques.

The role of insulin in ovarian size in patients with the polycystic ovary syndrome

The objective of this study was to evaluate whether the degree of suppression of ovarian volume effected by a gonadotropin releasing hormone (GnRH) agonist in patients with polycystic ovary syndrome (PCOS) correlated with basal insulin secretion and insulin secretion provoked by a glucose challenge. Eighteen PCOS patients received the GnRH agonist D-tryptophan-6-LHRH (Decapeptyl, 3.75 mg monthly i.m.) for 6 months and had blood glucose and insulin measured during a 75 g oral glucose tolerance test (OGTT) prior to and at the end of therapy. According to ovarian volume suppression after GnRH agonist therapy, two groups were defined: in group A (n = 10; mean body mass index (BMI) +/- SEM, 25.6 +/- 1.6 kg/m2) ovarian volume regressed from 17.9 +/- 1.6 to 6.7 +/- 0.3 ml (full responders) and in group B (n = 8; mean BMI +/- SEM, 28.1 +/- 2.3 kg/m2) from 21.5 +/- 1.1 to 15.1 +/- 1.0 ml (partial responders). Results showed that GnRH agonist therapy did not affect significantly BMI or fasting levels and area under the curve (AUC) for glucose and insulin in the respective groups. Fasting insulin levels correlated positively with ovarian volume prior to (r = 0.56, p < 0.05) and after 6 months of GnRH agonist therapy (r = 0.80, p < 0.005). The suppressibility of ovarian volume with GnRH agonist therapy correlated negatively with the difference between maximal and basal levels (r = -0.68), the area under the curve (r = -0.62) and maximal levels (r = -0.72) for insulin during the OGTT.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of luteinizing hormone and insulin on sex steroids and sex hormone-binding globulin in the polycystic ovarian syndrome

OBJECTIVE

To examine the relationship between hyperinsulinemia, sex hormone-binding globulin (SHBG), and body mass index (BMI) on LH-induced hyperandrogenemia in patients with polycystic ovarian syndrome (PCOS).

DESIGN

Insulin responses during an oral glucose tolerance test (OGTT) were assessed in 25 consecutive women with PCOS and 20 control women matched for BMI. Insulin responses and sensitivity (SI) were also determined using a frequently sampled intravenous glucose tolerance test (IVGTT).

SETTING

The clinical research center at a university medical center.

MAIN OUTCOME MEASURES

Serum LH, SI, and basal, peak, and area under the curve (AUC-insulin responses) were determined and correlated with SHBG, androstenedione (A), T, and free T concentrations.

RESULTS

Compared with controls, the AUC-insulin response during OGTT was greater in PCOS, with an average increase of 44%. During IVGTT, AUC-insulin response was also significantly higher in PCOS versus controls, with an average increase of 53%. In addition, SI was reduced in PCOS versus controls with an average decrease of 53%. The average differences in oral- and intravenous-glucose-induced hyperinsulinemia and in insulin sensitivity between PCOS and controls were relatively constant across the entire physiological range of BMI. In PCOS, baseline LH showed strong positive correlations with baseline A and T. However, there were no significant correlations between either basal, peak, or AUC-insulin response during OGTT and IVGTT with basal T or A concentrations or between insulin and androgen levels measured at 30-minute intervals throughout the OGTT. However, basal, peak, and AUC-insulin responses during OGTT were strongly correlated with fasting SHBG binding capacity.

CONCLUSIONS

These data are consistent with the hypothesis that hyperinsulinemia in PCOS influences the biologically active component of T by lowering SHBG concentrations while having little apparent impact on LH-induced secretion of androgens in vivo.

Treatment of polycystic ovarian disease during adolescence with ethinylestradiol/cyproterone acetate versus a D-Tr-6-LHRH analog

OBJECTIVE

This study was undertaken to compare the clinical and endocrinological results of two kinds of treatment on adolescents with polycystic ovarian disease (PCOD).

METHOD

Forty-five adolescents with PCOD were randomly allocated into two groups, treated either with ethinylestradiol (EE)/cyproterone acetate (group A) or the GnRH analog D-Tr-6-LHRH (group B).

RESULT

No significant changes were detected on the body mass index and waist-hip circumference. A significant improvement of hirsutism was noticed in both groups of patients. A normal menstrual period was recorded in group A adolescents while all group B patients became amenorrheic. A favorable decrease of ovarian volume was detected in both groups. LH/FSH ratio and delta 4-androstenedione serum levels were found significantly reduced in both groups in comparison to pre-treatment levels. The comparison between the two groups, after 6 months, showed significantly lower values of LH/FSH ratio in group B cases.

CONCLUSION

Both forms of treatment are safe and effective to a various degree for the management of PCOD adolescents.