Characterization of 24-h cortisol release in obese and non-obese hyperandrogenic women

Rodent models of mental illness in polycystic ovary syndrome: the potential role of hypothalamic-pituitary-adrenal dysregulation and lessons for behavioral researchers

Polycystic ovary syndrome (PCOS) is the most commonly diagnosed endocrine disorder in women of reproductive age, with phenotypes including ovarian and metabolic dysfunctions. Women with PCOS also show increased rates of mental illness, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, and altered responsiveness to stressors that may contribute to the higher rates of mental illness, specifically depression and anxiety. Animal models of PCOS have provided insight into the ovarian and metabolic mechanisms that underlie the syndrome, and several models have been used to study the behavioral consequences associated with PCOS in the laboratory. Several studies in rodent models of PCOS demonstrate changes in anxiety-like behavior, but researchers often neglect to report procedural details or behavioral data crucial to interpreting the differences observed in those studies. Additionally, the impact of potential HPA dysregulation in animal models of PCOS may influence behavioral findings, although only three studies to date have examined this. As such, researchers should consider and report stress-associated variables (e.g., time of day, light/dark cycle, light intensity, housing, and procedures to control experimenter and litter effects) that may influence depression- and anxiety-like behaviors in rodents. This review will summarize the behavioral and HPA-related studies in women with PCOS and rodent models of the disease, and provide considerations for future studies.

Significantly higher adrenocorticotropin-stimulated cortisol and 17-hydroxyprogesterone levels in 337 consecutive, premenopausal, caucasian, hirsute patients compared with healthy controls

OBJECTIVE

To investigate whether elevated ACTH-stimulated 17-hydroxyprogesterone (17OHP) levels are caused by CYP21 genetic defects or by a general adrenal hyperresponsiveness in hirsute patients.

METHODS

A total of 337 hirsute patients were evaluated by Ferriman-Gallwey score, serum testosterone, ACTH-stimulated 17OHP, and cortisol during the follicular phase. A cutoff value of 16 nmol/liter for maximum ACTH-stimulated 17OHP (M17OHP) responses was defined as the upper limit of the 95% confidence interval (CI) for the 97.5 percentile in 42 female controls. All patients were offered total screening of the CYP21 gene, and 252 healthy, premenopausal women with regular menses underwent genetic screening.

RESULTS

Patients were divided into idiopathic hirsutism (IH) (n = 180) and polycystic ovary syndrome (PCOS) (n = 157) groups. M17OHP levels were significantly higher in IH [geometric mean value (nmol/liter +/- 2 sd) 12.2 (4.6-32.3)] and PCOS [11.9 (5.3-27.2)] compared with controls [8.5 (5.1-14.2)] (P < 0.001). A similar percentage of IH and PCOS patients had elevated M17OHP (20.5 vs. 20.8%, not significant), and these also had significantly higher 30-min cortisol levels compared with controls (P < 0.05). The prevalence of CYP21 mutations in patients was 8.6% compared with 6.3% in controls (P = 0.38). Ten of 19 carriers had M17OHP levels below the cutoff limit.

CONCLUSION

The significantly higher ACTH-stimulated levels of cortisol and 17OHP in hirsute patients indicated adrenal hyperresponsiveness in IH and PCOS. CYP21-carrier status could not explain the observed high prevalence of abnormal ACTH-stimulated 17OHP levels in the hirsute population.

Polycystic ovary syndrome and insulin resistance: thrifty genes struggling with over-feeding and sedentary life style?

Almost two decades of research have greatly increased our knowledge in the complex field of metabolic aberrations in polycystic ovary syndrome, but still many problems remain unsolved. The statistical association between insulin levels and androgens originally put the focus on possible direct cause-and-effect relationships between these factors. Indeed there is evidence that insulin may affect ovarian functions in multiple ways, presumably in some cases causing anovulation and hyperandrogenism. Clearly, insulin may increase biologically active testosterone through reducing SHBG levels. Conversely, major increases in androgen levels may induce muscular changes leading to reduced insulin-mediated glucose uptake. There are suggestions of increased steroidogenesis in both ovarian and adrenal pathways, with the net result of increased androgen production. There are also findings supporting increased corticosteroid production, which could contribute to insulin resistance directly or through promoting accumulation of abdominal fat, a typical feature of over-weight women with PCOS. Free fatty acids, released in great amounts from abdominal fat, may induce insulin resistance. Insulin resistance may also be due to a primary aberration in the insulin receptor. Putatively increased serine phosphorylation may cause both impairment of the insulin signal and increased 17,20 lyase activity, thus suggesting a common cause for insulin resistance and increased androgen production. There are also findings supporting a high prevalence of beta-cell dysfunction in PCOS, ranging from increased insulin secretion, not explained by insulin resistance or BMI, to failing beta-cell function, mainly in obese women during progress to glucose intolerance and NIDDM. Recent genetic findings also support a multifactorial genesis to PCOS, notably with positive findings both in genes regulating steroidogenesis and insulin secretion. It is suggested that PCOS is the result of "thrifty" genes, providing advantages in times of shortage of nutrition such as muscular strength, moderate abdominal fatness and decreased insulin sensitivity, i.e. an anabolic, energy saving constitution. However, when this constitution is exposed to unlimited food supplies and modern sedentary life style a full-blown PCOS with insulin resistance and infertility is triggered, presumably via several mechanisms, which follow a logical amplification system between two basic anabolic hormones, insulin and testosterone.

Altered morning and nighttime pulsatile corticotropin and cortisol release in polycystic ovary syndrome

An overdrive of the hypothalamic-pituitary-adrenal (HPA) axis has been postulated in patients with polycystic ovary syndrome (PCOS). However, little is known concerning the pulsatile modes of corticotropin (ACTH) and cortisol secretion in these patients. To further investigate this issue, spontaneous ACTH and cortisol release were evaluated in 16 normal-weight patients with PCOS and 16 control women. Nine PCOS patients and eight controls were studied between 8 AM and 12 AM (noon), and seven PCOS patients and eight controls between 11 PM and 3 AM. Venous blood samples were taken at 10-minute intervals. Cluster analysis was used to assess ACTH and cortisol pulse frequency and amplitude, deconvolution to calculate mean hormone secretion rates, and approximative entropy (ApEn) to measure the orderliness of ACTH and cortisol time-series data. PCOS patients compared with controls displayed increased ACTH and cortisol release (area under the curve [AUC] and mean plasma concentration) both in the morning and at night. This was not due to increased hormonal secretory burst frequency, but to higher hormonal interpeak valley concentrations and, in the case of ACTH, nighttime pulse amplitudes. Mean ACTH and cortisol secretion rates also were increased in PCOS patients. Further, both controls and PCOS patients exhibited significant (0 to 20 minutes lagged) concordance between individual daytime pulsatile ACTH and cortisol release episodes. As shown by increased ApEn values, PCOS patients had more disorderly daytime cortisol release. In addition, the normal daytime correlation between the amount of pulsatile ACTH and cortisol release as observed in the controls was lost in PCOS patients. Finally, cross-correlation analysis showed a more prominent negative correlation in PCOS patients versus controls between plasma cortisol and 40- to 120-minute delayed ACTH concentrations in the morning, indicating a more sustained negative feedback of cortisol on ACTH release in PCOS at this time. Taken together, these findings demonstrate the existence of multifaceted dysregulation of the HPA axis in PCOS.

A long-term treatment with gonadotropin-releasing hormone agonist plus a low-dose oral contraceptive improves the recovery of the ovulatory function in patients with polycystic ovary syndrome

OBJECTIVE

To evaluate the hormonal and clinical follow-up after the suspension of a longterm therapy with GnRH-agonist (GnRH-a) plus oral contraceptive (OC) in comparison to OC alone in patients with polycystic ovary syndrome (PCOS).

DESIGN

Hormonal (plasma LH, FSH, sex steroid levels) and clinical (Ferriman-Gallwey score and ultrasound) parameters were monitored at various moments during the 6 months of treatment and during the 6 months after treatment suspension.

SETTING

Physiopathology of Human Reproduction, University of Modena, Italy.

PATIENT(S)

Thirty patients with PCOS were enrolled and randomly subdivided in two groups of 15 each.

INTERVENTION(S)

Group A was treated with 3.75 mg IM GnRH-a plus OC. Group B was treated only with OC.

RESULT(S)

Both therapeutical regimens were effective in reducing androgenic milieu, Ferriman-Gallwey score, and ovarian volume within the 6th month of treatment. However, only patients treated with GnRH-a + OC showed a normal LH:FSH ratio, adequate plasma E2 and P levels, and ovulatory cycles during the 6 months of the after treatment follow-up. Patients treated with OC alone showed no beneficial effect after the 3rd month of the follow-up.

CONCLUSION(S)

These data support the evidence of a higher efficacy of the combined regimen (GnRH-a + OC) than OC alone in the treatment of patients with PCOS. In addition, the former regimen is associated with recovery of normal ovulatory cycles.

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.