Interactions between insulin and insulin-like growth factor I in the pathogenesis of polycystic ovarian disease

Abnormalities in the serum insulin-like growth factor-1 axis in women with hyperandrogenism

OBJECTIVE

To study the insulin-like growth factor-1 (IGF-1) axis in hirsute women.

DESIGN

Controlled clinical study.

SETTING

Tertiary care institutional hospital.

PATIENT(S)

Forty hirsute women and 17 women with normal menstrual cycles.

INTERVENTION(S)

Basal and ACTH-stimulated samples were obtained, and sampling was repeated 1 (gonadal stimulation) and 21 (gonadal suppression) days after a single 3.75-mg IM dose of triptorelin. Controls did not receive triptorelin for ethical reasons.

MAIN OUTCOME MEASURE(S)

Serum GH, IGF-1, IGF-binding protein-3 (IGFBP-3), insulin, glucose, total testosterone, sex hormone-binding globulin, E2, and gonadotropin levels. Basal and ACTH-stimulated steroid precursors were measured.

RESULT(S)

Patients with idiopathic hirsutism were identified by normal serum androgen levels (n=17). Those with functional ovarian hyperandrogenism (n=15) were identified by an increase in the serum testosterone level that normalized during gonadal suppression, whereas those with functional adrenal hyperandrogenism (n=8) were identified by an initial increase in the testosterone level that persisted during gonadal suppression. The adrenal hyperandrogenism group had increased IGF-1 levels compared with the control, idiopathic hirsutism, and ovarian hyperandrogenism groups. Patients with ovarian hyperandrogenism had normal TGF-1 concentrations, but their IGFBP-3 concentrations were lower than those of controls. No differences were observed in GH levels between any of the groups. These results persisted when the influence of age was corrected for.

CONCLUSION(S)

The IGF-1 axis appears to be involved in the pathogenesis of hyperandrogenism, especially in patients with adrenal hyperandrogenism, who have a clear increase in IGF-1 levels. Moreover, patients with ovarian hirsutism have decreased IGFBP-3 concentrations, which might enhance IGF-1 bioavailability.

Effects of ovary suppression by a long-acting GnRH-agonist on circulating GH, insulin-like growth factor I and insulin levels in women with polycystic ovary syndrome

Our aim was to investigate the effect of GnRH-agonist (GnRH-a) induced suppression of plasma sex steroids on serum GH, insulin like growth factor-I (IGF-I) and insulin levels after an oral glucose load (OGTT) in women with polycystic ovary syndrome (PCOS). Serum insulin, GH and IGF-I levels during a 75-g 4-h OGTT were measured in 3 nonobese and 7 obese hyperandrogenic women with PCOS and normal glucose tolerance before and after 10 weeks of treatment with the GnRH-a triptorelin (3,75 mg im every 28 days). Basal estrogen and androgen levels were also measured at time 0 of the first and the second OGTT. After the therapy serum estrogens and androgens were significantly suppressed. Body weight remained unchanged. Basal GH significantly increased after the treatment while fasting IGF-I and insulin levels decreased from (mean +/- SE) 349.3 +/- 31.8 to 278.7 +/- 33.2 ng/mL and from 22.4 +/- 4.1 to 18.8 +/- 4.4 microU/mL, respectively. The insulin response to OGTT (area under curve) was also reduced (from 16,017 +/- 2598 to 11,736 +/- 2317 microU/mL/240 min). Our results suggest that the GnRH-a induced suppression of ovary secretion may modify the serum GH and IGF-I levels and the insulin response to an OGTT in women with PCOS.

Profactor-H (elevated circulating insulin): the link to health risk factors and diseases of civilization

We propose the term Profactor-H for chronic elevated circulating insulin. Profactor-H is common in atherosclerosis, essential hypertension, non-insulin dependent diabetes mellitus, some forms of obesity, some forms of cancer, cardiovascular disease, peripheral vascular disease and some forms of stroke. Profactor-H appears to be the central pathophysiologic consideration in the etiology of many diseases and health risk factors. Profactor-H's impact depends on genetic predisposition, frequency consumption of refined simple and complex carbohydrates, deficiency in dietary chromium, sedentary life style and stresses of modern day living. In many obese individuals, Profactor-H disturbs metabolic balance, favoring anabolic metabolism, and is exacerbated through chronic insulin production and impairment of insulin action. This vicious cycle also appears to be common in many apparently healthy, non-obese individuals destined to develop health risks and diseases in response to long-term adverse consequences of Profactor-H. We believe that a four-pronged program which 1) reduces the daily frequency of carbohydrate consumption, particularly refined foods and simple sugars, 2) supplements the daily dietary intake of chromium, 3) encourages activity, and 4) reduces stress, will minimize the impact of Profactor-H and thereby reduce health risks and result in improved health.

Diminished growth hormone responses to L-dopa in polycystic ovarian disease

OBJECTIVE

To investigate the GH secretion capacity in polycystic ovarian syndrome (PCOS).

DESIGN

Prospective.

SETTING

Reproductive endocrinology unit.

PATIENTS

Nineteen women with clinical and endocrinologic signs of PCOS were compared with 10 healthy weight-matched volunteers with normal menstrual rhythm and no history of endocrine or reproductive abnormality.

INTERVENTIONS

Standard GH reserve estimates were affected in all subjects using oral L-Dopa. The test was carried out after an overnight fast on cycle days 5 to 8 in menstruating subjects; the test was done randomly in patients with amenorrhea.

RESULTS

Both PCOS and control groups responded to L-Dopa over a 3-hour period with significant elevations in GH concentrations. The control group showed significantly higher values than the PCOS group at 90, 120, and 180 minutes.

CONCLUSION

The findings indicate that PCOS patients demonstrate a relative deficiency in GH reserve.

Ovulation induction in polycystic ovary syndrome: a review of conservative and new treatment modalities

Polycystic ovary syndrome (PCOS) is a complex disorder with heterogeneous clinical and endocrine features. Chronic anovulation and infertility are common and affect about 75% of the patients. Ovulation induction in PCOS patients is a challenge for the physicians who treat these patients. Several different treatment modalities have been proposed to induce ovulation in PCOS, each of which deals with a different clinical or endocrine disorder which is present in these patients. This review presents traditional and new methods for ovulation induction in PCOS patients, the theoretical background, the pros and cons for each treatment and success rate.