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

Association of diabetes mellitus with risk of reproductive impairment in females: A comprehensive review

Reproductive impairment is the most prevalent yet most ignored complication of diabetes mellitus. In diabetes, the problem associated with reproductive health is comprehensive in both males and females. Diabetic females have problems like delayed menarche, irregular menstrual cycle, subfertility, complications in pregnancy and early menopause. This may decrease reproductive age in diabetic females as the menarche is delayed and menopause is early in them. Like diabetic males, diabetic females also have the negative effect of oxidative stress on the reproductive system. This may lead to dysfunction of the ovary. It affects the physiological cycle like the ovary's maturation, embryo development and pregnancy. These complications also affect the offspring, and they may also become diabetic. This review aims to concentrate on the effect of diabetes on the reproductive system of females and the impairment caused by it. We will also discuss in detail the role of the hypothalamus-pituitary ovary axis, diabetes impact on different reproductive phases of females, and the sexual disorders that occur in them.

Diabetes and the female reproductive system

The insulin/insulin-like growth factor (IGF) pathways and glucose metabolism act as mediators of human ovarian function and female fertility. In normal insulin action, insulin binds to its own receptors in the ovary to mediate steroidogenesis and act as a co-gonadotropin. Insulin with other factors may influence ovarian growth and cyst formation. The IGF pathway also seems to influence normal ovarian function. Insulin signaling affects reproductive function. Dysregulation of this pathway leads to altered puberty, ovulation, and fertility. Better understanding of the normal physiology and pathophysiology of insulin, IGF, and glucose effects on the human reproductive system will allow for better outcomes.

Ovarian size and blood flow in women with polycystic ovary syndrome and their correlations with endocrine parameters

OBJECTIVE

To determine how common polycystic ovarian morphology may be in women given the clinical diagnosis of polycystic ovary syndrome (PCOS) based on chronic anovulation and hyperandrogenism and whether certain hormonal factors correlate with ovarian morphology and blood flow.

DESIGN

Prospective study.

SETTING

Two academic endocrinology centers in Italy.

PATIENT(S)

Three hundred twenty-six women with PCOS and 50 age-matched and weight-matched ovulatory women.

INTERVENTION(S)

Ultrasound assessment of ovarian morphology in patients and controls and ovarian blood flow and fasting hormone levels in a subset of 50 patients and matched controls.

MAIN OUTCOME MEASURE(S)

Ovarian morphological assessments, ovarian blood flow by pulsatility index (PI) and resistance index (RI), and measurements of gonadotropins, estrogen, sex hormone-binding globulin, androgens, inhibin B, glucose, and insulin.

RESULT(S)

Using strict ultrasound criteria, 195 woman (60%) had enlarged ovaries, 135 (35%) had normal ovarian size but characteristic morphology, and 16 (5%) had normal size and morphology. Ovarian blood flow was increased (reduced PI and RI) in PCOS. All hormonal parameters were elevated in PCOS. Ovarian size correlated only with insulin and a measure of insulin resistance. Ovarian blood flow correlated positively with insulin, T, free T, and E2 but not with luteinizing hormone. Inhibin B showed a negative correlation with ovarian blood flow.

CONCLUSION(S)

When a clinical diagnosis of PCOS was made, virtually all women were found to have characteristic ovarian morphology. Insulin correlated with increased ovarian size as well as with increased blood flow. Blood flow also correlated positively with sex steroids but negatively with inhibin B.

Subcutaneous administration of pulsatile gonadotropin-releasing hormone decreases serum follicle-stimulating hormone and luteinizing hormone levels in women with polycystic ovary syndrome: A preliminary study

OBJECTIVE

The main objectives of this study were to investigate whether [1] subcutaneous (SC) administration of pulsatile gonadotropin-releasing hormone (GnRH) decreases the increased levels of luteinizing hormone (LH) observed in women with polycystic ovary syndrome (PCOS); and [2] GnRH administration modifies the pattern of LH secretion observed in these patients.

DESIGN

Serum follicle-stimulating hormone (FSH) and LH levels and LH pulse amplitude and pulse interval were determined in 13 patients with PCOS during the first 3 days of the cycle following the administration of 10 mg of medroxyprogesterone acetate during 5 days.

SETTING

Infertility clinic.

PATIENT(S)

Thirteen women with PCOS.

INTERVENTION(S)

Determination of FSH and LH serum levels after SC administration of pulsatile GnRH.

MAIN OUTCOME MEASURE(S)

The FSH and LH levels in serum.

RESULT(S)

Mean FSH and LH levels in serum decreased following the administration of subcutaneous pulsatile GnRH in all treated women compared with baseline values. The LH pulse amplitude and pulse interval decreased in all patients following the administration of pulsatile GnRH.

CONCLUSION(S)

The SC administration of pulsatile GnRH in women with PCOS significantly decreases FSH and LH levels in serum. A decrease in the secretion of gonadotropins, without reaching the intense suppression observed with GnRH analogues, could be of great utility in in vitro fertilization (IVF) treatments.

Success of laparoscopic ovarian wedge resection is related to obesity, lipid profile, and insulin levels

OBJECTIVE

To evaluate the effects of laparoscopic ovarian wedge resection on hormonal and metabolic parameters of polycystic ovary syndrome (PCOS) and to compare profiles of women who achieved pregnancy with those who did not.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENT(S)

Thirty-three women with PCOS.

INTERVENTION(S)

Laparoscopic ovarian wedge resection using harmonic scalpel.

MAIN OUTCOME MEASURE(S)

Pregnancy; levels of testosterone, DHEAS, gonadotropins, sex hormone-binding globulin (SHBG), and glucose and insulin during 2-hour glucose tolerance test; lipid profile; body mass index; and waist-to-hip ratio.

RESULT(S)

Twenty-two women (67%) achieved clinical pregnancy within the mean of 4.9 months after surgery. Baseline parameters of women who became pregnant differed from those who did not: those who became pregnant were less obese, had lower levels of total cholesterol, low-density lipoprotein, and triglycerides; higher levels of SHBG; lower levels of fasting insulin; lower insulin area under the curve; and higher insulin sensitivity index. Subjects not pregnant by 12 weeks after surgery underwent repeat endocrine and metabolic evaluations. In these women, wedge resection was followed by declines in testosterone, LH, and insulin sensitivity index. Wedge resection had no significant effect on SHBG, DHEAS, or lipid profile.

CONCLUSION(S)

Laparoscopic wedge resections are associated with the highest pregnancy rates among less obese subjects with favorable lipid profiles and lower insulin. In this study, the postoperative decline of serum testosterone and LH is not attributable to improvement of insulin sensitivity.

Clinical manifestations and insulin resistance (IR) in polycystic ovary syndrome (PCOS) among South Asians and Caucasians: is there a difference?

OBJECTIVE

Polycystic ovary syndrome (PCOS) is more prevalent in South Asian women residing in the UK than in Caucasians. Insulin resistance (IR) is central to the pathogenesis of PCOS, while type 2 diabetes is commoner in South Asians. We aimed to determine a possible ethnic difference in the clinical and biochemical characteristics of South Asian vs. Caucasian women with PCOS.

PATIENTS AND DESIGN

A case-control cross-sectional observational study of consecutive women with anovular PCOS (47 South Asians, 40 Caucasians) and their age-matched controls (11 South Asians and 22 Caucasians).

MEASUREMENTS

Index subjects: a questionnaire-based interview on clinical symptoms and family history; anthropometric measurements, clinical observations of the presence and degree of acne, hirsutism and acanthosis nigricans; transvaginal pelvic ultrasound; biochemical analyses of fasting blood sugar, fasting plasma insulin, fasting lipids, testosterone, and SHBG concentrations.

CONTROL GROUP

age- and weight-matched unrelated women from the same ethnic backgrounds without PCOS seeking treatment for male infertility were studied by similar methods to those used with the index subjects.

RESULTS

South Asians with PCOS presented at a younger age (age 26 +/- 4 vs. 30.1 +/- 5 years, P = 0.005). Body mass index (BMI) and waist : hip ratios were similar in the two affected cohorts. More South Asians had oligomenorrhoea commencing at a younger age. Hirsutism (Ferriman Gallwey score 18 vs. 7.5, P = 0.0001), acne, acanthosis nigricans and secondary infertility were significantly more prevalent in South Asians. The fasting glucose was similar (4.52 +/- 0.08 vs. 4.62 +/- 0.09 mmol/l, P = 0.25), the fasting insulin higher (89.4 +/- 8.9 vs. 48.6 +/- 4.8 pmol/l, P = 0.0001) and insulin sensitivity (IS) lower (0.335 +/- 0.005 vs. 0.357 +/- 0.002, P = 0.0001) among South Asians. Serum SHBG was significantly less in South Asians (35 +/- 3.3 vs. 55 +/- 9.4 nmol/l, P = 0.02), while serum testosterone was similar (2.69 +/- 0.11 vs. 2.64 +/- 0.13 nmol/l, P = 0.37).

CONCLUSIONS

We conclude that South Asians with anovular PCOS seek treatment at a younger age, have more severe symptoms, and have higher fasting insulin concentrations and lower insulin sensitivity than Caucasians.

Normal ovulatory women with polycystic ovaries have hyperandrogenic pituitary-ovarian responses to gonadotropin-releasing hormone-agonist testing

Women with polycystic ovary syndrome (PCOS) have chronic anovulation and hyperandrogenism and frequently have abnormalities in their lipid profiles and insulin/insulin-like growth factor axis that increase their lifetime risk for cardiovascular disease. Normal ovulatory women may have polycystic ovaries on ultrasonography and yet lack the clinical features of PCOS. To further explore whether ovulatory women without clinical/biochemical hyperandrogenism but with polycystic appearing ovaries (ov-PAO) have subclinical features of PCOS, we prospectively characterized 26 ov-PAO women and matched them by age and body mass index to 25 ovulatory women with normal appearing ovaries (ov-NAO) and to 22 women with PCOS. After an overnight fast, all women had baseline endocrine and metabolic assessments. In addition, a subset of each group of women underwent GnRH-agonist (leuprolide acetate 1 mg s.c.) testing, ACTH stimulation, and an insulin tolerance test (ITT). At baseline, ov-PAO and ov-NAO women had similar endocrine profiles (LH, LH:FSH, androstenedione, and DHEAS). Compared with ov-NAO, 31% of ov-PAO women had reduced glucose responses after insulin (K(itt)), suggesting mild insulin resistance, and 35% had high density lipoprotein levels below 35 mg/dL, a level considered to represent significant cardiovascular risk. After GnRH-agonist, ov-PAO women had response patterns in LH, total testosterone, and 17-hydroxyprogesterone (17-OHP) that were intermediate between ov-NAO and women with PCOS. Ovarian responses were above the normal range in 30-40% of women with ov-PAO. In ov-PAO, peak responses of LH after leuprolide correlated with triglyceride levels (P < 0.05) and peak responses of 17-OHP correlated inversely with Kitt values (P < 0.05). No significant differences were noted with ACTH testing. In conclusion, occult biochemical ovarian hyperandrogenism may be uncovered using GnRH-agonist in ovulatory women with ov-PAO, while adrenal responses remain normal. Subtle metabolic abnormalities may also be prevalent.