Effects of caloric intake timing on insulin resistance and hyperandrogenism in lean women with polycystic ovary syndrome

Ovulatory and Metabolic Effects of D-chiro-inositol in the Polycystic Ovary Syndrome

Nestler JE et al., 1999 · Obstetrical & Gynecological Survey

Ovulatory and metabolic effects of D-chiro-inositol in the polycystic ovary syndrome

Nestler JE et al., 1999 · N Engl J Med

Women with the polycystic ovary syndrome have insulin resistance and hyperinsulinemia, possibly because of a deficiency of a D-chiro-inositol-containing phosphoglycan that mediates the action of insulin. We hypothesized that the administration of D-chiro-inositol would replenish stores of the mediator and improve insulin sensitivity. We measured steroids in serum and performed oral glucose-tolerance tests before and after the oral administration of 1200 mg of D-chiro-inositol or placebo once daily for six to eight weeks in 44 obese women with the polycystic ovary syndrome. The serum progesterone concentration was measured weekly to monitor for ovulation. In the 22 women given D-chiro-inositol, the mean (+/-SD) area under the plasma insulin curve after the oral administration of glucose decreased from 13,417+/-11,572 to 5158+/-6714 microU per milliliter per minute (81+/-69 to 31+/-40 nmol per liter per minute) (P=0.007; P=0.07 for the comparison of this change with the change in the placebo group); glucose tolerance did not change significantly. The serum free testosterone concentration in these 22 women decreased from 1.1+/-0.8 to 0.5+/-0.5 ng per deciliter (38+/-7 to 17+/-3 pmol per liter) (P=0.006 for the comparison with the change in the placebo group). The women's diastolic and systolic blood pressure decreased by 4 mm Hg (P<0.001 and P=0.05, respectively, for the comparisons with the changes in the placebo group), and their plasma triglyceride concentrations decreased from 184+/-88 to 110+/-61 mg per deciliter (2.1+/-0.2 to 1.2+/-0.1 mmol per liter) (P=0.002 for the comparison with the change in the placebo group). None of these variables changed appreciably in the placebo group. Nineteen of the 22 women who received D-chiro-inositol ovulated, as compared with 6 of the 22 women in the placebo group (P<0.001). D-Chiro-inositol increases the action of insulin in patients with the polycystic ovary syndrome, thereby improving ovulatory function and decreasing serum androgen concentrations, blood pressure, and plasma triglyceride concentrations.

Insulin and hyperandrogenism in women with polycystic ovary syndrome

Baptiste CG et al., 2010 · The Journal of steroid biochemistry and molecular biology · Free full text on PubMed Central

Polycystic ovary syndrome (PCOS) is a very common endocrine disorder characterized by chronic anovulation, clinical and/or biochemical hyperandrogenism, and/or polycystic ovaries. But most experts consider that hyperandrogenism is the main characteristic of PCOS. Several theories propose different mechanisms to explain PCOS manifestations: (1) a primary enzymatic default in the ovarian and/or adrenal steroidogenesis; (2) an impairment in gonadotropin releasing hormone (GnRH) secretion that promotes luteal hormone (LH) secretion; or (3) alterations in insulin actions that lead to insulin resistance with compensatory hyperinsulinemia. However, in the past 20 years there has been growing evidence supporting that defects in insulin actions or in the insulin signalling pathways are central in the pathogenesis of the syndrome. Indeed, most women with PCOS are metabolically insulin resistant, in part due to genetic predisposition and in part secondary to obesity. But some women with typical PCOS do not display insulin resistance, which supports the hypothesis of a genetic predisposition specific to PCOS that would be revealed by the development of insulin resistance and compensatory hyperinsulinemia in most, but not all, women with PCOS. However, these hypotheses are not yet appropriately confirmed, and more research is still needed to unravel the true pathogenesis underlying this syndrome. The present review thus aims at discussing new concepts and findings regarding insulin actions in PCOS women and how it is related to hyperandrogenemia.

Insulin secretion in polycystic ovarian disease: effect of ovarian suppression by GnRH agonist

Lanzone A et al., 1990 · Hum Reprod

Nine obese and ten non-obese women with polycystic ovarian disease (PCO), and seven obese and eight non-obese normal women, had an oral glucose tolerance test (OGTT) before and after treatment with GnRH agonist (buserelin 400 micrograms/day s.c. for 8 weeks) in order to investigate the effect of ovarian suppression on their insulinaemic secretion. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), oestradiol (E2), androstenedione (A), testosterone (T), DHEAS, cortisol and insulin (I) were measured at time 0 of OGTT; in all samples of OGTT, E2, T, A and I were also assayed. PCO patients showed higher basal androgen levels than control patients. All subjects showed a normal glycaemic response to OGTT. The mean fasting and areas under the curve (ISA) of plasma I were significantly greater in the obese PCO women than in non-obese PCO, the normal obese and non-obese women. All PCO patients showed significantly higher fasting I and ISA values in respect to all control patients. Hyperinsulinaemic responses were 89% in PCO obese, 30% in non-obese PCO and 29% in obese control patients. After buserelin treatment, these values did not change significantly in respect to pretreatment in all groups, in spite of a significant decrease of androgen secretion. During OGTT, no variations of steroid plasma concentrations were seen in both normal or hyperinsulinaemic PCO patients. The data of this study show that hyperandrogenism, hyperinsulinism and obesity were associated with different modalities in PCO patients and that a marked decrease of androgen secretion did not restore a normal insulinaemic response to OGTT, suggesting that hyperandrogenism does not produce hyperinsulinism.

Insulin-lowering treatment reduces aromatase activity in response to follicle-stimulating hormone in women with polycystic ovary syndrome

la Marca A et al., 2002 · Fertil Steril

To investigate the effects of reduction of insulin resistance and hyperinsulinemia associated with the polycystic ovary syndrome (PCOS) on FSH-stimulated ovarian aromatase activity. Prospective study. Academic health center, Siena, Italy. PATIENT(S): Twenty women 18 to 26 years of age in whom PCOS was diagnosed on the basis of oligomenorrhea or amenorrhea and hyperandrogenemia. INTERVENTION(S): Recombinant FSH was administered. The next day, therapy with metformin (500 mg t.i.d.) was begun. After 35 to 40 days of treatment, the pretreatment protocol was repeated. MAIN OUTCOME MEASURE(S): Plasma levels of estradiol (E(2)), androstenedione (A), and testosterone (T). The ratios of basal levels and areas under the curve (AUCs) of products and substrates were compared before and after metformin administration to detect differences in aromatase activity. RESULT(S): Metformin treatment was associated with significant reduction in basal free testosterone plasma levels, insulin plasma levels, and insulin response to oral glucose tolerance testing. Administration of FSH was followed by a significantly lesser E(2) response after metformin therapy than before this therapy. The ratios of AUC(E2) to AUC(A) and to AUC(T), indicative of aromatase activity in response to FSH, were significantly lower after metformin therapy than before. CONCLUSION(S): Metformin therapy in women with PCOS is associated with a reduction in aromatase activity in response to FSH. Insulin affects production of both androgen and estrogen. Insulin therefore plays a central role in regulating the activity of thecal and granulosa cells.

Hormonal Profile and Anthropometric Indices As Determinants of Metabolic Risk in Polycystic Ovary Syndrome: A Prospective Observational Study

Napolean N et al., 2026 · Cureus · Free full text on PubMed Central

Background Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine-metabolic disorder characterized by reproductive, hormonal, and metabolic disturbances. This study aimed to evaluate the association between clinical features, anthropometric indices, hormonal parameters, metabolic profile, ultrasonographic findings, and the second-to-fourth digit (2D:4D) ratio in women with PCOS compared to age-matched healthy controls. Methods A case-control study was conducted, including women diagnosed with PCOS and age-matched healthy controls. Clinical features, anthropometric measurements (BMI, waist-hip ratio (WHR), waist-height ratio (WHtR)), hormonal parameters (luteinizing hormone (LH), follicle-stimulating hormone (FSH), anti-Müllerian hormone (AMH)), metabolic variables (fasting glucose, lipid profile), ultrasonographic findings, and 2D:4D digit ratio were assessed. Statistical analysis was performed using appropriate tests, and a p-value < 0.05 was considered statistically significant. Results Women with PCOS exhibited a significantly higher prevalence of menstrual irregularity, polycystic ovarian morphology, hirsutism, and acne (p < 0.001). Hormonal analysis showed significantly elevated LH, FSH, and AMH levels in PCOS cases (p < 0.001). Anthropometric indices, including BMI, WHR, and WHtR, were significantly higher among PCOS cases (p < 0.01), indicating increased general and central adiposity. In contrast, fasting glucose and lipid profile levels did not differ significantly between groups. Additionally, the 2D:4D ratio was significantly lower in PCOS cases (p < 0.01) and showed significant negative correlations with BMI, WHR, WHtR, and cholesterol levels. Conclusion The study demonstrates that PCOS is associated with significant hormonal dysregulation, central obesity, and early metabolic alterations. The lower 2D:4D ratio observed in PCOS supports the role of prenatal androgen exposure in disease pathogenesis. These findings highlight the complex interplay between developmental, metabolic, and endocrine factors in PCOS and underscore the importance of early identification and comprehensive management strategies.