Effects of metformin and rosiglitazone, alone and in combination, in nonobese women with polycystic ovary syndrome and normal indices of insulin sensitivity.

OBJECTIVE: To determine whether insulin-sensitizing drugs would improve ovulation and T levels in women with polycystic ovary syndrome (PCOS), without clinical or biochemical criteria indicating insulin resistance and whether the combination of two distinct insulin-sensitizing drugs would be of any benefit over either drug alone. DESIGN: Randomized controlled double-blind trial. SETTING: A referral center in Caracas, Venezuela. PATIENT(S): One hundred twenty-eight nonobese PCOS women with normal indices of insulin sensitivity-that is, normal glucose tolerance, fasting insulin, peak insulin during an oral glucose tolerance test (OGTT), and fasting glucose-to-insulin ratio. Twenty-eight women were lost to follow-up initially and did not receive any intervention. INTERVENTION(S): One hundred women received twice daily one of the following for 6 months: metformin (850 mg), rosiglitazone (4 mg), combination of both drugs, or at least one placebo. MAIN OUTCOME MEASURE(S): Frequencies of ovulation and serum free T after 6 months. RESULT(S): Frequencies of ovulation were higher after treatment with an insulin-sensitizing drug (ovulations per subject in 6 months: metformin, 3.3; rosiglitazone, 2.4; and combination, 3.4) than with placebo (0.4). Ovulatory frequencies increased significantly more with metformin than rosiglitazone, and the combination was not more potent. After treatment, serum free-T levels were comparable among all active treatment groups (metformin: 2.34 pg/mL, rosiglitazone: 3.06 pg/mL, and combination: 2.39 pg/mL) and were significantly lower than in the placebo group (7.26 pg/mL). Compared with placebo, fasting insulin levels, area under the insulin curve during OGTT, the homeostatic model assessment of insulin sensitivity, and OGTT-derived insulin sensitivity index improved significantly after metformin or combination therapies but not after rosiglitazone. CONCLUSION(S): These findings suggest that insulin-sensitizing drugs increase ovulatory frequency and ameliorate hyperandrogenemia, even in nonobese women with PCOS who appear to have normal insulin sensitivity.

Reduced serum glycodelin and insulin-like growth factor-binding protein-1 in women with polycystic ovary syndrome during first trimester of pregnancy.

The polycystic ovary syndrome (PCOS) is associated with an increased rate of early pregnancy loss (EPL). Hyperinsulinemia is an independent risk factor for EPL and has been found to decrease levels of glycodelin and IGF binding protein-1 (IGFBP-1), two major endometrial proteins. We hypothesized that serum glycodelin IGFBP-1 concentrations would be reduced in women with PCOS during the first trimester of pregnancy. Fasting serum insulin, glycodelin, and IGFBP-1 were measured, and oral glucose tolerance tests were performed in 72 women with PCOS and 62 normal women. Each woman was seen once and assigned to one of three gestational groups: wk 3-5, 6-8, and 9-11. The insulin sensitivity index during oral glucose tolerance test was lower in women with PCOS compared with normal women throughout the first trimester (P < 0.0001). Both serum glycodelin and IGFBP-1 were markedly lower in women with PCOS (for glycodelin: wk 3-5, P < 0.0001; wk 6-8, P = 0.03; wk 9-11, P = 0.19; and for IGFBP-1: wk 3-5 and 6-8, P < 0.0001; wk 9-11, P = 0.0003). Comparing women with PCOS who experienced EPL with those who did not, serum glycodelin was significantly lower during wk 3-8 (P < 0.02) and serum IGFBP-1 during wk 9-11 (P = 0.003). During the first trimester, serum glycodelin and IGFBP-1 concentrations are markedly decreased in PCOS, implicating endometrial epithelial and stromal dysfunction during periimplantation and early pregnancy as a possible mechanism for EPL in PCOS. These decreases are likely to be secondary to hyperinsulinemia and reduced insulin sensitivity.

Metformin therapy increases insulin-stimulated release of D-chiro-inositol-containing inositolphosphoglycan mediator in women with polycystic ovary syndrome.

Some actions of insulin are mediated by putative inositolphosphoglycan mediators, and a deficiency in D-chiro-inositol-containing inositolphosphoglycan (DCI-IPG) may contribute to insulin resistance in women with polycystic ovary syndrome (PCOS). Furthermore, similar effects of DCI and metformin, an insulin-sensitizing drug, have been demonstrated in PCOS women. To determine whether metformin improves insulin actions by increasing biologically active DCI-IPG in women with PCOS, we analyzed DCI-IPG during an oral glucose tolerance test in 19 obese women with PCOS before and after 4-8 wk of metformin or placebo. After treatment, the mean (+/-SE) area under the curve (AUC) during the oral glucose tolerance test of insulin (AUC(insulin)) decreased significantly more in the metformin group, compared with the placebo group [-3574 +/- 962 vs. +1367 +/- 1021 micro IU/min.ml (-26 +/- 7 vs. +10 +/- 7 nmol/min.liter), P = 0.003], but the AUC of DCI-IPG (AUC(DCI-IPG)) decreased similarly in both groups (-1452 +/- 968 vs. -2207 +/- 1021%/min, P = 0.60). However, the ratio of AUC(DCI-IPG)/AUC(insulin) increased by 160% after metformin and decreased by 29% after placebo (P = 0.002 between groups). Moreover, metformin seemed to improve the positive correlation between AUC(DCI-IPG) and AUC(insulin) but not placebo (r = 0.32, P = 0.68 at baseline; r = 0.52, P = 0.12 after metformin; and r = -0.39, P = 0.30 after placebo). We conclude that in obese women with PCOS, metformin may improve the action of insulin in part by improving insulin-mediated release of DCI-IPG mediators, as evidenced by increased bioactive DCI-IPG released per unit of insulin.

Strategies for the use of insulin-sensitizing drugs to treat infertility in women with polycystic ovary syndrome.

OBJECTIVE: Insulin resistance and its compensatory hyperinsulinemia play a key pathogenic role in the infertility of the polycystic ovary syndrome. Numerous studies indicate that insulin-sensitizing drugs can be used to enhance spontaneous ovulation and the induction of ovulation in the syndrome. The aim of this review is to summarize the studies in which insulin-sensitizing drugs were used to increase ovulation rate or improve fertility in women with the PCOS and to translate the information into practical guidelines for the use of these drugs by reproductive endocrinologists. DESIGN: Review and critique of studies in which an insulin-sensitizing drug was used to increase ovulation rate or improve infertility in women with the polycystic ovary syndrome. MAIN OUTCOME MEASURE(S): Ovulation rate and pregnancy rate. RESULT(S): Studies have demonstrated that insulin-sensitizing drugs can increase spontaneous ovulation, enhance the induction of ovulation with clomiphene citrate, and increase clinical pregnancy rates. CONCLUSION(S): An algorithmic approach is provided for the use of insulin-sensitizing drugs to treat the anovulation and infertility of women with the polycystic ovary syndrome.

Effects of metformin on early pregnancy loss in the polycystic ovary syndrome.

Polycystic ovary syndrome is the most common form of female infertility in the United States. In addition to poor conception rates, pregnancy loss rates are high (30-50%) during the first trimester. We hypothesized that hyperinsulinemic insulin resistance contributes to early pregnancy loss in the syndrome, and that decreasing hyperinsulinemic insulin resistance with metformin during pregnancy would reduce the rate of early pregnancy loss. We conducted a retrospective study of all women with polycystic ovary syndrome who were seen in an academic endocrinology clinic within the past 4.5 yr and who became pregnant during that time. Sixty-five women received metformin during pregnancy (metformin group) and 31women did not (control group). The early pregnancy loss rate in the metformin group was 8.8% (6 of 68 pregnancies), as compared with 41.9% (13 of 31 pregnancies) in the control group (P < 0.001). In the subset of women in each group with a prior history of miscarriage, the early pregnancy loss rate was 11.1% (4 of 36 pregnancies) in the metformin group, as compared with 58.3% (7 of 12 pregnancies) in the control group (P = 0.002). Metformin administration during pregnancy reduces first-trimester pregnancy loss in women with the polycystic ovary syndrome.

Effects of d-chiro-inositol in lean women with the polycystic ovary syndrome.

OBJECTIVE: To determine whether the administration of D-chiro-inositol, a putative insulin-sensitizing drug, would affect the concentration of circulating insulin, the levels of serum androgens, and the frequency of ovulation in lean women with the polycystic ovary syndrome. METHODS: In 20 lean women (body mass index, 20.0 to 24.4 kg/m 2) who had the polycystic ovary syndrome, treatment was initiated with either 600 mg of D-chiro-inositol or placebo orally once daily for 6 to 8 weeks. We performed oral glucose tolerance tests and measured serum sex steroids before and after therapy. To monitor for ovulation, we determined serum progesterone concentrations weekly. RESULTS: In the 10 women given D-chiro-inositol, the mean (+/- standard error) area under the plasma insulin curve after oral administration of glucose decreased significantly from 8,343 +/- 1,149 mU/mL per min to 5,335 +/- 1,792 mU/mL per min in comparison with no significant change in the placebo group (P = 0.03 for difference between groups). Concomitantly, the serum free testosterone concentration decreased by 73% from 0.83 +/- 0.11 ng/dL to 0.22 +/- 0.03 ng/dL, a significant change in comparison with essentially no change in the placebo group (P = 0.01). Six of the 10 women (60%) in the D-chiro-inositol group ovulated in comparison with 2 of the 10 women (20%) in the placebo group (P = 0.17). Systolic (P = 0.002) and diastolic (P = 0.001) blood pressures, as well as plasma triglyceride concentrations (P = 0.001), decreased significantly in the D-chiro-inositol group in comparison with the placebo group, in which these variables either increased (blood pressure) or decreased minimally (triglycerides). CONCLUSION: We conclude that, in lean women with the polycystic ovary syndrome, D-chiro-inositol reduces circulating insulin, decreases serum androgens, and ameliorates some of the metabolic abnormalities (increased blood pressure and hypertriglyceridemia) of syndrome X.