Clomiphene citrate challenge test and serum anti-Müllerian hormone levels in women with menstrual irregularities and/or infertility.

AIM: Evaluation of CCCT results and anti-Müllerian hormone (AMH) plasma levels in women with menstrual cycle irregularities and/or infertility. PATIENTS AND METHODS: 70 patients with menstrual cycle disturbances were recruited to the study. Clomiphene citrate challenge test (CCCT) was carried out in each patient enrolled. At day 3 of the cycle plasma basic levels of FSH, estradiol, progesterone, IGFBP-1, TSH, prolactin, DHEAS and anti-Müllerian hormone were measured. At day 10 of the cycle plasma levels of FSH and estradiol were evaluated. Plasma levels of hormones were measured by commercially available ELISA kits. RESULTS: 50 women with normal result of CCCT (group A) had higher mean plasma level of AMH compared to 20 women with abnormal result of CCCT (group B). Mean plasma FSH level at day 3 of the cycle was lower in group A compared to group B. There were no other statistically significant differences in mean values of assessed parameters between groups A and B. Taking into account all patients enrolled to the study AMH correlated significantly with patients' age and plasma levels of FSH at day 3 and day 10 of the cycle). Basic AMH plasma levels in group A correlated negatively with plasma levels of FSH at day 3 and day 10. In group B plasma levels of FSH at day 10 of the cycle also correlated with basic AMH plasma levels. Plasma levels of estradiol at day 10 of the cycle were related inversely with basic AMH plasma levels in group A, but directly in group B. CONCLUSION: It should be recommended to perform the CCCT before infertility treatment. Evaluation of the anti-Müllerian hormone plasma level reflects the results of the CCCT.

[Molecular action of insulin-sensitizing agents]. / Molekularne podstawy antynowotworowego dzialania uwrazliwiaczy na insuline.

Atypical endometrial hyperplasia has been associated with progression to endometrial cancer, the most common genital malignancy. There are multiple risk factors for endometrial cancer, such as early menarche, exogenous estrogen exposure, obesity and diabetes. Diabetics have a 3-4 fold relative risk of endometrial cancer. Also, several studies have demonstrated an association between insulin resistance and endometrial cancer. There is known the first description of atypical endometrial hyperplasia resistant to progestogen therapy, which was subsequently treated with an insulin-sensitizng agent, metformin. Metformin is a biguanide antihyperglycemic agent used in the treatment of adult-onset diabetes. Unlike the sulfonylureas, metformin does not act primarily by increasing insulin secretion. In contrast, metformin lowers the rate of gluconeogenesis in the presence of insulin. Therefore, it is considered an insulin-sensitizer. Increased insulin sensitivity may improve the metabolic effect of insulin and decrease its mitogenic effect by tissue-specific mechanisms. One explanation for tissue specific differences in insulin binding and action may be through the relative expression of the insulin receptor (IR) isoforms. The IR isoforms IR-A and IR-D differ by 12 amino acid residues, owing to the alternative splicing of exon. The IR-A is predominantly expressed in malignant tissues and may lead to mitogenic effects within the cell. The relative expressions of IR-A and IR-B in normal and malignant endometrial tissue is not known. Besides direct effects on the IR, several additional mechanisms have been proposed for the mitogenic effect of insulin in endometrial cancer. In addition to the possible direct mitogenic effects of insulin through the IR-A, insulin resistance may be associated with alterations in expression of insulin-like growth factors (IGFs) and the IGF binding proteins (IGFBPs) or may inhibit the protective effect of progestagens. Binding sites for IGF-1 and IGF-2 have been confirmed in both normal and malignant endometrium. Binding of IGF-1 is significantly higher in endometrial cancer compared to normal endometrium. In the Ishikawa human endometrial cancer cell line IGF-1 was a more potent mitogen than insulin or IGF-2. Insulin may increase mitogenicity by regulating the expression of IGFBPs. The IGFBPs are a family of proteins that have both proliferative and anti-proliferative effects. While all six high-affinity IGFBPs are expressed in the endometrium, IGFBP-1 is the best characterized. Hyperinsulinemia can decrease IGFBP-1 even in the presence of progesterone, perhaps inhibiting progesterone's protective effects. Interestingly, IGFBP-1 was undetectable or minimally expressed in endometrial cancers. Nestler discussed results of a 6-month treatment of 100 nonebese women with PCOS, which showed a somewhat greater effect of metformin than rosiglitazone and no benefit of administering both agents in combination. Long-term treatment with oral contraceptives decreases endometrial cancer, with a reduction in serum androgens and a decreases in hirsutism and acne, but may worsen insulin resistance and lead to deteriration in glucose tolerance. Insulin sensitizers, on the other hand, should decrease endometrial hyperplasia by inducing regular menses, but may not be as beneficial in improving androgen - related symptoms. Note that the Nurses Health Study (NHS) showed increased risk of diabetes in oral contraceptive users. These considerations may be related to the finding that women who used oral contraceptives have increased risk of myocardial infarction. Thus, in view of the particular increase in CVD risk among women with PCOS, one might be less likely to recommend oral contraceptives, while insulin sensitizers may be of particular benefit, decreasing androgens, improving ovulation and fertility, and reducing the risk of diabetes and CVD. Theoretically, metformin, a treatment which is now widely used to treat infertile women with PCOS, may have a role in preventing endometrial hyperstimulation by lowering insulin concentrations and restoring ovulation. However, the long-term effects of this drug in women with PCOS are not known and more studies are required before suggesting its use for preventing endometrial cancer.