Myo-inositol modulates insulin and luteinizing hormone secretion in normal weight patients with polycystic ovary syndrome.

AIM: To investigate hormonal dynamics in a group of non-obese polycystic ovary syndrome (PCOS) patients under myo-inositol (MYO) administration. METHODS: Hormonal profiles, insulin response to oral glucose tolerance test (OGTT) and luteinizing hormone (LH) response to gonadotropin-releasing hormone (GnRH) stimulation test before and after the administration of a preparation of MYO (3 g p.o. daily) mixed with lactoferrin and bromelin, in a group (n = 24) of normal weight PCOS patients. RESULTS: After the treatment interval, body mass index (BMI) did not change while LH, LH/follicle-stimulating hormone, 17-hydroxy-progesterone and androstenedione decreased significantly. Insulin response to OGTT was significantly reduced after the treatment interval (P < 0.05) as well as GnRH-induced LH response (P < 0.05). High-sensitivity C-reactive protein decreased significantly after the treatment interval. CONCLUSION: MYO administration positively modulates insulin sensitivity in non-obese PCOS patients without compensatory hyperinsulinemia, improving hormonal parameters. The presence of bromelin in the formulation modulated the pro-inflammatory state that characterizes PCOS, independently of BMI.

Differential insulin response to myo-inositol administration in obese polycystic ovary syndrome patients.

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, chronic anovulation, polycystic ovaries at ultrasound evaluation, and quite frequently by insulin resistance or compensatory hyperinsulinemia. Attention has been given to the role of inositol-phosphoglycan (IPG) mediators of insulin action and growing evidences suggest that a deficiency of D-chiro-inositol (DCI) containing IPG might be at the basis of insulin resistance, frequent in PCOS patients. On such basis, we investigated the efficacy on insulin sensitivity and hormonal parameters of 8 weeks treatment with myo-inositol (MYO) (Inofert, ItalPharmaco, Milano, Italy) at the dosage of 2 g day in a group (n = 42) of obese PCOS patients,. After the treatment interval body mass index (BMI) and insulin resistance decreased together with luteinizing hormone (LH), LH/FSH and insulin. When subdividing the patients according to their fasting insulin levels, Group A (n = 15) insulin below 12 µU/ml and Group B (n = 27) insulin above 12 µU/ml, MYO treatment induced similar changes in both groups but only patients of Group B showed the significant decrease of both fasting insulin plasma levels (from 20.3 ± 1.8 to 12.9 ± 1.8 µU/ml, p < 0.00001) and of area under the curve (AUC) of insulin under oral glucose tolerance test (OGTT). In conclusion, our study supports the hypothesis that MYO administration is more effective in obese patients with high fasting insulin plasma levels.

Estimation of instantaneous secretory rates and intrinsic characteristics of luteinizing hormone secretion in women with Kallmann syndrome before and after estriol administration.

Three Kallmann syndrome (KS) patients were examined to assess characteristics of LH response to GnRH bolus, with and without GnRH sensitization using Instantaneous Secretory Rate (ISR) computation before and after estriol treatment (60 days, 2 mg/day). Six healthy women were enrolled as controls and underwent GnRH bolus during the early follicular phase (days 3-5 of the menstrual cycle). After estriol treatment, the KS patients showed a higher LH response to GnRH bolus and similar LH pulse duration to healthy controls. These data support the hypothesis that the administration of weak estrogen improves LH response to GnRH in hypogonadotropic women with KS.