Insulin, leptin, IGF-I and insulin-dependent protein concentrations after insulin-sensitizing therapy in obese women with polycystic ovary syndrome

Abstract

Objective: To determine the clinical, hormonal and biochemical effect of 4±5 months of insulinsensitizing therapy (hypocaloric diet metformin) in obese patients with polycystic ovary syndrome (PCOS). Design: Prospective study. Methods: Twenty-three obese patients with PCOS, 19 obese patients without menstrual disturbances and 11 healthy control women were recruited from the Department of Endocrinology and Endocrine Gynecology, Medical Academy, Biaøystok, Poland. Obese patients received 500 mg metformin together with hypocaloric diet three times daily for 4±5 months, after baseline study. The clinical parameters, menstrual pattern and serum concentrations of insulin, leptin, IGF-I, insulin-dependent proteins (sex hormone-binding protein (SHBG), insulin-like growth factor-binding protein-1 (IGFBP-1)), gonadotropins and sex steroids were determined before and after treatment. Results: In the baseline study, obese patients with PCOS had significantly higher insulin, testosterone and LH concentrations in comparison with the other groups. The serum leptin, IGF-I, IGFBP-1 and SHBG were not different between the two groups of obese patients, but there was a significant difference in comparison with the control group. After metformin therapy a significant reduction in BMI, % of body fat and leptin concentration were observed in both groups of obese patients. Fasting insulin, testosterone and LH concentrations decreased significantly only in the PCOS group. Six out of 11 patients in the PCOS group had more regular menstrual cycles; two patients conceived. Conclusions: Insulin-sensitizing therapy could be considered as an additional therapeutic option in obese women with PCOS.

Is it Time to Test Metformin in Breast Cancer Clinical Trials?

“…In general, patients present lower levels of IGF binding protein-I, leading to increased ovarian bioavailability of IGF-I. On the basis of these observations, clinical trials have been conducted to assess whether metformin affects IGF pathways or its binding proteins (20)(21)(22)(23). Unfortunately, this issue remains controversial.…”

20 YEARS OF LEPTIN: Role of leptin in human reproductive disorders

“…Studies have been conflicting on whether women with PCOS have higher or similar concentrations of leptin compared with weight-matched controls, but, as expected, leptin concentrations correlate strongly with BMI in both groups (Brzechffa et al 1996, Mantzoros et al 1997b, Kowalska et al 2001, Yildizhan et al 2011. Women with PCOS may actually have higher free concentrations of leptin.…”

“…Leptin concentrations do not seem to correlate with concentrations of LH, testosterone, dehydroepiandrosterone sulfate, and estradiol (Brzechffa et al 1996, Mantzoros et al 1997b, Kowalska et al 2001. Pulses of leptin have been found to synchronized with pulses of LH in patients with PCOS, as they are in regularly menstruating women (Sir-Petermann et al 1999).…”

Medical management of clomiphene-resistant polycystic ovarian syndrome: an update

“…Metformin has a considerable beneficial role in obese PCOS. 17 In a randomized control trial by Batukan et al 4.2% of patients got pregnant at the end of CC cycles and 65.2% of the remaining group got pregnant with metformin plus CC cycles (p=0.0001). 18 Heard et al reported that, metformin alone in patients with PCOS results in a substantial number of pregnancies, with 69% (20/29) of those who ovulated on receiving in less than 6 months.…”