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 insulin-sensitizing 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, Bialystok, 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.