Efecto de la metformina sobre la resistencia insulínica en mujeres obesas y obesas hiperandrogénicas / Effects of metformin on insulin resistance in obese and hyperandrogenic women

Background: Metformin is a biguanide often used in obese diabetics that improves tissue sensitivity to insulin. Aim:To assess the effects of metformin on tissue insulin sensitivity in obese and byperandrogenic women. Patients and methods: Eight obese and eight obese and eight and hyperandrogenic women received metformin 850 mg orally during 12 weeks. Before and at the end of the treatment period, an insulin tolerance test to measure insulin sensitivity was performed and blood was drawn to measure sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS), testosterone, triglycerides, total and HDL cholesterol. The free androgen index was calculated for each sample. Results: After metformin treatment, the insulin sensitivity index improved from 0.38 (0.05-0.5) to 0.43 (0.25-0.59) in obese and hyperandrogenic women. SHBG increased and total cholesterol and triglycerides decreased significantly in both groups. No other significant changes were observed. Conclusions: Metformin has a favorable effect on tissue sensitivity to insulin, SHBG and serum lipids in obese and hyperandrogenic women

Marcadores bioquímicos y métodos de cuantificación de insulinorresistencia en mujeres normales, obesas e hiperandrogénicas / Biochemical markers and methods to assess insulin resistance in normal, obese and hyperandrogenic women

Six normal, 6 obese and 12 hyperandrogenic women of similar ages, were studied. In two consecutive days, the ITT and the IVGTT were performed and a basal blood sample was obtained to measure SHBG, DHEAS and IGFBP-1. Insulin sensitivity was calculated as the blood glucose slope in the ITT and with the minimal model of Bergman in the IVGTT. Insulin sensitivity, measure with ITT was 0.58 (0.53-0.63) in normal, 0.38(0.05-0.59) in obese and 0.20(0.0-0.36) in hyperandrogenic women. The figures for the IVGTT were 7.97(4.1-15.4), 2.41 )0.81-4.89) and 1.1 (0.46-1.88), respectively. Both methods had a positive correlation coefficient of 0.792 (p 0.09). IGFBP-1 values were 3.0, 2.1 and 1.6 ng/ml respectively (p 0.05). DHEAS values were 132, 190 and 206 ug/dl, respectively (ND). ITT is a sample and reliable method to asses insulin sensitivity. SHBG discriminates subjects with different levels of insulin sensitivity