July - September 2014, Volume 10, Issue 3

Surcel M, Stamatian F

The Follicular IGFBP Changes after Metformine Administration in Polycystic Ovary Syndrome and its Impact on the Fertility Rate. A randomized Study

Acta Endo (Buc) 2014, 10 (3): 383-395
doi: 10.4183/aeb.2014.383

Background. Polycystic ovarian syndrome (PCOS) involves various changes within folliculogenesis. Aside from its systemic action, metformin seems to exert a local direct effect independent of insulinemia. The IGF system appears to be an important local target for metformin although the evidence we possess is circumstantial. Objective. The aim of this study was to evaluate the impact of metformin on insulin growth factor (IGF) system proteins and steroids production in PCOS patients and to analyze potential involvement in oocyte quality. Material and methods. This prospective study was performed on 86 in vitro fertilization (IVF) patients who were categorized into three groups as follows: Group 1 formed of PCOS patients who received metformin (n=27); Group 2 with PCOS patients who did not receive metformin (n=29) and Group 3 with controls (n=30). Interventions. Interventions included controlled ovarian stimulation for IVF and metformin (at least 16 weeks prior to the time of ovarian puncture). Main Outcome Measures.Follicular fluid analysis was performed using radioimmunoassay with specific kits (estradiol, testosterone, progesterone, IGF I, IGF II, IGF binding protein 1 - IGFBP1, IGFBP2, IGFBP3, IGFBP4). Results. Important differences were measured for the three types of steroids among the three studied groups (PCOS treated, PCOS not treated, controls) estradiol (538 vs. 466 vs. 688 ng/mL p < 0.0001), testosterone (6.7 vs. 7.6 vs. 5.1 ng/mL p<0.01), progesterone (8899 vs. 7878 vs. 9755 pg/mL p<0.0001) while for IGF system proteins important differences were noted only regarding IGFBP1 (114 vs. 107 vs. 121 p<0.002) IGFBP2 (263 vs. 268 vs. 252 ng/mL p<0.04), and IGFBP4 (128 vs. 138 vs. 118 p<0001). Correlations were also established between fertilization rate and estradiol (R: 0.53 p<0.5), testosterone (R: -0.39 p<0.05), IGFBP1 (R: 0.48 p< 0.05), IGFBP4 (R: 0.39, p<0.05). Conclusions. Patients with PCOS and hyperinsulinemia have the greatest benefit from metformin treatment. However, metformin action surpasses correction of systemic differences having a direct action at the level of follicular structures. Alteration of IGF system proteins does not concern only hyperinsulinic patients and can be partially amended by metformin administration.

Keywords: PCOS, metformin, IGF

Correspondence: Mihai Surcel MD, UMF Cluj-Napoca, Clinicilor nr 3, Cluj-Napoca, 400006, Romania, E-mail: Mihai_Surcel@yahoo.com