Metformin improves endothelial function and carotid intima media thickness in patients with PCOS

Objective: Oral contraceptive pills (OCP) are widely used for treating women with polycystic ovary syndrome (PCOS). Metformin has beneficial effects on insulin resistance and endothelial functions. The aim of this study was to investigate the effects of treatment with drospirenone/ethinyl estradiol (EE) alone or in combination with metformin on the flow-mediated vasodilatation (FMD) and carotid intima media thickness (CIMT) in women with PCOS. Methods: Fifty women with PCOS (mean age 23 +/- 5) were randomized to oral treatment of OCP alone (n=25) or an OCP combination with metformin (n=25) for 6 months. FMD from the brachial artery and CIMT were calculated. The hormonal profile, HOMA-IR score, basal insulin and glucose levels were studied in both groups. Before and after 6 months' treatment, echocardiographic measurements and laboratory tests were also obtained. Results: After 6 months' treatment we observed a small decrease in FMD in the OCP group (14.9 +/- 9.4 versus 14.4 +/- 9.9, p=0.801) and a slight increase in the combination group (14.5 +/- 9.1 versus 15.0 +/- 8.0, p=0.715) but neither of them reached significance. CIMT increased in the OCP group (0.048 +/- 0.011 to 0.050 +/- 0.010 cm, p=0.433) and decreased slightly in the combination group (0.049 +/- 0.012, 0.048 +/- 0.011 cm, p=0.833). Conclusion: We demonstrated that adding metformin to OCP treatment may have beneficial effect on FMD and CIMT that represent vascular function in patients with PCOS. These results suggest that adding metformin to OCP treatment for PCOS could preserve the cardiovascular system and improve it.