Endocrine Abstracts

Introduction: Polycystic ovary syndrome (PCOS) is associated with known cardiovascular risk factors, consequently predisposing to premature cardiovascular disease. Blood clot structure has been shown to predict predisposition to atherothrombosis and the aim of this study was to investigate the effects of rimonabant and metformin on clot structure/function in women with PCOS.

Methods: Twenty women with PCOS were recruited in a randomised open labelled parallel study of metformin (1.5 g/day) and rimonabant (20 mg daily) treatment for 3 months. After this period all individuals received metformin treatment for another 3 months. Clot structure and fibrinolysis was investigated ex vivo using a validated turbidimetric assay. Maximum absorbance (MA), a measure of clot density, and time from full clot formation to 50% lysis (LT), an indicator of fibrinolysis potential, were subsequently calculated.

Results: Treatment with metformin or rimonabant for 3 months had no significant effect on clot MA. However, metformin reduced LT from 2450±469 to 1678±425 s (P=0.01) at 3 months, whereas rimonabant had no effect. Switching all patients to metformin had no effect on MA but there was a non-significant decrease in lysis time in the group previously treated with rimonobant from 1925±711 to 789±41 s (P=0.1), whereas a further decrease in LT to 668±39 s (P<0.01) was observed in the group initially treated with metformin.

Conclusion: This study demonstrates that metformin use in PCOS is associated with a favourable effect on clot lysis, which is evident 3 months after initiation of treatment and becomes more pronounced at 6 months. In contrast, rimonabant treatment for 3 months has no significant effect on clot structure or fibrinolysis. These preliminary data suggest that metformin reduces thrombosis risk in PCOS and future clinical studies are warranted to clarify the potential cardioprotective role of metformin in women with this condition.