Context: Metformin administration in women with polycystic ovary syndrome (PCOS) improves hormonal and metabolic patterns with beneficial effects in terms of reproductive outcomes and intermediate cardiovascular disease risk factors. Furthermore, reduced folate and vitamin B12, and increased homocysteine (Hcy) levels have been found in type-2 diabetes mellitus patients treated with metformin.

Objective: To evaluate if metformin administration exerts any effects on Hcy levels, and if folate supplementation may improve endothelial structure and function in PCOS patients.

Fifty patients affected by PCOS without additional metabolic or cardiovascular diseases grouped in two age- and body mass index-matched treatment arms.

Interventions: A six-month course of metformin (1700 mg daily) plus folic acid (400 microgram daily) (experimental group, n=25) or placebo (control group, n=25) supplementation.

In each patient were evaluated: Complete hormonal and metabolic patterns, serum Hcy, folate, vitamin B12, and endothelin-1 (ET-1) concentrations, brachial artery diameter at baseline (BAD-B) and after reactive hyperemia (BAD-RH), flow-mediated dilation (FMD), and intima-media thickness (IMT) on both common carotid arteries.

Inclusion Criteria:

• PCOS

Exclusion Criteria:

• age <18 or >35 years
• BMI >35 kg/m2
• neoplastic, metabolic, hepatic, renal, and cardiovascular disorders
• Current or previous use of oral contraceptives, glucocorticoids, antiandrogens, ovulation induction agents, antidiabetic and anti-obesity drugs or other hormonal drugs.