Received July 30, 2014
Accepted October 01, 2014

Objective: It is well defined that ovarian steroids play a role in the cardiovascular system, acting as vasoactive compounds. The aim of this study is to assess the endothelial function during the menstrual cycle using flow-mediated dilation of the brachial artery. Study design: A total of 21 healthy premenopausal women, with regular menstrual cycles, were included in this observational, longitudinal, and prospective study. The endothelium function was assessed by ultrasound during four phases of the menstrual cycle: early follicular phase (EFP), late follicular phase (LFP), early luteal phase (ELP) and late luteal phase (LLP). Results: We observed a significant variation among the vasodilatation response during the menstrual cycle phases (p<0.001). The result was higher during LFP than during ELP (p<0.001) or LLP (p<0.001). Late luteal phase had higher response than observed during ELP (p=0.003) and EFP was higher than LLP (p=0.003). There were no significant differences between the results observed during EFP and LFP (p=1.0), or EFP and ELP (p=0.137). Conclusion: Our results suggest that the ovarian steroids may play an important role in modulating endothelial function.