Assessment of Vascular Function throughout the Menstrual Cycle

Abstract

BACKGROUND: Fluctuating sex hormones throughout the menstrual cycle, particularly endogenous estrogen, have been documented to correspond with nitric oxide (NO) bioavailability and likely have a cardioprotective effect in premenopausal women. However, the corresponding temporal changes in vascular function are not entirely understood. METHODS: Passive leg movement (PLM) is a relatively novel technique assessing NO-mediated vascular function, with a higher degree of NO-dependence than the traditionally used flow-mediated dilation (FMD) technique that could provide additional insight. PURPOSE: To assess vascular function throughout the menstrual cycle in premenopausal women using PLM, in addition to FMD. RESULTS: Brachial artery FMD tended to be increased during the OV phase (8.8±1%) compared to the EF (7.8±1%) and ML (7.6±1%) phases. The femoral artery PLM AUC response during the ML phase was significantly lower than the EF response (leg blood flow AUC EF: 154±41 mL, OV: 79±24 mL, and ML: 44±15 mL). CONCLUSION: These findings support the importance of menstrual cycle when interpreting vascular function data as measured by FMD and PLM.