Decreased large-artery stiffness in midluteal phase of the menstrual cycle in healthy women of reproductive age

Objectives: Sex hormones are specific factors contributing to the regulation of cardiovascular system. Studies on the effects of hormonal fluctuations during the menstrual cycle on hemodynamics and arterial stiffness in young women are limited and provide conflicting results. Aim: The aim of the study was to assess arterial stiffness, peripheral/central blood (pBP and cBP) and pulse (pPP and cPP) pressures throughout the single, natural menstrual cycle (early follicular [EFP], late follicular [LFP] and midluteal [LP] phase). Materials and methods: Forty two healthy, regularly menstruating women (28.6 +/- 5.1 yrs of age; BMI 22.0 +/- 3.5 kg/m(2)) were evaluated during EFP (Estradiol [E], FSH, LH, PRL, TSH, Testosterone [T], DHEAS, and SHBG), LFP (E, FSH, LH) and LP (Progesterone, E, FSH, LH). Transvaginal ultrasound was performed to confirm ovulatory cycle. Resting radial and aortic BP were assessed noninvasively and continuously using tonometric measurement of peripheral PP wave-PPW (Colin BMP7000, Japan) and on-line reconstruction of central PPW (Sphygmocor Mx, Australia) at EFP, LFP and LP. ANOVA and Friedman test were used in statistical analysis. Results: There were no significant differences in systolic/diastolic BP and PP both at the periphery and at ascending aorta throughout the menstrual cycle. Comparable observations of no interphasal differences were noted for peripheral Augmentation Index (AI). Central AI and augmentation pressure (AP) were significantly lower in LP than in LFP (by 4%; p<0.05 and by 37%; p<0.05, respectively). Conclusions: We demonstrated significant differences in mechanical properties of large arteries at the midluteal phase of natural menstrual cycle. We conclude that sex hormones may play role in the regulation of arterial stiffness in the reproductive age women.