Abstract 176: The Effects of Age, Menopause, and Body Mass Index on Blood Pressure and Radial Pulse Wave in Women

Age, gender, and body mass index (BMI) play an important roles in cardiovascular risk. However, the independent effects of menopause on the ventricular-arterial system in female individuals have not been fully investigated. Thus, this study aimed to assess the effect of age, menopause and body mass index on different hemodynamic parameters including systolic blood pressure (SBP), diastolic blood pressure (DBP) and harmonics of radial pulse wave. This study enrolled 327 female subjects(230 pre-menopausal and 97 post-menopausal), aged 20-87 and without cardiovascular history. SBP and DBP were evaluated by an automatic blood pressure monitor. A 12-second continuous radial pulse data was recorded using medical grade pulse measuring instrument and standard protocol. Spectrum analysis of radial pressure wave was calculated and transformed into first five harmonic amplitudes(C1~C5). We further performed multivariable linear regression models to assess the independent effects of age, menopause, and body mass index on SBP, DBP, and C1 to C5 respectively. The mean age, BMI, SBP, and DBP in enrolled subjects were 43±13 yeas, 23±4 kg/m 2 , 116±16 mmHg, and 69±11 mmHg. Regression analysis demonstrated that age was positively correlated with SBP(P<0.001), whereas effect of age exerted no significant influence on DBP. BMI had positive associations with SBP and DBP(P<0.001), while menopause had no significant effect on neither SBP nor DBP. Multivariable linear regression showed that menopause had significant effects on C1 (P<0.05) and C3 (P<0.05). C1 is associated with atherosclerosis and is an independent risk predictor for adverse cardiac events. We proposed that an increase in cardiovascular risk during menopause may be due to hormonal changes exacerbating the progression of atherosclerosis and reflected in the radial pulse spectrum. Conclusively, this study demonstrates that age and BMI have an independent effect on SBP, whereas menopause has no significant independent effect on SBP. The effects of menopause on C1 and C3, independent of age and BMI, may partially explain the reasons of dramatically increased cardiovascular risk during menopause and provide clues to the underlying mechanisms of the change in cardiovascular system.