Elevated Central Arterial Stiffness In Normotensive Postmenopausal Women

Abstract

Arterial stiffness of central elastic arteries increases with age and is a predictor of cardiovascular risk. This is associated with age-related increases in systolic and pulse blood pressure which are also independent predictors of cardiovascular risk in individuals after the fifth decade of life. However, little is known about relationship between agerelated changes in brachial and aortic blood pressure, and central arterial stiffness in postmenopausal women (PMW). PURPOSE To determine if there is an age-related difference between brachial blood pressure, aortic blood pressure, and central arterial stiffness in young and PMW women. METHODS Fifteen sedentary, normotensive PMW (age 57 ± 5 years; BP <140/90 mmHg) not taking hormone replacement therapy, and 15 young normotensive women (YW; age 24 ± 4 years) were studied. High-fidelity radial artery pressure waveforms were recorded non-invasively by applanation tonometry and ascending aortic pressure waveforms were generated using a generalized transfer function (Sphygmocor® system). Brachial blood pressure was assessed in triplicate using standardized oscillometric sphygmomanometer techniques and was used to calibrate the radial artery waveform. RESULTS There were no significant differences (p ≥ 0.05) between PMW and YW in brachial systolic, diastolic, mean, or pulse pressure as assessed by standard sphygmomanometry. However, central aortic systolic pressure (114 ± 8 vs. 102 ± 10 mmHg, p ≤ 0.01) and aortic pulse pressure (37 ± 7 vs. 27 ± 6 mmHg, p ≤ 0.001) were significantly greater in PMW when compared to YW. In addition, augmentation index corrected to a heart rate of 75 beats/min was significantly greater in PMW than YW (27 ± 10 vs. 5 ± 11 %, p ≤ 0.001, respectively), and duration of the reflected pressure wave from the periphery and back to the aorta was significantly shorter in PMW than YW (140 ± 11 vs. 151 ± 13 ms, p ≤ 0.05, respectively). CONCLUSIONS PMW had increased aortic systolic pressure, aortic pulse pressure, aortic augmentation index, and reduced total travel time of the reflected wave compared to YW, despite similar normotensive blood pressure in the brachial artery. The data suggests that central arterial stiffness is increased in PMW, but this age-related change is not detected by standard brachial sphygmomanometer assessment.