Assessment of Vascular Endothelium Function Based on the Analysis of Central Arterial Pressure Waveform during Dynamic Exercise
【Supercategory：7. DESCENTE SPORTS SCIENCE Subcategory：7.38 Vol.38】
ABSTRACT
The aim of this study was to investigate the usefulness of the central arterial pressure waveform measured during dynamic exercise in the evaluation of peripheral vasodilatory dysfunction of individuals at the early stage of hypertension. We examined ninety-five volunteers (42±9years) composed of normotensive and untreated hypertensive subjects who had resting blood pressure (BP) ranging from the normal to stage 1 hypertension. They exercised for 10 min on a bicycle ergometer at a heart rate (HR) equal to 50% of their HR reserve. At baseline, immediately (<1min) and 5 min after the dynamic exercise, the peripheral pulse waveforms were recorded by a radial applanation tonometry. Central pressure waveforms were estimated using a generalized transfer function. Pulse pressure (PP) amplification, defined as the ratio of peripheral to central PP, was used as a marker of wave reflection. Endothelium-dependent peripheral vasodilatory response was assessed as flow-mediated dilation of the brachial artery. Compared to the resting state before exercise, the PP amplification significantly increased at the end of exercise, and thereafter it gradually decreased toward the baseline level. Before the exercise, the hypertensive subjects showed the lower PP amplification than normotensive subjects (1.32 vs. 1.46, P<.001), and the differences between groups became more prominent at the end of exercise (1.66 vs. 1.85, P<.001). When the subjects were divided into subgroups according to the tertiles of PP amplification after exercise, the subjects in the bottom tertile showed significantly reduced flow-mediated dilation (7.5±2.5%) than those in the intermediate and top tertiles (9.3±2.6% and 10.9±2.4%, P=.026). Multivariate regression analysis revealed that the low PP amplification (β=0.435, P=.002) was independently associated with the decrease of flow-mediated dilation, independent of age, body mass index, brachial systolic BP, HDL-cholesterol, and HbA1c (R²=.381, P<.001). These results suggest that the response of central arterial pressure waveform during dynamic exercise is associated with peripheral vasodilatory dysfunction and hence may be useful as a marker of subclinical vascular alterations in the early stages of hypertension.
DESCENTE SPORTS SCIENCE Vol.38/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
The aim of this study was to investigate the usefulness of the central arterial pressure waveform measured during dynamic exercise in the evaluation of peripheral vasodilatory dysfunction of individuals at the early stage of hypertension. We examined ninety-five volunteers (42±9years) composed of normotensive and untreated hypertensive subjects who had resting blood pressure (BP) ranging from the normal to stage 1 hypertension. They exercised for 10 min on a bicycle ergometer at a heart rate (HR) equal to 50% of their HR reserve. At baseline, immediately (<1min) and 5 min after the dynamic exercise, the peripheral pulse waveforms were recorded by a radial applanation tonometry. Central pressure waveforms were estimated using a generalized transfer function. Pulse pressure (PP) amplification, defined as the ratio of peripheral to central PP, was used as a marker of wave reflection. Endothelium-dependent peripheral vasodilatory response was assessed as flow-mediated dilation of the brachial artery. Compared to the resting state before exercise, the PP amplification significantly increased at the end of exercise, and thereafter it gradually decreased toward the baseline level. Before the exercise, the hypertensive subjects showed the lower PP amplification than normotensive subjects (1.32 vs. 1.46, P<.001), and the differences between groups became more prominent at the end of exercise (1.66 vs. 1.85, P<.001). When the subjects were divided into subgroups according to the tertiles of PP amplification after exercise, the subjects in the bottom tertile showed significantly reduced flow-mediated dilation (7.5±2.5%) than those in the intermediate and top tertiles (9.3±2.6% and 10.9±2.4%, P=.026). Multivariate regression analysis revealed that the low PP amplification (β=0.435, P=.002) was independently associated with the decrease of flow-mediated dilation, independent of age, body mass index, brachial systolic BP, HDL-cholesterol, and HbA1c (R²=.381, P<.001). These results suggest that the response of central arterial pressure waveform during dynamic exercise is associated with peripheral vasodilatory dysfunction and hence may be useful as a marker of subclinical vascular alterations in the early stages of hypertension.
DESCENTE SPORTS SCIENCE Vol.38/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE
| Researcher | Nobuyuki Miyai*1, Kanae Mure*1, Mikio Arita*1, Kazuhisa Miyashita*1, Kazufumi Terada*2 |
|---|---|
| University or institution | *1 Wakayama Medical University, *2 Tenri University |
Keywords
aortic pressure waveform, endothelial function, exercise test, blood pressure, cardiovascular risk factors