─122 ─

運動負荷時の中心動脈圧波形の解析に基づく新しい血管内皮機能評価法の確立と評価基準の作成
和歌山県立医科大学

宮 井 信 行（共同研究者） 同牟 礼 佳 苗

同有 田 幹 雄

同宮 下 和 久天理大学

寺 田 和 史Assessment of Vascular Endothelium Function Based on the Analysis ofCentral Arterial Pressure Waveform during Dynamic Exercise

byNobuyuki Miyai, Kanae Mure,

Mikio Arita, Kazuhisa Miyashita
Wakayama Medical UniversityKazufumi TeradaTenri UniversityABSTRACT
The aim of this study was to investigate the usefulness of the central arterialpressure waveform measured during dynamic exercise in the evaluation of peripheralvasodilatory dysfunction of individuals at the early stage of hypertension. We examined
ninety-five volunteers（42±9 years）composed of normotensive and untreatedhypertensive 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 heartrate（HR）equal to 50% of their HR reserve. At baseline, immediately（<1 min）and
5 min after the dynamic exercise, the peripheral pulse waveforms were recorded by
デサントスポーツ科学 Vol. 38─123 ─a radial applanation tonometry. Central pressure waveforms were estimated using ageneralized transfer function. Pulse pressure（PP）ampliﬁcation, deﬁned as the ratioof peripheral to central PP, was used as a marker of wave reflection. Endotheliumdependent 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 thelower PP amplification than normotensive subjects（1.32 vs. 1.46, P<.001），and thedifferences 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 thetertiles of PP amplification after exercise, the subjects in the bottom tertile showedsigniﬁcantly 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 massindex, 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 usefulas a marker of subclinical vascular alterations in the early stages of hypertension.

要 旨た．対象者を負荷終了 5 分後の脈圧比の 3 分位数（tertile）で分類して比較した結果，血管内皮機能

本研究では，運動負荷中の中心動脈圧波形の解の指標の FMD（内皮依存性血管拡張反応）は，析に基づく血管内皮機能の評価法の有効性につ低位群＜中位群＜高位群の順に連続的に高値とないて検討した．対象者は脳 ･ 心血管疾患，糖尿り群間に有意な差が認められた．また，FMD を病，腎疾患の治療歴がなく，血圧が正常域また従属変数とした重回帰分析において，脈圧比は年はⅠ度高血圧にある健康な成人男性 95 名（平均齢，BMI，上腕収縮期圧，HDL コレステロール，年齢 41.9±8.7 歳）であった．運動負荷試験は自HbA1c の補正後も独立の有意な規定因子であっ転車エルゴメーターを使用し，50％の相対心拍数た．以上のことから，運動負荷中また終了後の中に相当する強度で 10 分間の固定負荷運動を行っ心動脈圧波形には，運動誘発性の血管拡張反応がた．負荷試験中は左上腕部より上腕血圧を測定す反映され，その波形変化を解析することで内皮機るとともに，負荷前，終了直後および 5 分後にト能の低下などの早期の血管障害を適切に評価できノメトリ法による橈骨動脈の圧波形の記録を行っることが示唆された．

た．さらに，この波形を一般化伝達関数により大動脈起始部の圧波形に変換して中心血圧を求め，橈骨動脈と中心動脈の脈圧比を反射指数としデサントスポーツ科学 Vol. 38