Open AccessMorning attenuation of endothelium‐dependent, flow‐mediated dilation in healthy young men: Possible connection to morning peak of cardiac events?
Author(s) -
Etsuda Hirokuni,
Takase Bonpei,
Kusano Hiroyuki,
Hamabe Akira,
Kuhara Ryoji,
Akima Takashi,
Matsushima Yoshihiro,
Arakawa Koh,
Satomura Kimio,
Ohsuzu Fumitaka,
Kurita Akira,
Uehata Akimi
Publication year - 1999
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.4960220610
Subject(s) - medicine , morning , brachial artery , reactive hyperemia , circadian rhythm , cardiology , endothelium , endothelial dysfunction , diurnal temperature variation , blood flow , blood pressure , atmospheric sciences , geology
Abstract Background and hypothesis : Brachial artery flow‐mediated dilation (FMD), a noninvasive, widely used clinical index of endothelial function and magnitude of FMD, has been reported to be closely related to many coronary risk factors and coronary atherosclerosis. However, there has been no study that examines the diurnal change of FMD. We designed this study to reveal the diurnal variation of FMD in healthy volunteers. Methods : We examined FMD in response to reactive hyperemia by high resolution ultrasound in 13 healthy young men (age 25–32) at four different times over the course of a day. Results : Mean measures of brachial artery FMD was 4.0% at 8:00, 5.3% at 12:00, 9.7% at 17:00, and 6.9% at 21:00 hours. Flow‐mediated dilation at 8:00 and at 12:00 hours was significantly lower than that at 17:00 (p <0.05). Conclusions : These results show that endothelial function has diurnal variation and is significantly attenuated in the morning. Morning attenuation of endothelial function should be recognized in clinical research and may play an important role in the circadian variation of the occurrence of acute cardiovascular events.