Effect of caffeine contained in a cup of coffee on microvascular function in healthy subjects.
Recent epidemiological studies have demonstrated that coffee drinking is associated with reduced mortality of cardiovascular disease. However, its precise mechanisms remain to be clarified. In this study, we examined whether single ingestion of caffeine contained in a cup of coffee improves microvascular function in healthy subjects. A double-blind, placebo-controlled, crossover study was performed in 27 healthy volunteers. A cup of either caffeinated or decaffeinated coffee was drunk by the subjects, and reactive hyperemia of finger blood flow was assessed by laser Doppler flowmetry. In an interval of more than 2 days, the same experimental protocol was repeated with another coffee in a crossover manner. Caffeinated coffee intake slightly but significantly elevated blood pressure and decreased finger blood flow as compared with decaffeinated coffee intake. There was no significant difference in heart rate between caffeinated and decaffeinated coffee intake. Importantly, caffeinated coffee intake significantly enhanced post-occlusive reactive hyperemia of finger blood flow, an index of microvascular endothelial function, compared with decaffeinated coffee intake. These results provide the first evidence that caffeine contained in a cup of coffee enhances microvascular function in healthy individuals.
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan. Electronic address: noguchi@med.u-ryukyu.ac.jp.
Katsuhiko
K
Noguchi
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Toshihiro
T
Matsuzaki
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Mayuko
M
Sakanashi
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Naobumi
N
Hamadate
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Taro
T
Uchida
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Mika
M
Kina-Tanada
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Haruaki
H
Kubota
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Junko
J
Nakasone
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Matao
M
Sakanashi
Department of Clinical Pharmacology and Therapeutics, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Shinichiro
S
Ueda
Second Department of Internal Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Hiroaki
H
Masuzaki
Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Shogo
S
Ishiuchi
Third Department of Internal Medicine, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Yusuke
Y
Ohya
Department of Pharmacology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan. Electronic address: tsutsui@med.u-ryukyu.ac.jp.
Masato
M
Tsutsui
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D003069:Coffee / Q000737:chemistry; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D005385:Fingers / Q000098:blood supply; D064368:Healthy Volunteers; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D015990:Placebo Effect; D012039:Regional Blood Flow / Q000187:drug effects; D055815:Young Adult
D003069:Coffee; D002110:Caffeine
Caffeine; Coffee; Endothelial function; Laser-Doppler flowmetry; Microcirculation