title: Acute effect of coffee drinking on dynamic cerebral autoregulation.
abstract: OBJECTIVE
  Drinking coffee causes caffeine-induced physiological alterations such as increases in arterial blood pressure, sympathetic nerve activity, cerebral vasoconstriction, etc., and these physiological alterations may be associated with a reduced risk of cerebral vascular disease. However, the effect of coffee drinking on dynamic cerebral blood flow (CBF) regulation remains unclear. The aim of this study was to test our hypothesis that coffee drinking enhances dynamic cerebral autoregulation.
  
  
  METHODS
  Twelve healthy young subjects participated in the present study. After a 5 min baseline measurement in a semi-recumbent position on the hospital bed, each subject drank water (CON) as a placebo condition or coffee beverage (Coffee INT). Arterial blood pressure and middle cerebral artery blood velocity (MCAv) were measured continuously throughout the experiment. At 30 min after the intake of either water or coffee, dynamic cerebral autoregulation was examined using a thigh cuffs occlusion and release technique. Each condition was randomly performed on a different day.
  
  
  RESULTS
  Under Coffee INT condition, mean arterial blood pressure was increased (P = 0.01) and mean MCAv was decreased (P = 0.01) from the baseline. The rate of regulation (RoR), as an index of dynamic cerebral autoregulation, during coffee condition was significantly higher than that during CON (P = 0.0009).
  
  
  CONCLUSIONS
  The findings of the present study suggest that coffee drinking augments dynamic CBF regulation with cerebral vasoconstriction. This phenomenon may be associated with a reduction in the risk of cerebral vascular disease.
authors.affiliation: Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama, 350-8585, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sasaki
authors.affiliation: Advanced Triage Team, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Hirasawa
authors.affiliation: Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama, 350-8585, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Washio
authors.affiliation: Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama, 350-8585, Japan. ogoh@toyo.jp.
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Ogoh
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002110:Caffeine / Q000008:administration & dosage*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D003069:Coffee; D006339:Heart Rate / Q000187:drug effects; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects; D055815:Young Adult
chemical_list: D003069:Coffee; D002110:Caffeine
keywords: Caffeine; Cerebral blood flow; Cerebral vascular disease; Hypertension; Hypocapnia; Sympathetic nerve activity