title: Sex differences in the hemodynamic responses to mental stress: Effect of caffeine consumption.
abstract: The effect of caffeine on stress responses was compared in 25 men and 22 women in a 2-week placebo-controlled, double-blind, randomized crossover trial. On each week, participants abstained from all dietary sources of caffeine before undergoing a 6-h laboratory protocol under placebo or caffeine exposure followed by a 30-min mental stressor with blood pressure (BP) and cardiovascular hemodynamic assessments. On the placebo session, men and women showed a significant BP increase to stress, although women had significant cardiac responses whereas men had vascular responses. Caffeine ingestion before stress caused both men and women to have enhanced hemodynamic responses to the stressor associated with an increase in cardiac index and a drop in the peripheral resistance index. Caffeine enhances the cardiovascular fight-or-flight response pattern to stress in men and women.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA. Noha-farag@ouhsc.edu
authors.forename: Noha H
authors.initials: NH
authors.lastname: Farag
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Vincent
authors.forename: Barbara S
authors.initials: BS
authors.lastname: McKey
authors.forename: Mustafa
authors.initials: M
authors.lastname: Al'Absi
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Whitsett
authors.forename: William R
authors.initials: WR
authors.lastname: Lovallo
mesh_terms: D000328:Adult; D002110:Caffeine / Q000494:pharmacology*; D002307:Cardiography, Impedance; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008597:Menstrual Cycle / Q000502:physiology; D012727:Sex Characteristics; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine