title: Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.
abstract: Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses.
authors.affiliation: Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Wawrzyniak
authors.affiliation: National Centre for Sport & Exercise Medicine, Loughborough University, Loughborough, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Hamer
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Steptoe
authors.affiliation: Department of Medical & Clinical Psychology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.
authors.forename: Romano
authors.initials: R
authors.lastname: Endrighi
mesh_terms: D000368:Aged; D001143:Arousal / Q000502:physiology; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology*; D002319:Cardiovascular System / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology*; D013315:Stress, Psychological / Q000503:physiopathology*
keywords: Acute stress; Cardiovascular; Reaction times; Reactivity and recovery