title: Hemodynamic responses to mental stress during salt loading.
abstract: OBJECTIVE
  The purpose was to examine whether prolonged moderate stress associated with a student exam would increase the blood pressure response to a salt load in young healthy normotensive individuals.
  
  
  METHODS
  Ten healthy young subjects were examined at two different occasions in random order (i) during preparation for a medical exam (prolonged stress) and (ii) outside the exam period (low stress). All subjects consumed a controlled diet for 3 days with low- or high-salt content in randomized order. The subjective stress was measured by Spielberger's State-Trait Anxiety Inventory-Scale, SCL Symptom Checklist for stress and the Visual Analogue Scale. On each level of stress, 24-h ambulatory blood pressure and cardiac output (CO) were measured. Furthermore, plasma norepinephrine (NE), epinephrine (E) and plasma renin activity (PRA) were measured.
  
  
  RESULTS
  Twenty-four-hour ABP, 24-h heart rate, CO as well as plasma levels of NE, E and PRA remained unchanged by changes in stress level. Day-night reduction in SAP was significantly larger during moderate stress and high-salt intake; however, no significant difference was observed during daytime and night-time. Individual increase in mental stress correlated significantly with an individual decrease in PRA (SCL-17, r = -0·80, P<0·05, STAIr = -0·64 P<0·05) during high-salt intake.
  
  
  CONCLUSIONS
  Moderate stress over a period of time in young healthy normotensive individuals does not lead to changes in 24-h ABP. However, the augmented reduction in day-to-night systolic blood pressure during high-salt intake and moderate stress may indicate that stress affects blood pressure regulation.
authors.affiliation: Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Maria
authors.initials: M
authors.lastname: Gefke
authors.affiliation: Department of Medicine O, Herlev University Hospital, Herlev, Denmark.
authors.forename: Niels Juel
authors.initials: NJ
authors.lastname: Christensen
authors.affiliation: Psychiatric Research Department, Frederiksborg General Hospital, Hillerød, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Bech
authors.affiliation: Department of Diagnostics, Clinical Physiology and Nuclear Medicine, Glostrup University Hospital, Glostrup, Denmark.
authors.forename: Erik
authors.initials: E
authors.lastname: Frandsen
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine 239, Faculty of Health Sciences, Hvidovre Hospital, Centre of Functional Imaging and Research, University of Copenhagen, Hvidovre, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Damgaard
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Bispebjerg University Hospital, Copenhagen NV, Denmark.
authors.forename: Ali
authors.initials: A
authors.lastname: Asmar
authors.affiliation: Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.|Division of Space Life Sciences (DSLS), Universities Space Research Association (USRA) & Biomedical Research & Environmental Sciences division, NASA, Johnson Space Center, Houston, TX, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Norsk
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002302:Cardiac Output; D004837:Epinephrine / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D009638:Norepinephrine / Q000097:blood; D011897:Random Allocation; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology* / Q000523:psychology; D013564:Sympathetic Nervous System / Q000503:physiopathology; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D017673:Sodium Chloride, Dietary; D012083:Renin; D009638:Norepinephrine; D004837:Epinephrine
keywords: blood pressure; mental stress; norepinephrine; renin; salt sensitivity; sympathetic nervous activity