title: The acute effects of passive heat exposure on arterial stiffness, oxidative stress, and inflammation.
abstract: OBJECTIVE
  The aim of the study was to determine the acute effect of passive heat exposure (PHE) on arterial stiffness, oxidative stress (OxS) and inflammatory parameters.
  
  
  METHODS
  Subjects were studied in thermoneutral conditions before and after PHE in a climatic chamber. Pulse wave analysis was used for assessment of central hemodynamic and arterial stiffness parameters. Venous blood samples were obtained to measure OxS and inflammatory parameters.
  
  
  RESULTS
  Rectal temperature increased after PHE exposure compared to baseline: 37.01°C±0.19°C and 36.4°C±0.31°C, respectively (P<0.001). There was a 17% (P<0.05) decrease in large artery elasticity index (from 24.68±5.53 to 20.42±2.65mL/mmHg*10), which was predicted upon normothermic value (r=-0.878, P<0.01). However, no significant changes were found in others arterial stiffness parameters. A 30% (P<0.05) increase occurred in blood IL-6 concentration (from 0.43±0.15 to 0.56±0.23pg/mL), but OxS parameters remained significantly unchanged.
  
  
  CONCLUSIONS
  This study describes for the first time acute PHE effects on arterial stiffness, inflammation and OxS. PHE significantly decreases large artery elasticity index and increases inflammatory IL-6 level. However, further larger investigations are needed for clarifying acute PHE effects on arterial function and biomarkers.
authors.affiliation: Institute of Exercise Biology and Physiotherapy, University of Tartu, Tartu, Estonia; Estonian Centre of Behavioural and Health Sciences, University of Tartu, Tartu, Estonia. Electronic address: triin.kaldur85@gmail.com.
authors.forename: Triin
authors.initials: T
authors.lastname: Kaldur
authors.affiliation: Estonian Centre of Behavioural and Health Sciences, University of Tartu, Tartu, Estonia; Department of Cardiology, University of Tartu, Tartu, Estonia; Department of Sports Medicine and Rehabilitation, University of Tartu, Tartu, Estonia; Sports Medicine and Rehabilitation Clinic, Tartu University Hospital, Tartu, Estonia.
authors.forename: Eve
authors.initials: E
authors.lastname: Unt
authors.affiliation: Institute of Exercise Biology and Physiotherapy, University of Tartu, Tartu, Estonia; Estonian Centre of Behavioural and Health Sciences, University of Tartu, Tartu, Estonia.
authors.forename: Vahur
authors.initials: V
authors.lastname: Ööpik
authors.affiliation: Institute of Biomedicine and Translational Medicine, Centre of Excellence for Translational Medicine, University of Tartu, Tartu, Estonia.
authors.forename: Mihkel
authors.initials: M
authors.lastname: Zilmer
authors.affiliation: Department of Cardiology, University of Tartu, Tartu, Estonia.
authors.forename: Jaan
authors.initials: J
authors.lastname: Eha
authors.affiliation: Institute of Biomedicine and Translational Medicine, Centre of Excellence for Translational Medicine, University of Tartu, Tartu, Estonia.
authors.forename: Kaido
authors.initials: K
authors.lastname: Paapstel
authors.affiliation: Institute of Biomedicine and Translational Medicine, Centre of Excellence for Translational Medicine, University of Tartu, Tartu, Estonia; Department of Vascular Surgery, Tartu University Hospital, Tartu, Estonia.
authors.forename: Jaak
authors.initials: J
authors.lastname: Kals
mesh_terms: D000328:Adult; D001158:Arteries / Q000502:physiology*; D015415:Biomarkers; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature; D018869:Heat-Shock Response / Q000502:physiology; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D007249:Inflammation / Q000503:physiopathology*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D063177:Pulse Wave Analysis; D012881:Skin Temperature / Q000502:physiology; D059289:Vascular Stiffness / Q000502:physiology*
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6
keywords: Arterial elasticity; Climatic chamber; Heat stress; Pulse wave analysis