title: Seven-day remote ischemic preconditioning improves local and systemic endothelial function and microcirculation in healthy humans.
abstract: BACKGROUND
  Ischemic preconditioning (IPC) protects tissue against ischemia-induced injury inside and outside ischemic areas. The purpose was to examine the hypothesis that daily IPC leads to improvement in endothelial function and skin microcirculation not only in the arm exposed to IPC but also in the contralateral arm.
  
  
  METHODS
  Thirteen healthy, young, normotensive male individuals (aged 22±2 years) were assigned to 7-day daily exposure of the arm to IPC (4×5 minutes). Assessment of brachial artery endothelial function (using flow-mediated dilation (FMD)) and forearm microcirculation (cutaneous vascular conductance (CVC) at baseline and during local heating) was performed before and after 7 days to examine the local (i.e., intervention arm) and remote (i.e., control arm) effect of IPC. We repeated the assessment tests 8 days after the intervention (Post+8).
  
  
  RESULTS
  FMD increased after repeated IPC (P = 0.03) and remained significantly elevated at Post+8 in the intervention (5.0±2.2%, 6.1±2.2%, and 6.6±2.3%) and contralateral arms (5.4±2.2%, 6.0±2.2%, and 7.5±2.2%). Forearm CVC also increased following repeated IPC (P = 0.006) and remained elevated at Post+8 in both arms (intervention: 0.12±0.03, 0.14±0.04, 0.16±0.04 mV/mm Hg; contralateral: 0.14±0.04, 0.015±0.04, 0.17±0.07). No interaction between IPC arm and time was evident for FMD and CVC (both P > 0.05). IPC intervention did not alter CVC responses to local heating (P > 0.05).
  
  
  CONCLUSIONS
  Daily exposure to IPC for 7 days leads to local and remote improvements in brachial artery FMD and resting skin microcirculation that remain after cessation of the intervention and beyond the late phase of protection. These findings may have clinical relevance for micro- and macrovascular improvements.
authors.affiliation: Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK;
authors.forename: Helen
authors.initials: H
authors.lastname: Jones
authors.affiliation: Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK;
authors.forename: Nicola
authors.initials: N
authors.lastname: Hopkins
authors.affiliation: Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK;
authors.forename: Tom G
authors.initials: TG
authors.lastname: Bailey
authors.affiliation: Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK; School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia, Australia;
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Green
authors.affiliation: Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK;
authors.forename: N Timothy
authors.initials: NT
authors.lastname: Cable
authors.affiliation: Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK;Department of Physiology, RRadboud University Medical Center, Nijmegen, The Netherlands. D.Thijssen@ljmu.ac.uk.
authors.forename: Dick H J
authors.initials: DH
authors.lastname: Thijssen
mesh_terms: D001916:Brachial Artery / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology*; D005542:Forearm / Q000098:blood supply*; D006801:Humans; D019194:Ischemic Preconditioning; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D055815:Young Adult
keywords: blood pressure; cardiovascular risk; endothelial function; hypertension; microcirculation; remote ischemic preconditioning; vascular adaptation.