title: Impact of lifelong exercise training on endothelial ischemia-reperfusion and ischemic preconditioning in humans.
abstract: Reperfusion is essential for ischemic tissue survival, but causes additional damage to the endothelium [i.e., ischemia-reperfusion (I/R) injury]. Ischemic preconditioning (IPC) refers to short repetitive episodes of ischemia that can protect against I/R. However, IPC efficacy attenuates with older age. Whether physical inactivity contributes to the attenuated efficacy of IPC to protect against I/R injury in older humans is unclear. We tested the hypotheses that lifelong exercise training relates to1) attenuated endothelial I/R and2) maintained IPC efficacy that protects veteran athletes against endothelial I/R. In 18 sedentary male individuals (SED, <1 exercise h/wk for >20 yr, 63 ± 7 yr) and 20 veteran male athletes (ATH, >5 exercise h/wk for >20 yr, 63 ± 6 yr), we measured brachial artery endothelial function with flow-mediated dilation (FMD) before and after I/R. We induced I/R by 20 min of ischemia followed by 20 min of reperfusion. Randomized over 2 days, participants underwent either 35-min rest or IPC (3 cycles of 5-min cuff inflation to 220 mmHg with 5 min of rest) before I/R. In SED, FMD decreased after I/R [median (interquartile range)]: [3.0% (2.0-4.7) to 2.1% (1.5-3.9),P= 0.046] and IPC did not prevent this decline [4.1% (2.6-5.2) to 2.8% (2.2-3.6),P= 0.012]. In ATH, FMD was preserved after I/R [3.0% (1.7-5.4) to 3.0% (1.9-4.1),P= 0.82] and when IPC preceded I/R [3.2% (1.9-4.2) to 2.8% (1.4-4.6),P= 0.18]. These findings indicate that lifelong exercise training is associated with increased tolerance against endothelial I/R. These protective, preconditioning effects of lifelong exercise against endothelial I/R may contribute to the cardioprotective effects of exercise training.
authors.affiliation: Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Martijn F H
authors.initials: MFH
authors.lastname: Maessen
authors.affiliation: Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands.|Research Institute for Sports and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
authors.forename: Anke C C M
authors.initials: ACCM
authors.lastname: van Mil
authors.affiliation: Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Yaïra
authors.initials: Y
authors.lastname: Straathof
authors.affiliation: Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands; and.
authors.forename: Niels P
authors.initials: NP
authors.lastname: Riksen
authors.affiliation: Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands; and.|Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Gerard A P J M
authors.initials: GAPJM
authors.lastname: Rongen
authors.affiliation: Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Maria T E
authors.initials: MTE
authors.lastname: Hopman
authors.affiliation: Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands.|Research Institute for Sports and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
authors.forename: Thijs M H
authors.initials: TMH
authors.lastname: Eijsvogels
authors.affiliation: Radboud Institute for Health Sciences, Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands; dick.thijssen@radboudumc.nl.|Research Institute for Sports and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom.
authors.forename: Dick H J
authors.initials: DHJ
authors.lastname: Thijssen
mesh_terms: D004730:Endothelium, Vascular / Q000503:physiopathology*; D015444:Exercise; D000070497:Healthy Lifestyle; D006801:Humans; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064797:Physical Conditioning, Human / Q000379:methods*; D015427:Reperfusion Injury / Q000503:physiopathology* / Q000517:prevention & control*
keywords: endothelial cell function; exercise physiology; flow-mediated dilation; ischemic preconditioning; vascular physiology