Adaptations following an intermittent hypoxia‐hyperoxia training in coronary artery disease patients: a controlled study

Abstract

Background Repeated exposure to intermittent normobaric hypoxia improves exercise tolerance in cardiac patients. Little is known on the effects of intermittent normobaric hypoxia‐hyperoxia exposure in coronary artery disease (CAD) patients (New York Heart Association II–III). Hypothesis IHHT improves exercise tolerance, cardiometabolic profile, and quality of life in CAD patients. Methods The study design was a nonrandomized, controlled, before‐and‐after trial. Forty‐six CAD patients volunteered to take part in the study: a group of 27 patients undertook the intermittent hypoxia (O2 at 10%)–hyperoxia (O2 at 30%) training (IHHT), whereas a control group (CTRL) of 19 patients, who already completed an 8‐week standard cardiac rehabilitation program, was allocated to sham‐IHHT treatment (breathing room air, O2 at 21%). Exercise performance, blood and metabolic profiles, and quality of life (Seattle Angina Questionnaire [SAQ]) were measured before and after in the IHHT group (IHHG) and sham‐IHHT in the CTRL group. Results The IHHG showed improved exercise capacity, reduced systolic and diastolic blood pressures, enhanced left ventricle ejection fraction, and reduced glycemia, but only at 1‐month follow‐up. Angina as a reason to stop exercising was significantly reduced after treatment and at 1‐month follow‐up. The IHHT SAQ profile was improved in the IHHG and not significantly different to the CTRL group after standard rehabilitation. The IHHG was also compared to the CTRL group at 1‐month follow‐up, and no differences were found. Conclusions In CAD patients, an IHHT program is associated with improved exercise tolerance, healthier risks factors profile, and a better quality of life. Our study also suggests that IHHT is as effective as an 8‐week standard rehabilitation program.

Influence of Hypoxic and Hyperoxic Preconditioning on Endothelial Function in a Model of Myocardial Ischemia-Reperfusion Injury with Cardiopulmonary Bypass (Experimental Study)

“…In experimental studies, exposure to hyperoxia for a limited time before ischemia induces a low-grade systemic oxidative stress, evokes a preconditioning-like effect of the myocardium, and reduces the infarction area by 20% and the number of arrhythmias after ischemia-reperfusion [ 7 , 9 , 10 , 18 , 21 , 22 ]. The interval hypoxic-hyperoxic training increases the exercise tolerance of patients with ischemic heart disease [ 23 ].…”

Effects of intermittent hypoxia-hyperoxia on mobility and perceived health in geriatric patients performing a multimodal training intervention: a randomized controlled trial

“…IHHT was suggested to produce a faster membrane-stabilizing effect in cells of the heart, liver and brain compared to IHT in a study with male Wistar rats [17]. This new approach is more economical than IHT, as the recovery time between bouts of hypoxia exposure is shortened to 3 min, allowing for a higher number of hypoxia–hyperoxia cycles during the same session [18]. Exercise combined with hypoxic training also improved cognitive function of older individuals [14], and the addition of hyperoxic intervals might have accelerated clearance of metabolites negatively impacting on neuronal metabolism in dementia [19].…”

Subchronic hypoxia pretreatment on brain pathophysiology in unilateral common carotid artery occluded albino rats

“…Further, it has been reported from a clinical study that hypoxia preconditioning provides more protective cardiometabolic profile. [ 19 ] Hypoxia preconditioning was also found to be beneficial to promote mesenchymal stem cells proliferation which facilitates intrastriatal transplantation and support therapeutically to fight against Parkinson's disease. [ 20 ]…”