Hannes Gatterer

Eurac Research · Institute of Mountain Emergency Medicine

In lowlanders, high altitude (HA) acclimatization induces hemoconcentration by reducing plasma volume (PV) and increasing total hemoglobin mass (Hb mass ). Conversely, Tibetan highlanders living at HA are reported to have a similar hemoglobin concentration ([Hb]) as lowlanders near sea level and we investigated whether this reflects alterations in...

Introduction: The human brain is a highly oxygen-dependent organ. Low environmental oxygen availability (e.g., hypobaric hypoxia at altitude) is a major challenge to the brain and numerous endogenous cellular and systemic hypoxia responses therefore are in place to mitigate hypoxic stress. When the dose of the hypoxic stress surpasses the adaptive...

Recently, chronic intermittent inhalation of low-dose carbon monoxide (CO) has been postulated as a practice to increase total hemoglobin mass with potential beneficial effects on endurance performance. In this perspective article, we discuss the potential performance enhancing capabilities as well as the safety concerns, which include individual v...

Purpose There is controversy whether there are meaningful physiological differences between hypobaric (HH) and normobaric hypoxia (NH). This study aimed to compare the cardiorespiratory responses to acute HH and NH under strictly controlled conditions. We hypothesized no differences at rest and during submaximal exercise, whereas during maximal exe...

Every year millions of people fly to high-altitude destinations. They thereby expose themselves to specific high-altitude conditions. The hypoxic environment (low ambient oxygen availability) constitutes a major factor affecting health and well-being at high altitude. While the oxygen availability is already moderately reduced inside the aircraft c...

Millions of people visit high-altitude regions annually and more than 80 million live permanently above 2,500 m. Acute high-altitude exposure can trigger high-altitude illnesses (HAIs), including acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE). Chronic mountain sickness (CMS) can affect...

Millions of people visit high-altitude regions annually and more than 80 million live permanently above 2,500 m. Acute high-altitude exposure can trigger high-altitude illnesses (HAIs), including acute mountain sickness (AMS), high-altitude cerebral oedema (HACE) and high-altitude pulmonary oedema (HAPE). Chronic mountain sickness (CMS) can affect...

During acute hypoxic exposure, cerebral blood flow (CBF) increases to compensate for the reduced arterial oxygen content (CaO2). Nevertheless, as exposure extends, both CaO2 and CBF progressively normalize. Haemoconcentration is the primary mechanism underlying the CaO2 restoration and may therefore explain, at least in part, the CBF normalization....

Hypoxia at high altitude facilitates changes in ventilatory control that can lead to nocturnal periodic breathing (nPB). Here, we introduce a placebo‐controlled approach to prevent nPB by increasing inspiratory CO2 and used it to assess whether nPB contributes to the adverse effects of hypoxia on sleep architecture. In a randomized, single‐blinded,...

Parkinson’s disease (PD) is associated with various deficits in sensing and responding to reductions in oxygen availability (hypoxia). Here we summarize the evidence pointing to a central role of hypoxia in PD, discuss the relation of hypoxia and oxygen dependence with pathological hallmarks of PD, including mitochondrial dysfunction, dopaminergic...

Intermittent hypoxia (IH) is commonly associated with pathological conditions, particularly obstructive sleep apnoea. However, IH is also increasingly used to enhance health and performance and is emerging as a potent non‐pharmacological intervention against numerous diseases. Whether IH is detrimental or beneficial for health is largely determined...

Faulhaber, M, Schneider, S, Rausch, LK, Dünnwald, T, Menz, V, Gatterer, H, Kennedy, MD, and Schobersberger, W. Repeated short-term bouts of hyperoxia improve aerobic performance in acute hypoxia. J Strength Cond Res 37(10): 2016–2022, 2023—This study aimed to test the effects of repeated short-term bouts of hyperoxia on maximal 5-minute cycling per...

Psychosis is a psychopathological syndrome that can be triggered or caused by exposure to high altitude (HA). Psychosis can occur alone as isolated HA psychosis or can be associated with other mental and often also somatic symptoms as a feature of delirium. Psychosis can also occur as a symptom of high altitude cerebral edema (HACE), a life-threate...

Kammerer, Tobias, Anna Walzl, Thomas Müller, Philipp Groene, Giulia Roveri, Rachel Turner, Johanna Roche, Hannes Gatterer, Christoph Siebenmann, and Simon T. Schäfer. Effects of hypobaric hypoxia on coagulation in healthy subjects exposed to 3,500 m altitude. High Alt Med Biol. 24:94-103, 2023. Background: Hypoxia is discussed as a trigger for prot...

Background: During the COVID-19 pandemic, the use of face masks has been recommended or enforced in several situations, however their effects on physiological parameters and cognitive performance at high altitude are unknown. Methods: Eight healthy participants (four females) rested and exercised (cycling, 1 W/kg) while wearing no mask, a surgic...

Altitude exposure may suppress appetite and hence provide a viable weight-loss strategy. While changes in food intake and availability as well as physical activity may contribute to altered appetite at altitude, herein we aimed to investigate the isolated effects of hypobaric hypoxia on appetite regulation and sensation. Twelve healthy women (age:...

We sought to determine the effects of prolonged moderate hypobaric hypoxia (HH) on cardiac baroreflex sensitivity (cBRS) in young women, and whether these effects are a consequence of the reduced arterial oxygen (O2) tension and/or increased pulmonary ventilation in HH. We hypothesised that HH would reduce cBRS and that this effect would be counter...

We have recently reported that hypobaric hypoxia (HH) reduces plasma volume (PV) in men by decreasing total circulating plasma protein (TCPP). Here, we investigated whether this applies to women and whether an inflammatory response and/or endothelial glycocalyx shedding could facilitate the TCCP reduction. We further investigated whether acute HH i...

Introduction: A lack of knowledge among laypersons about the hazards of high-altitude exposure contributes to morbidity and mortality from acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE) among high-altitude travelers. There are guidelines regarding the recognition, prevention, and treatme...

Desflurane, isoflurane and sevoflurane, three halogenated ethers, are commonly used inhaled anesthetics, both in the operating room and in the intensive care unit (ICU). The potency and dosage of these drugs is expressed by the MAC value (minimum alveolar concentration). Their interaction with hemoglobin and its affinity for oxygen, best described...

Adequate oxygen supply is essential for the human brain to meet its high energy demands. Therefore, elaborate molecular and systemic mechanism are in place to enable adaptation to low oxygen availability. Anxiety and depressive disorders are characterized by alterations in brain oxygen metabolism and of its components, such as mitochondria or hypox...

Background Inhalational prostacyclins act as strong vasodilators, potentially improving oxygenation by reducing shunt fraction and ventilation-perfusion mismatch. As prostacyclin receptors are known to be present on human erythrocytes, possible direct effects on oxygenation were further explored by examining the sole in-vitro influence of prostacyc...

Whereas the negative effects of aging and smoking on pulmonary function are undisputed, the potential favorable effects of physical activity on the aging process of the otherwise healthy lung remain controversial. This question is of particular clinical relevance when reduced pulmonary function compromises aerobic exercise capacity (maximal oxygen...

Completely avalanche-buried patients are frequently exposed to a combination of hypoxia and hypercapnia with a risk of normothermic cardiac arrest. Patients with a long burial time and an air pocket are exposed to a combination of hypoxia, hypercapnia, and hypothermia which may lead to the development of the "triple H syndrome". This specific combi...

Introduction: Extreme levels of sleep deprivation, fragmentation and management, are major problems in many sportive disciplines, ultramarathons, polar or extreme altitude expeditions, and in space operations. Material and methods: Polysomnographic (PSG) data was continuously recorded (total sleep time and sleep stage distribution) in a 34-year-ol...

Pühringer, Reinhard, Hannes Gatterer, Martin Berger, Michael Said, Martin Faulhaber, and Martin Burtscher. Does moderate altitude affect VO2max in acclimatized mountain guides? High Alt Med Biol 00:000-000, 2021. Background: Altitude exposure reduces maximal oxygen uptake (VO2max). Usually, the reduction is not restored with acclimatization (at lea...

Overdrinking and non-osmotic arginine vasopressin release are the main risk factors for exercise-associated hyponatremia (EAH) in ultra-marathon events. However, particularly during ultra-marathon running in mountainous regions, eccentric exercise and hypoxia, which have been shown to modulate inflammation, hormones regulating fluid homeostasis (hy...

The purpose of the study was (1) to investigate the effects of regular long-term circuit training (once per week) on cardiorespiratory fitness (CRF) in sedentary adults and (2) to compare training progress with the effects of continued exercise participation by regularly active age-matched individuals. Ten sedentary, middle-aged (51 ± 6 years) indi...

5-Hydroxymethylfurfural (5-HMF) is known to increase hemoglobin oxygen affinity (Hb-O2 affinity) and to induce a left shift of the oxygen dissociation curve (ODC). It is under investigation as a therapeutic agent in sickle cell anemia and in conditions where pulmonary oxygen uptake is deteriorated or limited (e.g., various clinical conditions or al...

Although not a barrier to perform sport, cold weather environments (low ambient temperature, high wind speeds, and increased precipitation, i.e., rain/water/snow) may influence sport performance. Despite the obvious requirement for practical recommendations and guidelines to better facilitate training and competition in such cold environments, the...

In vitro determination of the hemoglobin oxygen dissociation curve (ODC) requires highly elaborate, specialized, and costly technical equipment. In addition, there is a lack of methods that combine reliable ODC recordings with high throughput in small blood samples for routine analysis. We here introduce a modified, commercial 96‐well plate with an...

The present project compared acute hypoxia-induced changes in lactate thresholds (methods according to Mader, Dickhuth and Cheng) with changes in high-intensity endurance performance. Six healthy and well-trained volunteers conducted graded cycle ergometer tests in normoxia and in acute normobaric hypoxia (simulated altitude 3000 m) to determine po...

Bioelectrical impedance vector analysis (BIVA) is a method used to estimate variation in body hydration. We assessed the potential of BIVA for monitoring daily body hydration fluctuations in nine healthy, normally active males under matching normoxic (NX) and hypobaric hypoxic (HH) experimental conditions. Furthermore, we aimed to investigate wheth...

Dünnwald, T, Morawetz, D, Faulhaber, M, Gatterer, H, Birklbauer, C, Koller, A, Weiss, G, and Schobersberger, W. Supplemental O2 during recovery does not improve repeated maximal concentric-eccentric strength-endurance performance in hypoxia. J Strength Cond Res XX(X): 000-000, 2021-An alpine ski racing training session typically includes repeated b...

High-altitude cerebral edema (HACE) and acute mountain sickness (AMS) are neuro-pathologies associated with rapid exposure to hypoxia. However, speculation remains regarding the exact etiology of both HACE and AMS and whether or not they share a common mechanistic pathology. This mini-review outlines the basic principles of HACE development, highli...

In severe hypoxia, single-leg peak oxygen uptake (VO2peak) is reduced mainly due to the inability to increase cardiac output (CO). Whether moderate altitude allows CO to increase during single-leg cycling, thereby restoring VO2peak, has not been extensively investigated. Five healthy subjects performed an incremental, maximal, two-legged cycle ergo...

Purpose: Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T levels show a transient increase after marathon running. The aim of this study was to investigate whether running duration influences the patterns of changes in cardiac biomarkers. Methods: Twenty participants with fast and slow finishing times were incl...

Recreational outdoor activities like mountain sports are gaining large popularity all over the world and particularly in the Alpine regions [...]

We investigated whether low arterial oxygen tension (PaO 2 ) or hypoxia-induced plasma volume (PV) contraction, which reduces central blood volume (BV) and atrial distension, explain reduction in circulating atrial natriuretic peptide (ANP) after prolonged hypoxic exposure. Ten healthy males were exposed for four days to hypobaric hypoxia correspon...

Key points Acclimatization to hypoxia leads to a reduction in plasma volume (PV) that restores arterial O2 content. Findings from studies investigating the mechanisms underlying this PV contraction have been controversial, possibly as experimental conditions were inadequately controlled. We examined the mechanisms underlying the PV contraction evok...

Background A sufficient supply of oxygen is crucial to avoid hypoxic cardiac arrest and brain damage within 30 min in completely-buried avalanche victims. Snow density influences levels of hypoxia and hypercapnia. The goal of this study was to investigate the effects of hypoxia and hypercapnia on cerebral oxygenation (ScO2) in humans breathing into...

Background: Excess body fat is a major health risk to various chronic diseases. Given the ease of measurement and low cost of body weight and height, body mass index (BMI) has been widely used to estimate body fatness. The present study evaluates the accuracy of BMI as an indicator of body fatness, measured via bioelectric impedance (BIA) during th...

To elucidate patterns of and risk factors for acute traumatic injuries in climbers in need of professional rescue, a retrospective evaluation was performed of the Austrian National Registry of Mountain Accidents regarding rock climbing incidents over a 13-year timeframe from 2005 to 2018. From 2992 recorded incidents, 1469 were uninjured but in nee...

Purpose: Severely fractured sleep is mostly portrayed negatively, but investigations in extreme sports have shown that humans can maintain performance with a minimum amount of sleep. With two cases of long-lasting extreme sports performances, we demonstrate that severely fragmented sleep does not necessarily lead to a deterioration of physical and...

High altitude exposure typically reduces endothelial function, and this is modulated by hemoconcentration resulting from plasma volume contraction. However, the specific impact of hypobaric hypoxia, independent of external factors (e.g. cold, varying altitudes, exercise, diet, dehydration) on endothelial function is unknown. We examined the tempora...

The literature suggests that acute hypobaric (HH) and normobaric (NH) hypoxia exposure elicits different physiological responses. Only limited information is available on whether maximal cardiorespiratory exercise test outcomes, performed on either the treadmill or the cycle ergometer, are affected differently by NH and HH. A focused literature rev...

Background: This study assessed heart rate variability (HRV) after a single power strength training session performed at different hypoxic levels. Materials and Methods: Eight physically active subjects (31.1 ± 4.3 years; 177.6 ± 3.0 cm; 70.1 ± 5.2 kg) performed 6 bouts of 15-second continuous maximal jump exercises interspersed by 3 minutes of re...

Background Standard performance parameters measured during a laboratory test have been shown to be related to mountain ultra-marathon performance up to a competition length of 75 km. It is not known if a similar relationship exists for longer races. Objective This study aimed to investigate the association between laboratory-based performance param...

This opinion paper aims at discussing the potential impact of modulating the Hb-O2 affinity by the nutritional supplement 5-HMF on patients affected by COVID-19. The paper describes the critical role of the oxygen affinity in hypoxemic COVID-19 patients and the potential positive effect of 5-HMF, a compound shown to increase the Hb-O2 affinity.

Annually, millions of people engage in mountain sports activities all over the world. These activities are associated with health benefits, but concurrently with a risk for injury and death. Knowledge on death rates is considered important for the categorization of high-risk sports in literature and for the development of effective preventive measu...

Introduction: Suspension syndrome describes a potentially life-threatening event during passive suspension on a rope. The pathophysiological mechanism is not fully understood; however, the most widespread hypothesis assumes blood pools in the lower extremities, prompting a reduction in cardiac preload and cardiac output and leading to tissue hypop...

Bioimpedance standards are well established for the normal healthy population and in clinical settings, but they are not available for many sports categories. The aim of this study was to develop reference values for male and female athletes using classic bioimpedance vector analysis (BIVA). In this study, 1556 athletes engaged in different sports...

The current study introduces a new index for external and internal workload, “workload efficiency”, and assesses in professional soccer the influence of pre-match training load on match workload efficiency. External and internal workloads were determined for 44 training sessions and 16 competitive matches using a 10-Hz global positioning system (GP...

Millions of people engage in mountain sports activities worldwide. Although leisure-time physical activity is associated with significant health benefits, mountain sports activities also bear an inherent risk for injury and death. However, death risk may vary across various types of mountain sports activities. Epidemiological data represent an impo...

Hüfner, Katharina, Hermann Brugger, Fabio Caramazza, Agnieszka Elzbieta Stawinoga, Monika Brodmann-Maeder, Hannes Gatterer, Rachel Turner, Iztok Tomazin, Paolo Fusar-Poli, and Barbara Sperner-Unterweger. Development of a self-administered questionnaire to detect psychosis at high altitude: the HAPSY questionnaire. High Alt Med Biol 00:000-000, 2019...

Objective: This study aimed to quantify the sedative effects, detection rates and cardiovascular responses to xenon. Methods: On three occasions, participants breathed xenon (FiXe 30%, for 20 min; FiXe 50% for 5 min; FiXe 70% for 2 min) in a non-blinded design. Sedation was monitored by a board certified anesthesiologist. During 70% xenon, parti...

Background: This study aimed to assess the efficacy of acute sub-anesthetic dosages of xenon inhalation to cause erythropoiesis, and determine the effect of chronic xenon dosing on hematological parameters and athletic performance. Methods: To assess the acute effects, 7 subjects breathed three sub-anesthetic concentrations of xenon: FiXe 30% fo...

This double-blinded, randomized and placebo-controlled, crossover study investigated whether α-ketoglutaric-acid (α-KG) and 5-hydroxymethylfurfural (5-HMF) supplementation improves exercise performance in hypoxia and affects physiological responses during the exercise task. Eight moderately trained male participants (age: 25.3 ± 2.0 y, VO2max: 48.0...

Background: The associations among cortisol levels, body water status, and acute mountain sickness (AMS) remain unclear. We investigated associations between AMS prevalence and severity with resting saliva cortisol levels at low altitude (LA) and high altitude (HA) and with fluid balance during a HA stay. Methods: Twenty-two physically fit and hea...

Purpose: The purpose of this study was to investigate whether oxygen supplementation immediately prior to exercise (FiO2=1.0) improves all-out exercise performance in normobaric hypoxia (3500m) in highly skilled skiers. Methods: In this single-blind, randomized, crossover study, 17 subjects performed a 60 s constant-load, all-out test in a normo...

Purpose Suspension syndrome describes a potentially life-threatening event during passive suspension on a rope. The pathophysiological mechanism is not fully understood and optimal treatment unknown. We aimed to elucidate the pathophysiology and to give treatment recommendations. Methods In this experimental, randomized crossover trial, 20 healthy...

The original version of this article unfortunately contained a mistake. Information was missing in the acknowledgements section. The correct information is given below.

The peripheral T-cell pool undergoes a striking age associated remodeling which is accelerated by progressive insulin resistance. Exercise training is known to delay several aspects of T-cell senescence. The purpose of the current study was to investigate the effect of three weeks regular concentric or eccentric endurance exercise training on the c...