Persisting Elevation of Total Hemoglobin Mass After Altitude Training in Elite Swimmers: a Potential Role of Prolonged Erythrocyte Survival.

Altitude training camps are frequently used by endurance athletes to increase total hemoglobin mass (Hb) and potentially aerobic performance. However, the effects of such intervention on red blood cell (RBC) properties remain largely unexplored, although these factors could influence the physiological responses following altitude training. This self-controlled study investigated the effects of a "Live High-Train High" (LHTH) altitude training camp on RBC senescence and Hb in 9 elite swimmers.

Differences in oxygen-gradient ektacytometry parameters and blood viscosity between patients with sickle cell anemia and patients with sickle cell-hemoglobin C disorder.

Oxygen-gradient ektacytometry (oxygenscan) has been recently used in the context of sickle cell disease (SCD) to determine the ability of red blood cells (RBCs) to deform in normoxia and during deoxygenation. While several studies focused on the determinants of oxygenscan parameters in the homozygous form of SCD (i.e.

Addressing Anemia in High-Altitude Populations: Global Impact, Prevalence, Challenges, and Potential Solutions.

Anemia, a global health challenge affecting a quarter of the global population, results from diverse causes such as nutritional deficiencies, chronic diseases, and genetic factors. It disproportionately impacts women of reproductive age and children, leading to significant morbidity and mortality. While high-altitude populations face unique diagnostic challenges due to natural hemoglobin increases, the current World Health Organization cutoffs often overestimate anemia in these regions.

Recovery of Fatigue, Cardiorespiratory Fitness, and Neuromuscular Function in Covid-19 ICU Patients: A 6-Month Follow-Up Study.

Purpose: Although most patients recover well from Covid-19 infection, this may not be the case of those who experienced severe dysfunction after being admitted to intensive care unit (ICU). This study aimed to assess the recovery of patients who experienced severe multiple dysfunctions after being admitted to intensive care unit (ICU) for Covid-19 infection.

Methods: Forty-seven patients hospitalized and mechanically ventilated in ICU for SARS-CoV-2 infection underwent evaluations at 4-8 weeks (T1) and 6 months (T2) post ICU discharge.

Changes in Retinal Vasculature Phenotype and Choroidal Blood Flow at High Altitude in Healthy Lowlanders.

Purpose: The aim of this study was to characterize changes in retinal vessel diameters and choroidal blood flow in healthy lowlanders during a high-altitude expedition.

Methods: Ocular examination, fundus images acquired using a handheld camera, and laser Doppler flowmetry (LDF) measurements within the subfoveal choroid (blood flow = ChBF, blood velocity = ChVel, and blood volume = ChVol) were carried out at 200 m and after 9 days at 5100 m in 11 healthy participants. Fundus images were analyzed with the semi-automatic software Vessel Assessment and Measurement Platform for Images of the Retina (VAMPIRE) version 3.

Long-Distance Trail Running Induces Inflammatory-Associated Protein, Lipid, and Purine Oxidation in Red Blood Cells.

Unlabelled: Ultra-endurance exercise places extreme physiological demands on oxygen transport, yet its impact on red blood cells (RBCs) remains underexplored. We conducted a multi-omics analysis of plasma and RBCs from endurance athletes before and after a 40-km trail race (MCC) and a 171-km ultramarathon (UTMB ). Ultra-running led to oxidative stress, metabolic shifts, and inflammation-driven RBC damage, including increased acylcarnitines, kynurenine accumulation, oxidative lipid and protein modifications, reduced RBC deformability, enhanced microparticle release, and increased senescence markers such as externalized phosphatidylserine (PS).

Cerebral blood flow in Andean children and adolescents living above 5,000 m.

A number of indigenous populations have resided at high-altitude for generations, resulting in various phenotypical adaptations promoting successful high-altitude adaptation. Although many of these adaptations have been investigated in adults, little is known regarding how children residing at high-altitudes adapt, particularly with regards to the cerebrovasculature. Under hypoxic environments, compensatory changes in cerebral blood flow (CBF) are necessary to couple oxygen delivery to metabolic demand in the face of reduced oxygen availability.

Passive hamstring muscles rigidity throughout the menstrual cycle and the effect of oral contraception.

Objectives: Female athletes have a lower risk of hamstring strain injuries than males. The variations in oestradiol and progesterone concentrations happening during the menstrual cycle and oral contraceptive use may influence muscle mechanical properties, potentially affecting muscle injury risk. However, to date, no study has combined an assessment of hamstring muscles' mechanical properties spread over the full knee range of motion with rigorous hormonal control of the menstrual cycle, electromyographic monitoring and inclusion of oral contraceptive users.

Residual sleepiness and impaired alertness in treated obstructive sleep apnoea: role of hypoxic burden and sleep fragmentation.

The pathophysiology of residual sleepiness in treated obstructive sleep apnoea (OSA) remains poorly understood. Animal models suggest that it may involve neuronal damage due to intermittent hypoxia and sleep fragmentation. In a cohort of 122 continuous positive airway pressure (CPAP) treated OSA patients referred for maintenance of wakefulness test, we explored the determinants of (objective) alertness and those of (subjective) sleepiness assessed by Epworth Sleepiness Scale.

Acclimatized Lowlanders Exhibit a Hypocoagulable Profile after a Passive Ascent at High Altitude.

Stauffer, Emeric, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V. Brugniaux, Samuel Verges, and Benoit Champigneulle. Acclimatized lowlanders exhibit a hypocoagulable profile after a passive ascent at high altitude.

Micro- and macrovascular function in the highest city in the world: a cross sectional study.

Background: Since vascular responses to hypoxia in both healthy high-altitude natives and chronic mountain sickness (a maladaptive high-altitude pathology characterised by excessive erythrocytosis and the presence of symptoms-CMS) remain unclear, the role of inflammation and oxidative/nitrosative stress on the endothelium- and - responses in both the micro- and macrocirculation, in healthy Andeans at different altitudes and in CMS patients, was examined.

Methods: 94 men were included: 18 lowlanders (LL), 38 healthy highlanders permanently living at 3800 m (n = 21-HL-3800) or in La Rinconada, the highest city in the world (5100-5300 m) (n = 17-HL-5100/No CMS). Moreover, 14 participants with mild (Mild CMS) and 24 with moderate to severe CMS (Mod/Sev CMS) were recruited.

Phenotyping patients treated for obstructive sleep apnea with persistent objective impaired alertness or subjective sleepiness.

Background And Objectives: Sleepiness in patients with obstructive sleep apnea (OSA) is associated with accidental and economic burden, as well as cardiovascular risk. Despite OSA treatment, 10-28 % of patients report residual sleepiness. Its determinants, as well as those of objective impaired alertness remain poorly known.

Exercise and training in sickle cell disease: Safety, potential benefits, and recommendations.

Sickle cell disease (SCD) is a genetic disorder characterized by complex pathophysiological mechanisms leading to vaso-occlusive crisis, chronic pain, chronic hemolytic anemia, and vascular complications, which require considerations for exercise and physical activity. This review aims to elucidate the safety, potential benefits, and recommendations regarding exercise and training in individuals with SCD. SCD patients are characterized by decreased exercise capacity and tolerance.

Making a virtue out of an evil: Are red blood cells from chronic mountain sickness patients eligible for transfusions?

We investigated highlanders, permanently living at an altitude of 5100 m and compared Chronic Mountain Sickness (CMS) patients with control volunteers. While we found differences in systemic parameters such as blood oxygen content, hematocrit, hemoglobin concentration, and blood viscosity, the mechanical and rheological properties of single red blood cells did not differ between the two investigated groups.

Are coagulation profiles in Andean highlanders with excessive erythrocytosis favouring hypercoagulability?

Chronic mountain sickness is a maladaptive syndrome that affects individuals living permanently at high altitude and is characterized primarily by excessive erythrocytosis (EE). Recent results concerning the impact of EE in Andean highlanders on clotting and the possible promotion of hypercoagulability, which can lead to thrombosis, were contradictory. We assessed the coagulation profiles of Andeans highlanders with and without excessive erythrocytosis (EE+ and EE-).

Impaired post-sleep apnea autonomic arousals in patients with drug-resistant epilepsy.

Objective: Sudden and unexpected deaths in epilepsy (SUDEP) pathophysiology may involve an interaction between respiratory dysfunction and sleep/wake state regulation. We investigated whether patients with epilepsy exhibit impaired sleep apnea-related arousals.

Methods: Patients with drug-resistant (N = 20) or drug-sensitive (N = 20) epilepsy and obstructive sleep apnea, as well as patients with sleep apnea but without epilepsy (controls, N = 20) were included.

Genetic polymorphisms and expression of Rhesus blood group RHCE are associated with 2,3-bisphosphoglycerate in humans at high altitude.

Red blood cell (RBC) metabolic reprogramming upon exposure to high altitude contributes to physiological human adaptations to hypoxia, a multifaceted process critical to health and disease. To delve into the molecular underpinnings of this phenomenon, first, we performed a multi-omics analysis of RBCs from six lowlanders after exposure to high-altitude hypoxia, with longitudinal sampling at baseline, upon ascent to 5,100 m and descent to sea level. Results highlighted an association between erythrocyte levels of 2,3-bisphosphoglycerate (BPG), an allosteric regulator of hemoglobin that favors oxygen off-loading in the face of hypoxia, and expression levels of the Rhesus blood group RHCE protein.

Expedition 5300: limits of human adaptations in the highest city in the world.

Exposure to chronic hypobaric hypoxia imposes a significant physiological burden to more than 80 million humans living above 2500 m throughout the world. Among them, 50 000 live in the world's highest city, La Rinconada, located at 5000-5300 m in southern Peru. Expedition 5300 is the first scientific and medical programme led in La Rinconada to investigate the physiological adaptations and altitude-related health issues in this unique population.

Unveiled central hypoventilation after tracheotomy in anti-IgLON5 disease: a case report.

Unlabelled: Anti-IgLON5 disease is a recently described entity that has been associated with neurological symptoms and sleep disturbances including sleep breathing disorders. Sleep stridor as well as obstructive and less often central sleep apnea have been reported but rarely needing ventilation on tracheotomy. We report the case of a patient in whom obstructive sleep apnea with secondary development of dysphagia and recurrent aspiration pneumonia led to the diagnosis of anti-IgLON 5 disease.

Effects of a Maximal Exercise Followed by a Submaximal Exercise Performed in Normobaric Hypoxia (2500 m), on Blood Rheology, Red Blood Cell Senescence, and Coagulation in Well-Trained Cyclists.

Acute normoxic exercise impacts the rheological properties of red blood cells (RBC) and their senescence state; however, there is a lack of data on the effects of exercise performed in hypoxia on RBC properties. This crossover study compared the effects of acute hypoxia vs. normoxia on blood rheology, RBC senescence, and coagulation during exercise.

Cardiorespiratory Fitness and Neuromuscular Function of Mechanically Ventilated ICU COVID-19 Patients.

Objectives: The aim of the current study was to investigate the level of cardiorespiratory fitness and neuromuscular function of ICU survivors after COVID-19 and to examine whether these outcomes are related to ICU stay/mechanical ventilation duration.

Design: Prospective nonrandomized study.

Setting: Patients hospitalized in ICU for COVID-19 infection.

The human blood transcriptome exhibits time-of-day-dependent response to hypoxia: Lessons from the highest city in the world.

High altitude exposes humans to hypobaric hypoxia, which induces various physiological and molecular changes. Recent studies point toward interaction between circadian rhythms and the hypoxic response, yet their human relevance is lacking. Here, we examine the effect of different high altitudes in conjunction with time of day on human whole-blood transcriptome upon an expedition to the highest city in the world, La Rinconada, Peru, which is 5,100 m above sea level.