Altitude And Coagulation

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-). Blood samples were collected from 30 EE+ and 15 EE- in La Rinconada (Peru, 5100-5300 m a...

BACKGROUND: Thromboelastogram (TEG) is an effective indicator that monitors the dynamic changes of blood coagulation in real-time. It still remains controversial about the performance and influence of coagulation at high altitude. The present study intends to describe comprehensively the clinical features of TEG in populations exposed to or transferring from high altitude. METHODS: Two groups were recruited in the present study. Group A included young males who worked at high-altitude (4888 m or 5418 m) areas for some time, while Group B included young males who had recently returned from high-altitude (4888 m or 5418 m) areas...

Hypoxia plays an important role in several pathologies, e.g. chronic obstructive pulmonary disease and obstructive sleep apnea syndrome, and is linked to an increased thrombosis risk. Furthermore, oxygen deprivation is associated with hypercoagulability. In this study, we investigated the effect of gender and exercise on the coagulation potential under hypoxic conditions at high altitude by assessing thrombin generation (TG) and platelet activation. Hereto, ten healthy volunteers were included (50 % male, median age of 27...

High altitude acclimatization and disease have been the centerpiece of investigations concerning human health at high altitude. Almost all investigations have focused on either understanding and ameliorating high altitude disease or finding better methods of acclimatization/training at high altitude. The aspect of altitude de-induction/de-acclimatization has remained clouded despite the fact that it was documented since the first decade of twentieth century. A few recent studies, particularly in China, have stated unanimously that high altitude de-acclimatization involved multiple observable clinical symptoms ranging from headache to abdominal distention...

Dangi, Meenu, Arnab Sadhukhan, Poninder Kumar, S. Bandopadhayay, Vijay K. Sharma, V.K. Patra, Manu Chaudhary, and Vipin Rana. Retinal manifestations in high altitude. High Alt Med Biol. 00:000-000, 2023. Aim: To study the high altitude (HA)-related retinal manifestations among security personnel and thus to provide new insights into the characteristics and mechanisms of retinopathy. Materials and Methods: This was a multicentric, nonrandomized prospective observational and descriptive study. We studied 54 security personnel over 1 year, who were referred from HA areas of northern India and north-eastern India for ocular problems...

BACKGROUND: Previous literature suggests that thrombosis is more common in lowlanders sojourning at high altitude (HA) compared to near-sea-level. Though the pathophysiology is partly understood, little is known of its epidemiology. To elucidate this, an observational prospective longitudinal study was conducted in healthy soldiers sojourning for months at HA. METHODS: A total of 960 healthy male subjects were screened in the plains, of which 750 ascended, to altitudes above 15,000ft (4,472m)...

High‑altitude acute hypoxia is commonly associated with respiratory cardiovascular diseases. The inability to adapt to acute hypoxia may lead to cardiovascular dysfunction, lung injury and even death. Therefore, understanding the molecular basis of the adaptation to high‑altitude acute hypoxia may reveal novel therapeutic approaches with which to counteract the detrimental consequences of hypoxia. In the present study, a high‑altitude environment was simulated in a rat model in order to investigate the role of the high mobility group protein‑1 (HMGB1)/receptor for advanced glycation end products (RAGE)/NF‑κB and F2/Rho signaling pathways in lung injury induced by acute hypoxia...

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 prothrombotic changes both in intensive care and high altitude medicine. This research study aimed to evaluate the effect of isolated hypobaric hypoxia (HH) on coagulation in females in a highly standardized setting...

OBJECTIVE: Cerebral venous sinus thrombosis (CVST) is believed to be associated with high-altitude exposure and has worse clinical prognosis in plateau areas than in plain areas, although this needs to be further verified. This retrospective study aims to compare the clinical differences of patients with CVST in plateau and plain areas and further ascertain the role of high-altitude exposure in the etiology of aggravating predisposition toward CVST. METHODS: Twenty-four symptomatic CVST patients occurring at plateau areas (altitude ≥ 4000 m), in corresponding with 24 CVST patients occurring at plain areas (altitude ≤ 1000 m), were recruited according to the inclusion and exclusion criteria from June 2020 to December 2021...

BACKGROUND: In high-altitude areas, hypoxic stress can elicit a series of physiological responses in humans. Exosomes play important roles in both local and distal cellular communications. METHODS: We used ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) studies to analyze the differentially expressed metabolomics and proteomics in serum exosome of hypoxic preconditioning participants and control subjects in the hypoxic conditions...

BACKGROUND: The purpose of this study was to explore the changes in blood cellular and biochemical parameters of rats in a natural environment of low pressure and low oxygen on the plateau. METHODS: Male Sprague-Dawley rats in two groups were raised in different environments from 4 weeks of age for a period of 24 weeks. They were raised to 28 weeks of age and then transported to the plateau medical laboratory of Qinghai University. Blood cellular and biochemical parameters were measured and the data of the two groups were statistically analyzed...

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. Nine trained male cyclists completed both a session in normoxia (FiO2 = 21%) and hypoxia (FiO2 = 15.3% ≈ 2500 m). The two sessions were randomly performed, separated by one week, and consisted of an incremental and maximal exercise followed by a 20 min exercise at the first ventilatory threshold (VT1) on a home-trainer...

As an indigenous breed, the Tibetan chicken is found in highland regions and shows physiological adaptations to high altitude; however, the genetic changes that determine these adaptations remain elusive. We assumed that the microevolution of the Tibetan chicken occurred from lowland to highland regions with a continuous elevation range. In this study, we analyzed the genome of 188 chickens from lowland areas to the high-altitude regions of the Tibetan plateau with four altitudinal levels. Phylogenetic analysis revealed that Tibetan chickens are significantly different from other altitude chicken populations...

Objective: To explore the application value of plasma proteomics in the diagnosis and pathogenesis of high altitude polycythemia (HAPC). Methods: Ten patients with HAPC in Qinghai Provincial People's Hospital from January 2020 to January 2021 were selected as the experimental group, including 4 males and 6 females, aged (46±4) years. Ten healthy controls at the same altitude in the same period were selected as the control group, including 5 males and 5 females, aged (44±4) years. The differential proteins were identified and quantified by high performance liquid chromatography-mass spectrometry (HPLC-MS), and the gene ontology (GO) functional enrichment analysis, the Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis and interaction network analysis were conducted for the selected differential proteins...

OBJECTIVE: Post-operative bleeding after total knee arthroplasty (TKA) is a frequent cause of post-operative complications. This study compared blood loss and indicators of coagulation and fibrinolysis between TKA patients living at low or high altitudes. METHODS: We retrospectively analyzed 120 patients at our institution who underwent primary TKA from May 2019 to March 2020, and we divided them into those living in areas about 500 m or > 3000 m above sea level...

The purpose of this study was to explore the effect of acute hypoxia on urine proteome in rats. In this study, rats were placed in a hypoxic chamber simulating a plateau environment at an altitude of 5 000 m for 24 hours. Urine samples were collected at 0, 12, and 24 h after hypoxia. Urinary proteins were profiled using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Compared with the control (before hypoxia), a total of 144 differentially expressed proteins were identified in the hypoxia 12 h group, and 129 differentially expressed proteins were identified in the hypoxia 24 h group...

Objective: Hemostatic gauze application is an effective way to control major bleeding, which is the most common cause of death in trauma in both civilian and military settings. Coagulation derangement after acute exposure to high altitude might alter the effects of hemostatic gauzes. The present study aimed to observe the hemostatic effects of bio-zeolite gauze (BZG) and QuikClot Combat Gauze® (QCG) on major bleeding in rabbits acutely exposed to high altitude. Methods: Sixty rabbits were randomly and evenly divided into six groups...

Studies have shown significantly increased thromboembolic events at high altitude. We recently reported that transferrin could potentiate blood coagulation, but the underlying mechanism for high altitude-related thromboembolism is still poorly understood. Here, we examined the activity and concentration of plasma coagulation factors and transferrin in plasma collected from long-term human residents and short-stay mice exposed to varying altitudes. We found that the activities of thrombin and factor XIIa (FXIIa) along with the concentrations of transferrin were significantly increased in the plasma of humans and mice at high altitudes...

NEW FINDINGS: What is the central question of this study? Is the expression of platelet-derived growth factor (PDGF) and thromboxane A2 (TXA2) elevated in chronic altitude patients, and are they related to thrombosis in chronic mountain sickness? What is the main finding and its importance? The expression of PDGF and TXA2 in both the bone marrow and the peripheral blood of patients with chronic mountain sickness is elevated, and they are considered to be correlated in the mechanism of thrombosis in the chronic mountain sickness...

Preeclampsia is a multi-organ complication of pregnancy characterized by sudden hypertension and proteinuria that is among the leading causes of preterm delivery and maternal morbidity and mortality worldwide. The heterogeneity of preeclampsia poses a challenge for understanding its etiology and molecular basis. Intriguingly, risk for the condition increases in high-altitude regions such as the Peruvian Andes. To investigate the genetic basis of preeclampsia in a population living at high altitude, we characterized genome-wide variation in a cohort of preeclamptic and healthy Andean families (n = 883) from Puno, Peru, a city located above 3,800 meters of altitude...