altitude exposure
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Author(s):  
Michael M. Tymko ◽  
Christopher K. Willie ◽  
Connor A. Howe ◽  
Ryan L. Hoiland ◽  
Rachel Stone ◽  
...  

High-altitude exposure results in a hyperventilatory-induced respiratory alkalosis followed by renal compensation (bicarbonaturia) to return arterial blood pH(a) toward sea-level values. However, acid-base balance has not been comprehensively examined in both lowlanders and indigenous populations - where the latter are thought to be fully adapted to high-altitude. The purpose of this investigation was to compare acid-base balance between acclimatizing lowlanders, and Andean and Sherpa highlanders at various altitudes (~3,800, ~4,300, and ~5,000 m). We compiled data collected across five independent high-altitude expeditions and report the following novel findings: 1) at 3,800 m, Andeans (n=7) had elevated pHa compared to Sherpas (n=12; P<0.01), but not to lowlanders (n=16; nine days acclimatized; P=0.09); 2) at 4,300 m, lowlanders (n=16; 21 days acclimatized) had elevated pHa compared to Andeans (n=32) and Sherpas (n=11; both P<0.01), and Andeans had elevated pHa compared to Sherpas (P=0.01); and 3) at 5,000 m, lowlanders (n=16; 14 days acclimatized) had higher pHa compared to both Andeans (n=66) and Sherpas (n=18; P<0.01, and P=0.03, respectively), and Andean and Sherpa highlanders had similar blood pHa (P=0.65). These novel data characterize acid-base balance acclimatization and adaptation to various altitudes in lowlanders and indigenous highlanders.


2022 ◽  
Vol 8 ◽  
Author(s):  
Renzheng Chen ◽  
Xiaowei Ye ◽  
Mengjia Sun ◽  
Jie Yang ◽  
Jihang Zhang ◽  
...  

Background: Acute high altitude (HA) exposure results in blood pressure (BP) variations in most subjects. Previous studies have demonstrated that higher BP is potentially correlated with acute mountain sickness (AMS). The BP load may be of clinical significance regarding systemic circulation status.Objectives: This study aimed to examine HA-induced BP changes in patients with AMS compared to those in healthy subjects. Further, we provided clinical information about the relationship between variations in 24-h ambulatory parameters (BP level, BP variability, and BP load) and AMS.Methods: Sixty-nine subjects were enrolled and all participants ascended Litang (4,100 m above sea level). They were monitored using a 24-h ambulatory blood pressure device and underwent echocardiography within 24 h of altitude exposure. The 2018 Lake Louise questionnaire was used to evaluate AMS.Results: The AMS group comprised more women than men [15 (65.2%) vs. 13 (28.3%), P &lt; 0.001] and fewer smokers [4 (17.4%) vs. 23 (50.0%), P = 0.009]. The AMS group exhibited significant increases in 24-h BP compared to the non-AMS group (24-h SBP variation: 10.52 ± 6.48 vs. 6.03 ± 9.27 mmHg, P = 0.041; 24-h DBP variation: 8.70 ± 4.57 vs. 5.03 ± 4.98 mmHg, P = 0.004). The variation of mean 24-h cBPL (cumulative BP load) (mean 24-h cSBPL: 10.58 ± 10.99 vs. 4.02 ± 10.58, P = 0.016; 24-h mean cDBPL: 6.03 ± 5.87 vs. 2.89 ± 4.99, P = 0.034) was also obviously higher in AMS subjects than in non-AMS subjects after HA exposure. 24-h mean cSBPL variation (OR = 1.07, P = 0.024) and 24-h mean cDBPL variation (OR = 1.14, P = 0.034) were independent risk factors of AMS. Moreover, variation of 24-h mean cSBPL showed a good correlation with AMS score (R = 0.504, P &lt; 0.001).Conclusions: Our study demonstrated that patients with AMS had higher BP and BP load changes after altitude exposure than healthy subjects. Excessive BP load variations were associated with AMS. Thus, BP load could be an effective indicator regarding systemic circulation status of AMS.


2021 ◽  
Vol Volume 16 ◽  
pp. 3503-3512
Author(s):  
Martina Meszaros ◽  
Tsogyal D Latshang ◽  
Sayaka S Aeschbacher ◽  
Fabienne Huber ◽  
Deborah Flueck ◽  
...  

2021 ◽  
Author(s):  
Mengxue Liu ◽  
Man Wang ◽  
Jia Huang ◽  
Zuojia Zeng ◽  
Keli Huang ◽  
...  

Abstract Objective Chronic high-altitude exposure has been shown to reduce ischemia-reperfusion injury in animal experiments. The objective was to evaluate the clinical protective effect of long-term high-altitude hypoxic exposure for patients undergoing cardiac surgery with cardiopulmonary bypass. Methods In this retrospective cohort study, data from patients who underwent cardiac procedures between January 2013 and December 2019 at a single center was collected. Patients were divided into highlander group (> 2500 m) and lowlander group (< 1500 m) according to the altitude of their residence. A propensity-score-matched analysis was performed to estimate the association of long-term high-altitude exposure and cardiac surgery outcomes. Results In a total of 2085 patients, 128 highlander patients were matched to 248 lowlander patients. The levels of CK-MB and hs-TnI upon arrival at the intensive care unit were lower in the highlander group compared to the lowlander group [70.6 U/L (56.0, 92.6) vs 85.0 U/L (68.5, 113.5), P < 0.001; 6.1 ng/mL (3.3,11.2) vs 7.9 ng/mL (3.6, 14.1), P = 0.011, respectively]. The highlander group also had a lower incidence of acute kidney injury (13.3% vs 21.8%, P = 0.046). The in-hospital mortality in the highlander group was lower than in the lowlander group without statistical significance (0.8% vs 4.0%, P = 0.107). Conclusions Long-term high-altitude exposure was associated with less myocardial injury and a lower incidence of acute kidney injury after cardiac surgery.


Author(s):  
Diana Elizabeth Alcantara-Zapata ◽  
Aníbal J Llanos ◽  
Carolina Nazzal

Abstract Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to acute, chronic, or intermittent hypobaric hypoxia turn on several mechanisms at the system, cellular and molecular level to cope with oxygen atmosphere scarcity maintaining the oxygen homeostasis. This exposure affects the whole organism and function of many systems, such as cardiovascular, respiratory, and reproductive. On the other hand, malignant prostate is related to the scarcity of oxygen in the tissue microenvironment due to its low availability and high consumption due to the swift cell proliferation rates. Based on the literature, this similarity in the oxygen scarcity suggests that hypobaric hypoxia, and other common factors between these two conditions, could be involved in the aggravation of the pathological prostatic status. However, there is still a lack of evidence in the association of this disease in males at high altitudes. This review aims to examine the possible mechanisms that hypobaric hypoxia might negatively add to the pathological prostate function in males who live and work at high altitudes. More profound investigations of hypobaric hypoxia’s direct action on the prostate could help understand this exposure’s effect and prevent worse prostate illness impact in males at high altitudes.


2021 ◽  
pp. 1-4
Author(s):  
Christopher Stremmel ◽  
Nikolay Vdovin ◽  
Antonia Kellnar ◽  
Wolfgang Hamm ◽  
Anna Strüven ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Isaie Sibomana ◽  
Daniel P. Foose ◽  
Michael L. Raymer ◽  
Nicholas V. Reo ◽  
J. Philip Karl ◽  
...  

Individuals sojourning at high altitude (≥2,500m) often develop acute mountain sickness (AMS). However, substantial unexplained inter-individual variability in AMS severity exists. Untargeted metabolomics assays are increasingly used to identify novel biomarkers of susceptibility to illness, and to elucidate biological pathways linking environmental exposures to health outcomes. This study used untargeted nuclear magnetic resonance (NMR)-based metabolomics to identify urine metabolites associated with AMS severity during high altitude sojourn. Following a 21-day stay at sea level (SL; 55m), 17 healthy males were transported to high altitude (HA; 4,300m) for a 22-day sojourn. AMS symptoms measured twice daily during the first 5days at HA were used to dichotomize participants according to AMS severity: moderate/severe AMS (AMS; n=11) or no/mild AMS (NoAMS; n=6). Urine samples collected on SL day 12 and HA days 1 and 18 were analyzed using proton NMR tools and the data were subjected to multivariate analyses. The SL urinary metabolite profiles were significantly different (p≤0.05) between AMS vs. NoAMS individuals prior to high altitude exposure. Differentially expressed metabolites included elevated levels of creatine and acetylcarnitine, and decreased levels of hypoxanthine and taurine in the AMS vs. NoAMS group. In addition, the levels of two amino acid derivatives (4-hydroxyphenylpyruvate and N-methylhistidine) and two unidentified metabolites (doublet peaks at 3.33ppm and a singlet at 8.20ppm) were significantly different between groups at SL. By HA day 18, the differences in urinary metabolites between AMS and NoAMS participants had largely resolved. Pathway analysis of these differentially expressed metabolites indicated that they directly or indirectly play a role in energy metabolism. These observations suggest that alterations in energy metabolism before high altitude exposure may contribute to AMS susceptibility at altitude. If validated in larger cohorts, these markers could inform development of a non-invasive assay to screen individuals for AMS susceptibility prior to high altitude sojourn.


Author(s):  
Martina Meszaros ◽  
Tsogayl D Latshang ◽  
Sayaka Aeschbacher ◽  
Fabienne Huber ◽  
Deborah Flueck ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Hebing Xie ◽  
Gang Xu ◽  
Jiye Aa ◽  
Shuhua Gu ◽  
Yuqi Gao

High-altitude hypoxia has long been recognized as a vital etiology for high-altitude illnesses. High-altitude myocardial injury (HAMI) usually occurs in people who suffered from high-altitude exposure. To date, the molecular mechanism of HAMI remains elusive, which seriously hinders the prevention and treatment of HAMI. L-carnitine and trimetazidine are classic cardiovascular protective medicines. In this study, we used the metabolomic method, based on GC/MS, to explore the changes in metabolites in rats exposed to high-altitude hypoxia and then illustrate the metabolic pathways associated with the modulatory effect of L-carnitine combined with trimetazidine on rats with high-altitude exposure. The results showed that metabolites in the myocardium in rats under high-altitude hypoxia were markedly changed, such as branched-chain amino acids (BCAA, leucine, isoleucine, and valine), taurine, succinic acid, fumaric acid, lactic acid, pyruvic acid, 3-hydroxybutyrate, and docosahexaenoic acid (DHA), while L-carnitine combined with trimetazidine modulated and improved the abnormal changes in energy substances caused by high-altitude hypoxia. L-carnitine mainly promoted the metabolism of fatty acids, while trimetazidine enhanced the glycolysis process. The combined administration of the two components not only increased the metabolism of fatty acids but also promoted aerobic glycolysis. Meanwhile, it contributed to the decrease in the elevation in some of the intermediates of the tricarboxylic acid (TCA) cycle, decrease in the production of 3-hydroxybutyric acid, and relief of the abnormal energy metabolism process in organisms and the cardiac tissue. Our analysis delineates the landscape of the metabolites in the myocardial tissue of rats that were exposed to high altitude. Moreover, L-carnitine combined with trimetazidine can relieve the HAMI through modulated and improved abnormal changes in energy substances caused by high-altitude hypoxia.


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