scholarly journals Urinary Metabolites as Predictors of Acute Mountain Sickness Severity

2021 ◽  
Vol 12 ◽  
Author(s):  
Isaie Sibomana ◽  
Daniel P. Foose ◽  
Michael L. Raymer ◽  
Nicholas V. Reo ◽  
J. Philip Karl ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
High Altitude ◽  
Acute Mountain Sickness ◽  
Urinary Metabolites ◽  
Individual Variability ◽  
Differentially Expressed ◽  
Urine Metabolites ◽  
Altitude Exposure ◽  
Novel Biomarkers ◽  
Mountain Sickness

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.

scholarly journals Oxidative stress and erythropoietin response in altitude exposure

2008 ◽  
Vol 31 (6) ◽  
pp. 380 ◽  
Author(s):  
Hsien-Hao Huang ◽  
Chih-Ly Han ◽  
Horng-Chin Yan ◽  
Woei-Yau Kao ◽  
Chu-Dang Tsai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
High Altitude ◽  
Sea Level ◽  
Ferritin Level ◽  
Acute Mountain Sickness ◽  
Thiobarbituric Acid ◽  
Altitude Exposure ◽  
Delayed Recovery ◽  
Mountain Sickness ◽  
Stress Burden

Purpose: Oxidative stress and erythropoietin (EPO) levels are increased following high altitude exposure. We hypothesized that the altitude-oxidative stress and EPO response would be associated with the presence or absence of acute mountain sickness (AMS) in subjects exposed at high altitude. Methods: The study enrolled 29 healthy volunteers exposed at altitudes without strenuous physical exercise. Oxidative stress was determined by the spectrophotometric measurement of the colour occurring during the reaction of malondialdehyde (MDA) with thiobarbituric acid (TBA) on blood samples. Ferritin and EPO were also measured simultaneously. Results: During a rise in altitude at 2000 and 3000 m, there were no changes in plasma ferritin level in either of the 2 groups with or without AMS. In contrast, EPO increased at an altitude of 3000 m and after returning to sea level (28.2±2.7, 26.9±3.3 vs 12.2±1.4 and 17.1±1.6, P < 0.05, in group without AMS; 29.3±4.5, 22.8±2.7 vs 10.6±1.0 and 16.1±1.5, # P < 0.05, in group with AMS; compared with the baseline level and at the height of 2000 meters). At a height of 3000 m, plasma MDA level was elevated compared with that at the altitude of baseline and 2000 m in both groups of subjects with and without AMS (3.77±0.29 vs 1.14±0.17, and 1.64±0.22, P < 0.001, in subjects with AMS; 3.65±0.39 vs 1.71±0.21, and 1.73±0.21, P < 0.001, in subjects without AMS) . After returning to sea level, subjects without AMS had lower MDA oxidative stress compared with those with AMS (2.58±0.26 vs 3.51±0.24, P = 0.0223). Along with a rise in altitude, the oxidative stress in these both groups was not correlated with the changes in EPO (r2 = 0.0728, P = 0.1096). Conclusion: High altitude-induced oxidative stress, detected by MDA assay, is not different between the two groups of subjects with and without AMS. Upon return to sea level, subjects without AMS had lower MDA oxidative stress burden and higher EPO level than those with AMS. Whether the subjects with altitude illness had delayed recovery from oxidative stress merits further investigation.

Relationship of Activity Patterns to Acute Mountain Sickness in South Pole Workers

2019 ◽  
Vol 40 (07) ◽  
pp. 440-446
Author(s):  
Girish Pathangey ◽  
Courtney M. Wheatley-Guy ◽  
Glenn Stewart ◽  
Paul J. Anderson ◽  
Maile L. Ceridon Richert ◽  
...  
Keyword(s):  
Physical Activity ◽  
High Altitude ◽  
Vigorous Physical Activity ◽  
Venous Blood ◽  
Acute Mountain Sickness ◽  
South Pole ◽  
Initial Exposure ◽  
Altitude Exposure ◽  
Activity Intensity ◽  
Mountain Sickness

AbstractThis study aimed to evaluate the influence of physical activity on incidence of acute mountain sickness (AMS) by continuous activity monitoring in a free-living sample of South Pole workers over the initial 72 h at altitude exposure of 2,840 m (9,318 ft). Body Media activity monitors were worn by 47 healthy participants. AMS was defined by the Lake Louise symptom questionnaire. Venous blood samples were taken at sea level and approximately 48 h after high altitude exposure. AMS incidence was 34% (n=16/47) over the first 48 h and 40% (n=19/47) over 72 h. On day 2 at high altitude, individuals with AMS demonstrated a significantly greater increase in the percent change in physical activity metrics from baseline: total energy expenditure 19±13 vs. 5±7%, total steps 65±51 vs. 10±18%, metabolic equivalent of tasks 21±13 vs. 7±13%, and time spent performing moderate to vigorous physical activity 114±79 vs. 26±27% for individuals with AMS vs. no AMS, respectively, p<0.05. In addition, erythropoietin and vascular endothelial growth factor were 1.69 and 1.75 times higher, respectively, in those with AMS. In conclusion, workers who engaged in increased physical activity and activity intensity during initial exposure to the South Pole were more susceptible to developing AMS.

scholarly journals Influence of Acetazolamide on Hand Strength and Manual Dexterity During a 30-h Simulated High Altitude Exposure

2020 ◽  
Vol 185 (7-8) ◽  
pp. e1161-e1167 ◽  
Author(s):  
Beau R Yurkevicius ◽  
Karleigh E Bradbury ◽  
Adam C Nixon ◽  
Katherine M Mitchell ◽  
Adam J Luippold ◽  
...  
Keyword(s):  
High Altitude ◽  
Statistical Significance ◽  
Hand Function ◽  
Acute Mountain Sickness ◽  
Manual Dexterity ◽  
Hand Strength ◽  
Repeated Measure ◽  
Pinch Strength ◽  
Altitude Exposure ◽  
Mountain Sickness

Abstract Introduction High altitude missions pose significant challenges to Warfighter medical readiness and performance. Decreased circulating oxygen levels cause a decrease in exercise performance and can cause debilitating symptoms associated with acute mountain sickness, especially with rapid ascent. Acetazolamide (AZ) is known to minimize symptoms of acute mountain sickness, but it is unknown whether this medication alters hand strength and manual dexterity during altitude exposure. Materials and Methods Ten male volunteers (22 ± 4 yr, 75.9 ± 13.7 kg, 174.9 ± 9.3 cm) participated in two separate 30 h simulated altitude exposures (496 mmHg, equivalent to 3,500 m, 20°C, 20% RH) in a hypobaric chamber. Participants were given either a placebo or 250 mg of AZ twice daily for 3.5 d (2 sea-level [SL] days + the 30 h altitude exposure) in a randomized, single-blind, crossover design. During SL and both altitude (ALT) exposures, hand function tests were performed, including hand grip and finger pinch strength tests, as well as the Purdue Pegboard (PP) and magazine loading tests to assess manual dexterity. Paired T tests and two-way repeated measure analysis of variance were used as appropriate to evaluate the effects of AZ and ALT. The value of p &lt; 0.05 was accepted for statistical significance. Results There were no influences of acute ALT exposure or AZ treatment on hand strength (eg, grip strength; SL: 39.2 ± 5.5 kg vs. ALT: 41.5 ± 6.9 kg, p &gt; 0.05) or dexterity (eg, PPassembly; placebo: 35.5 ± 5.3 vs. AZ: 34.3 ± 4.6, p &gt; 0.05) in our volunteers. Two dexterity tests (PPsum and magazine loading) showed improvements over time at ALT, regardless of treatment, where scores were improved after 10 h of exposure compared to at 1 h (eg, magazine loading: 56 ± 12 vs. 48 ± 10, p &lt; 0.001). This pattern was not seen in the PPassembly test or any strength measurements. Conclusions Our results suggest that 500 mg/d of AZ does not influence hand strength or manual dexterity during a 30 h exposure to 3,500 m simulated ALT. Acute ALT exposure (1 h) did not influence dexterity or strength, although some measures of dexterity showed improvements as exposure time increased. We conclude that use of AZ to optimize medical readiness at ALT is unlikely to impair the Warfighter’s ability to complete mission tasks that depend on hand function.

Optic nerve oedema at high altitude occurs independent of acute mountain sickness

2018 ◽  
Vol 103 (5) ◽  
pp. 692-698 ◽  
Author(s):  
Andreas Schatz ◽  
Vanessa Guggenberger ◽  
M Dominik Fischer ◽  
Kai Schommer ◽  
Karl Ulrich Bartz-Schmidt ◽  
...  
Keyword(s):  
Optic Nerve ◽  
High Altitude ◽  
Optic Disc ◽  
Acute Mountain Sickness ◽  
Optic Nerve Sheath Diameter ◽  
Future Research ◽  
Oedema Formation ◽  
Altitude Exposure ◽  
Mountain Sickness ◽  
High Altitude Illness

Background/aimsThe study aims to investigate changes in the optic nerve sheath diameter (ONSD) at high altitude and to assess correlation to optic disc oedema (ODE) and acute mountain sickness (AMS). This investigation is part of the Tübingen High Altitude Ophthalmology study.MethodsFourteen volunteers ascended to 4559 m for 4 days before returning to low altitude. Ultrasonography of ONSD, quantification of optic disc parameters using a scanning laser ophthalmoscope and fluorescein angiography were performed at 341 m and at high altitude. Pearson’s coefficient was used to correlate changes in ONSD with the optic disc and AMS. Assessment of AMS was performed using the Lake Louise (LL) and AMS-cerebral (AMS-C) scores of the Environmental Symptom Questionnaire-III. All volunteers were clinically monitored for heart rate (HR) and oxygen saturation (SpO2).ResultsThe mean ONSD at high altitude (4.6±0.3 mm, p<0.05) was significantly increased compared with baseline (3.8±0.4 mm) and remained enlarged throughout high-altitude exposure. This change in ONSD did not correlate with AMS (AMS-C, r=0.26, p=0.37; LL, r=0.21, p=0.48) and high-altitude headache (r=0.54, p=0.046), or clinical parameters of SpO2 (r=0.11, p=0.72) and HR (r=0.22, p=0.44). Increased ONSD did not correlate with altered key stereometric parameters of the optic disc describing ODE at high altitude (r<0.1, p>0.5).ConclusionHigh-altitude exposure leads to marked oedema formation of the optic nerve independent of AMS. Increased ONSD and ODE reflect hypoxia-driven oedema formation of the optic nerve at high altitude, providing important pathophysiological insight into high-altitude illness development and for future research.

scholarly journals Multiple Sclerosis Exacerbation Associated With High-Altitude Climbing Exposure

2019 ◽  
Vol 185 (7-8) ◽  
pp. e1322-e1325
Author(s):  
David T Hsieh ◽  
Graham I Warden ◽  
Jay M Butler ◽  
Erika Nakanishi ◽  
Yuri Asano
Keyword(s):  
Multiple Sclerosis ◽  
High Altitude ◽  
Air Force ◽  
Acute Mountain Sickness ◽  
Neurological Deficits ◽  
Altitude Exposure ◽  
High Altitude Cerebral Edema ◽  
Potential Trigger ◽  
Mountain Sickness ◽  
Neurological Effects

Abstract The spectrum of the neurological effects of high-altitude exposure can range from high-altitude headache and acute mountain sickness, to the more severe end of the spectrum with high-altitude cerebral edema. In general, patients with known unstable preexisting neurological conditions and those patients with residual neurological deficits from a preexisting neurological condition are discouraged from climbing to high altitudes because of the risk of exacerbation or worsening of symptoms. Although multiple sclerosis exacerbations can be triggered by environmental factors, high-altitude exposure has not been reported as a potential trigger. We are reporting the case of a multiple sclerosis exacerbation presenting in an active duty U.S. Air Force serviceman upon ascending and descending Mt. Fuji within the same day.

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