New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles

Medical personnel need practical guidelines on how to construct high altitude ascents to induce altitude acclimatization and avoid acute mountain sickness (AMS) following the first night of sleep at high altitude. Using multiple logistic regression and a comprehensive database, we developed a quanti...

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Autores principales: Beidleman, Beth A., Fulco, Charles S., Cymerman, Allen, Staab, Janet E., Buller, Mark J., Muza, Stephen R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6817994/
https://www.ncbi.nlm.nih.gov/pubmed/31660703
http://dx.doi.org/10.14814/phy2.14263
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author Beidleman, Beth A.
Fulco, Charles S.
Cymerman, Allen
Staab, Janet E.
Buller, Mark J.
Muza, Stephen R.
author_facet Beidleman, Beth A.
Fulco, Charles S.
Cymerman, Allen
Staab, Janet E.
Buller, Mark J.
Muza, Stephen R.
author_sort Beidleman, Beth A.
collection PubMed
description Medical personnel need practical guidelines on how to construct high altitude ascents to induce altitude acclimatization and avoid acute mountain sickness (AMS) following the first night of sleep at high altitude. Using multiple logistic regression and a comprehensive database, we developed a quantitative prediction model using ascent profile as the independent variable and altitude acclimatization status as the dependent variable from 188 volunteers (147 men, 41 women) who underwent various ascent profiles to 4 km. The accumulated altitude exposure (AAE), a new metric of hypoxic dose, was defined as the ascent profile and was calculated by multiplying the altitude elevation (km) by the number of days (d) at that altitude prior to ascent to 4 km. Altitude acclimatization status was defined as the likely presence or absence of AMS after ~24 h of exposure at 4 km. AMS was assessed using the Cerebral Factor Score (AMS‐C) from the Environmental Symptoms Questionnaire and deemed present if AMS‐C was ≥0.7. Other predictor variables included in the model were age and body mass index (BMI). Sex, race, and smoking status were considered in model development but eliminated due to inadequate numbers in each of the ascent profiles. The AAE (km·d) significantly (P < 0.0001) predicted AMS in the model. For every 1 km·d increase in AAE, the odds of getting sick decreased by 41.3%. Equivalently, for every 1 km·d decrease in AAE, the odds of getting sick increased by 70.4%. Age and BMI were not significant predictors. The model demonstrated excellent discrimination (AUC = 0.83 (95% CI = 0.79–0.91) and calibration (Hosmer‐Lemeshow = 0.11). The model provides a priori estimates of altitude acclimatization status resulting from the use of various rapid, staged, and graded ascent profiles.
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spelling pubmed-68179942019-11-04 New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles Beidleman, Beth A. Fulco, Charles S. Cymerman, Allen Staab, Janet E. Buller, Mark J. Muza, Stephen R. Physiol Rep Original Research Medical personnel need practical guidelines on how to construct high altitude ascents to induce altitude acclimatization and avoid acute mountain sickness (AMS) following the first night of sleep at high altitude. Using multiple logistic regression and a comprehensive database, we developed a quantitative prediction model using ascent profile as the independent variable and altitude acclimatization status as the dependent variable from 188 volunteers (147 men, 41 women) who underwent various ascent profiles to 4 km. The accumulated altitude exposure (AAE), a new metric of hypoxic dose, was defined as the ascent profile and was calculated by multiplying the altitude elevation (km) by the number of days (d) at that altitude prior to ascent to 4 km. Altitude acclimatization status was defined as the likely presence or absence of AMS after ~24 h of exposure at 4 km. AMS was assessed using the Cerebral Factor Score (AMS‐C) from the Environmental Symptoms Questionnaire and deemed present if AMS‐C was ≥0.7. Other predictor variables included in the model were age and body mass index (BMI). Sex, race, and smoking status were considered in model development but eliminated due to inadequate numbers in each of the ascent profiles. The AAE (km·d) significantly (P < 0.0001) predicted AMS in the model. For every 1 km·d increase in AAE, the odds of getting sick decreased by 41.3%. Equivalently, for every 1 km·d decrease in AAE, the odds of getting sick increased by 70.4%. Age and BMI were not significant predictors. The model demonstrated excellent discrimination (AUC = 0.83 (95% CI = 0.79–0.91) and calibration (Hosmer‐Lemeshow = 0.11). The model provides a priori estimates of altitude acclimatization status resulting from the use of various rapid, staged, and graded ascent profiles. John Wiley and Sons Inc. 2019-10-29 /pmc/articles/PMC6817994/ /pubmed/31660703 http://dx.doi.org/10.14814/phy2.14263 Text en © 2019 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Research
Beidleman, Beth A.
Fulco, Charles S.
Cymerman, Allen
Staab, Janet E.
Buller, Mark J.
Muza, Stephen R.
New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles
title New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles
title_full New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles
title_fullStr New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles
title_full_unstemmed New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles
title_short New metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles
title_sort new metric of hypoxic dose predicts altitude acclimatization status following various ascent profiles
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6817994/
https://www.ncbi.nlm.nih.gov/pubmed/31660703
http://dx.doi.org/10.14814/phy2.14263
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