{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T12:58:58Z","timestamp":1791291538026,"version":"4.3.0"},"reference-count":29,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000855","name":"University of Birmingham","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000855","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Physiol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Acute mountain sickness (AMS) affects a large proportion of individuals ascending to high altitude every year. While AMS is not life threatening, if left untreated it can progress to serious illness (e.g., high altitude cerebral oedema). Current assessment tools rely on subjective symptom reporting and do not enable prospective prediction. Objective, field-deployable methods for early risk stratification remain limited. This study evaluated whether physiological biomarkers derived from overnight pulse oximetry can predict subsequent AMS during ascent to Everest Base Camp (EBC).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      A field study was conducted in the Khumbu region of Nepal. Healthy lowlanders (n = 139\u2013144 across datasets) underwent overnight pulse oximetry recordings at Namche Bazaar (3,440 m) and Dingboche-level (4,371-4,730 m). A total of 125 physiological features were extracted from continuous, overnight oxygen saturation (SpO\n                      <jats:sub>2<\/jats:sub>\n                      ) and heart rate recordings. Supervised machine-learning models were trained to classify physician-diagnosed AMS at Lobuche (~4,940 m) using: 1) physiological biomarkers alone and 2) biomarkers combined with clinical and contextual metadata. Model performances were assessed using repeated stratified k-fold cross-validation, with area under the receiver operating characteristic curve (AUC) as the primary metric.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Biomarker-only models demonstrated consistent above-chance discrimination at both altitudes (mean AUC 0.74 at both Namche and Dingboche-level). At lower altitude, predictive performance was achieved using a small set of physiological features, and inclusion of metadata did not improve model performance. At higher altitude, combining biomarkers with contextual variables improved discrimination (AUC 0.84 \u00b1 0.08; sensitivity 0.73 \u00b1 0.23). Selected features were primarily related to nocturnal oxygenation burden, desaturation dynamics, and heart rate variability.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Overnight pulse oximetry captures physiological signals associated with subsequent AMS development prior to symptom onset. These findings support the feasibility of objective, non-invasive risk stratification during early ascent. Integration of wearable monitoring with computational modelling may provide a complementary tool to support preventative decision-making along high-altitude trekking routes.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fphys.2026.1939874","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T13:55:16Z","timestamp":1790776516000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Prediction of acute mountain sickness from overnight pulse oximetry during ascent to Everest Base Camp: a field-based machine learning study"],"prefix":"10.3389","volume":"17","author":[{"given":"Helen","family":"Abbott","sequence":"first","affiliation":[{"name":"Research Software Group, Advanced Research Computing, University of Birmingham","place":["Birmingham, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luke R.","family":"Cutts","sequence":"additional","affiliation":[{"name":"Salford Royal, National Health Service (NHS) Trust","place":["Salford, United Kingdom"]},{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ben","family":"Stanley","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Anaesthetics Department, Lancashire Teaching Hospitals, Royal Preston Hospital","place":["Preston, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suniva","family":"Kansakar","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Queen Elizabeth II, University Hospitals National Health Service (NHS) Trust","place":["Birmingham, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sophie E.","family":"Broughton","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Medical School, University of Birmingham","place":["Birmingham, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taea","family":"Scott","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Occupational Performance Research Group, University of Chichester","place":["Chichester, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sam","family":"Davis","sequence":"additional","affiliation":[{"name":"Medical School, University of Birmingham","place":["Birmingham, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah","family":"Clarke","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Anaesthesia & Intensive Care Medicine, Royal Blackburn Teaching Hospital, National Health Service (NHS) Trust","place":["Salford, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tim","family":"Clark","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Anaesthesia & Intensive Care Medicine, Royal Blackburn Teaching Hospital, National Health Service (NHS) Trust","place":["Salford, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ciaran","family":"Simpkins","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"United Lincolnshire Hospital, National Health Service (NHS) Trust","place":["Lincoln, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johnathan","family":"Goves","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Anaesthesia & Intensive Care Medicine, Royal Blackburn Teaching Hospital, National Health Service (NHS) Trust","place":["Salford, United Kingdom"]},{"name":"Nuffield Department of Clinical Neurosciences, University of Oxford","place":["Oxford, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ewein","family":"Howes","sequence":"additional","affiliation":[{"name":"Medical School, University of Cardiff","place":["Cardiff, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kyle T.","family":"Pattinson","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Nuffield Department of Clinical Neurosciences, University of Oxford","place":["Oxford, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adrian","family":"Garcia","sequence":"additional","affiliation":[{"name":"Research Software Group, Advanced Research Computing, University of Birmingham","place":["Birmingham, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William","family":"Trender","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"H2 Cognitive Diagnostics","place":["London, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arthur R.","family":"Bradwell","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Medical School, University of Birmingham","place":["Birmingham, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Santosh","family":"Baniya","sequence":"additional","affiliation":[{"name":"Emergency Medicine, Western Regional Hospital, Pokhara Academy of Health Sciences (PAHS)","place":["Pokhara, Nepal"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark","family":"Edsell","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Anaesthesia and Critical Care, Royal Brompton Hospital","place":["London, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kimberly","family":"Ashdown","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Occupational Performance Research Group, University of Chichester","place":["Chichester, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kelsey E.","family":"Joyce","sequence":"additional","affiliation":[{"name":"Birmingham Medical Research Expeditionary Society, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"School of Sport Exercise and Rehabilitation Sciences, University of Birmingham","place":["Birmingham, United Kingdom"]},{"name":"Human Integrative Physiology Lab, Mayo Clinic Arizona","place":["Scottsdale, AZ, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6579\/acd51a","article-title":"A review of the effect of skin pigmentation on pulse oximeter accuracy","volume":"44","author":"Al-Halawani","year":"2023","journal-title":"Physiol. Meas."},{"key":"B2","first-page":"867","article-title":"Everest or bust: a cross sectional, epidemiological study of acute mountain sickness at 4243 meters in the Himalayas","volume":"70","author":"Basnyat","year":"1999","journal-title":"Aviat. Space Environ. Med."},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.48550\/arXiv.2309.04498","article-title":"PhysioZoo: the open digital physiological biomarkers resource","author":"Behar","year":"2023","journal-title":"Quant. Biol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1136\/bmjsem-2017-000302","article-title":"Acetazolamide reduces exercise capacity following a 5-day ascent to 4559 m in a randomised study","volume":"4","author":"Bradwell","year":"2018","journal-title":"BMJ Open Sport Exercise Med."},{"key":"B5","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1089\/ham.2017.0160","article-title":"The STAR data reporting guidelines for clinical high altitude research","volume":"19","author":"Brodmann Maeder","year":"2018","journal-title":"High Alt. Med. Biol."},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.2196\/12866","article-title":"Wearable finger pulse oximetry for continuous oxygen saturation measurements during daily home routines of patients with chronic obstructive pulmonary disease (COPD) over one week: observational study","volume":"7","author":"Buekers","year":"2019","journal-title":"JMIR Mhealth Uhealth"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1136\/bmj-2023-078378","article-title":"TRIPOD+ AI statement: updated guidance for reporting clinical prediction models that use regression or machine learning methods","volume":"385","author":"Collins","year":"2024","journal-title":"bmj"},{"key":"B8","unstructured":"Tourism Trend in Sagarmatha National Park\n          \n          2021"},{"key":"B9","doi-asserted-by":"publisher","first-page":"403","DOI":"10.1111\/jtm.12160","article-title":"Serious altitude illness in travelers who visited a pre-travel clinic","volume":"21","author":"Croughs","year":"2014","journal-title":"J. Travel Med."},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1113\/EP093777","article-title":"Prediction of acute mountain sickness using overnight pulse oximetry during ascent to 4,554 m","author":"Cutts","year":"2026","journal-title":"Experimental Physiology"},{"key":"B11","doi-asserted-by":"publisher","first-page":"730","DOI":"10.1001\/jamainternmed.2022.1906","article-title":"Racial and ethnic discrepancy in pulse oximetry and delayed identification of treatment eligibility among patients with COVID-19","volume":"182","author":"Fawzy","year":"2022","journal-title":"JAMA Intern. Med."},{"key":"B12","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1097\/01.ASW.0000721168.40561.a3","article-title":"Validity of the fitzpatrick skin phototype classification in Ecuador","volume":"33","author":"Fors","year":"2020","journal-title":"Adv. Skin Wound Care"},{"key":"B13","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1113\/EP091875","article-title":"Pulse oximetry for the prediction of acute mountain sickness: A systematic review","volume":"109","author":"Goves","year":"2024","journal-title":"Exp. Physiol."},{"key":"B5001","article-title":"Effects of acetazolamide on exercise capacity in older adults at high-altitude: a systematic review. International Hypoxia Symposia. February 11th \u2013 15th","author":"Hand","year":"2025"},{"key":"B15","doi-asserted-by":"publisher","first-page":"446","DOI":"10.1016\/j.sleep.2007.06.017","article-title":"High-altitude sleep disturbance: results of the Groningen Sleep Quality Questionnaire survey","volume":"9","author":"Jafarian","year":"2008","journal-title":"Sleep Med."},{"key":"B16","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1113\/EP091691","article-title":"Nocturnal pulse oximetry for the detection and prediction of acute mountain sickness: An observational study","volume":"109","author":"Joyce","year":"2024","journal-title":"Exp. Physiol."},{"key":"B17","doi-asserted-by":"publisher","first-page":"1891","DOI":"10.1080\/14656566.2018.1528228","article-title":"Advances in the available non-biological pharmacotherapy prevention and treatment of acute mountain sickness and high altitude cerebral and pulmonary oedema","volume":"19","author":"Joyce","year":"2018","journal-title":"Expert Opin. Pharmacother."},{"key":"B18","doi-asserted-by":"publisher","first-page":"301","DOI":"10.1089\/ham.2008.1008","article-title":"Prevalence of acute mountain sickness among Finnish trekkers on Mount Kilimanjaro, Tanzania: an observational study","volume":"9","author":"Karinen","year":"2008","journal-title":"High Alt. Med. Biol."},{"key":"B19","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1089\/ham.2012.1092","article-title":"Variations in pulse oximetry at high altitude","volume":"14","author":"Kidd","year":"2013","journal-title":"High Alt. Med. Biol."},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6579\/abf5ad","article-title":"Machine learning for nocturnal diagnosis of chronic obstructive pulmonary disease using digital oximetry biomarkers","volume":"42","author":"Levy","year":"2021","journal-title":"Physiol. Meas."},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1038\/s41746-020-00373-5","article-title":"Digital oximetry biomarkers for assessing respiratory function: standards of measurement, physiological interpretation, and clinical use","volume":"4","author":"Levy","year":"2021","journal-title":"NPJ Digit Med."},{"key":"B22","doi-asserted-by":"publisher","first-page":"2S","DOI":"10.1016\/j.wem.2023.05.013","article-title":"Wilderness medical society clinical practice guidelines for the prevention, diagnosis, and treatment of acute altitude illness: 2024 update","volume":"35","author":"Luks","year":"2024","journal-title":"Wilderness Environ. Med."},{"key":"B23","doi-asserted-by":"publisher","first-page":"1810","DOI":"10.1001\/jama.2017.16192","article-title":"Does this patient have acute mountain sickness?: the rational clinical examination systematic review","volume":"318","author":"Meier","year":"2017","journal-title":"JAMA"},{"key":"B24","doi-asserted-by":"publisher","first-page":"4","DOI":"10.1089\/ham.2017.0164","article-title":"The 2018 lake louise acute mountain sickness score","volume":"19","author":"Roach","year":"2018","journal-title":"High Alt. Med. Biol."},{"key":"B25","first-page":"872","article-title":"The environmental symptoms questionnaire: revisions and new filed data","volume":"51","author":"Sampson","year":"1980","journal-title":"Aviat. Space Environ. Med."},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1136\/bmjopen-2017-017058","article-title":"Relationship of altitude mountain sickness and smoking: a Catalan traveller's cohort study","volume":"7","author":"S\u00e1nchez-Mascu\u00f1ano","year":"2017","journal-title":"BMJ Open"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.1136\/bmjresp-2020-000557","article-title":"Side effects of acetazolamide: a systematic review and meta-analysis assessing overall risk and dose dependence","volume":"7","author":"Schmickl","year":"2020","journal-title":"BMJ Open Respir. Res."},{"key":"B28","doi-asserted-by":"publisher","first-page":"2477","DOI":"10.1056\/NEJMc2029240","article-title":"Racial bias in pulse oximetry measurement","volume":"383","author":"Sjoding","year":"2020","journal-title":"N. Engl. J. Med."},{"key":"B29","doi-asserted-by":"publisher","first-page":"991","DOI":"10.1093\/sleep\/20.11.991","article-title":"Automated detection and classification of sleep-disordered breathing from conventional polysomnography data","volume":"20","author":"Taha","year":"1997","journal-title":"Sleep"}],"container-title":["Frontiers in Physiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphys.2026.1939874\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T12:39:58Z","timestamp":1791290398000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphys.2026.1939874\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,30]]},"references-count":29,"alternative-id":["10.3389\/fphys.2026.1939874"],"URL":"https:\/\/doi.org\/10.3389\/fphys.2026.1939874","relation":{},"ISSN":["1664-042X"],"issn-type":[{"value":"1664-042X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,30]]},"article-number":"1939874"}}