{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T18:04:49Z","timestamp":1790877889824,"version":"4.1.0"},"reference-count":38,"publisher":"BMJ","issue":"1","license":[{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001711","name":"Schweizerischer Nationalfonds zur F\u00f6rderung der Wissenschaftlichen Forschung","doi-asserted-by":"publisher","award":["32003B_219199\/1"],"award-info":[{"award-number":["32003B_219199\/1"]}],"id":[{"id":"10.13039\/501100001711","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open Resp Res"],"accepted":{"date-parts":[[2026,9,16]]},"published-print":{"date-parts":[[2026,10]]},"abstract":"<jats:sec>\n                    <jats:title>Question addressed by the study<\/jats:title>\n                    <jats:p>Hypoxic pulmonary vasoconstriction increases systolic pulmonary artery pressure (sPAP) and may contribute to high-altitude pulmonary hypertension (HAPH). While supplemental oxygen therapy (SOT) lowers sPAP during acute hypoxic exposure, its haemodynamic effects in permanent high-altitude residents remain unclear. In particular, the relative contribution of fixed vascular remodelling to chronically elevated sPAP is uncertain.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants and methods<\/jats:title>\n                    <jats:p>In this open-label, non-randomised, sequential interventional trial, Kyrgyz highlanders living &gt;2500\u2009m with tricuspid regurgitation velocity &gt;2.8 m\/s underwent echocardiography under ambient air and after &gt;15\u2009min of high-dose SOT (FiO\u2082\u22480.95, 10\u202fL\/min) at 3250\u2009m.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>48 participants (56% females, mean\u00b1SD\u2009age 53\u00b112 years) completed the study per-protocol. SOT reduced sPAP from 45\u00b111\u2009to 31\u00b15\u2009mm Hg, cardiac output (CO) from 5.1\u00b11.2\u2009to 4.3\u00b11.4\u2009L\/min and total pulmonary resistance (TPR) from 9.2\u00b12.7\u2009to 7.5\u00b11.5 WU (all p&lt;0.001). In an exploratory subanalysis, a larger sPAP decrease was associated with higher baseline sPAP and younger age.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Answer to the question<\/jats:title>\n                    <jats:p>High-dose SOT acutely lowers sPAP in high-altitude residents at risk for HAPH. The decrease in sPAP is driven by reductions in both CO and TPR. The decline in TPR indicates a largely reversible hypoxic-vasoconstrictor component, whereas the contribution of fixed vascular remodelling to elevated PAP appears minimal. These findings underscore the physiological potential of short-term high-dose oxygen to reduce right ventricular afterload and improve pulmonary haemodynamics in this high-altitude population at risk for HAPH.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT06489756\">NCT06489756<\/jats:ext-link>\n                      .\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjresp-2026-004376","type":"journal-article","created":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T17:35:16Z","timestamp":1790876116000},"page":"e004376","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Effects of high-dose supplemental oxygen therapy on 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Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adilet","family":"Omuralieva","sequence":"additional","affiliation":[{"name":"National Centre for Cardiology and Internal Medicine, Bishkek, Kyrgyzstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Titz","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Mayer","sequence":"additional","affiliation":[{"name":"Department of Pulmonology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maamed","family":"Mademilov","sequence":"additional","affiliation":[{"name":"National Centre for Cardiology and Internal Medicine, Bishkek, 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