{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T20:25:55Z","timestamp":1772828755275,"version":"3.50.1"},"reference-count":29,"publisher":"BMJ","issue":"1","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2016,12,2]]},"published-print":{"date-parts":[[2017,1]]},"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Inflammatory bowel disease (IBD) is a chronic intestinal disorder, often leading to an impaired quality of life in affected patients. The importance of environmental factors in the pathogenesis of IBD, including their disease-modifying potential, is increasingly recognised. Hypoxia seems to be an important driver of inflammation, as has been reported by our group and others. The aim of the study is to evaluate if hypoxia can alter disease activity of IBD measured by Harvey-Bradshaw Activity Index in Crohn's disease (increase to \u22655 points) and the partial Mayo Score for ulcerative colitis (increase to \u22652 points). To test the effects of hypoxia under standardised conditions, we designed a prospective and controlled investigation in healthy controls and patients with IBD in stable remission.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods and analysis<\/jats:title>\n                    <jats:p>This is a prospective, controlled and observational study. Participants undergo a 3-hour exposure to hypoxic conditions simulating an altitude of 4000\u2005metres above sea level (m.a.s.l.) in a hypobaric pressure chamber. Clinical parameters, as well as blood and stool samples and biopsies from the sigmoid colon are collected at subsequent time points.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Ethics and dissemination<\/jats:title>\n                    <jats:p>The study protocol was approved by the Ethics Committee of the Kanton Zurich (reference KEK-ZH-number 2013-0284). The results will be published in a peer-reviewed journal and shared with the worldwide medical community.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trials registration number<\/jats:title>\n                    <jats:p>\n                      <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"https:\/\/clinicaltrials.gov\/show\/NCT02849821\" ext-link-type=\"uri\">NCT02849821<\/jats:ext-link>\n                      ; Pre-results.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2016-013477","type":"journal-article","created":{"date-parts":[[2017,1,5]],"date-time":"2017-01-05T21:25:29Z","timestamp":1483651529000},"page":"e013477","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":9,"title":["Protocol for a prospective, controlled, observational study to evaluate the influence of hypoxia on healthy volunteers and patients with inflammatory bowel disease: the Altitude IBD Study"],"prefix":"10.1136","volume":"7","author":[{"given":"Stephan","family":"Vavricka","sequence":"first","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"},{"name":"Division of Gastroenterology, Triemli Hospital, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pedro A","family":"Ruiz","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sylvie","family":"Scharl","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luc","family":"Biedermann","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Scharl","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cheryl","family":"de Valli\u00e8re","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"},{"name":"Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Carsten","family":"Lundby","sequence":"additional","affiliation":[{"name":"Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland"},{"name":"Institute of Physiology, University of Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Roland H","family":"Wenger","sequence":"additional","affiliation":[{"name":"Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland"},{"name":"Institute of Physiology, University of Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Leonhard","family":"Held","sequence":"additional","affiliation":[{"name":"Institute of Biostatistics, University of Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tobias M","family":"Merz","sequence":"additional","affiliation":[{"name":"Department of Intensive Care Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Max","family":"Gassmann","sequence":"additional","affiliation":[{"name":"Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland"},{"name":"Vetsuisse Faculty, Institute of Veterinary Physiology, Zurich, Switzerland"},{"name":"Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas","family":"Lutz","sequence":"additional","affiliation":[{"name":"Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland"},{"name":"Vetsuisse Faculty, Institute of Veterinary Physiology, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andres","family":"Kunz","sequence":"additional","affiliation":[{"name":"Swiss Aeromedical Center, Dubendorf, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Denis","family":"Bron","sequence":"additional","affiliation":[{"name":"Swiss Aeromedical Center, Dubendorf, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Adriano","family":"Fontana","sequence":"additional","affiliation":[{"name":"Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Laura","family":"Strauss","sequence":"additional","affiliation":[{"name":"Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Achim","family":"Weber","sequence":"additional","affiliation":[{"name":"Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland"},{"name":"Institute of Pathology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Fried","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gerhard","family":"Rogler","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"},{"name":"Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0885-0064","authenticated-orcid":false,"given":"Jonas","family":"Zeitz","sequence":"additional","affiliation":[{"name":"Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2017,1,5]]},"reference":[{"key":"2025121509531703000_7.1.e013477.1","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1159\/000442932","article-title":"High altitude journeys, flights and hypoxia: any role for disease flares in IBD patients?","volume":"34","author":"Vavricka","year":"2016","journal-title":"Dig Dis"},{"key":"2025121509531703000_7.1.e013477.2","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.mam.2015.12.004","article-title":"The role of HIF in immunity and inflammation","volume":"47\u201348","author":"Cummins","year":"2016","journal-title":"Mol Aspects Med"},{"key":"2025121509531703000_7.1.e013477.3","doi-asserted-by":"publisher","DOI":"10.1006\/cyto.1999.0533"},{"key":"2025121509531703000_7.1.e013477.4","doi-asserted-by":"publisher","DOI":"10.1016\/j.crohns.2013.07.011"},{"key":"2025121509531703000_7.1.e013477.5","doi-asserted-by":"publisher","DOI":"10.1084\/jem.20050177"},{"key":"2025121509531703000_7.1.e013477.6","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2007-10-117044"},{"key":"2025121509531703000_7.1.e013477.7","doi-asserted-by":"publisher","DOI":"10.1084\/jem.20030891"},{"key":"2025121509531703000_7.1.e013477.8","doi-asserted-by":"publisher","DOI":"10.1084\/jem.20040915"},{"key":"2025121509531703000_7.1.e013477.9","doi-asserted-by":"publisher","DOI":"10.1038\/ni.1683"},{"key":"2025121509531703000_7.1.e013477.10","doi-asserted-by":"publisher","DOI":"10.1042\/bj3500307"},{"key":"2025121509531703000_7.1.e013477.11","doi-asserted-by":"crossref","first-page":"557","DOI":"10.1002\/ibd.21388","article-title":"Seroreactivity against glycolytic enzymes in inflammatory bowel disease","volume":"17","author":"Vermeulen","year":"2011","journal-title":"Inflamm Bowel Dis"},{"key":"2025121509531703000_7.1.e013477.12","doi-asserted-by":"publisher","DOI":"10.1172\/JCI200421086"},{"key":"2025121509531703000_7.1.e013477.13","doi-asserted-by":"publisher","DOI":"10.1136\/jcp.56.3.209"},{"key":"2025121509531703000_7.1.e013477.14","doi-asserted-by":"publisher","DOI":"10.1093\/carcin\/bgu004"},{"key":"2025121509531703000_7.1.e013477.15","first-page":"6248","article-title":"Vascular endothelial growth factor (VEGF) modulation by targeting hypoxia-inducible factor-1alpha--> hypoxia response element--> VEGF cascade differentially regulates vascular response and growth rate in tumors","volume":"60","author":"Tsuzuki","year":"2000","journal-title":"Cancer Res"},{"key":"2025121509531703000_7.1.e013477.16","doi-asserted-by":"publisher","DOI":"10.1007\/s00394-012-0366-9"},{"key":"2025121509531703000_7.1.e013477.17","doi-asserted-by":"publisher","DOI":"10.1152\/ajpgi.00353.2013"},{"key":"2025121509531703000_7.1.e013477.18","doi-asserted-by":"publisher","DOI":"10.1089\/ham.2010.1075"},{"key":"2025121509531703000_7.1.e013477.19","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00248.2015"},{"key":"2025121509531703000_7.1.e013477.20","first-page":"147","article-title":"Gastrointestinal problems at high altitude","volume":"27","author":"Anand","year":"2006","journal-title":"Trop Gastroenterol"},{"key":"2025121509531703000_7.1.e013477.21","doi-asserted-by":"publisher","DOI":"10.3748\/wjg.v13.i5.774"},{"key":"2025121509531703000_7.1.e013477.22","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1016\/S0016-5085(10)62235-4","article-title":"T1080 Unsedated transnasal esophago-gastroduodenoscopy at 4559 M (14957 Ft) -endoscopic findings in healthy mountaineers after rapid ascent to high altitude","volume":"138","author":"Fruehauf","year":"2010","journal-title":"Gastroenterology"},{"key":"2025121509531703000_7.1.e013477.23","unstructured":"http:\/\/www.phadia.com\/PageFiles\/29347\/Product%20information%20EliA%20Calprotectin.pdf"},{"key":"2025121509531703000_7.1.e013477.24","unstructured":"Swenson ER . High altitude diuresis: fact or fancy. In: Houston CS , Coates G, eds . Hypoxia: women at altitude. Burlington, VT: Queen City Press, 1997:272\u201383."},{"key":"2025121509531703000_7.1.e013477.25","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1016\/S0140-6736(80)92767-1","article-title":"A simple index of Crohn's-disease activity","volume":"1","author":"Harvey","year":"1980","journal-title":"Lancet"},{"key":"2025121509531703000_7.1.e013477.26","doi-asserted-by":"publisher","DOI":"10.1002\/ibd.20520"},{"key":"2025121509531703000_7.1.e013477.27","doi-asserted-by":"publisher","DOI":"10.1038\/labinvest.2013.9"},{"key":"2025121509531703000_7.1.e013477.28","doi-asserted-by":"publisher","DOI":"10.1053\/j.gastro.2007.10.012"},{"key":"2025121509531703000_7.1.e013477.29","doi-asserted-by":"publisher","DOI":"10.1053\/j.gastro.2010.06.068"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2016-013477","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,15]],"date-time":"2025-12-15T17:53:25Z","timestamp":1765821205000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2016-013477"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,1]]},"references-count":29,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2017,1,5]]},"published-print":{"date-parts":[[2017,1]]}},"alternative-id":["10.1136\/bmjopen-2016-013477"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2016-013477","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,1]]}}}