{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T05:06:21Z","timestamp":1790139981359,"version":"4.0.1"},"reference-count":27,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T00:00:00Z","timestamp":1790121600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Thyroid dysfunction has been implicated in neurovascular pathologies, but its role in intracranial aneurysm formation and rupture is uncertain. Materials and.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This is a retrospective single-centre case\u2013control study of patients with unruptured (UIA) or ruptured intracranial aneurysms (RIA) and aneurysm-free controls. Low free triiodothyronine (fT3) was defined as below 3.5\u202fpmol\/L. Multivariable logistic regression was adjusted for age, sex, hypertension, alcohol abuse, and smoking.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The cohort comprised 1,100 patients (60.0% female), including UIA (\n                      <jats:italic>n<\/jats:italic>\n                      \u202f=\u202f213), RIA (\n                      <jats:italic>n<\/jats:italic>\n                      \u202f=\u202f629), and controls (CTRL,\n                      <jats:italic>n<\/jats:italic>\n                      \u202f=\u202f258). Low fT3 was observed in 58.8% of RIA patients (\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.001). In multivariable logistic regression analysis including age, sex, hypertension, alcohol abuse, and smoking, female sex (OR 4.90; 95% CI 2.70\u20138.92) and low fT3 (OR 3.05; 95% CI 1.28\u20137.28) were independently associated with UIA. Low fT3 was less frequent in UIA (3.8%) than in CTRL (14.0%) but was independently associated with UIA after risk-factor adjustment. Low fT3 was strongly associated with ruptured-aneurysm status (OR 38.0; 95% CI 15.90\u201390.89), a contrast likely driven by acute non-thyroidal illness syndrome after haemorrhage rather than a rupture-risk estimate. The fT3-UIA association was sex-dependent (interaction\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.030; females OR 2.43,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.003; males OR 1.02,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f0.938).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion and conclusion<\/jats:title>\n                    <jats:p>Reduced fT3 in RIA may partly reflect impaired peripheral conversion after haemorrhage, but low fT3 was also independently associated with aneurysm presence in females. Low fT3 may be a candidate endocrine marker associated with aneurysm presence. Whether thyroid optimisation influences aneurysm development remains to be tested in prospective studies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fneur.2026.1873351","type":"journal-article","created":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T04:47:03Z","timestamp":1790138823000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Free triiodothyronine in intracranial aneurysms: a sex-specific association with unruptured disease and a non-thyroidal illness signal after rupture"],"prefix":"10.3389","volume":"17","author":[{"given":"Maximilian","family":"Bschorer","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maximilian","family":"Middelkamp","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marius","family":"Mader","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shiva Sophia","family":"Nicolay","sequence":"additional","affiliation":[{"name":"III. Department of Medicine (Nephrology, Endocrinology), University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miriam","family":"Heise","sequence":"additional","affiliation":[{"name":"Department of Spine Surgery, Sch\u00f6n Klinik Hamburg Eilbek","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrick","family":"Czorlich","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]},{"name":"Division of Critical Care, Integrated Hospital Care Institute, Cleveland Clinic Abu Dhabi","place":["Abu Dhabi, United Arab Emirates"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lasse","family":"D\u00fchrsen","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Sauvigny","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"Sauvigny","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medical Center Hamburg-Eppendorf","place":["Hamburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,23]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"626","DOI":"10.1016\/S1474-4422(11)70109-0","article-title":"Prevalence of unruptured intracranial aneurysms, with emphasis on sex, age, comorbidity, country, and time period: a systematic review and meta-analysis","volume":"10","author":"Vlak","year":"2011","journal-title":"Lancet 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