Front Neurol. 2026 Sep 23;17:1873351. doi: 10.3389/fneur.2026.1873351. eCollection 2026.
ABSTRACT
INTRODUCTION: Thyroid dysfunction has been implicated in neurovascular pathologies, but its role in intracranial aneurysm formation and rupture is uncertain. Materials and.
METHODS: This is a retrospective single-centre case-control 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 pmol/L. Multivariable logistic regression was adjusted for age, sex, hypertension, alcohol abuse, and smoking.
RESULTS: The cohort comprised 1,100 patients (60.0% female), including UIA (n = 213), RIA (n = 629), and controls (CTRL, n = 258). Low fT3 was observed in 58.8% of RIA patients (p < 0.001). In multivariable logistic regression analysis including age, sex, hypertension, alcohol abuse, and smoking, female sex (OR 4.90; 95% CI 2.70-8.92) and low fT3 (OR 3.05; 95% CI 1.28-7.28) 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 15.90-90.89), 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 p = 0.030; females OR 2.43, p = 0.003; males OR 1.02, p = 0.938).
DISCUSSION AND CONCLUSION: 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.
PMID:42846038 | PMC:PMC13642133 | DOI:10.3389/fneur.2026.1873351