Increased prevalence and size of incidental unruptured intracranial aneurysms in male smokers: A case-control study

The prevalence of unruptured intracranial aneurysms (UIA) among female cigarette smokers has been explored in recent studies; however, their occurrence in male smokers remains unexplored.

This study aims to investigate the prevalence of incidental unruptured intracranial aneurysms (UIA) among male smokers and to evaluate risk factors for development including hypertension and other comorbidities.

We conducted a dual center case-control study from a cohort of male patients aged 20-80 with a brain magnetic resonance imaging (MRI) between 2019 and 2022. Incidental UIA were compared to patients with normal MRI in a 1:2 ratio. The association between smoking, hypertension, and other comorbidities with a diagnosis of incidental UIA was evaluated using logistic regression.

A total of 15,100 male patients aged 20-80 years who underwent MRI Head from 2019 to 2022 were included. Of 8532 never-smoker patients, 69 had incidental UIA (0.81%), while 23 of 1280 active smokers had incidental UIA (1.8%). Former smokers had 70 incidental UIA in a population of 5288(1.32%). 486 patients of the initial sample were included in the 2:1 case-control study. Of 162 aneurysm patients and 324 random controls, aneurysm patients were more likely to have a positive smoking history compared with healthy controls (57.2% vs 45.5% p = 0.01). Multivariate analysis demonstrated a significant association between active smoking (OR 2.69, 95% CI 1.34-5.45) and hypertension (OR 6.32, 95% CI 3,98-10,26) with incidental UIAs. Current and former smokers had larger aneurysms, areas of excrescences, and more frequent anterior circulation aneurysms compared to never-smokers (p = 0.004, p = 0.07, p = 0.006, respectively).

Males with a positive smoking history have a higher prevalence of UIA than the general population, with larger and more irregular aneurysm morphology, that increases their rupture risk. Smoking and hypertension confer a higher risk of having a silent UIA. This population may represent a target for screening.