Apolipoprotein A1 Levels Are Inversely Associated with Aneurysm Wall Enhancement in Unruptured Intracranial Aneurysms.

Current magnetic resonance vessel wall imaging enables the detection of atherosclerotic changes in the walls of intracranial aneurysms. Lipid accumulation in the intracranial aneurysm wall is involved in aneurysm neovascularization and chronic inflammation and may lead to aneurysm enlargement and rupture. Therefore, in the present study, we examined the relationship between atherosclerotic changes identified by vessel wall imaging and systemic atherosclerosis-related risk factors. A total of 111 patients with 156 unruptured intracranial aneurysms who underwent magnetic resonance vessel wall imaging and atherosclerotic protein examinations between April 2021 and November 2023 were reviewed. Data on atherosclerotic proteins were obtained from peripheral blood samples. The relationships between aneurysm wall enhancement and patient demographic data, aneurysm morphology, and atherosclerosis-related risk factors were assessed. Fifty-seven of 156 unruptured intracranial aneurysms (36.5%) showed aneurysm wall enhancement. In a univariate logistic regression analysis, age (p = 0.007), male sex (p = 0.023), morphological factors such as maximum diameter (p < 0.001) and irregular shape (p < 0.001), and the levels of apolipoprotein A1 (<0.001) and apolipoprotein B/apolipoprotein A1 (0.004) correlated with aneurysm wall enhancement. In the multivariate logistic regression analysis, age (odds ratio: 1.05, 95% confidence interval: 1.02-1.10), male sex (odds ratio: 3.83, 95% confidence interval: 1.46-10.01), maximum diameter (odds ratio: 1.19, 95% confidence interval: 1.01-1.45), irregular shape (odds ratio: 5.01, 95% confidence interval: 2.10-12.73), and apolipoprotein A1 levels (odds ratio: 0.97, 95% confidence interval: 0.94-0.99) correlated with aneurysm wall enhancement. Low levels of apolipoprotein A1, which may function as an atherosclerotic protein, were associated with specific aneurysm wall features in vessel wall imaging. In future studies, these results will contribute to the identification of factors that promote the destabilization of unruptured intracranial aneurysms.