Prevalence of Intracranial Aneurysms in Patients With Systemic Vessel Aneurysms: A Nationwide Cohort Study.

Background and Purpose- Most aneurysms are a focal manifestation of a systemic condition. Some reports have suggested genetic and environmental factors may play a role in pathogenesis. The aim of the present study was to evaluate the prevalence of intracranial aneurysms (IA) in a large cohort of patients with other systemic vessel aneurysms and dissections (OVAD) and identify potential risk factors for IA in this population. Methods- We defined OVAD as systemic vessel aneurysms, excluding aortic dissections and aneurysms. A cohort of 1.1 million patients was extracted from the population-based cohort from the Korea National Health Insurance Service, which holds almost all medical data including diagnostic codes, procedures, and personal information. Using χ or Fisher exact test, the prevalence of the IA concerning OVAD status was analyzed. Results- In OVAD individuals, 25.7% (261/1017) of patients had been concurrently diagnosed with IA. The odds ratios for having concurrent IA in patients with OVAD were 56.31 (95% CI, 48.821-64.949; =0.000). OVAD patients with dyslipidemia were >7× likely to be affected by IA (adjusted odds ratio, 7.7 [95% CI, 6.59-9.01]; =0.000). Hypertension, diabetes mellitus, old age (>60 years), and male sex had increased odds for having concurrent IA by 5.89, 3.48, 1.83, and 1.35, respectively. Subgroup analysis with socioeconomic or disability revealed that the prevalence of IA was significantly higher in all groups. Uncertainty regarding the temporal sequence of onset and lack of detail on disease severity and subtype prevented more conclusive results. Conclusions- Patients with OVAD have a higher prevalence of IA than control groups. Therefore, we may approach aneurysms as systemic disease, and further investigations about their pathophysiology must follow.