Do statins reduce the risk of aneurysm development? A case-control study

Recent studies in rats have demonstrated that statins may have an inhibitory effect on intracranial aneurysm (IA) development. The purpose of this study was to assess whether long-term statin use is associated with a reduced risk of IA formation in humans. This was a single-center case-control study that included consecutive patients admitted to the authors' institution between January 1, 2005, and December 31, 2008. A case was defined as a patient with a cerebral angiography-confirmed diagnosis of IA. Three controls were matched to each case based on age, sex, and index year of hospital admission. The primary exposure of interest was cumulative statin use. Conditional logistic regression was used to assess the relationship between statin intake and incidence of IA. In total, 1200 patients were included in the study. No overall association was found between statin use and incidence of IA formation (OR 1.08, 95% CI 0.69-1.69), nor when dichotomized into hydrophilic and lipophilic user, or between short (≤ 12-month) and long (≥ 36-month) duration of intake. Hypertension and smoking significantly increased the risk of IA development (OR 4.02, 95% CI 2.49-6.45, and OR 1.67, 95% CI 1.02-2.72, respectively). In contrast to recent experimental reports of the association between statins and a reduction of IA formation, the authors' findings suggest that in humans statins may have no significant beneficial effect on IA suppression.