Marijuana Use and the Risk of Ischemic Stroke: The Stroke Prevention in Young Adults Study (S55.003)

OBJECTIVE: The goal of this study was to determine the effect of marijuana use on the risk of young-onset IS among Caucasians and African-Americans. BACKGROUND: The association between marijuana use and ischemic stroke (IS) risk remains controversial. DESIGN/METHODS: 1,101 cases and 1,154 controls, aged 15-49 years old, were recruited from the greater Baltimore-Washington area between 1992-2008. Subjects were interviewed to assess the presence of stroke risk factors and history of illicit drug use. Participants who used any illicit drug other than marijuana or hashish were excluded from the analyses, resulting in 783 cases and 794 controls for analyses. Logistic regression was used to determine the association between marijuana/hashish use and IS. RESULTS: 35% of cases and 37% of controls reported ever using marijuana or hashish. Men were more likely than women to report a history of marijuana or hashish use (41% vs. 32%; p<0.0001), and African-Americans less likely than Caucasians (32% vs. 40%; p=0.003). Having a history of marijuana/hashish use was not associated with IS in the overall sample or any gender-/ethnic-specific subgroup. Evaluating the timing of last use, stroke risk was not significantly increased among those who used marijuana or hashish in the year prior (OR=1.54; 95%CI=0.77-3.09), in the month prior (OR=0.96; 95%CI=0.47-1.95), or within 24 hours prior (OR=0.92; 95%CI=0.30-2.83) to stroke onset after adjustment for age, gender and current smoking. Compared with persons who did not use marijuana or hashish in the past year, there was an increased risk of stroke among frequent users (蠅1.88 times per month), but not among non-frequent users (< 1.88 times per month), although neither association was statistically significant (adjusted OR=1.56; 95%CI=0.79-3.06 vs. OR=0.55; 95%CI=0.26-1.20, respectively). CONCLUSION: Our data does not demonstrate a risk of ischemic stroke as associated with marijuana use. Additional studies are warranted examining the effect of heavy or frequent use. Disclosure: Dr. Dutta has nothing to disclose. Dr. Ryan has nothing to disclose. Dr. Cheng has nothing to disclose. Dr. Kittner has nothing to disclose. Dr. Cole has received research support from the University of Maryland.