Louis and Gertrude Feil Professor and Chair, Department of Neurology, Associate Dean for Clinical Affairs, New York Presbyterian/Weill Cornell Medical College
SOURCE: Dutta T, Ryan KA, Thompson O, et al. Marijuana use and the risk of early ischemic stroke: The Stroke Prevention in Young Adults Study. Stroke 2021; Jul 16. doi: 10.1161/STROKEAHA.120.032811. [Online ahead of print].
The incidence of ischemic stroke in young adults is increasing, and one of the common modifiable risk factors is drug use. Tobacco smoking and cocaine use are well-known risk factors, but the role of marijuana is unclear. Marijuana use, both recreational and medical, is increasing among young adults, and many states are legalizing its use. A variety of cardiovascular effects have been described, which could increase the risk of cardiovascular complications, including stroke, and some observational studies have suggested an increased stroke risk from marijuana use. But there are few epidemiological studies that have evaluated this association.
The Stroke Prevention in Young Adults Study is a population-based case-control study of young onset ischemic stroke that collected data from 59 acute care hospitals in the greater Baltimore-Washington, DC, area. Exposure information was collected by self-report through a standardized face-to-face interview, and patients were asked specifically to recall use of medications and drugs, whether medical, nonmedical, or recreational. Traditional stroke risk factors also were collected. Current smoking was defined as tobacco smoking within 30 days before the stroke and the amount was based on the average number of cigarettes smoked per day. Subjects were excluded if they were known to have used cocaine or other vasoactive substances. The final study sample consisted of 751 cases and 813 controls. Logistic regression analysis was used to assess the relationship between marijuana use and risk of ischemic stroke, adjusting for other risk factors, including current tobacco smoking, current alcohol use, hypertension, and diabetes.
After adjusting for age, sex, race, and other risk factors, including tobacco smoking, the use of marijuana was not associated with ischemic stroke regardless of the timing of use in relationship to the stroke. There was a trend toward increased stroke risk among those who smoked marijuana at least once a week, but this was not statistically significant.
In this careful epidemiological study, the analysis does not demonstrate an association between marijuana use and increased risk of early onset ischemic stroke. However, no statement can be made regarding heavy users because of the small numbers of subjects considered to be heavy users at the time of data collection.