Association Between Marijuana Use and Cardiovascular Disease in US Adults

Introduction The prevalence of marijuana use has increased by about 16% since 2006, translating to approximately 200 million people worldwide. Being so widely used, long-term effects of marijuana use on cardiovascular health are largely unknown. Previous studies have had conflicting results, either showing marijuana use having a negative impact or no significant impact on cardiovascular health. This study aims to add evidence regarding the impact marijuana use has on the prevalence of cardiovascular disease. Methods This retrospective study was conducted using the Behavioral Risk Factor Surveillance System (BRFSS) database. Patients who completed the questionnaire and answered all questions in relation to marijuana use and the diagnosis of cardiovascular disease in 2017 were a part of this study. Subjects were excluded if they were children (<18 years old) or had missing data for marijuana use or cardiovascular disease. Age, gender, race/ethnicity, body mass index (BMI), income, exercise, tobacco use, alcohol use, and depression were all considered as potential confounders. Bivariate analysis was conducted to find an initial association between marijuana use and cardiovascular disease, which was followed by a multivariate regression analysis to adjust for confounders. Odds ratios and 95% confidence intervals were calculated.  Results A total of 56,742 subjects were included in the analysis. The unadjusted bivariate analysis showed a reduced prevalence of cardiovascular disease in individuals using marijuana (OR 0.65, 95%CI [0.50-0.84]). After adjustment with all additional variables, an adjusted model showed a similar odds ratio, but statistical significance of the association was lost (OR 0.74, 95%CI [0.54-1.01]). Discussion A systematic review by Ravi et al in 2018, which looked at marijuana use, cardiovascular risk factors, and clinical outcomes concluded that there was insufficient data to make conclusions regarding the effect of marijuana use and negative long-term cardiovascular effects. Our study lends support to the notion that marijuana use does not have an association with cardiovascular disease. A limitation in our study was that there was missing data from the BRFSS questionnaire due to participants not fully answering all questions concerning cardiovascular disease and marijuana use. This decreased our sample size from 67,974 to 56,742 subjects. The missing participants led to a decrease in the power of our odds ratio, which may have impacted statistical significance of our results.  Conclusion Although previous literature has shown that marijuana use has a negative impact on cardiovascular health, our study suggests that users and non-users of marijuana did not have an association with the prevalence of cardiovascular disease. Varying levels of support within the literature highlights the need for further research of this association.