Background:
Marijuana use is increasing in the United States, and its effect on
cardiovascular health is unknown.
Purpose:
To review harms and benefits of marijuana use in relation to
cardiovascular risk factors and clinical outcomes.
Data Sources:
PubMed, MEDLINE, EMBASE, PsycINFO, and the Cochrane Library between 1
January 1975 and 30 September 2017.
Study Selection:
Observational studies that were published in English, enrolled adults
using any form of marijuana, and reported on vascular risk factors
(hyperglycemia, diabetes, dyslipidemia, and obesity) or on outcomes (stroke,
myocardial infarction, cardiovascular mortality, and all-cause mortality in
cardiovascular cohorts).
Data Extraction:
Study characteristics and quality were assessed by 4 reviewers
independently; strength of evidence for each outcome was graded by
consensus.
Data Synthesis:
13 and 11 studies examined associations between marijuana use and
cardiovascular risk factors and clinical outcomes, respectively. Although 6
studies suggested a meta bolic benefit from marijuana use, they were based
on cross-sectional designs and were not supported by prospective studies.
Evidence examining the effect of marijuana on diabetes, dyslipidemia, acute
myocardial infarction, stroke, or cardiovascular and all-cause mortality was
insufficient. Although the current literature includes several long-term
prospective studies, they are limited by recall bias, inadequate exposure
assessment, minimal marijuana exposure, and a predominance of low-risk
cohorts.
Limitation:
Poor- or moderate-quality data, inadequate assessment of marijuana
exposure and minimal exposure in the populations studied, and variation in
study design.
Conclusion:
Evidence examining the effect of marijuana on cardiovascular risk
factors and outcomes, including stroke and myocardial infarction, is
insufficient.
Primary Funding Source:
National Heart, Lung, and Blood Institute. (PROSPERO:
CRD42016051297)
