Does Heavy Cannabis Use in Young Adults Cause Cerebrovascular Occurrences?
August 26, 2020 in General News
There have been conflicting studies about whether heavy cannabis usage by young people increases their risk for stroke. I will present the studies that support the claim and those that refute it. I will also present a study which supports the claim that cannabis use disorder in young people increases their risk for hospitalization for arrhythmias or heart rhythm disturbances.
Supporting Studies on Cerebrosvascular Occurrences
CDC Study on Cannabis Usage and Stroke in Young Adults
An observational study, Marijuana Use Among Young Adults (18-44) and Risk of Stroke, was published in November, 2019 in the journal Stroke. It was conducted by Tarang Parekh of the Department of Health Administration and Policy, George Mason University, Fairfax, VA. The data was collected through telephone surveys by the Behavioral Risk Factor Surveillance System; the data collection system used by the CDC.
The authors of this nationwide, cross-sectional study acknowledged that their research was not able to identify a biological link between cannabis use and stroke. However, they still concluded that young, heavy cannabis consumers, who used it at least 10 days a month, were almost 2.5 times more likely to suffer a stroke than non-cannabis users. Cannabis users were identified as more likely to use combustible cigarettes/e-cigarettes and large amounts of alcohol than non-users. The researchers admitted that these other factors could impact the results of the study. It is interesting to note that there was less prevalence among cannabis users for diabetes, hypertension and high cholesterol.
Their final conclusion was that there was no cause and effect but there was a possible link which merited further investigation.
Dr. Aditi Kalla Study on Cannabis Usage and Stroke/Heart Failure
In March, 2017 Dr. Aditi Kalla, Cardiology Fellow at Einstein Medical Center in Philadelphia, presented the results of her study at the American College of Cardiology’s 66th Annual Scientific Session and Expo in Washington DC. Her study, Cannabis Use Predicts Risks of Heart Failure and Cerebrovascular Accidents: Results from the National Inpatient Sample, focused on patients 18-55 released from hospitals in 2009-10.
She used the National Inpatient Sample (NIS) database to view the medical records of patients in more than 1,000 hospitals across the US. Cannabis usage was identified in about 1.5% of the sample. Dr. Kalla and her team concluded the following about cannabis users:
1. 26% would experience an increase in risk of stroke
2. 10% would suffer possible heart failure in the future
This study has some serious flaws. No data was compiled on how patients ingested cannabis, how much they consumed or when they last used it. This data was also compiled prior to the establishment of any legal medical or recreational cannabis programs, so patients were using black market cannabis.
Study on Cannabis Use Disorder and Arrhythmias in Young Adults
A preliminary study about cannabis use disorder and heart rhythm disturbances (arrhythmias) was presented at the Heart Associations Scientific Session in Philadelphia in November, 2019. It was conducted by Dr. Rikinkumar S. Patel, resident physician in the Department of Psychiatry at the Griffin Memorial Hospital in Norman, OK.
This study suggested that a young person with cannabis use disorder had an increased risk of 50% for hospitalization due to arrhythmia. African American males between 15 and 24 years were at the highest risk. It is interesting to note that the disorder is more common among white men between 45 and 54 years of age.
The Agency for Healthcare Research and Quality’s Nationwide Inpatient Sample provided the data from 2010-2014. This is the first large-scale, population-based study that has investigated a correlation between cannabis use disorder and hospitalizations for arrhythmias. While no cause and effect was established, the author believes that the data demonstrates a trend in that direction.
According to Dr. Patel, some arrhythmias are benign but they can also be life-threatening. He believes that at a low dosage, cannabis use may cause a rapid heartbeat. At a higher dosage, it may cause too slow a heartbeat. He has recommended that physicians with patients with arrhythmias should ask them about their use of cannabis and other substances.
The study has not been published in a peer review journal.
Study Which Refutes The Claim That Cannabis Usage Causes Stroke
A recent study, Association Between Recent Cannabinoid Use and Acute Ischemic Stroke, was published in the journal Neurology Clinical Practice in June, 2020. It was conducted by the Department of Neurology, Division of Neurosciences Critical Care, Division of Cerebrovascular Diseases, University of Mississippi Medical Center, Jackson, Mississippi. The lead researcher and author, Dr. Carmela San Luis, and her team concluded that there is no link between cannabis use and risk of stroke.
The team’s observational study used the medical records database to identify 9,350 patients admitted to hospitals who had taken a urine test for drug use. This included all patients 18 years and older during the period of January 1, 2015 to December 31, 2017. Those who tested positive for substances other than cannabis were excluded from the study. This left 1,643 patients who tested positive for cannabis. In fact, contrary to other studies, the team found that those who tested positive for cannabis were less likely to suffer an acute ischemic stroke (AIS).
Adjustments were made to take into account significant stroke factors such as age, race, ethnicity, sickle cell disease, hypertension, obesity, diabetes, high cholesterol, cigarette smoking and other cardiac conditions. As a result, the effect of a 50% decrease in risk of stroke for cannabis users vanished.
San Luis and her team recognized that their study had limitations. The following pertinent information was unavailable:
1. The dose and frequency of cannabis use
2. Synthetic cannabinoids use was excluded; the urine drug screen (UDS) does not test for them
3. The amount of physical activity in which test subjects participated
4. Body Mass Index (BMI)
The team felt that more research, which included much more comprehensive data on modifiable risk factors and a larger pool of participants, was needed to substantiate their conclusion.
einstein.edu, Einstein’s Dr. Aditi Kalla Finds Marijuana Use Associated with Increased Risk of Stroke, Heart Failure, March 09, 2017
cp.neurology.org, Association Between Recent Cannabinoid Use and Acute Ischemic Stroke, June 3, 2020
thefrenchtoast.com, Heavy Marijuana Use Could Double Stroke Risk for Young People, Brendan Bures, Nov 13, 2019
eurekalert.org, Cannabis May Be Linked To Strokes and Heart Rhythm Disturbances in Young People, Nov. 11, 2019