In the United States, marijuana is becoming increasingly legalized for medicinal or recreational purposes. However, new research warns of the harms of marijuana use after finding that the drug may have negative implications for cardiovascular health.
Lead study author Dr. Aditi Kalla, of the Einstein Medical Center in Philadelphia, PA, and colleagues say that their findings help shed to light on the possible side effects of marijuana use, enabling doctors to better educate patients about such risks.
The researchers recently presented their results at the American College of Cardiology's 66th Annual Scientific Session, held in Washington, D.C.
According to the National Institute on Drug Abuse, marijuana remains the "most commonly used illicit drug" in the U.S.
However, the drug has now been legalized for either medicinal or recreational use in 28 U.S. states and Washington, D.C., and more states are expected to follow suit.
As such, there is more focus than ever on determining the benefits and risks of marijuana use. The new study claims to shed light on the latter, after uncovering a link between marijuana use and poor cardiovascular health.
Higher cardiovascular risk for marijuana users
Dr. Kalia and colleagues came to their results by reviewing data from the Nationwide Inpatient Sample. This database holds the health records of more than 1,000 hospitals in the U.S., representing around 20 percent of hospitals in the country.
In total, the team analyzed more than 20 million health records of adults aged between 18 and 55 years, all of whom were discharged from the hospital between 2009 and 2010. The team notes that during this period, marijuana was illegal in most U.S. states.
Marijuana use was identified in around 316,000 of the health records, or 1.5 percent.
The team compared cardiovascular disease rates among those who used marijuana with those who did not use the drug.
The researchers found that adults who used marijuana were at much greater risk of heart failure, coronary artery disease, stroke, and sudden cardiac death than those who did not use the drug.
"Even when we corrected for known risk factors, we still found a higher rate of both stroke and heart failure in these patients," says Dr. Kalla, "so that leads us to believe that there is something else going on besides just obesity or diet-related cardiovascular side effects."
The study was not designed to pinpoint the mechanisms by which marijuana use might raise the risk of stroke and heart failure. However, they point to studies that have shown heart muscle cells to have cannabis receptors, which may be one way by which the drug affects the cardiovascular system.
Findings may help doctors to educate patients about marijuana use
The researchers caution that because the findings are based on data from hospital records, they may not apply to the general population.
Still, the team says that the results provide further insight into the health effects of marijuana use.
"Like all other drugs, whether they're prescribed or not prescribed, we want to know the effects and side effects of this drug.
It's important for physicians to know these effects so we can better educate patients, such as those who are inquiring about the safety of cannabis or even asking for a prescription for cannabis."
Dr. Aditi Kalla