October 27, 2020
Cannabis use is associated with a decrease in the prevalence of steatohepatitis and a slowing of its progression in patients with obesity, results from a retrospective cohort study show.
This suggests "that the anti-inflammatory effects of cannabis may be leading to reduced prevalence of steatohepatitis in cannabis users," said Ikechukwu Achebe, MD, from the John H. Stroger, Jr. Hospital of Cook County in Chicago.
Liver injuries such as nonalcoholic steatohepatitis are characterized by hepatocellular injury and inflammation, which combine to contribute to an increase in the risk for liver failure, cirrhosis, and hepatocellular carcinoma.
"This is where cannabis comes in," said Achebe, who presented the study results at the virtual American College of Gastroenterology (AGC) 2020 Annual Scientific Meeting. "It is the most commonly used psychoactive substance worldwide and has been shown to reduce hepatic myofibroblast and stellate cell injury. Studies using mouse models have demonstrated reduced liver fibrosis and cirrhosis as a consequence of cannabis exposure."
Given this possible connection, Achebe and his colleagues set out to determine whether cannabis use affects the prevalence and progression of nonalcoholic fatty liver disease (NAFLD) in obese patients.
To do so, they analyzed the discharge records of 879,952 obese adults in the 2016 Healthcare Cost and Utilization Project National Inpatient Sample. The primary outcome was the prevalence of the four presentations of NAFLD: steatosis, steatohepatitis, cirrhosis, and hepatocellular carcinoma.
The researchers compared disease stages in cannabis users and nonusers. In the study cohort of 14,236 patients, 1.6% used cannabis. Steatohepatitis was less common among cannabis users than among nonusers (0.4% vs 0.7%; P < .001), as was cirrhosis (1.1% vs 1.5%; P < .001).
After propensity matching, the association between cannabis use and lower rates of steatohepatitis remained significant (0.4% vs 0.5%; P = .035), but the association between cannabis use and the prevalence of nonalcoholic fatty liver, cirrhosis, and hepatocellular carcinoma did not.
These results might be partly explained by the protective effect of cannabis on hepatocytes regulated by the endocannabinoid system, the researchers conclude.
More studies are needed to explore this relation, said Achebe.
The Challenge of Self-Reported Use
The study is "incredibly interesting," said Nancy S. Reau, MD, from Rush University Medical Center in Chicago. However, she cautioned, the association between cannabis and nonalcoholic fatty liver needs to be further investigated before clinicians can counsel their patients to use the agent to prevent progression.
It is difficult in a study such as this to tease out other lifestyle factors that might be linked to cannabis use, she explained. For example, "is it possible that the cannabis users exercise more, drink more coffee, or eat differently?"
And "self-reported use is challenging," Reau told Medscape Medical News. "This cannot differentiate someone who occasionally uses from someone who is a heavy daily user. There must be some minimum level of exposure needed for it to have protective effects, if they exist."
This study was honored at the meeting as an ACG Newsworthy Abstract and an ACG Outstanding Poster Presenter.
Achebe has disclosed no relevant financial relationships. Reau reports receiving research support from Genfit and having a consultant relationship with Intercept Pharmaceuticals, Inc.