The Impact of Chronic Cannabis Use on Esophageal Motility in Patients Referred for Esophageal Manometry

Tetrahydrocannabinol, the main psychoactive compound in cannabis, binds with high affinity to the cannabinoid 1 receptor. Small randomized controlled studies using conventional manometry have shown that the cannabinoid 1 receptor can modulate esophageal function, namely transient lower esophageal sphincter relaxation frequency and lower esophageal sphincter tone. The effect of cannabinoids on esophageal motility in patients referred for esophageal manometry has not been fully elucidated using high-resolution esophageal manometry (HREM). We aimed to characterize the clinical effect of chronic cannabis use on esophageal motility utilizing HREM.

Patients who underwent HREM from 2009 to 2019 were identified at 4 academic medical centers. The study group consisted of patients with a noted history of chronic cannabis use, a diagnosis of cannabis-related disorder, or a positive urine toxicology screen. Age and gender-matched patients with no history of cannabis use were selected to form the control group. Data on HREM metrics based on the Chicago classification V3, and the prevalence of esophageal motility disorders were compared. Confounding effects of BMI and medications on esophageal motility were adjusted for.

Chronic cannabis use was found to be an independent negative predictor of weak swallows (β=-8.02, P =0.0109), but not a predictor of failed swallows ( P =0.6890). The prevalence of ineffective esophageal motility was significantly lower in chronic cannabis users compared with nonusers (OR=0.44, 95% CI 0.19-0.93, P =0.0384). There was no significant difference in the prevalence of other esophageal motility disorders between the 2 cohorts. In patients with dysphagia as their primary indication for HREM, chronic cannabis use was found to be independently associated with increased median integrated relaxation pressure (β=6.638, P =0.0153) and increased mean lower esophageal sphincter resting pressure (β=10.38, P =0.0084).

Chronic cannabis use is associated with decreased weak swallows and reduced prevalence of ineffective esophageal motility in patients referred for esophageal manometry. In patients referred for dysphagia, chronic cannabis use is associated with increased integrated relaxation pressure and lower esophageal sphincter resting pressure, though not to levels above the normal range.