The effect of marijuana use on short-term outcomes with bariatric surgery.

Background: Despite increasing marijuana use nationwide, there are limited data on implications of marijuana use on bariatric surgery outcomes.
Objective: We investigated associations between marijuana use and bariatric surgery outcomes.
Setting: Multicenter statewide study utilizing data from the Michigan Bariatric Surgery Collaborative, a payor-funded consortium including over 40 hospitals and 80 surgeons performing bariatric surgery statewide.
Methods: We analyzed data from the Michigan Bariatric Surgery Collaborative clinical registry on patients who underwent a laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass between June 2019 and June 2020. Patients were surveyed at baseline and annually on medication use, depression symptoms, and substance use. Regression analysis was performed to compare 30-day and 1-year outcomes between marijuana users and nonusers.
Results: Of 6879 patients, 574 reported baseline marijuana use and 139 reported use at baseline and 1 year. Marijuana users were more likely to be current smokers (14% versus 8%, P < .0001), screen positive for alcohol use disorder (20.0% versus 8.4%, P < .0001), and score higher on the Patient Health Questionnaire-8 (6.1 versus 3.0, P < .0001). There were no statistically significant differences in 30-day outcomes or co-morbidity remission at 1 year. Marijuana users had higher adjusted total mean weight loss (47.6 versus 38.1 kg, P < .0001) and body mass index reduction (17 versus 14 kg/m ² , P < .0001).
Conclusions: Marijuana use is not associated with worse 30-day outcomes or 1-year weight loss outcomes and should not be a barrier to bariatric surgery. However, marijuana use is associated with higher rates of smoking, substance use, and depression. These patients may benefit from additional mental health and substance abuse counseling.
(Copyright © 2023 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)