乌鸦传媒

In a large study of patients who underwent bariatric surgery, self-reported marijuana use was not associated with diminished efficacy from the procedure.

If anything, according to a study presented at the , users did slightly better than non-users in terms of weight loss and metabolic comorbidity remission.

But that doesn't mean bariatric surgery patients should start using cannabis, said John Hammond, a medical student at the University of Michigan in Ann Arbor who led the study and reported the results in a video.

Those reporting marijuana use in the study were also substantially more likely than non-users to have mental disorders and use tobacco and alcohol -- the latter to excess, he noted.

"Patients who use marijuana are likely to potentially benefit from psychological intervention and behavioral consult," he said.

Moreover, his group was careful not to claim a weight-loss benefit for cannabis: "Marijuana use does not appear to negatively impact weight loss or comorbidity remission following bariatric surgery" was their bottom-line conclusion.

The study drew on data collected by a consortium of 40 bariatric surgery programs in Michigan. As part of this program, patients are asked to complete a survey that includes questions on marijuana use: yes/no, preferred methods, and frequency. The survey also inquires about use of other substances, mood, and other aspects of overall health.

Data on 11,592 patients undergoing a variety of bariatric procedures from 2014 to 2019 were analyzed, with an eye toward two outcomes: annual weight loss and resolution of comorbidities. The latter was defined as "discontinuation of medication or treatment" as indicated in patients' records.

In this group, 863 patients (7.4%) said they used marijuana, although about 30% indicated that they did so no more than once a month.

About 80% of users and non-users were women. Mean age was 43 for users and 48 for non-users; baseline body mass index (BMI) averaged slightly higher in the user group (48.0 vs 46.8). Users were less likely to have private insurance (70% vs 77%) and more likely to be on Medicaid (10% vs 5%; both P<0.0001).

Comorbidity burdens also were somewhat greater in marijuana users. Rates of asthma, smoking, alcohol use disorder, and psychological disorders were significantly higher, although hypertension and hyperlipidemia were more common in the non-user group. Notably, psychological disorders were the most common comorbidity in both groups, reported for 68% of marijuana users and 58% of non-users.

Users fared slightly better than non-users for first-year weight loss after surgery (all reflecting adjustment for covariates; P<0.0001):

• Loss in pounds: 94.0 vs 85.7 for non-users

• Percentage total weight loss: 31.4% vs 29.5%

• Percentage loss in excess weight: 61.3% vs 58.9%

• BMI decrease: 15.1 vs 13.9 points

Similarly, rates of discontinuation of diabetes medications (oral and insulin) were significantly higher in users; no difference was seen for stoppage of sleep apnea, hypertension, or hyperlipidemia treatments.

Hammond noted a number of limitations to the study, including lack of detail on cannabis use other than self-reported frequency, which was given only as daily, weekly, monthly, or yearly. Other data were self-reported as well.

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