Alcohol Misuse post Metabolic and Bariatric Surgery: A Systematic Review of Longer-term Studies with Focus on new Onset Alcohol use Disorder and Differences Between Surgery Types.

Background: Evidence suggests an increased risk of alcohol problems post-surgery where no problematic alcohol use was present prior to surgery which may be different across types of surgery.

Objective: To characterise the risk of new onset alcohol misuse post bariatric surgery, differences between surgeries and the impact over time.

Methods: All published studies on new and relapsing alcohol use were reviewed. Data were classed as 'subjective' (clinical interview, self-report questionnaires) and 'objective' (hospital admissions, substance misuse programmes) and further categorised by follow up time - 'shorter-term' (one year), 'medium-term' (one year to two years) and 'long-term' (> two years).

Results: Twenty-three of the forty-two studies included in the review reported new onset data. Nine studies reported on differences between surgery types. In those reporting objective measures, all of which were long term, RYGB carried a higher risk than SG, followed by LAGB. All but one study using subjective measures reported a small but significant number of new onset concerning alcohol use, and comparisons between surgery types had more varied results than the objective measures. Studies of substance abuse programmes found high rates of new onset cases (17-60%).

Conclusion: This systematic review provides support for the consensus guidance suggesting patients should be informed of a small but significant risk of new onset alcohol use following bariatric surgery, with the strongest evidence in the medium- to long-term and in those who have had RYGB followed by SG.