The rewarding effects of alcohol after bariatric surgery: do they change and are they associated with pharmacokinetic changes?

Background: Research shows that surgery patients who have undergone Roux-en-Y gastric bypass (RYGB) are at increased risk for an alcohol use disorder (AUD). However, the mechanisms through which this increased risk is incurred are poorly understood. A host of variables have been proposed as potentially causal in developing AUDs, but empirical examination of many of these variables in human samples is lacking. Objectives: Our objective was to examine the extent to which alcohol pharmacokinetics (PK), the rewarding effects of alcohol, and the relationship between these variables change from before to after weight loss surgery. Setting: Large healthcare facility in the Midwest United States Methods: Thirty-four participants completed assessments before and 1 year after RYGB. They completed laboratory sessions and provided data on the PK of alcohol and the extent to which alcohol was reinforcing to them at each timepoint. Results: Findings show that the PK effects of alcohol (P < .01) and how rewarding alcohol was reported to be (P < .01) changed from before to 1 year after weight loss surgery. Further, statistically significant increases in the association between these variables were witnessed from before to 1 year after surgery (P < .01). Conclusion: These results implicate changes (from before surgery to one year after) in the reinforcing and PK effects of alcohol as possible mechanisms for increased risk of alcohol use disorder following Roux-en-Y gastric bypass surgery.