Y gastric bypass surgery reached certain blood alcohol concentrations in half the number of drinks compared to women who didn't have the surgery, and reported a greater feeling of drunkenness, according to a study published online by JAMA Surgery. Roux-en-Y gastric bypass (RYGB) is the most common bariatric surgical procedure performed in the world. Although RYGB surgery causes a marked reduction in food intake and induces remission of food addiction, it is associated with an increased risk of developing alcohol use disorders. It is likely that RYGB-related changes in gastrointestinal anatomy alter the pharmacokinetics and subjective effects of ingested alcohol, which contributes to the increased risk of alcohol use disorders. However, results from previous studies have been limited, according to background information in the article.

Marta Yanina Pepino, Ph.D., of the Washington University School of Medicine, St. Louis, and colleagues conducted a study that included eight women who had RYGB surgery (RYGB+ group) within the last 1 to 5 years and 9 women scheduled to have RYGB surgery (RYGB- group). All participants completed 2 sessions about 1 week apart in which their response to alcohol (equivalent to approximately 2 standard alcoholic beverages) or a nonalcoholic placebo beverage was evaluated via blood alcohol concentration (BAC) and a questionnaire.

The researchers found that BAC increased faster, the peak BAC was approximately 2-fold higher, and feelings of drunkenness were greater in the RYGW+ group than in the RYGB- group.

"The results from our study demonstrate that RYGB increases the rate of delivery of ingested alcohol into the systemic circulation," the authors write. "The alteration in alcohol pharmacokinetics means that the peak in BAC observed after consuming approximately 2 drinks in women who have had RYGB surgery resembles that observed after consuming approximately 4 drinks in women who have not had surgery."

"These findings have important public safety and clinical implications. The BACs in the RYGB+ group exceeded the legal driving limit for 30 minutes after alcohol ingestion, but the BACs in the RYGB- group never even reached the legal driving limit. The peak BAC in the RYGB+ group also met the National Institute on Alcohol Abuse and Alcoholism criteria used to define an episode of binge drinking, which is a risk factor for developing alcohol use disorders. These data underscore the need to make patients aware of the alterations in alcohol metabolism that occur after RYGB surgery, to help reduce the risk of potential serious consequences of moderate alcohol consumption."