For patients suffering from morbid obesity, gastric bypass surgery can make life drastically better. But new evidence backs up anecdotal reports that the procedure could lead to a different—but quite serious—health problem: alcohol use disorder (AUD).

Wendy King, Ph.D., a research assistant professor in the Department of Epidemiology at the University of Pittsburgh, and her colleagues recently investigated this phenomenon, which has become increasingly apparent as the popularity of the Roux-en-Y gastric bypass (RYGB) procedure, first performed in 1993, has risen dramatically.

“There have been anecdotal reports of postoperative patients having alcohol-related problems,” King explained to Psychiatric News. “And pharmacokinetic studies have shown that RYGB patients experience alcohol differently: They reach a higher peak alcohol level, they reach it more quickly, and it takes a longer time to return to a sober state. But only three small studies had previously examined pre- and postoperative prevalence of AUD in RYGB patients. And due to study limitations such as small sample size, poor response rate, retrospective assessment, and comparison of different time periods, it wasn’t possible to determine whether there was in fact an increase in AUD following bariatric surgical procedures. It was a question that needed to be addressed.”

King and her colleagues designed a prospective cohort study to determine the prevalence of perioperative and postoperative AUD, and independent predictors of postoperative AUD, in patients undergoing bariatric surgery at 10 U.S. hospitals. Their study, the Longitudinal Assessment of Bariatric Surgery-2, consisted of 2,458 participants, 1,945 of whom successfully completed the necessary preoperative and postoperative assessments from 2006 to 2011.

Their results, published online June 18 in JAMA, appear to bear out the anecdotes, yet with a time lag: While the prevalence of AUD symptoms did not significantly differ from one year before to one year after bariatric surgery, it was significantly higher in the second postoperative year, particularly in patients who had undergone the RYGB form of surgery.

The numbers were small, but the researchers noted the potential for disruption in the lives of the people involved. “Although the increase in prevalence of AUD from 7.6 percent prior to surgery to 9.6 percent at the two-year postoperative assessment may seem small, that 2 percent increase potentially represents more than 2,000 additional people with AUD in the United States each year, with accompanying personal, financial, and societal costs,” they pointed out.

King and colleagues intend to continue to evaluate this particular group of patients. “We are continuing to assess AUD symptoms at annual research follow-up visits and plan to report on longer follow-up time points in the future. Some of my colleagues are also working on pharmacokinetic studies to better determine how alcohol influences patients after surgery,” said King.

Should concerns about AUD dissuade patients who are considering RYGB surgery? King hopes not. “RYGB is a very effective treatment for severe obesity. Just as with any medical procedure, patients and their health care providers should discuss all of the potential risks and benefits. I hope that this study prompts more alcohol education in pre- and post-operative care.

In addition to concerns about AUD, this study brought to light another crucial concern about alcohol consumption in general for patients who’ve had bariatric surgery. “In addition to assessing symptoms of AUD, we examined postoperative alcohol consumption and found that by the second postoperative year 1 in 8 patients (of all bariatric surgical procedures) reported drinking at least three drinks per typical drinking occasion, and 1 in 8 reported drinking six or more drinks at one time in the past year,” she said. “This level of drinking may have negative consequences on nutritional status, liver function, and weight loss. Thus, in addition to educating patients about the risk of AUD, patients need education on how alcohol may affect their health and their ability to realize their postoperative health goals.”

The Longitudinal Assessment of Bariatric Surgery-2 was funded by the National Institute of Diabetes and Digestive and Kidney Diseases.

“Prevalence of Alcohol Use Disorders Before and After Bariatric Surgery” is posted at http://jama.jamanetwork.com/article.aspx?articleID=1185618.