Study shows high-risk drinking may improve post weight loss surgery

Much has been reported about the potential for increased risk of alcohol misuse after weight loss surgery (WLS), with most theories pointing to lower alcohol tolerance and a longer time to return to a sober state after surgery, but a new study from Beth Israel Deaconess Medical Center suggests that upwards of half of high-risk drinkers are actually less likely to report high-risk drinking behavior after weight loss surgery.

The results appear in the journal, Surgery for Obesity and Related Diseases.

"This is the first study to show that high-risk drinking may actually improve post weight loss surgery," says lead author and principal investigator Christina Wee, MD, Director of Obesity Research in the Division of General Medicine and Primary Care.

Wee and colleagues interviewed patients who participated in the Assessment of Bariatric Surgery or ABS Study, which aims to understand patient preferences and decision making processes about weight loss and weight loss surgery. They followed 541 clinically obese patients who underwent weight loss surgery, interviewing them at baseline and then twice again at the end of one and two years.

Study participants were asked questions assessing frequency of drinking over the past year, quantity of alcohol consumed on an average daily, and binge drinking over the past month. Results were used to determine which individuals were high-risk drinkers.

"Given the greater clinical attention being paid to caloric intake and substance abuse issues after WLS, we hypothesized that a subset of high-risk drinkers who undergo WLS may actually experience amelioration of their high-risk drinking," write the authors.

It turns out they were right.

"So much of the existing literature focuses on increased risk", says senior author George Blackburn, MD, Director of the Center for Nutrition Medicine. "Even though we expected to see something different with this data, we were still surprised by the findings."

About one in six patients reported high-risk drinking before weight loss surgery. At one year after surgery two thirds of gastric bypass patients and nearly half of gastric banding patients reported ceasing high-risk drinking. And at year two "half of gastric bypass and more than half of gastric banding patients reported this improvement," write the authors.

"It's possible that previous studies may have missed this positive effect because post-surgery alcohol use wasn't compared against baseline consumption," says Wee.

While this decrease in high-risk drinking is important, the study also found that seven percent of weight loss surgery patients who did not report high-risk drinking at baseline reported new high-risk drinking at year one and two years post-surgery. These findings were similar between gastric bypass and gastric banding patients.

Wee thinks understanding the complete picture can better prepare clinicians to counsel their patients who are considering weight loss surgery and follow up with them after surgery.

"Often, high-risk drinkers are steered away from weight loss surgery. Knowing that a significant percentage of these patients may actually cease high-risk drinking after weight loss surgery may help us recommend more patients for surgery," says Wee.

"We routinely screen for alcohol misuse as part of routine pre- and post-operative care, with a heavy emphasis on patients who are known to be at risk," says co-author Dan Jones, MD, Director of BIDMC's Bariatric Surgery Center. "This study tells us that we can do a better job of screening for and supporting patients who are newly at risk as opposed to only focusing on those who may have had a problem before surgery."

Wee says more research is necessary to understand why weight loss surgery seems to help some patients improve alcohol misuse, while it increases misuse in others. "We also need to better understand which patients are at highest risk for developing alcohol misuse so that we might better counsel and monitor them."