Updated

A new study has found that adults who undergo a common type of bariatric surgery to lose weight appear to have a significantly higher risk of abusing alcohol two years after the procedure, according to researchers the University of Pittsburgh.

The study investigated alcohol consumption and abuse in nearly 2,000 patients across the United States.  Researchers surveyed bariatric patients on their alcohol consumption 30 days before surgery, then again one and two years after surgery.

Nearly 70 percent of the participants had gastric bypass surgery – which reduces the side of the stomach and shortens the intestine – and were most at risk for alcohol disorders.  Another 25 percent had laparoscopic adjustable gastric banding surgery, which uses a band to make the stomach smaller, and the remaining 5 percent had other, less-common surgeries.

Of those patients who had gastric bypass, 7 percent reported symptoms of alcohol disorders before surgery.  That rate increased to 10.7 percent two years after surgery – a relative increase of more than 50 percent.  Translated to the entire population of people who undergo gastric bypass in the U.S., this could mean an increase of 2000 people suffering from alcohol disorders per year.

Though a prior problem with drinking was one of the best predictors of having a disorder later, more than half of the participants who developed disorders two years after surgery did not have a prior history of alcohol abuse, according to the researchers.

“There have been several studies showing if you give gastric bypass patients a standard amount of alcohol, they reach a higher peak alcohol level, they reach the level more quickly, and they take longer to return to a sober state – they’re experiencing alcohol differently after surgery,” study researcher Mary King, an assistant professor of epidemiology at the Graduate School of Public Health at the University of Pittsburgh, told FoxNews.com.  “So we weren’t entirely surprised to find a significant increase.  It could be a combination of the change in alcohol sensitivities coupled with higher levels of drinking.”

In contrast, among patients who had lap band surgery, about 5 percent suffered from alcohol use disorders two years after surgery, which was similar to pre-surgery rates.  According to King, while there have been no formal studies done, it is unlikely lap band surgeries affect patients’ sensitivities to alcohol like gastric bypass procedures do.

The survey the researchers used, known as the Alcohol Use Disorders Identification (AUDIT) test, was developed by the World Health Organization to identify symptoms of alcohol use disorders, which include alcohol abuse and dependence, or alcoholism.

The participants were categorized as having an alcohol-related disorder if they had at least one symptom of dependence.  Symptoms of dependence included not being able to stop drinking after having started or not being able to remember what happened after a night of drinking.

The patients most at risk of developing an alcohol-related disorder were those with little social support, those who had engaged in recreational drug or alcohol abuse in the past, those who suffered from depressive symptoms, men, and young adults.  King said that while ‘addiction shifting’ – such as a switch from binge eating disorder to alcoholism – is a topic of focus in the media, the researchers did not find any evidence that a prior history of binge eating symptoms increased a patient’s risk of developing an alcohol use disorder.

According to King, the results indicate that more needs to be done as far as educating patients about the potential risks and benefits of bariatric surgery, especially with the rise of obesity rates in the U.S.

“This is really something that needs to be a part of patients’ discussions with their surgeons – but as just one of the potential risks in the context of all potential risks and benefits of surgery,” King said.  “The study shouldn’t be used to suggest that gastric bypass surgery isn’t a good weight loss strategy, but it should be used to educate patients.”

King added that a mere pre-operative discussion may not be enough, considering the majority of patients did not show an increase in alcohol consumption until two years after surgery.  “I definitely think this has implications for long-term clinical care,” she said.  “Patients need to hear information when it’s applicable to them.  They need to be reminded at annual follow-up screenings as a part of clinical care, so referrals to counseling can be given, if needed.”

The study was published Monday in the Journal of the American Medical Association. It was funded by the National Institutes of Health.