Researchers found that patients who had the Roux-en-Y procedure — in which a small stomach pouch is created and connected to the middle of the small intestine — had a higher prevalence of problems with alcohol consumption compared to the year before surgery and the year immediately after.
"We found that seven per cent of Roux-en-Y gastric bypass patients reported symptoms of alcohol use disorder (AUD) in the year prior to surgery," said lead author Wendy King, an epidemiologist at the University of Pittsburgh.
That percentage didn't change much in the first year following surgery. But by Year 2, almost 11 per cent of patients were reporting potentially problematic changes in their alcohol consumption, King said from San Diego, where she presented the findings Monday at a meeting of the American Society for Metabolic and Bariatric Surgery.
"Among patients who had laparoscopic adjustable gastric banding, we did not find a significant difference," said King, referring to the procedure in which a band is placed around the upper stomach to reduce the amount of food that can be ingested.
To conduct the study, researchers assessed alcohol consumption patterns in 1,945 bariatric surgery patients at 10 hospitals across the United States. Within 30 days before surgery, and again one and two years after their operations, patients completed an audit to identify symptoms of alcohol use disorders, a condition that includes alcohol abuse and dependence.
Participants were categorized as having AUD if they had at least one symptom of alcohol dependence, including not being able to stop drinking once started, or alcohol-related harm, such as not being able to remember a certain event.
About 70 per cent of participants had Roux-en-Y surgery, also known as gastric bypass; another 25 per cent had lap banding, while the other five per cent had less common weight-loss surgical procedures.
Overall, one in eight participants reported having at least three drinks on a typical drinking day the second year after surgery. Another one in eight said they had at least six drinks on one occasion.
"And they were actually drinking more frequently by the second post-operative year than they were pre-operatively or the first year," said King.
"So that's really heavy levels of drinking, especially for post-operative patients," said King. "This is concerning, given the negative impact heavy drinking may have on vitamin and mineral status, liver function and weight loss."
Weight-loss specialist Dr. Yoni Freedhoff said it's been known for some time that alcohol abuse is a risk for some people following stomach-shrinking surgery.
"And it's certainly one that I've been counselling patients about for years prior to their surgical procedures," Freedhoff, medical director of the Bariatric Medical Institute, said Monday from Ottawa.
In Canada, he said, about three per cent of the population would qualify for bariatric surgery, which is performed on people with a body mass index of 40 and higher or with a BMI of 35 plus a weight-related condition such as Type 2 diabetes, sleep apnea or high blood pressure.
But Freedhoff said the number of bariatric surgeries performed in Canada severely lag behind demand, and are proportionately far below the rate in the United States.
Researchers don't know why the Roux-en-Y surgery increases the risk for alcohol consumption problems, but previous studies have hypothesized that having a smaller stomach area and a shorter route to the small intestine means alcohol is absorbed by the body more quickly.
"And also if they lose 100 pounds, the same amount of alcohol may affect them differently too," King said of patients.
"I think that patients really need to be educated about the potential risks and also the effects of heavy drinking, and how that may negatively impact their weight-loss goals and their health."
King said the study, which is also being published online Monday by the Journal of the American Medical Association, suggests doctors should continue monitoring bariatric surgery patients for signs of alcohol abuse.
Freedhoff said the study found a very minor increase in rates of alcohol abuse post-surgery, so "it's difficult to ascertain how much of a problem this really is."
"But given the incredible damage that can be wrought by alcoholism, I think it's definitely something that should be counselled about pre-surgically for anybody considering a bariatric procedure, especially the gastric bypass," he said.
"And if patients aren't warned about the potential risk of alcohol and how it will be different post-surgically, perhaps they will fall into that particular rabbit hole and struggle."