CHICAGO — The most common type of obesity surgery may increase patients' chances for alcohol abuse, according to the largest study to demonstrate a potential link.
Patients who had gastric bypass surgery faced double the risk for excessive drinking, compared with those who had a less drastic weight-loss operation.
Gastric bypass surgery shrinks the stomach's size and attaches it to a lower portion of the intestine.
Dr. Clinton Hall, medical director of bariatric surgery at South Florida Baptist Hospital in Plant City, said doctors have known for a long time that the surgery can increase the effects of alcohol.
After surgery, there is less acid in the stomach to break down alcohol, so more is absorbed from each drink and absorbed faster, he said. "My patients all undergo psychological evaluations before surgery, and if there's any substance or alcohol abuse, that has to be addressed first," he said.
There are other risks to ingesting too much alcohol, he said. It can lead to ulcerations in the new gastric pouch, affect blood sugar and insulin levels and have other effects that could compromise the surgery.
The researchers asked nearly 2,000 women and men who had various kinds of obesity surgery about their drinking habits one year before their operations and then one and two years afterward. Most didn't drink excessively before or after surgery, and increases in drinking didn't occur until two years post-surgery.
More than two-thirds had gastric bypass surgery and were most at risk. Two years after the surgery, almost 11 percent, or 103 of 996 bypass patients, had drinking problems, a 50 percent increase from before surgery.
Five percent of patients who had stomach-banding surgery drank excessively two years later, similar to presurgery numbers.
The study was released online Monday in the Journal of the American Medical Association.
Times staff writer Irene Maher contributed to this report.