Bariatric surgery is an increasingly popular option for those looking to lose weight. The American Society for Metabolic and Bariatric Surgery (ASMBS) report that the number of weight loss surgeries in the U.S. has increased from 158,000 in 2011 to almost 200,000 in 2015.
Researchers led by Wendy C. King, Ph.D., associate professor of epidemiology at the University of Pittsburgh Graduate School of Public Health in Pennsylvania, set out to examine the long-term evolution of patients who have undergone bariatric surgery. King and colleagues found a link between having the procedure and alcohol problems.
Specifically, the team focused on Roux-en-Y gastric bypass (RYGB) - a type of weight loss surgery that changes the structure of the small intestine and makes the stomach smaller, reducing it to the size of an egg.
The findings were published in Surgery for Obesity and Related Diseases.
One in 5 patients developed alcohol problems within 5 years of surgery
The team examined more than 2,300 patients who were enrolled in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) over a follow-up period of 7 years. LABS-2 is a prospective, observational cohort study of people who had weight loss surgery in 10 hospitals across the U.S.
During the follow-up, RYGB was the most popular procedure, undergone by 1,481 patients. Most of the remaining patients (522) had another procedure called laparoscopic gastric banding, in which an adjustable band is inserted around the upper part of the patient's stomach, limiting their intake of food.
Over the 7-year follow-up period, both the RYGB group and the laparoscopic gastric banding group consumed more alcohol. However, only RYGB patients also presented with symptoms of alcohol use disorder.
The symptoms were measured using the Alcohol Use Disorders Identification Test - a 10-item alcohol use assessment tool developed by the World Health Organization (WHO).
The study revealed that 20.8 percent of RYGB patients went on to develop alcohol use disorder symptoms within 5 years of having the procedure. By contrast, only 11.3 percent of the laparoscopic gastric banding patients developed similar problems.
Additionally, of those participants without alcohol use issues in the year before the intervention, RYGB patients were over twice as likely to develop alcohol use problems over a 7-year period, compared with those who had laparoscopic gastric banding.
How RYGB may lead to alcohol use disorder
This is one of the largest and longest studies to date of people who undergo weight loss procedures.
The study being observational, it cannot explain the reason why RYGB may increase the risk so much more than other surgical procedures. However, the authors cite previous studies that have suggested that RYGB may raise alcohol levels in the bloodstream quicker and higher compared with other procedures.
Another possibility is that RYGB increases tolerance by altering the genetic expression of the hormones that deal with reward circuits in the brain.
The study's lead author comments on the results:
"We knew there was an increase in the number of people experiencing problems with alcohol within the first 2 years of surgery, but we didn't expect the number of affected patients to continue to grow throughout 7 years of follow-up.
Because alcohol problems may not appear for several years, it is important that doctors routinely ask patients with a history of bariatric surgery about their alcohol consumption and whether they are experiencing symptoms of alcohol use disorder, and are prepared to refer them to treatment."
Wendy C. King, Ph.D.
The ASMBS recommend that patients be screened for alcohol dependence before the procedure, as well as be advised of the risks that it carries.