WEDNESDAY, Aug. 22, 2012 (HealthDay News) -- Weight-loss surgery can significantly reduce the incidence of overweight people who develop type 2 diabetes, new research indicates.
Over 15 years, the study found that only 13 percent of people who'd had weight-loss (bariatric) surgery developed type 2 diabetes vs. 38 percent of those who didn't have surgery, said senior study author Dr. Lars Sjostrom, a senior professor at the Institution of Internal Medicine at Gothenburg University in Sweden.
"These figures correspond to an 80 percent risk reduction with bariatric surgery," he noted. "Bariatric surgery is markedly reducing the risk of developing type 2 diabetes in all kinds of obese patients -- men, women, severe obesity, modest obesity and patients with impaired or normal fasting [blood sugar levels]."
Sjostrom said that the dramatic weight loss caused by bariatric surgery is of importance in preventing diabetes, but it wasn't the only factor. "Several gastrointestinal signaling systems to the brain and other organs may also be involved. This is an area that needs much more research," he noted.
Results of the study are published in the Aug. 23 issue of the New England Journal of Medicine.
Exercise and weight loss are known ways to prevent type 2 diabetes. They're also important factors in the management of type 2 diabetes. Recent research has found that when obese people undergo bariatric surgery, their diabetes often improves dramatically.
The current study looked at whether the same types of surgery could also prevent type 2 diabetes from developing in the first place.
The study included 1,658 people who underwent bariatric surgery in Sweden between 1987 and 2001. They compared these people to obese people who didn't have surgery (the control group). No one in either group had type 2 diabetes when they entered the study.
All of the study volunteers were between the ages of 37 and 60. The body mass index (BMI), a measure of body fat, was at least 34 for men and 38 for women. A BMI of 30 or over is considered obese.
People in the bariatric surgery group had several types of surgery, including banding, vertical banded gastroplasty and gastric bypass. During the 15-year follow-up, 392 people in the control group developed diabetes compared with 110 in the bariatric surgery group.
The rate of death related to surgery was 0.2 percent. And, 2.8 percent of the people who had surgery, had to have a second surgery within 90 days due to complications.
Sjostrom said the cost of bariatric surgery is about $11,500 in Sweden, but he suspects it costs considerably more in the United States. Still, he said, if the surgery can prevent type 2 diabetes, the cost of the surgery is likely cost-effective over time.
He said that people with high fasting blood sugar levels that are still considered non-diabetic might be the ones who could benefit most from bariatric surgery.
However, Sjostrom said he would still recommend that people try diet, exercise and medications to prevent diabetes first. But, he added, it's often difficult to sustain those changes.
One expert urged caution in interpreting the findings.
"I don't think we're going to suddenly start doing bariatric surgery on everyone to prevent type 2 diabetes," said Dr. Spyros Mezitis, an endocrinologist at Lenox Hill Hospital, in New York City. "But, this is an important study that makes us think about who might benefit from bariatric surgery more. If the heart is healthy enough for surgery, someone who is morbidly obese, with a BMI over 40 or more, bariatric surgery may be something we should be recommending. In this population, you see a drastic improvement in health after bariatric surgery. As they're losing weight, they feel better, they're more agile and they have more energy."
Learn more about preventing diabetes from the National Diabetes Education Program.