A study of the two most popular weight-loss surgeries found obese diabetics who had gastric bypass surgery lost 64 percent of their excess weight after a year, compared with 36 percent in those treated with Allergan Inc's Lap-Band device, researchers said on Monday.
Complication rates were about the same with both procedures.
"It's a dramatic difference," said Dr. Guilherme Campos of the University of Wisconsin School of Medicine in Madison, and formerly of the University of California, San Francisco, whose study appears in the Archives of Surgery.
Weight loss surgery is becoming increasingly popular as obese people struggle to lose weight and avoid the health complications that accompany the extra pounds, including diabetes, heart disease, joint pain and some cancers.
Prior studies have suggested gastric banding was safer than gastric bypass surgery, in which doctors surgically reduce the size of the stomach to limit the amount a person can eat.
With gastric banding, doctors insert an adjustable silicone band around the upper part of the stomach, giving the patient the illusion of fullness with small meals.
Last week, the Food and Drug Administration approved expanded use of the stomach band, allowing it to be implanted in less obese people.
In this study, researchers compared Allergan's Lap-Band device with a form of gastric bypass surgery known as Roux-en-Y. The surgery was done laparoscopically, through small incisions in the belly.
The study involved 100 morbidly obese people who underwent Lap-Band surgery. These patients were matched by sex, race, age and weight with 100 patients who underwent gastric bypass.
All of the bypass surgeries were performed by expert surgeons in high-volume weight loss centers.
"In the gastric bypass patients, about 86 percent of patients successfully lost more than 40 percent of excess weight. Only about 31 percent of the Lap-Band patients lost that amount of weight," Campos said in a telephone interview.
"That is significant," he said.
Overall, 12 percent of patients in the Lap-Band group and 15 percent of patients in the gastric bypass group experienced complications. Patients who got gastric banding were more likely to have complications right after their surgeries, while Lap-Band patients were more likely to need a second operation. There were no deaths in either group.
The study shows that gastric bypass provides better weight loss, better resolution of diabetes and an improvement in quality of life compared to the Lap-Band, Campos said.
He said obese patients need to be informed of the results of the two procedures, and if they choose gastric bypass they need to make sure their surgeon is highly experienced.