Weight loss surgery helps for Type 2 diabetes

Weight loss surgery reverses or improves Type 2 diabetes, a review of previous studies suggests.

About 90 per cent of Type 2 diabetes is attributed to obesity, researchers say.

In the June issue of the Archives of Surgery, Dutch researchers reviewed data from nine studies of people with Type 2 diabetes who had either gastric bypass or another form of weight loss surgery called gastric banding. 

In gastric bypass, a surgeon reduces the capacity of the stomach to hold food by creating a small pouch that diverts food. The amount of food a person can eat is reduced and absorption is hindered.

The most common alternative to gastric bypass surgery is adjustable gastric banding. In this procedure, a surgeon places a doughnut-shaped device, with an inflatable balloon on the inside, around the upper part of the stomach to reduce the ability to consume large amounts of food.

In 2008, about 344,000 weight loss or bariatric surgeries were performed worldwide, including 220,000 in the U.S. and Canada, an earlier study said.

The new review looked at eight studies that included between 23 and 177 patients, and another study that tracked 82,000 patients. All patients were followed for at least 12 months after surgery.

On average and over different time frames, a type of gastric bypass known as Royx-en-Y or RYGB achieved a reversal rate of about 83 per cent compared with a reversal rate of 62 per cent for gastric banding, Dr. Rick Meijer at the Institute for Cardiovascular Research at Vrije Universiteit in Amsterdam and his co-authors said.

"In conclusion, bariatric surgery, especially RYGB, leads to a reversal of or improvement in [Type 2 diabetes]," the study's authors wrote.

"Bariatric surgery must be considered in patients with poorly controlled Type 2 diabetes and a body mass index greater than 35. In fact, this approach may be cost-effective.  However, the decision to perform surgery should not be delayed for long because the success rate depends partially on the duration of [Type 2 diabetes]."

More research is needed to assess bariatric surgery in patients with Type 2 diabetes and a BMI of less than 35, they said.

"In patients with morbid obesity and Type 2 diabetes, bariatric surgery offers a novel end point, namely, complete disease remission," Dr. Jon Gould, who heads the weight loss surgery program at the University of Wisconsin, said in a journal commentary accompanying the study.

"The effect of bariatric surgical procedures, particularly Roux-en-Y gastric bypass, on [Type 2 diabetes] can be profound and in some cases immediate."

The research was funded by the Dutch Heart Foundation.