Weight Loss Surgery Treats Diabetes

Study Shows Gastric Banding Surgery More Effective Than Lifestyle-Modification Programs

Medically Reviewed by Louise Chang, MD on January 22, 2008
From the WebMD Archives

Jan. 22, 2008 -- Weight loss surgery proved to be a highly effective treatment for type 2 diabetes in a newly published study, with almost three out of four surgically treated patients showing no evidence of the disease two years later.

Patients who had gastric banding surgery lost an average of 20% of their body weight within two years. That compares with less than 2% during the same time period in patients who had conventional therapy that focused on intensive lifestyle-modification programs involving diet and physical activity. Many of the patients were on diabetes medications.

The study included just 60 patients who had recently been diagnosed with type 2 diabetes. But if larger investigations confirm the findings, weight loss surgery may prove to be a cure for many people with diabetes, researcher John B. Dixon, MBBS, PhD, of Melbourne, Australia's Monash University, tells WebMD.

The findings appear in tomorrow's issue of The Journal of the American Medical Association.

"I really do think that within a few years surgery will become a common procedure for type 2 diabetes," Dixon says.

(Would you have weight loss surgery to control your diabetes? Share your thoughts on WebMD's Type 2 Diabetes Support Group board.)

Weight Loss Surgery and Diabetes

Gastric banding surgery reduces the size of the stomach to help patients eat less.

Both gastric banding surgery and gastric bypass surgery have been shown to be effective for weight loss, but their impact on obesity-related diseases like diabetes has only recently begun to be studied.

In the newly reported research, patients were randomly assigned to receive either laparoscopic adjustable gastric banding (also referred to as lap banding) or conventional diabetes treatment with a focus on lifestyle modifications though diet and exercise.

The patients had been diagnosed with diabetes no more than two years before entering the study.

Fifty-five patients completed the study, and 26 (43%) achieved diabetes remission at two years.

At the completion of the study, 22 of 30 (73%) surgically treated patients showed no evidence of type 2 diabetes, compared with four of 30 (13%) patients in the lifestyle-intervention group.

Surgically treated patients lost an average of 62% of their excess weight, compared with an average loss of 4.3% in patients who did not have the surgery.

No serious complications occurred in either treatment group. Two of the surgical patients required nonurgent surgical replacement of their bands.

'Surgery Not a Last Resort'

It is increasingly clear that early, intensive treatment is associated with better outcomes among patients with type 2 diabetes.

Because of this, Dixon says weight loss surgery should no longer be considered a last resort used only in patients who are very obese.

Weight loss surgery is generally not considered for people with body mass indexes (BMI) of below 35, even if they have diabetes or other obesity-related maladies.

To put this number in perspective, a 5-foot 8-inch person who weighs 230 has a BMI of 35.

"Why shouldn't this very safe operation be offered to a diabetic with a BMI of 34 who has already struggled for years to lose weight?" Dixon asks.

Endocrinologist David E. Cummings, MD, says the evidence in favor of weight loss surgery as an early treatment for type 2 diabetes is mounting.

But in an editorial accompanying the study, Cummings questions whether the dramatic results achieved by Dixon and his colleagues would be seen in centers with less experience performing weight loss surgery and less intensive patient follow-up.

Cummings is a professor of medicine at the University of Washington, Seattle.

"The authors' surgical team in Melbourne, Australia, is among the most experienced groups in the world ... and their excellent results may not be readily reproducible elsewhere," he notes.

Cummings tells WebMD that the benefits of weight loss surgery as a treatment for diabetes appear to extend beyond weight loss alone.

This is illustrated by the fact that blood glucose levels often normalize in patients who have gastric bypass surgery within days or weeks, long before significant weight loss has occurred.

"I think it is reasonable to conclude that [weight loss] surgery should be offered to more people with diabetes," he says.

Don't Give Up on Diet and Exercise

But American Diabetes Association President of Medicine and Science John B. Buse, MD, says patients shouldn't take from the study that surgery is the only effective treatment for diabetes.

"I have a problem with telling people that they need to be surgically altered because we can't help them deal with an unhealthful lifestyle in other ways," he tells WebMD.

Weight loss through diet and exercise does work, Buse says, but patients rarely get the support they need to succeed.

"The idea that health insurers might pay for surgery but not a dietitian or weight loss drugs is troubling," he says.

Show Sources


Dixon, J.B. The Journal of the American Medical Association, Jan. 23, 2008; vol 299: pp 316-323.

John B. Dixon, MBBS, PhD, Center for Obesity Research and Education, University of Melbourne, Australia.

David E. Cummings, MD, professor of medicine, University of Washington, Seattle.

John B. Buse, MD, PhD, president, medicine and science, American Diabetes Association; chief of endocrinology, department of medicine, University of North Carolina, Chapel Hill.

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