Weight-Loss Surgery to Treat Diabetes

Mary Stanford knew the deal. Diagnosed with type 2 diabetes 13 years ago at age 33, she was painfully aware that her weight, which hovered around 250 pounds, was a major factor. She knew all too well about the hazardous complications of diabetes, since her father-in-law had struggled with and eventually died of them. And she recognized that losing just 10 percent of her body weight would improve her symptoms—but simply couldn't keep the pounds off. "You know what you're doing to yourself," says the biotech company senior manager from Port Washington, N.Y. "You get to a point where it takes a toll on you." Desperate, she chose gastric bypass surgery in late 2004, when she'd peaked at a smidgen over 300 pounds. Today, at 46, Stanford weighs 160 and shows no sign of her disease. Last year, she ran the New York City Marathon.

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Stanford's story is a potent reminder of how intricately weight is entwined with type 2 diabetes—and an illustration of what many researchers now are calling the most effective treatment. The American Diabetes Association says that almost 90 percent of people newly diagnosed with the disease are overweight; obesity, a body mass index of higher than 30 (197 pounds at 5 feet, 8 inches tall, for example), considerably elevates risk. Because research suggests that one form of weight-loss or "bariatric" surgery—gastric bypass—offers health benefits beyond simply cutting the pounds, medical practitioners and patients are increasingly seeing surgery not as a last resort but as a really good option, as well as an avenue to learn more about the mechanisms behind the disease.

"The insights already beginning to be gained by studying surgical interventions for diabetes may be the most profound since the discovery of insulin," wrote David Cummings, an associate medical professor in the division of metabolism, endocrinology, and nutrition at the University of Washington, in an editorial that appeared in the Journal of the American Medical Association last month.

Cummings's comments accompanied a report by Australian researchers that underscores the promise—and unresolved questions—surrounding surgery to treat diabetes. In a small group of 60 patients with BMIs between 30 and 40, one form of surgery combined with conventional therapy sent the disease into remission in 73 percent of the cases, meaning normal blood sugar levels and no need for diabetes medication. In the therapy-only group, just 13 percent went into remission.

It comes as no surprise to obesity experts that something as drastic as surgery is now being used to make people lose weight. One of the key findings of the JAMA study was that the nonsurgical patients, even with medical and behavioral help following a diet and exercise program, lost only 1.7 percent of their body weight, compared with almost 21 percent in the surgical group. When it comes to preventing diabetes through lifestyle changes, the failure rate runs about 95 percent outside of a research study or similarly intensive program. "There isn't anything that really works for obese people—the heavier you are, the harder it is," says Edward Livingston, chairman of GI/endocrine surgery at the University of Texas Southwestern Medical Center.

But several questions about surgery to treat type 2 diabetes remain. The biggie: Which patients stand to get the biggest benefit? Right now, National Institutes of Health guidelines recommend this sort of surgery only for patients with a body mass index over 40—about 262 pounds at 5 feet, 8 inches tall—and for people with diabetes or other life-threatening disease whose BMI is over 35. "It's a good parameter to use when operating on those who are only obese," says Francesco Rubino, director of the newly created gastrointestinal metabolic surgery program at New York-Presbyterian Hospital/Weill Cornell Medical Center. But that might not be the case, he says, "if we are treating a patient with diabetes. There's a strong need for doing carefully conducted trials."

His program plans to do just that. Meantime, the Cleveland Clinic is recruiting patients for a five-year study that will compare medical therapy by itself with bariatric surgery combined with medical therapy for type 2 diabetics who have a BMI as low as 30. "I can envision a day when mildly obese and even overweight [those with a BMI between 25 and 30] diabetics make even better candidates," says Rubino. "In the end, what affects the choice is the risk of dying from the disease and the risks of the surgery." Patients need to be studied over the long haul, too, not just for a few years. "We haven't felt that the longer-term studies are really sufficient to really know what the risks and benefits are" over 10 or 20 years," says John Buse, president of medicine and science at the American Diabetes Association.