Does Metabolic Surgery Cure Diabetes?

Experts disagree about how surgery treats diabetes but agree more research needs to be done

Wednesday, May 14, 2014 - Tuesday, September 30, 2014

By Robin Eisner; Illustrations by Adam Niklewicz

The combination of type 2 diabetes and being significantly overweight is a huge burden. Doctors tell you to lose weight, in essence, to save your life. Weight loss, in addition to diabetes medications, they say, will manage the major symptom of your diabetes: high blood glucose. If not controlled, experts warn, the excess glucose will lead to circulatory problems, high blood pressure, heart and kidney disease, blindness, limb amputations, and the many other complications of diabetes. Also, an obese person, or someone with a body mass index – BMI – over 30, has an increased risk of heart disease, cancer, arthritis, and sleep apnea. The solution: two simple words, lose weight.

The reality: not that simple. Losing so much weight by diet alone and keeping the weight off are extremely difficult
for someone with a BMI over 30. Exercise also is likely to be difficult for someone with a high BMI. Various types of weight loss surgery help people who have type 2 diabetes and BMIs over 35 lose weight, sometimes as much as 50 percent or more of their original weight, depending on the surgery. Besides allowing these patients to lose and keep off excess weight, surgery helps most patients manage their diabetes and blood glucose levels, with some people needing fewer medications and others stopping drugs completely. 

The Debate About the Surgery and Diabetes

Although weight loss surgery helps patients with diabetes and BMIs over 35 (the minimum BMI for surgery) lose weight, it remains unclear how it helps treat diabetes. Because most patients have substantially improved glucose control soon after surgery and before losing significant weight, some clinicians argue that the surgery alters the gastrointestinal system’s anatomy and hormonal milieu to cause the remission of symptoms. The new hormone balance, they say, influences insulin and glucose levels,
appetite, and overall metabolism. As a result, they call these procedures metabolic instead of bariatric, the traditional term for weight loss surgery.
Other physicians, however, say it is more likely the reduction in the amounts of food patients eat before and soon after surgery, not altered hormones, that leads to the metabolic changes and rapid glucose control after surgery. Calorie restriction can directly lower glucose levels. It is not hormonal changes contributing to the diminution of diabetes symptoms, they say, but reduced calories and, ultimately, weight loss. Still others say hormonal changes and weight loss may act together.

Read the full article