Obesity, Type 2 Diabetes and Bariatric Surgery: The Real Story

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For several years now, bariatric surgeons have been touting weight-loss surgery as a treatment for type 2 diabetes. Some claim it’s a way to reduce the symptoms of diabetes in obese patients — or even reverse the condition entirely. In this article, I will attempt to separate the facts from fiction. Here’s what you need to know about obesity, type 2 diabetes and bariatric surgery.

First, some definitions for anyone who is unfamiliar with these concepts:

Obesity — A condition of excess body fat that leads to a variety of health problems. In most cases, obesity is identified by using the person’s body mass index, or BMI. The number is calculated by dividing a person’s body weight (in kilograms) by his height (in meters). There are other methods for determining obesity, such as waist circumference. But the BMI measurement is the most widely used method today. A person with a BMI of 30 kg/m² or higher is said to be obese.

Type 2 Diabetes — A medical condition frequently seen in obese people. This condition results in high levels of sugar (glucose) in the blood. Type 2 was formerly referred to as adult-onset diabetes, and you may still see it labeled this way in some medical literature. Type 2 diabetics are often overweight. The initial diagnosis usually occurs when the patient is older than 35 years. Diabetes can lead to a variety of serious health problems, such as heart disease and nerve damage.

Bariatric Surgery — This refers to a variety of surgical procedures intended to help the patient lose weight. The bariatric “umbrella” includes stomach-banding procedures such as the LAP-BAND® System, as well as gastric bypass surgery. These procedures used to be reserved for patients who were obese. But the spectrum of eligibility has widened in recent years to include those who are merely overweight.

Does Bariatric Surgery Actually Cure Diabetes?

So what’s the connection between obesity, type 2 diabetes, and bariatric surgery for weight loss? Can these procedures actually cure diabetes, the way some people say they can? Yes and no.

Significant weight loss can certainly improve the health of an obese person with type 2 diabetes. And bariatric procedures are one way to achieve that level of weight reduction. Diet and exercise can accomplish the same thing, but without the risks of an invasive surgical procedure.

So the best option, clearly, is to reduce body weight by making dietary and lifestyle changes. But that’s not always easy for some folks. According to the National Institutes of Health, obese people “whose diabetes is not well managed with diet and medicine may consider bariatric (weight loss) surgery.”

So it’s the weight loss that reduces the effects of type 2 diabetes in patients suffering obesity. If you underwent bariatric surgery but did not lose a significant amount of weight and body fat, then you might not see any improvements at all. But if you lost a great deal of weight (and body fat in particular), the symptoms of your type 2 diabetes could very well subside.

According to numerous studies over the last few years, bariatric weight-loss surgery can reduce the severity of diabetes in obese patients. In 2010, the American Diabetes Association (ADA) began studying the potential benefits of these procedures last year.

Reviewing the Research

Erika Gebel, PhD, wrote an article on this subject for the Diabetes Forecast (the healthy living journal published by the ADA). In her March 2010 article, she explained that definitive studies on the link between bariatric surgery and type 2 diabetes could take years to complete. So we clearly don’t have all the answers yet. She goes on to point out the well-known connection between obesity and this form of diabetes. So it stands to reason that anything the reduces the patients weight will also improve the symptoms of their type 2 condition.

“Still,” she said, “the numbers are startling.” Here are the numbers Ms. Gebel was referring to:

• In 2009, a meta-analysis of 600 studies covering more than 135,000 patients found that 78% of patients with type 2 diabetes experienced total resolution of the disease after having weight-loss surgery.
• Additionally, 87% of patients studied saw improved blood-glucose levels.

So based on these studies, yes — bariatric surgery can effectively resolve type 2 diabetes in obese patients. But it all comes down to the amount of weight lost. If the procedure does not result in a significant reduction in weight, the person may not experience the same positive effects as those discussed above.

But here’s the interesting part. Certain types of surgery have been shown to resolve symptoms of type 2 diabetes even before the weight comes off. This is supposedly the case with gastric bypass surgeries. There are several theories as to why this occurs. Some researchers believe it has to do with the “rerouting” of food that results from a gastric bypass. When the path of food is altered within the stomach and intestines, the cells in the lower small intestines release more of an agent that reduces blood-glucose levels (and the effects of diabetes). Research is still ongoing in this area.

In March 2011, the International Diabetes Federation (IDF) released a position statement that promoted the use of bariatric surgery for eligible patients with type 2 diabetes. According to the press release that accompanied their statement, weight-loss surgery is a cost-effective treatment option for obese patients who are suffering from the disease. Professor George Alberti, a co-chairperson at the IDF, said bariatric surgery should be considered earlier in the treatment path, instead of being viewed as a last resort.

So is bariatric surgery the cure for type 2 diabetes in obese patients? I think it’s too soon to use the word “cure.” But it certainly shows promise in resolving the condition. We do not yet know the long-term effects, because most of the research is still young. You can rest assured this is one story we will follow closely in the coming months and years.