Bariatric Surgery for Diabetes

New guidelines last week recommended surgery as Type 2 diabetes treatment for people who are obese, including some who are mildly obese. Is “metabolic surgery” something you should consider?

The guidelines were approved by the American Diabetes Association, the International Diabetes Federation, and 43 other medical groups around the world. They were published in the June issue of the journal Diabetes Care.

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If you are heavy and have an HbA1c of 7.0 or above, your doctor may soon advise you to have one of these surgeries. You will be told the surgery will lower your blood sugar and your weight, which usually happens. You may not be told the negative effects. How do you decide?

When performed to manage diabetes, bariatric or weight-loss surgery is known as “metabolic surgery.” The term covers Roux-en-Y “gastric bypass” surgeries, which reduce your stomach to a small pouch and plug it into the middle of the small intestine. It also includes “sleeve gastrectomy,” in which the deep part of the stomach is removed and the rest stapled together into a sleeve shape. Wrapping a band around the stomach to shrink it (“gastric banding“) is also now considered metabolic surgery. There are other surgeries that restructure the bowel in different ways, which I’ll write about next week.

Surgeons have been pleased to learn that their weight-loss operations also lower blood sugars, though they are working to fully understand how that happens. It’s probably not the weight loss. Often, the improvements in diabetes numbers come long before significant weight loss occurs.

A conference in Rome in 2007 reported that people were getting off their diabetes medications and lowering their HbA1c scores after surgery. Eight years later, a follow-up conference in London decided to make metabolic surgery an official recommendation.

Not all people with diabetes will be told to get surgery. People with Type 2 diabetes and a body-mass index (BMI) equal to or over 40.0, or a BMI from 35.0 to 39.9 and poorly controlled Type 2 diabetes, will be advised to get it. People with poor control and BMI from 30.0 to 34.9 should “consider” surgery. You can calculate your own BMI here.

What’s the evidence?
The evidence for diabetic surgery is building up slowly and still does not have long-term follow up. One of the longest trials, called STAMPEDE, is following roughly 150 people with high BMIs and poorly controlled diabetes. One group got gastric bypass; one got sleeve gastrectomy; and one got intensive non-surgical medical care, including counseling and medicines.

At five years, half of the patients in the surgery groups had their HbA1c level below 7.0%. Less than a quarter in the medical therapy group did. One in five patients in the surgery groups had their HbA1c down to 6.0% or less, without medications, meaning their diabetes was in remission. Nobody in the medical therapy group did that well.

There were no significant differences between groups in eye or kidney function, blood pressure, or cholesterol. The surgical groups lost much more weight than the medically managed group. They also needed fewer heart medications and scored higher on quality-of-life measures.

Other studies have showed similar benefits. Results vary depending on the patients and the types of procedures.

None of the studies say much about the negative effects, but there are many. A big one is malnutrition because people eat less and absorb less of what they eat. The government’s health information site MedlinePlus warns: “If you have gastric bypass surgery, you will need to take extra vitamins and minerals for the rest of your life,” but that might not completely prevent malnutrition problems like osteoporosis.

All the surgeries have significant risks, though they are becoming safer. Sleeve gastrectomy often causes anemia because blood leaks through the stapled stomach. Gastric bypass has risks of infection and blood clots, and digestive problems including ulcers, reflux, and gallstones.

WebMD reported that, “About 20% of people who opt for weight-loss surgery require further procedures for complications, and as many as 30% deal with complications relating to malnutrition.” These malnutrition effects can include “cognitive decline, neuropathy, and loss of muscle strength,” according to clinical psychologist and eating disorder specialist Deb Burgard, PhD, FAED.

All these procedures permanently change your relationship with food. It’s common to get nausea and abdominal pain. You can eat only small amounts at a time, very slowly, chewing well, avoiding certain foods, and constantly deciding what is safe to eat. It’s a lot like managing a diabetes diet, only more so. Eating for pleasure may become a thing of the past.

You can see more about the various procedures and their pros and cons here.

Are the findings biased?
Twenty-five percent of the authors of the guidelines in Diabetes Care are weight-loss surgeons. The guidelines are clearly trying to persuade insurers and governments to fund the surgeries, which can cost $25,000, even if there are no complications.

According to CBS News, “Insurance coverage has become more common over the past decade but remains spotty, and many insurers limit coverage to severely obese patients.”

“The clinical community,” say the guidelines, “should work together with health-care regulators to recognize metabolic surgery as an appropriate intervention for Type 2 diabetes in people with obesity and to introduce appropriate reimbursement policies.”

Translation: Insurers should cover the surgery and governments should tell them to do so.

But what should you do? What do you need to know about these procedures to make an informed decision? More next week on what the different surgeries are, how they work, and how they affect your life.