HealthLeader

An Online Wellness Magazine produced by The University of Texas Health Science Center at Houston (UTHealth)

Bypassing Diabetes

New evidence shows that weight-loss surgery can reverse—even cure—obesity-related Type 2 diabetes

Bypassing Diabetes

Editor’s Note: Gastric bypass surgery, sleeve gastrectomy, duodenal switch and the lap band procedure are among the surgical methods to help reduce weight in morbidly obese patients. Together they comprise the surgical side of what’s called bariatric medicine, the treatment of obesity. The New England Journal of Medicine recently published two studies online that confirm weight-loss surgery can reverse and possibly cure Type 2 diabetes brought on by obesity. In addition, doctors at UTHealth are currently conducting a surgical clinical trial using experimental surgery aimed at overweight or obese (but not morbidly obese) adults who have Type 2 diabetes.

At 535 pounds, Rex Adams felt like a prisoner, not just because of his weight, but because he was taking as many as a dozen pills a day to help manage complications of obesity.

“When I was diagnosed with type 2 diabetes and had to go on oral medication, that’s when it really hit me,” Adams says. “I had done this to myself. I knew I had to do something to lose the weight and free myself from all the pills I was taking.”

Adams sought a surgical solution to control the weight and his blood sugar. He took one last pill the day before the surgery.

Since then, he hasn’t required any medication to manage his type 2 diabetes and is no longer considered diabetic.

“It was like a complete release,” Adams says. “I had the surgery, and I never looked back.”

Weight-loss surgery is increasingly becoming an option for those who are morbidly obese, which is defined by a Body Mass Index, or BMI, of 40 or higher. Those who have diabetes or other co-morbidities such as hypertension, along with a BMI of 35 to 39, also are considered surgical candidates.

Different types of weight-loss surgery can have a dramatic impact on morbidly obese patients with type 2 diabetes, a condition affecting 21 million Americans – many of them overweight –that is characterized by high levels of blood sugar due to defects in insulin production and resistance to insulin’s actions. Some are able to go off diabetes medications entirely. Others may be able to significantly reduce the amount of insulin or other medication they require to keep their blood sugar in check. Patients who are classified as “pre-diabetic” may be able to avoid the disease all together.

“Patients with diabetes often see immediate improvements in their blood sugar levels after weight-loss surgery, especially those who have gastric bypass, duodenal switch or even sleeve gastrectomy” says Erik B. Wilson, MD, chief of Elective General Surgery for UTHealth Medical School and medical director of Bariatric Surgery for Memorial Hermann-Texas Medical Center. “The surgery appears to facilitate hormonal changes that help resolve diabetes.”

Two studies recently published online by The New England Journal of Medicine are the first to compare the effect of these weight-loss surgeries to medications for treating Type 2 diabetes brought on by obesity. Both studies found that surgery helped far more patients achieve normal blood sugar levels than the medications alone.

In fact, the studies stated that some people were even able to stop taking insulin as soon as three days after their operations. In one study, most patients were even able to stop taking all diabetes medications since their disease has stayed in remission for at least two years. No patients treated with medications alone were able to do that.

Cut for the cure?

The evidence of weight-loss surgery’s impact on diabetes is so convincing that some physicians are exploring it as a possible cure for Type 2 diabetes.

“Previous data was anecdotal or from uncontrolled studies,” says Philip Orlander, MD, a professor of internal medicine at UTHealth Medical School. “Now we have significant information from two randomized studies demonstrating the profound benefit of bariatric surgery on remission from diabetes.”

He says the important new information from the Cleveland Clinic study was that it demonstrated that patients benefited from this surgery even if they had the disease for more than eight years and were unable to adequately control their blood sugars on several medications. Patients also benefited even if they were only mildly obese. In the individuals assigned to medical therapy only, there was a progressive need for increasing the number of medications; whereas, in the surgical group, more than half of the individuals no longer required any diabetic medications.

Doctors at UTHealth are currently recruiting participants in their surgical clinical trial aimed at overweight or obese (but not morbidly obese) adults who have Type 2 diabetes. The clinical team – Wilson, Orlander, Brad Snyder, MD, assistant professor of surgery at UTHealth Medical School, and Kelly Wirfel, MD, assistant professor of internal medicine at UTHealth Medical School – is using an experimental procedure, called ileal transposition with sleeve gastrectomy, which is intended to improve or resolve Type 2 diabetes.

In the procedure, surgeons remove a section of the ileum that is about 5 feet in length and reattach it. In addition, they remove about 80 percent of the stomach. It is a “band-aid” procedure that is performed through tiny incisions on the abdomen. As with surgical procedures, there is a risk of complication and the risk is anticipated to be in the 1 to 2 percent range. The procedure is similar to treatment for morbid obesity, which can involve surgery on the stomach and intestines.

“No one has compared this surgery directly to medical therapy in a randomized, prospective study like this,” Snyder says. “If we can get patients into remission and off their medications, then we could open the door for people who want to pursue careers as firefighters, police officers, commercial pilots or other professionals who may at times be limited by this disease.”

Orlander says, “Additional research is needed to understand the long-term consequences of the different types of surgery and whether the remission from diabetes would be permanent or temporary. We will need to pay special attention to the overall nutritional impact of these procedures and provide the necessary nutritional support.”

Even with these emerging surgical options, Orlander says he often begins treating his patients by recommending they lose weight through conventional means such as restricting their calories and exercising more, as well as taking commonly used medications for diabetes. If that fails and they are eligible for bariatric surgery, Orlander will recommend it as a way to control their Type 2 diabetes.

Hefty hormones

Patients who undergo a conventional gastric bypass procedure typically have more weight loss and less hunger than those who undergo other gastric restriction procedures, Orlander says. This could be related to hormones such as ghrelin, an appetite stimulator made in the stomach, and glucagon-like polypeptide-1 (GLP-1), a hormone secreted from the intestines that stimulates insulin secretion, among other actions. The GLP-1 hormone is the basis for the action of a commonly used diabetes medication, exenetide (Byetta), which is associated with improved glucose control, decrease appetite and weight loss, Orlander says.

“So, although weight loss is important and certainly contributes to the improved glucose control, the changes in the hormones also are playing an important role,” Orlander says. “This is the rationale for research into medications that could have a similar effect or other surgical procedures that impact the hormonal milieu.”

Carol Wolin-Riklin, a registered dietitian at UTHealth Medical School, works with diabetic patients at The University of Texas Bariatric & Metabolic Surgery Center after their weight-loss surgery.

“It’s a bit of a rocky transition,” Wolin-Riklin says. “They have to do more frequent fingertip blood sugar testing after the surgery because their body is going through so many changes. We may need to put them on sliding-scale insulin coverage with their medication, and as they move farther out from their surgery date, they require less and less medication.”

“The typical carbohydrate load is quite high in these patients before surgery,” Wolin-Riklin explains. “After surgery, they are consuming fewer carbohydrates such as pastas, breads and sweets that have been eliminated from the diet. They are eating a high-protein, low-carb diet. They aren’t bombarding the body with a large carbohydrate load that requires increased amounts of insulin to maintain a normal level of glucose in the bloodstream.”

The patient’s newly changed eating habits, combined with weight loss, are ideal for improving or resolving type 2 diabetes, Wolin-Riklin says.

“I don’t know that I would use the word 'cure.’ Does it help diabetes resolve? Absolutely. Do some patients’ diabetes resolve completely? Yes,” Wolin-Riklin says. “Bariatric surgery is a phenomenal tool to help resolve diabetes and the whole metabolic syndrome that goes along with obesity.”

Orlander says it’s important for patients to maintain a healthy weight and diet, because if they start to add on pounds and revert to their old eating habits, the diabetes could return.

In addition, Orlander says, delaying the disease process, even for a short period of time, could result in fewer diabetic complications, such as poor circulation, infection, heart disease, blindness, amputation and kidney failure.

“Preventing or delaying those complications could have a dramatic impact on the patient’s quality of life,” Orlander says.