Bariatric Medicine:  Part 1
Editor’s Note: Gastric bypass surgery, Roux-en-Y, 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 next two issues of HealthLeader are devoted to the surprising health benefits of profound weight loss through bariatric surgery.

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 – a Roux-en-Y gastric bypass – 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 type 2 diabetes. He 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, including gastric bypass and the lap band, can have a dramatic impact on morbidly obese patients with type 2 diabetes, a condition characterized by high levels of blood sugar as a result of 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,” says weight-loss surgeon Erik B. Wilson, MD, chief of the Division of Minimally Invasive and General Elective Surgery at The University of Texas Medical School at Houston. “The surgery appears to facilitate hormonal changes that help resolve diabetes, and we’re beginning to research why this occurs.”

In his practice at The University of Texas Bariatric and Metabolic Surgery Center, Wilson says, 75 percent of patients who are morbidly obese are “cured” of type 2 diabetes in the weeks and months following their weight-loss surgery. For the other 25 percent with diabetes, the disease usually becomes more easily managed.

Cut for the cure?

The evidence of weight-loss surgery’s impact on diabetes is so convincing that some physicians are even contemplating whether bariatric surgery should be explored as a possible cure for type 2 diabetes in patients who are only moderately overweight. An estimated 21 million Americans have type 2 diabetes.

“The jury is still out,” says Philip Orlander, MD, professor and division director of Endocrinology, Diabetes and Metabolism in the Department of Internal Medicine at the UT Medical School at Houston. “This would be a radical treatment, and I think there is a lot more we need to understand about the surgery and its effect on the body before we can start recommending it for everyone with type 2 diabetes.”

Currently, weight-loss surgery is recommended to 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. Weight-loss surgery is not recommended for patients of normal weight who have diabetes.

“We are doing this surgery to help patients become healthier by resolving existing medical problems and preventing other medical complications from developing,” says Wilson, who operates at Memorial Hermann-Texas Medical Center.

Orlander says weight-loss surgery appears to be most effective in resolving diabetes in patients who have had type 2 diabetes for less than five years and still have the ability to produce some insulin.

“The advantage of bariatric surgery is that it allows you to control your weight and calories,” Orlander says. “Even 10-15 pounds of weight loss can improve insulin sensitivity, and the act of not being able to overeat drops their insulin resistance and improves their glucose.”

Those with type 1 diabetes or patients whose long-term type 2 diabetes has permanently damaged insulin-producing cells would not be expected to get relief from their diabetes with weight-loss surgery, Orlander says.

Still, many patients who seek out weight-loss surgery to manage their obesity are able to reduce or eliminate their need for type 2 diabetes medications.

Hefty hormones

Patients who undergo the convention, Roux-en-Y 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 the UT Medical School at Houston, works with diabetic patients at The University of Texas Bariatric & Metabolic Surgery Center after their weight-loss surgery.

“It’s a little 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, is 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 too early to say whether weight-loss surgery is a permanent treatment for diabetes. 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.

Even if the surgery can’t keep diabetes away forever, 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.

 

Last Updated: 7-15-2009

 

 

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