Weight-loss surgery has benefits beyond slimming down

[January 2010] Bariatric surgery, long a popular operation for patients wanting to lose weight, has gained some weight of its own in recent years. Once called “stomach stapling” and viewed simply as a technique to help the obese shed pounds, physicians now know the surgery cures or improves such conditions as type 2 diabetes and obstructive sleep apnea, often long before the weight is lost.

Robert Bell, MD, says diabetes, hypertension and sleep apnea can all be cured by weight-loss surgery.

"There’s been a huge change in the way we think about this surgery,” says Robert Bell, MD, MA, director of the Yale Bariatric Surgery Program. “We used to think that if you helped the person lose weight, these weight-related problems would slowly get better as a function of the weight loss.”

What actually happens is that metabolic changes brought on by the surgery cause immediate improvements in the weight-related disorders, according to Bell. These metabolic changes don’t occur if the patient loses weight naturally.

Shift in emphasis

This finding prompted the American Society of Bariatric Surgery in June of 2007 to change its name to the American Society of Metabolic and Bariatric Surgery, signifying “a shift in emphasis of weight-loss surgery,” Bell says. “It’s really not so much about weight loss; it’s really more about getting patients healthier.”

A study published in the Journal of the American Medical Association (JAMA) in January 2008 found that 73 percent of patients resolved their type 2 diabetes after gastric banding surgery. A JAMA study published in October 2004 found that after bariatric surgery, diabetes was eradicated in 76.8 percent of patients and eradicated or improved in 86 percent of patients.

Bell, Hui Sen Chong, MD, (left) and Kurt Roberts, MD, (right), review a patient’s records.

The first surgical procedure to aid in weight loss was introduced in the 1950s and was purely malabsorptive, meaning that after surgery, a patient could eat anything but only a small percentage would be absorbed. Gastric bypass surgery began catching on in the 1970s. The procedure reduces the size of the stomach, thereby restricting the amount of food a patient can eat.

Hormonal changes

“Sort of unbeknownst to everybody doing that surgery was that there’s a lot more going on than just that the patient filled up more easily,” Bell says. “There’s a variety of hormonal changes that occur that really were not described until this decade. It is these hormonal changes that confer the added medical benefits.”

While doctors are learning more about the metabolic side of the surgery, the process is still not completely understood, Bell says. What is known is that favorable changes occur in Ghrelin, an endocrine hormone that stimulates appetite, and in GLP-1 and GIP, two gastrointestinal hormones that increase the amount of insulin released after eating.

How long after surgery it takes for weight-related disorders to improve depends on how long they’ve existed and how severe they are. “In somebody who has only had type 2 diabetes for two years, it’s going to be gone before they leave the hospital,” Bell says. “If they’ve had type 2 diabetes for 15 years and have been on insulin for seven, it’s going to get better, but may not go away.”

Implications for the future

The implications of these findings are significant, Bell says. He predicts there will be a move toward earlier interventions, with surgeons operating on patients who are over-weight but not yet obese. This, most likely, would require the compilation of long-term efficacy data to convince insurance companies to change their coverage policies.

“Right now you have to be a certain size and have a body mass index (BMI) of 40 or more to be covered,” Bell says. A BMI of between 19 and 24 is considered normal; 25 to 30 is overweight, 30 to 35 is obese, and 35 to 40 is morbidly obese.

Most insurers require bariatric surgery patients to be at least 18 years old, but Bell anticipates the procedure will be done on younger patients in the future. He performs about 100 gastric bypass surgeries a year, and has done four procedures on 17 year olds. “It makes sense to help these patients when they’re younger,” he says, “because the years of obesity haven’t added up, causing destruction to bones and joints that limit their exercise, which is key to the success of this surgery.”

Jane Bederhoff’s high blood pressure and hypertension abated almost immediately after her bariatric surgery.

Bell knows it will take time for patients and physicians to view gastric bypass surgery as more than just a weight-loss operation. “I don’t even talk about the obesity part anymore,” he says. “I prefer to focus on the fact that it’s a cure for diabetes, hypertension, sleep apnea and high cholesterol.” Medications just manage the symptoms, he says. “Surgery eradicates the disease. It’s gone.”

Story by Jennifer Kaylin
Photography by Robert A. Lisak