Obesity can cause type 2 diabetes, so the typical medical recommendation is to shed some serious pounds. But the question remains: Which method maximizes weight loss and works best to treat or cure diabetes?
That's the puzzle bariatric surgeon Anita P. Courcoulas hopes to help solve with a pilot study that's already begun enrolling 60 patients.
In the $2 million, two-year project funded by the National Institutes of Health, overweight patients with type 2 diabetes will be divided randomly into three groups of 20. Patients then will undergo one of two methods of bariatric surgery or follow a more traditional but intensive nonsurgical process known as Lifestyle Weight-Loss Intervention.
Methods of bariatric surgery to be tested include Roux-en-Y Gastric Bypass surgery and Laparoscopic Adjustable Gastric Banding. Studies already have shown that Roux-en-Y has an 80-percent success rate in resolving or curing diabetes, while gastric banding has a 60 percent to 65 percent resolution rate for diabetes, albeit over a longer timeline.
All three methods have been proven to help obese patients with body mass indexes exceeding 40 to lose weight and improve or even cure their diabetes. A BMI over 40 means a person is 100 pounds or more over ideal body weight.
The pilot study, with Dr. Courcoulas as principal investigator, will seek to determine whether these methods also work on people with type 2 diabetes and BMIs of 30 to 40, or 65 to 95 pounds of excess weight.
Another research goal is determining the feasibility of a national, multi-site follow-up study to settle the debate over which procedure works best in treating overweight people with diabetes.
To qualify for the study, patients must be 25 to 55 years old, have type 2 diabetes, and have a BMI of 30 to 40, while having sufficient good health to withstand surgery. To enroll, call Jessie Eagleton at 412-641-3743.
Dr. Courcoulas, chief of minimally invasive bariatric and general surgery at Magee-Womens Hospital of UPMC, said the Roux-en-Y procedure has a 1 percent to 2 percent risk of major surgical complications. Banding is done under general anesthesia with low surgical risks, but with a 1 percent to 2 percent risk of device failure that requires replacement.
Roux-en-Y Gastric Bypass surgery, performed laparoscopically, divides the stomach into a small upper pouch and rearranges the small intestine to connect to that pouch, a study brochure states. The procedure restricts how much food can be consumed while reducing food absorption.
In laparoscopic adjustable gastric banding, a silicon band is placed around the upper portion of the stomach, then adjusted to restrict how much food can be consumed, the brochure states.
Lifestyle Weight Loss Intervention is a year-long weight-control program. For six months, the patient receives behavioral lessons and undergoes self-monitoring, diet and exercise counseling, all while using meal replacements under the direction of lifestyle coaches. For the remainder of the year, the patient meets with coaches every two weeks. Nonsurgical treatment has brought short-term improvements in patients.
The NIH is funding the study with federal stimulus money appropriated to tackle priority health issues.
"The issue will help decide which type of bariatric surgery works best and whether that shows better results than lifestyle coaching," Dr. Courcoulas said. "All three have been shown to be effective."
The study also will seek to explain how bariatric surgeries improve diabetes.
With Roux-en-Y, for example, food bypasses the first part of the small intestine, which is thought to alter chemical signalling to the pancreas and improve diabetes on a cellular level.
Banding reduces food consumption, leading to weight loss and improvements with diabetes.
Improvements through intervention include weight loss and the beneficial health effects of exercise.
David Templeton: firstname.lastname@example.org or 412-263-1578. First Published March 3, 2010 5:00 AM