(Adds independent doctor and researcher comment, study details, paragraphs 16-24)
By Bill Berkrot and Ransdell Pierson
WASHINGTON, March 31 (Reuters) - Bariatric weight loss surgery on obese patients with type 2 diabetes helped many get their blood sugar to healthy levels and to no longer require any diabetes medicines, including insulin, three years after the procedure, according to data presented at a major medical meeting on Monday.
The surgery also helped patients reduce the need for high blood pressure and cholesterol medicines and led to quality of life improvements compared with those who received medical weight-loss therapy, researchers found.
The study called Stampede, which involved 150 obese patients who had poorly controlled type 2 diabetes for at least eight years, was conducted by Cleveland Clinic researchers.
It compared two types of weight loss surgery against weight loss attained by diet and exercise along with nutrition counseling and, for some, additional diabetes medicines that can help promote weight loss, such as Victoza from Novo Nordisk . All patients were already taking at least three diabetes drugs and at least three heart medicines.
More than a third - 37.5 percent - of patients who underwent gastric bypass surgery and a quarter of those who had a sleeve gastrectomy procedure achieved blood sugar levels below the American Diabetes Association target and most no longer needed diabetes medicines, researchers said. That compared with just 5 percent of patients in the medical therapy group who got their A1c blood sugar levels down to 6 percent or less. ADA recommendations call for A1c levels of 7 percent or less.
"Initially we thought diabetes was a disease you could not reverse or end. We do realize now that there may be a treatment that could end diabetes for some people and that's exciting," said Dr. Sangeeta Kashyap, one of the study's lead investigators, who presented the data at the American College of Cardiology scientific meeting in Washington.
At three years, only 5 to 10 percent of the surgery patients who had been using insulin still needed the treatment, compared with a comparable rate 55 percent in the medical therapy group.
An estimated one third of Americans are considered obese and obesity is the leading contributor to the growing type 2 diabetes epidemic.
Bariatric surgery is a drastic measure and not without potential complications, such as infections or blood clots. But for some obese patients it may be worthwhile if it can stave off the toll of advanced diabetes that can include heart and kidney disease, as well as vascular problems that may lead to amputations or blindness.
"The fact that the surgeries can reverse the path of physiology of the disease is pretty remarkable," said Kashyap, a Cleveland Clinic endocrinologist.
Should the findings lead to a surge in weight loss surgery, it could be a boon to companies that make products used in the procedures, such as Johnson & Johnson's Ethicon unit, a study sponsor, Stryker Corp, Intuitive Surgical Inc and Covidien, among others.
Data from the study was presented in 2012 showing the effect of the surgery on diabetes after one year. The latest data answers questions of whether the effect could be lasting.
"The results were durable and they were far better than the people in the medical arm," said Kashyap. "It's effect is persistent for three years, which we think is very encouraging."
On average, gastric bypass patients lost 24 percent of their body weight and sleeve gastrectomy led to a 21 percent weight reduction, about five or six times more weight than the medical group, and more than has been demonstrated by new weight loss drugs that were not used in the study. The medical therapy group on average lost about 12 pounds each (5.4 kg).
Gastric bypass and sleeve gastrectomy both restrict the food capacity of the stomach. Bypass also involves connecting a new gastric pouch directly into the intestine, bypassing the stomach and part of the intestines.
Kashyap said loss of abdominal fat may be driving the anti-diabetes effect. She also said the surgery leads to increased insulin production after meals, "which is a great sign that the pancreas is starting to work again."
Some doctors have suggested that other factors could be at work in bypass patients, such as changes in microbes or hormones in the gut.
"It's something about altered food delivery. It's not as simple as calories," said Dr. Robert Siegel, co-chair of the ACC meeting, who was not involved in the study.
Siegel, director of the Cardiac Noninvasive Laboratory at Cedars-Sinai Medical Center in Los Angeles, said the findings could lead to new targets for future diabetes drug development.
"This opens up a whole new field of investigation and a lot of potential hope," he said. "This is a totally different way of thinking about diabetes."
Bypass patients also had significantly lower levels of albumin in the urine, a marker of kidney damage due to diabetes. That benefit was not seen in the other two groups.
As many as a third of all Americans could have diabetes by 2050 if present trends continue unabated, according to the ADA.
Patients in the trial not considered severely obese appeared to gain the same benefit as those with higher body mass index.
Dr. Philip Schauer, the study's other lead investigator, said he hopes the new data will encourage insurers to lower their threshold for covering the procedures for diabetics. (Reporting by Bill Berkrot and Ransdell Pierson; Editing by James Dalgleish, Sofina Mirza-Reid and Tom Brown)