Bypassing Diabetes

Turso is one of a handful of Americans who have undergone a novel procedure that proponents say appears to offer the most important advance since the discovery of insulin in treating one of the most common chronic diseases.

“It’s extremely promising,” said Madhu Rangraj, chief of laparoscopic surgery at the Sound Shore Medical Center in New Rochelle, New York, who performed the operation bypassing part of Turso’s small intestine in March. “It’s a surgical solution to diabetes.”

While many surgeons share Rangraj’s enthusiasm, and some diabetes experts agree that the operation and similar ones may lead to fundamental new insights into the disease, others remain cautious. Much more research is needed, they say, to validate the effectiveness of the procedure. They worry that the operations will start to proliferate before their long-term safety and effectiveness have been proven, as often occurs with novel surgeries.

“I’m skeptical,” said R Paul Robertson, president-elect of the American Diabetes Association. “It bothers me to see this message being put out there that we can now cure diabetes through surgery. They have to prove that to me.”

Turso’s operation is a variation of a procedure developed to treat severe obesity. Known as bariatric surgery or gastric bypass, the standard operations reduce the size of the stomach and bypass part of the intestine. That limits the amount of food a person can eat and the calories that can be absorbed. The procedures have soared in popularity as the obesity epidemic has spread and clinical trials have validated their safety and effectiveness.

Although doctors have long known that losing weight can alleviate Type 2 diabetes, the most common form of the disease, they were surprised to discover that many patients saw their blood sugar return to normal remarkably quickly after the operations, often within days — and before they had lost much weight.

“There’s something significant that’s happening as a result of this surgery that we haven’t yet identified,” said Neil Hutcher, a surgeon from Virginia and senior past president of the American Society for Metabolic and Bariatric Surgery. “I think it’s the most significant advance in the management of this chronic killing disease since the discovery of insulin.”

In dozens of studies involving thousands of patients, standard gastric bypass surgery cleared up diabetes in over 80 per cent of obese patients who had the disease, raising the possibility that surgery would help those who weigh less. Currently, the procedure is recommended only for those who are severely or moderately obese and have diabetes or other serious complications. But surgeons have started testing the operation on patients who are less obese, just overweight or even at normal weight.

“By operating on patients with lower body mass, the focus dramatically shifts from being a weight-loss procedure to being a diabetes-specific procedure,” said Philip Schauer, a bariatric surgeon at the Cleveland Clinic, who is comparing the procedure with standard drug treatment for diabetes in patients whose weight puts them below the current criteria for the surgery. “This treatment can essentially put a high percentage of patients into remission. It also improves their cholesterol and blood pressure. Those three things are key for diabetics to avoid complications.”

How the operation alleviates diabetes remains a mystery. But researchers suspect that they alter the elixir of hormones secreted by the digestive system to regulate hunger, store energy and influence other physiological functions, helping restore the body’s system for controlling blood sugar with insulin. One possibility is that they increase production of an insulin-boosting hormone known as GLP-1.

A key clue came from Francesco Rubino, an Italian surgeon who conducted a series of experiments in diabetic rats. When he bypassed parts of their upper intestines, leaving their stomachs intact, the animals’ diabetes disappeared. When he reversed the operation, the disease returned.

“That was seen as the first demonstration that there is an anti-diabetic effect that is intrinsic with the change in anatomy induced by the surgery,” said Rubino, who recently moved to New York Presbyterian Hospital/Weill Cornell Medical Center to open a diabetes surgery center.

He has launched another study comparing standard bariatric surgery with medical diabetes treatment for those with lower body weights. A similar trial is underway at the University of Minnesota.

“It’s one of the most exciting times in medicine,” said Rubino, who is organising an international meeting in New York in September to try to build consensus on the role of the procedures in treating diabetes. “For the first time in diabetes history, we have a concrete chance to create a major shift in treatment goals: from improving life with diabetes toward the hope of a life without it.”

Rubino’s experiments and the intriguing results with standard bariatric surgery have prompted surgeons in several countries to try the modified stomach-sparing operation in people who are not obese and sometimes not even overweight.

“It’s fantastic,” said Ricardo Cohen, director of the Baros Institute for Metabolic and Bariatric Surgery in Sao Paulo, Brazil, who has had the most experience with the laparoscopic procedure. Cohen said he has operated on about 65 diabetic patients who were not obese, producing full remission in 65 per cent and partial remission in an additional 12 per cent. “This is a paradigm shift in treating leaner diabetic patients,” he said.

Surgeons in several other countries, including Japan, Mexico and India, have also been testing the technique. In the US, Rangraj has operated on five patients, including Turso, and plans at least five more surgeries to evaluate the procedure’s effectiveness.

“We’re focusing on patients with diabetes that is way out of control,” Rangraj said. “So far, all of our patients have been absolutely thrilled.”

Rubino is also planning to study the stomach-sparing procedure in leaner diabetics, and surgeons at the Tufts Medical Center in Boston are beginning a trial comparing it with standard medical care. They expressed concern, however, about the operations being done outside careful clinical studies.

“I’m a little nervous that as more people find out about what’s being done, that every Tom, Dick and Harry surgeon is going to do this, and every patient will come out of the woodwork asking for it,” said Michael Tarnoff, an associate professor of surgery at the Tufts University School of Medicine. “I don’t think it’s ready for prime time. It’s ready for cautious, well-controlled trials.”