Weight Loss Surgery Cuts Type 2 Diabetes

It’s been less than one month since two studies — conducted independently by researchers in the United States and Italy — concluded that bariatric surgery may be the best treatment for obese people who suffer from type 2 diabetes.

Now a new study, conducted by yet another institution, also in Italy, comes to the same conclusion. All three studies found that patients who underwent weight loss surgery enjoyed improved diabetes outcomes compared to patients who received standard therapy and medications to control diabetes.

Obesity and diabetes are two major health challenges across the world, and for both diseases, the increasing prevalence has reached epidemic proportions. Even as the prevalence of diabetes in the U.S. and across the world is surging in parallel with obesity’s rise, the link between the two conditions is also well established: Some 80 percent of the 23 million adult Americans who have type 2 diabetes are either overweight or obese.

If children are included, the number of people in the U.S. living with type 2 diabetes comes to about 25.8 million and about 1.9 million new cases were diagnosed in 2010. And the annual cost of caring for patients with diabetes will approach US$192 billion in 2020, according to the American Diabetes Association.

In the latest of the three studies — involving 60 morbidly obese patients with type 2 diabetes — researchers from the University of Rome in Italy find that patients were cured of their diabetes a year and a half after undergoing bariatric surgery. The findings of the study, led by Dr. Frida Leonetti of the Policlinico Umberto I, University of Rome’s teaching hospital, are published in the Archives of Surgery April 16 issue.

That new study comes on the heels of two randomized trials published late last month in the New England Journal of Medicine. Similarly, the two trials found that compared to medications, two forms of bariatric surgery — including Roux-en-Y gastric bypass and sleeve gastrectomy — led to significantly better control of diabetes.

Latest study shows: gastrectomy works
In the latest study, the University of Rome researchers divided the 60 participants into two groups:
• Half the patients underwent laparoscopic sleeve gastrectomy, or LSG.
• The other half received conventional medical therapy for type 2 diabetes.

LSG is surgical procedure in which a surgeon removes a major portion of the stomach and leaves a small banana-shaped pouch — usually about 20 to 25 percent of the original size of the stomach. This fills up quickly when a person eats, limiting the amount of calories taken in. The procedure is considered minimally invasive.

In the two previous studies, other bariatric surgeries were used:
• A biliopancreatic diversion — in which part of the stomach is removed to reduce its capacity
• Roux-en-Y bypass — in which the stomach is shrunk by stapling off a large part of it.
• In both procedures, the stomach is relocated so that its contents are routed past much of the lower intestine, where the most calories and nutrients are absorbed.
• In contrast, sleeve gastrectomy doesn’t move the stomach or alter the way food enters or leaves it.

Conventional medical therapy for diabetes, for its part, involves medical staff consultations, lifestyle modifications, medications, regular physical activity and a 1200-calorie diet.

What the Italian researchers found was that 18 months after their surgery:
• 80 percent of patients who underwent the surgery were cured of diabetes
• Their BMI — which averaged 41.3 before the LSG procedure — was reduced to 28.3 after the study period. A person with a BMI of 30 or above is considered obese.
• Patients who received diabetes medications didn’t improve and remained diabetic during and after the study.
• Patients who underwent surgery also enjoyed improvements in blood pressure, cholesterol levels and obstructive sleep apnea.
• Over time, medically treated patients required more medication for blood pressure and cholesterol control.

Writing in the Archives of Surgery, the authors admit that, “Midterm and long-term results are needed to confirm the positive effect — remission and/or improvement — of (laparoscopic sleeve gastrectomy) on diabetes and, overall, on the chronic complications of the disease.”

“Most importantly, the longer-term results will allow us to compare the costs and benefits of bariatric surgery versus conventional medical treatments,” they add.

While many reports have shown LSG to be effective in improving diabetes or prompting its remission, the researchers believe this is the first study to compare LSG directly with intensive medical therapy.

Meanwhile, it’s been observed that diabetics often fail to control their blood sugar levels even after a year or so of rigorously supervised diet regimens, exercise and medications.

2 earlier studies support the new findings
Late last month, two studies, both published in the New England Journal of Medicine, also found that surgical procedures to reduce the size — and sometimes placement — of the stomach often allowed patients to discontinue diabetes medications within weeks. The studies were conducted by two teams of researchers — one in Italy, the other in the U.S.

The first study, the STAMPEDE trial by researchers at the Cleveland Clinic and Harvard University was presented at the American College of Cardiology’s annual meeting held in Chicago on March 24-27.

In this trial, 150 obese patients with uncontrolled type 2 diabetes were grouped randomly into two groups: the “medical therapy alone” group or the “medical therapy plus either Roux-en-Y gastric bypass or sleeve gastrectomy” group.

After one year, this is what the researchers found:

Percent of patients with glycated hemoglobin level of 6 percent or less:
• medical: 12 percent
• gastric bypass: 42 percent
• sleeve gastrectomy: 37 percent

Mean glycated hemoglobin:
• medical: 7.5
• gastric bypass: 6.4
• sleeve gastrectomy: 6.6

Weight loss:
• medical: 5.4 kg
• gastric bypass: 29.4 kg
• sleeve gastrectomy: 25.1 kg

Patients that used insulin:
• medical: 38 percent
• gastric bypass 4 percent
• sleeve gastrectomy: 8 percent

• The surgical patients also dropped their use of insulin and other diabetes medications significantly
• By contrast, patients in the medical-therapy group increased their use of diabetes medications over time

The authors concluded, “Bariatric surgery represents a potentially useful strategy for management of uncontrolled diabetes, since it has been shown to eliminate the need for diabetes medications in some patients and to markedly reduce the need for drug treatment in others.”

In a second study, bariatric surgery was also found to be highly effective for diabetic subjects. The researchers started out by grouping 60 obese patients into three groups: the Roux-en-Y gastric bypass group, the biliopancreatic diversion group and the conventional medical therapy group.

Diabetes remission at 2 years:
• medical therapy: 0%
• gastric-bypass: 75%
• biliopancreatic-diversion: 95%

In an editorial accompanying the two studies in the journal, diabetes specialists Dr. Paul Zimmet and K. Dr. George M.M. Alberti conclude that while surgical weight-loss procedures were “not yet” a panacea for the worldwide epidemic of type 2 diabetes, the new research “suggests they should not be seen as a last resort.”

Surgery for diabetes type 2: not first line, not last resort
“Such procedures might well be considered earlier in the treatment of obese patients with Type 2 diabetes,” Dr. Zimmet and Dr. Alberti say. Dr. Alberti is associated with the King’s College in London while Dr. Zimmet is a specialist at the Baker IDI Heart and Diabetes Institute in Melbourne, Australia.

“Now we know that treating diabetes can — and should — be a primary reason for doing this surgery,” says Dr. Lee M. Kaplan, director of the Massachusetts General Hospital Weight Center.

While such surgery should not be the first line of treatment, Kaplan said, but it should become a fallback for patients whose blood sugar control remains poor despite medications and lifestyle changes. “We ought to be using it more,” he concludes.

The STAMPEDE trial was funded by Ethicon Endo-Surgery, the National Institutes of Health and LifeScan. Dr. Schauer reported receiving payment for board membership and consulting fees from various bariatric surgery institutions. Dr. Mingrone’s study was funded by the Catholic University of Rome, and he reported having no conflicts of interest to disclose. Zimmet and Alberti reported having no financial relationships with industry to disclose.

Consider risks
After the New England Journal studies appeared last month, the Endocrine Society issued a statement cautioning against routine recommendations of bariatric surgery for obese diabetic patients.

The group told MedPage Today that not every patient can handle compliance with long-term lifestyle changes required of patients undergoing bariatric surgery. The risks of surgery are also a consideration, the society warned.

And while surgery is generally safe, it is also associated with complications like nutritional deficits and dehydration. Of the 100 patients who underwent surgery in the Cleveland Clinic study, for instance, four required reoperations due to complications.

Right now, about two percent of obese patients with diabetes are currently treated with bariatric surgeries — and bariatric surgery is a typically costly, running between US$10,000-US$15,000 in the U.S.

Experts say researchers should study the cost-effectiveness of the procedures further to gauge if these surgeries are appropriate for the general population of obese people with diabetes type 2.

Given the tens of millions of people who have diabetes, it is economically impossible to offer the surgery to everyone, says Dr. Gerald Bernstein, director of the Diabetes Management Program at the Friedman Diabetes Institute at New York’s Beth Israel Medical Center.

But it is important for primary care physicians, endocrinologists and surgeons to work together to decide which type 2 diabetes patients would benefit most from these surgeries.

“Doctors need to be sure they find patients who will make this surgery worthwhile,” Bernstein says. “If you’re going to do something like this that significantly changes the body, you need to make sure they have the motivation to follow doctor’s recommendations.” “There are a variety of treatments available in terms of altering the GI tract,” he adds.

“Right now, this is another tool and option in the arsenal for diabetes treatment,” he concludes.

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