Weight loss surgery treats type 2 diabetes in obese patients

New research published in the New England Journal of Medicine and presented at a scientific meeting shows that bariatric weight loss surgery is an effective and lasting treatment for type 2 diabetes in obese patients when compared with medical therapy.

Cleveland Clinic researchers presented the results of the STAMPEDE (Surgical Therapy And Medications Potentially Eradicate Diabetes Efficiently) trial to the Annual Scientific Session of the American College of Cardiology in Washington, DC.

The study showed how after undergoing bariatric surgery, nearly all the patients were free of insulin, and many no longer had to take diabetic medications 3 years after undergoing their weight loss surgery.

One of the lead investigators, Dr. Sangeeta Kashyap, an endocrinologist at the Endocrinology & Metabolism Institute at the Cleveland Clinic, says:

"We see patients whose lives are ravaged by diabetes. At the 3-year mark, this study shows that bariatric surgery is more effective with persistent benefits noted up to 3 years for treating type 2 diabetes in moderate and severely obese patients when compared to medical therapy."

Bariatric patients lost 25% body weight and did not require insulin, diabetes drugs

Dr. Kashyap says the study results show that over 90% of patients who had the weight loss surgery were able to lose 25% of their body weight, and they were able to control their diabetes without using insulin and multiple diabetes drugs.

Only 5-10% of the patients in the surgery group were on insulin 3 years afterwards, whereas in a comparison group that only received medical therapy, 55% were on insulin at that point.

The results also showed that the surgical patients experienced improved quality of life and a reduced need to take drugs for blood pressure and cholesterol.

Obesity is the main trigger for type 2 diabetes and affects around 1 in 3 adult Americans, prompting the term "diabesity" among health experts when they talk about this epidemic.

Over 90% of patients who had the weight loss surgery were able to control their diabetes without using insulin.

The American Diabetes Association says if present trends persist, then by 2050 around 1 in 3 adults in the US will have diabetes.

Short-term randomized trials lasting between 1 and 2 years have already shown that bariatric surgery has been associated with improvement in type 2 diabetes.

STAMPEDE is the largest and longest follow-up trial to date to compare bariatric surgery and medical therapy.

Bariatric surgery is a set of procedures that aim to achieve weight loss by reducing the size of the stomach. This study examined two of them: gastric bypass and sleeve gastrectomy. Gastric bypass is where the small intestines are resected and re-routed to a small stomach pouch, and sleeve gastrectomy removes a small portion of the stomach.

The study enrolled 150 overweight patients with poorly controlled diabetes and randomized them equally to receive one of three treatments: intensive medical therapy only (comprising counseling and medications), gastric bypass (Roux-en-Y plus medical therapy) or gastrectomy (sleeve gastrectomy with medical therapy).

After 3 years, 37.5% of patients in the gastric bypass group were controlling blood sugar without the use of diabetic medications. This compared with 5% in the medical therapy group and 24.5% of patients in the gastrectomy group.

Also, the average weight loss in the bariatric surgery groups was five to six times greater than for the medical therapy group.

Another lead investigator, Dr. Philip Schauer, Director of the Bariatric and Metabolic Institute at the Cleveland Clinic, says:

"The 3-year data confirm that bariatric surgery maintains its superiority over medical therapy for the treatment of type 2 diabetes in severely obese patients."

Plus, he notes, the results show that bariatric surgery is just as effective in treating mildly obese patients with type 2 diabetes.

Significant improvements in quality of life following surgery

From questionnaires the patients completed at the start and at the end of the 3-year period, the researchers found significant quality of life improvements in the two surgery groups, and none in the medical therapy group.

In the gastric bypass group, five out of eight areas of mental and physical quality of life had improved, and in the gastrectomy group, two out of the eight areas improved. Dr. Schauer says they looked at quality of life because, in the end, that is what it is all about - helping patients lead healthier, happier lives.

"When compared to sleeve gastrectomy and medical therapy, gastric bypass patients achieved greater weight loss, were on fewer medications, had a higher success rate in controlling their diabetes, and an improved quality of life," he explains.

Newer data also shows that albumin levels in urine - known to be a measure of kidney function - were significantly lower in the bariatric groups only.

The researchers say more research is now needed to push bariatric surgery as a treatment option for obese patients with diabetes.

Dr. Schauer is a paid consultant with Ethicon, a subsidiary of Johnson & Johnson that makes devices for surgical weight loss procedures.

In 2012, Medical News Today reported another study from the Cleveland Clinic that found bariatric surgery reduces heart disease and stroke risk dramatically. In the BMJ journal Heart, the researchers explain that the drop in risk happens surprisingly soon after the surgery.

Written by Catharine Paddock PhD

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