Bariatric surgery may keep type 2 diabetes at bay for good, researchers found.
In a single-center study, 50% of patients whose diabetes resolved following bariatric surgery still had complete or partial remission of the disease about 6 years later, Stacy Brethauer, MD, of the Cleveland Clinic, and colleagues reported at the American Surgical Association meeting in Indianapolis.
Of those who had a complete remission, 27% met the definition of a “functional cure” of diabetes, defined by the American Diabetes Association (ADA) as a glycated hemoglobin (HbA1c) under 6% and a fasting blood glucose under 100 mg/dL that lasts longer than 5 years, Brethauer told MedPage Today.
For their study, Brethauer and colleagues assessed 217 patients with type 2 diabetes who underwent bariatric surgery at the Cleveland Clinic between 2004 and 2007. They were followed for a median of 6 years, with a range of 5 to 9 years.
The majority had gastric bypass surgery, but some patients also had gastric banding or sleeve gastrectomy.
Brethauer and colleagues found that remission — including both partial and complete remission — occurred in 50% of patients.
Complete remission was defined as an A1c below 6% and a fasting blood glucose under 100 mg/dL for at least a year without any medications, and 24% of patients hit this target.
Partial remission was defined as an HbA1c between 6% and 6.4% and a fasting blood glucose between 100 and 125 mg/dL for at least a full year without anti-diabetic drugs, and 26% of patients hit this target.
Brethauer noted that 27% of those who achieved a complete remission maintained it longer than 5 years, which qualified them for the ADA definition of a functional cure.
The effects were most pronounced for patients who’d had gastric bypass — although Brethauer cautioned that selection bias could be at work because the trial was not randomized.
Still, after controlling for procedure in a multivariate analysis, bypass remained a significant predictor of long-term remission compared with the two other procedures, he said. Other predictors included a shorter duration of type 2 diabetes and greater weight loss.
Even though they didn’t meet the criteria for continued remission, another 34% of patients still had significant improvements in glycemic control 6 years later.
“A large population was still well controlled,” Brethauer told MedPage Today. “Many still met the ADA criteria [for being well controlled], even though we characterized them as recurrent diabetics.”
Just 16% of patients had glycemic control that was unchanged from or worse than baseline in the long run, he added.
Brethauer and colleagues also looked at a subgroup of patients who had laboratory data on urinary albumin to assess diabetic nephropathy. Among those 59 patients, 40 had normal albuminuria at baseline and only 2 went on to develop protein in the urine. The other 19 started out with albuminuria, and 53% of them had regression while 47% remained stable.
“That’s markedly different from what you’d expect, which is 2% to 4% progression to diabetic nephropathy [per year] in this patient population,” he said.
Bariatric surgery is not currently indicated as a treatment for type 2 diabetes; the disease is a comorbidity that makes patients at the lower range of obese — with a body mass index (BMI) of 35 to 40 — qualify for bariatric surgery.
Only patients with a BMI of 40 or above qualify for the surgery on the basis of weight alone.
However, some organizations, including the International Diabetes Federation, have been pushing for bariatric surgery to be indicated for type 2 diabetes patients with a BMI of 30 to 35.
Indeed, recent guidelines from the American Association of Clinical Endocrinologists, The Obesity Society, and the American Society for Bariatric and Metabolic Surgery also concluded that these patients may be offered bariatric surgery — with the caveat that the evidence is still limited.
“We feel that the benefits outweigh the risks for the majority of patients, but I think at this point many still consider it investigational,” Brethauer said. (Kristina Fiore/MedPage Today)