Bariatric Surgery May Induce Remission of Type 2 Diabetes in Obese Patients
DynaMed Weekly Update - Volume 7, Issue 18
Type 2 Diabetes is a common complication of obesity, and the prevalence of both conditions is rapidly increasing worldwide. Though originally developed as a treatment for weight loss in obese patients, observational data suggest that bariatric surgery may have a beneficial effect on the severity of diabetes in these patients, even to the point of complete resolution, with benefits for weight loss and diabetes lasting for up to 10 years (N Engl J Med 2004 Dec 23;351(26):2683). A recent randomized trial compared 2 forms of bariatric surgery, Roux-en-Y gastric bypass and biliopancreatic diversion, to medical management of diabetes in a small group of 60 patients (mean age 43 years) in Italy.
All patients had a history of type 2 diabetes for at least 5 years and had a body mass index (BMI) ≥ 35 kg/m2. For the medical therapy group, a multidisciplinary team provided oral hypoglycemic drugs and insulin with HbA1c target < 7%, programs for diet and lifestyle modification, and increased physical activity. The surgical groups also received medical therapy adjusted by glycemic levels, and could discontinue pharmacotherapy upon normalization of glycemic profile, HbA1c or both. The primary outcome was diabetes remission defined as fasting glucose < 100 mg/dL (5.5 mmol/L) and HbA1c < 6.5% for ≥ 1 year without pharmacologic therapy.
At 2 years follow-up, no patients in the medical therapy group had achieved diabetes remission. The remission rates in the surgical groups were 75% for Roux-en-Y bypass surgery (p < 0.001 vs. medical therapy, NNT 2) and 95% for biliopancreatic diversion (p < 0.001 vs. medical therapy, NNT 1) (level 2 [mid-level] evidence). Both surgical groups had significantly greater weight loss than the medical therapy group. The most common complication of surgery was iron deficiency anemia, which occurred in 11% for each group (N Engl J Med 2012 Apr 26;366(17):1577).
Longer follow-up studies will be needed to determine both the duration of these benefits and whether the improvement in diabetes outcomes from surgery leads to fewer cardiovascular events or reduced mortality.