Bariatric Surgery Versus Intensive Medical Therapy in Obese Patients With Diabetes

Study Questions:

What is the relative value of bariatric surgery compared to medical therapy for glycemic control in type 2 diabetes mellitus?

Methods:

STAMPEDE was a randomized controlled single-center trial comparing the efficacy of intensive medical therapy alone versus medical therapy plus Roux-en-Y gastric bypass or sleeve gastrectomy in 150 obese patients with uncontrolled type 2 diabetes. All patients were treated with lipid-lowering and antihypertensive medications with target systolic blood pressure ≤130 mm Hg, diastolic blood pressure ≤80 mm Hg, and low-density lipoprotein cholesterol ≤100 mg/dl. The primary endpoint was the proportion of patients with a glycated hemoglobin (HgbA1c) level of 6.0% or less 12 months after treatment.

Results:

The mean (± standard deviation) age was 49 ± 8 years, 66% were women, 44% in each group used insulin, average HgbA1c level was 9.2 ± 1.5%, and mean body mass index (BMI) was 36 kg/m2, with 34% having a BMI <35 kg/m2. Of the 150 patients, 93% completed 12 months of follow-up. The proportion of patients reaching an HgbA1c level of <6.0% was 12% (5 of 41 patients) in the medical-therapy group versus 42% (21 of 50 patients) in the gastric-bypass group (p = 0.002) and 37% (18 of 49 patients) in the sleeve gastrectomy group (p = 0.008), with no difference between surgical groups. Glycemic control improved in all three groups, with a mean HgbA1c level of 7.5 ± 1.8% in the medical-therapy group, 6.4 ± 0.9% in the gastric-bypass group (p < 0.001), and 6.6 ± 1.0% in the sleeve-gastrectomy group (p = 0.003). Weight loss was greater in the gastric-bypass group and sleeve-gastrectomy group (-29.4 ± 9.0 kg and -25.1 ± 8.5 kg, respectively) than in the medical-therapy group (-5.4 ± 8.0 kg) (p < 0.001 for both comparisons). Insulin use remained high at 38% in the medical-therapy group, but reduced to 4% in the gastric-bypass group and 8% in the sleeve-gastrectomy group (p < 0.001 for both). Triglycerides were reduced by (median percent) 14% with medical treatment and >40% in both surgical groups. The use of drugs to lower glucose, lipid, and blood pressure levels decreased significantly after both surgical procedures, but increased in patients receiving medical therapy only. The index for homeostasis model assessment of insulin resistance (HOMA-IR) improved significantly after bariatric surgery. Four patients underwent reoperation. There were no deaths or life-threatening complications.

Conclusions:

In obese patients with uncontrolled type 2 diabetes, 12 months of medical therapy plus bariatric surgery achieved glycemic control in significantly more patients than medical therapy alone. Further study will be necessary to assess the durability of these results.

Perspective:

The study was designed with a 4-year follow-up, but the 12-month benefits in glycemic, weight, and lipid control are very encouraging. The evidence accumulating regarding the value of bariatric surgery is impressive. The time seems right for a randomized trial comparing intense medical therapy with bariatric surgery in obese diabetics with poor glycemic control with cardiovascular event and mortality endpoints.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Hypertriglyceridemia, Lipid Metabolism, Nonstatins

Keywords: Bariatric Surgery, Insulin, Gastric Bypass, Weight Loss, Diabetes Mellitus, Type 2, Blood Pressure, Glucose, Lipoproteins, LDL, Hemoglobin A, Glycosylated, Cholesterol, Gastrectomy, Body Mass Index, Blood Glucose, Obesity, Triglycerides


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