STAMPEDE: Sustained glycemic benefit observed 5 years after gastric bypass in type 2 diabetes, obesity
Patients with type 2 diabetes and mild to moderate obesity who underwent Roux-en-Y gastric bypass or sleeve gastrectomy saw sustained improvements in HbA1c, body weight, lipid levels and quality of life 5 years after surgery that were superior to medical therapy alone, according to results from the STAMPEDE trial.
“Five years is a long time for follow-up, and that is one of the distinguishing features of this study,” Sangeeta Kashyap, MD, of the department of endocrinology, diabetes and metabolism at Cleveland Clinic, told Endocrine Today. “What is remarkable is patients who underwent bariatric surgery had far better glycemic control, with less use of insulin and medications. Almost 90% of patients did not need insulin after surgery. These patients had better triglycerides, higher HDL cholesterol levels, lower C-reactive protein levels, and maintained almost 20% total body weight loss. And, overall, based on their self-reported questionnaires, they had better quality of life.”
Kashyap and colleagues analyzed data from 150 patients with type 2 diabetes and a BMI between 27 kg/m² and 43 kg/m². Researchers randomly assigned patients to intensive medical therapy alone or intensive medical therapy plus Roux-en-Y gastric bypass or sleeve gastrectomy. Primary outcome was an HbA1c of 6% or less with or without the use of diabetes medications.
Within the cohort, 134 patients completed 5 years of follow-up (mean age at baseline, 50 years; 66% women; mean HbA1c, 9.2%; mean BMI, 37 kg/m²). At 5 years, the primary endpoint was met by 14 patients (29%) who underwent gastric bypass, 11 patients (23%) who underwent sleeve gastrectomy and two patients (5%) who underwent intensive medical therapy alone. Patients who underwent bariatric surgery had a greater mean percentage reduction in HbA1c vs. those assigned to medical therapy (2.1% vs. 0.3%; P = .03).
At 5 years, approximately 89% of patients in the surgical groups were not taking insulin and maintained an average HbA1c of 7% vs. 61% of patients in the medical therapy group, who had an average HbA1c of 8.5%, according to researchers.
Patients in the surgery groups also experienced greater weight loss (P < .05), a greater decrease in triglycerides and greater increase in HDL cholesterol vs. those in the medical therapy group. There were no between-group differences in blood pressure or LDL cholesterol.
Four patients in the surgery groups required subsequent surgical interventions during the first year after the initial procedure. One patient in the medical therapy group died after myocardial infarction; one patient in the sleeve gastrectomy group experienced stroke.
“It’s important to put the data in perspective,” Kashyap said in an interview. “The people who entered this trial were not garden variety type 2 diabetic patients. They were medical refractory diabetic patients who were anywhere from being overweight to having more severe obesity. But, even those with less severe obesity did just as well. It tells you that surgery is a good treatment option for diabetes, regardless of the BMI, because even at lower BMI people suffer from severe diabetes. These people had diabetes for at least 8 years, and over half were on multiple shots of insulin. We know that they’re not going to get better just by increasing or adding on medications.”
Kashyap said future research should focus on the long-term effects of bariatric surgery on diabetic complications, such as renal failure, diabetic retinopathy and heart disease, and on multicenter studies to better assess the safety profile of surgery in these patients.
“The message is we want to be careful,” Kashyap said. “We want to encourage providers to refer patients if they’re not getting better [with medication alone]. Only 1% of people who are overweight are referred for surgery, even when they have other comorbidities. For medically refractory patients who aren’t getting better despite adding on more drugs, don’t add on another drug. Consider talking to them about something different, which is surgery.” – by Regina Schaffer
For more information:
Sangeeta R. Kashyap, MD, can be reached at the department of endocrinology, diabetes and metabolism at Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195; email: email@example.com.
Disclosure: The STAMPEDE trial was funded by Ethicon, part of the Johnson & Johnson family of companies, through its Metabolic Applied Research Strategy (MARS) program. Kashyap reports receiving grant support from Covidien and Janssen, and grant support and personal fees from Ethicon Endosurgery outside the submitted work. Please see the full study for the other researchers’ relevant financial disclosures.