WASHINGTON – Bariatric surgery combined with intensive medical therapy had a significantly greater impact on glycemic control, compared with medical therapy alone, in a 3-year study of overweight and obese people with uncontrolled type 2 diabetes – providing evidence supporting the durability of the beneficial effects of surgery beyond 1 year.
In the study of 137 patients, who all received intensive medical therapy, 37.5% of patients who had a gastric bypass and 24.5% of those who had a sleeve-gastrectomy had achieved the primary endpoint, a hemoglobin A1c of 6% or lower, 3 years after surgery, compared with 5% of those who had received medical therapy alone, Dr. Sangeeta Kashyap said on March 31 at the annual meeting of the American College of Cardiology.
Dr. Sangeeta Kashyap
"Many surgical patients achieved this control without the use of any diabetic medications, particularly insulin; metabolic syndrome components improved, and quality of life was enhanced," said Dr. Kashyap, an endocrinologist at the Cleveland Clinic, where the study was conducted.
In addition, about two-thirds (65%) of those in the surgery groups met the American Diabetes Association HbA1c goal of 7% or less, compared with 40% of those in the medical group, she added.
These are the 3-year results of the Surgical Treatment and Medications Potentially Eradicate Diabetes Efficiently (STAMPEDE) trial. The 1-year results of STAMPEDE are among the data that have shown intensive medical therapy and surgery can result in the remission of type 2 diabetes, but the durability of these effects have been unclear.
STAMPEDE is an investigator-initiated study that enrolled 150 overweight or obese middle-aged adults who had had type 2 diabetes for an average of 8.3 years and HbA1c levels above 7% (mean baseline level was 9.3%) and a body mass index of 27-43 kg/m2 (mean baseline BMI was 36); their mean age was 48 years, two-thirds were white, 68% were women, and 43% required insulin. One-third had a BMI under 35, below the current National Institutes of Health guideline for bariatric surgery.
After randomization to intensive medical therapy alone or a Roux-en-Y gastric bypass or sleeve gastrectomy plus intensive medical therapy, treatment was adjusted every 3 months for the first 2 years, then every 6 months, aiming for a HbA1c of 6% or less. The results were based on the 137 patients who completed 3 years of follow-up.
Significantly more patients in the surgery groups achieved the primary endpoint at 3 years without diabetes medications: 35.4% in the bypass group and 20.4% in the sleeve group, compared with none of those on medical therapy. "Virtually all" of those in the gastric bypass group met the primary endpoint without the use of insulin, Dr. Kashyap noted.
Relapses of glycemic control, defined as those who met the primary endpoint at 12 months but not at 3 years, occurred in the bypass group (24%) but were higher in the sleeve group (50%) and in the medical therapy group (80%).
Other benefits identified at 3 years included improved measures of HDL and triglycerides in the surgery group, compared with the medical therapy group. There were no differences in changes in blood pressure or in LDL levels; or, at 2 years, no differences between carotid intimal medial thickness measures in the three groups. But there was a substantial decrease in the medications used for blood pressure and cholesterol in the surgery groups: At 3 years, about 40% of the patients in the two surgery groups were not taking any cardiovascular medications, vs. only 2% of those in the medical therapy group.
Those in the two surgery groups also had more favorable effects on secondary endpoints that included body weight, use of glucose-lowering medications, and quality of life, compared with the intensive medical therapy group. Those in the bypass group showed improvements in five of eight quality of life measures, including physical function and less body pain, and those in the sleeve gastrectomy group has improvements in two of the eight measures, compared with no improvements among those on medical therapy.
Dr. Kashyap said that being able to take fewer medications per day and mobility and physical function improvements in the significant number of patients with osteoarthritis contributed to the improved quality of life in the surgery patients.
There were no procedure-related deaths, and other than four patients in the surgery groups who required additional surgery in the first year, none needed surgery after that time, and there were no deaths or life-threatening complications in the three groups of patients.
Dr. Kashyap pointed out that bariatric surgery is considered optimal for people who are heavier than a proportion of the patients in this study, but in the study, people who might not normally be considered for bariatric surgery experienced significant benefits. Often an underused intervention in medicine, bariatric surgery "should be considered a treatment option for patients with uncontrolled type 2 diabetes with moderate to severe obesity," Dr. Kashyap concluded.