but the effect diminished over time, according to findings published Jan. 16 in JAMA.
In a randomized study of 113 obese patients with diabetes, about 50% of those who received gastric bypass in addition to lifestyle and medical management achieved the composite endpoint of a hemoglobin A1c (HbA1c) value of less than 7%, an LDL cholesterol level of less than 100 mg/dL, and a systolic blood pressure of less than 130 mm Hg after 1 year, reported Sayeed Ikramuddin, MD, FACS, of the department of surgery at the University of Minnesota, Minneapolis, and his coauthors. For comparison, just 16% in the lifestyle/medical management group achieved the endpoint (difference, 34%; 95% confidence interval, 14%-54%; P = .003) .
At 5 years’ follow-up, about 23% of patients in the gastric bypass group and 4% in the lifestyle/medical management group achieved the composite triple endpoint (difference, 19%; 95% CI, 4%-34%; P = .01), the authors reported.
The study included 120 patients at four sites in the United States and Taiwan, 7 of whom either died or were lost to follow-up before completion of the study. Participants had an HbA1c level of 8% or higher and a body mass index between 30 and 39.9 kg/m2.
Patients were randomized to receive either 2 years of lifestyle and medical management alone or in conjunction with standardized Roux-en-Y gastric bypass. During the first 2 years of intervention, patients were told to record weight, exercise, and food intake and were prescribed 325 minutes of physical activity per week. Participants also met regularly with a trained interventionist and an endocrinologist and were given pharmacologic therapy for hyperglycemia, cholesterol, and hypertension, the authors said. Aside from usual visits with a primary physician, all study interventions ceased after the initial 2-year period.
At baseline, the group that received only lifestyle/medical management had a mean BMI of 34.4 and HbA1c level of 9.6%, compared with a mean BMI of 34.9 and HbA1c level of 9.6% in the gastric bypass group.
Primary endpoint success rates decreased in both groups between years 1 and 3, going from 50% to 23% in the gastric bypass group and from 16% to 4% in the lifestyle/medical management group, but it remained stable from year 3 through year 5, Dr. Ikramuddin and his coauthors said in the report.
Overall, 26% of patients who had gastric bypass surgery during the first year achieved the triple endpoint at 5 years, compared with 8% of those who did not have surgery (difference, 18%; 95% CI, 6%-32%; P = .04).
The mean weight loss for participants in the gastric bypass group was 21.8% at 5 years, compared with 9.6% in the lifestyle/medical management group (difference, 12.2%; 95% CI, 8.9%-15.5%).
The results suggest that “gastric bypass provides significant benefit but with a smaller and less durable effect size than what is seen in the evaluation of glycemic control alone,” the authors wrote.
“Because the effect size diminished over 5 years, further follow-up is needed to understand the durability of the improvement,” Dr. Ikramuddin and his colleagues concluded.
Dr. Ikramuddin disclosed relationships with Novo Nordisk, USGI Medical, Medica, Metamodix, Medtronic, ReShape Medical, and EnteroMedics.
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SOURCE: Ikramuddin S. JAMA. 2018;319(3):266-278.