GRAPEVINE, TEX. — Greater initial weight loss following surgery and the ability to keep much of that excess weight off over time distinguished patients who achieved long-term remission of their type 2 diabetes after bariatric surgery.
Severely obese patients with type 2 diabetes had a 40% remission rate at 5 years after laparoscopic adjustable gastric banding (LAGB), in one large retrospective study presented at the annual meeting of the American Society for Metabolic and Bariatric Surgery. In a second study, those who had gastric bypass surgery maintained a 57% diabetes remission rate at a median of 8.6 years.
Samuel Sultan reported on 95 type 2 diabetic patients who underwent LAGB. They went from a mean preoperative body mass index of 46.3 kg/m
At 5 years' follow-up, 40% of patients were off all diabetes medications and had a hemoglobin A1c level below 6.0% or a fasting blood glucose below 100 mg/dL. In 80% of patients, diabetes was either in remission or improved as defined by reduced need for diabetes medications and fasting blood glucose of 100-125 mg/dL, said Mr. Sultan, a medical student at New York University.
The 5-year excess weight loss in the group with long-term diabetes remission was 57%, compared with 38% in those with recurrence. There was a trend toward a higher remission rate in patients whose presurgical duration of diabetes was shorter: The remission group had a mean 4.7-year history of diabetes, whereas those not in remission had a mean 7.3-year history. Viewed another way, the 5-year remission rate in patients with less than a 7-year history of type 2 diabetes was 44%, compared with 27% in those with diabetes for more than 7 years.
Mean fasting blood glucose in the overall study population was 146 mg/dL preoperatively and 118.5 mg/dL at 5 years. Mean HbA1c was 7.5% before LAGB and 6.6% after 5 years.
In a separate presentation, Dr. Silas M. Chikunguwo reported on 177 patients with type 2 diabetes who underwent open or laparoscopic gastric bypass for morbid obesity and were followed for a mean of 8.6 years. Their mean BMI went from 50 to 31.
Postoperatively, 89% of patients had complete remission of their diabetes. The remission proved durable in 57%, said Dr. Chikunguwo of Virginia Commonwealth University, Richmond.
One predictor of durable remission was less severe preoperative diabetes: The recurrence rate was 72% in patients on preoperative insulin, 34% in those on oral agents, and 24% in those on dietary control alone.
These studies are consistent with the results of a landmark recent systematic review and meta-analysis that included 621 studies involving more than 135,000 morbidly obese patients, 22% of them with type 2 diabetes, who underwent various forms of bariatric surgery. Complete resolution of the clinical and laboratory manifestations of diabetes was experienced in the first 2 years postsurgery by 82% of patients, dropping off to a 62% after 2 years (Am. J. Med. 2009;122:248-56.e5).
Diabetes can go into remission within days after bariatric surgery, before major weight loss has occurred, so surgically induced changes in the gut hormonal milieu may be involved.
How long these remissions will last remains unclear, but recurrence of type 2 diabetes shouldn't be misconstrued as indicating that a patient's bariatric surgery wasn't beneficial, according to Dr. Richard A. Perugini of the University of Massachusetts, Worcester.
“If you can keep someone off medications with good glycemic control for 5 years and then they have to go back on medications, we've still done a great service to that particular person and to the system,” he said.
Dr. Chikunguwo and Mr. Sultan reported having no conflicts of interest, but Mr. Sultan noted that his coinvestigators serve as consultants to Allergan, marketer of the LAP-BAND system.