MELBOURNE – Gastric banding can achieve significant weight loss and remission of diabetes in patients with type 2 diabetes who are overweight but not obese, suggesting that a lower body mass index threshold could be considered for the procedure, according to results from a randomized controlled trial.
Type 2 diabetes patients with a BMI of 25-30 kg/m2 who received a laparoscopic gastric band achieved significantly greater weight loss (11 kg vs. 1 kg) and significantly higher rates of diabetes remission (52% vs. 8%) than did those who were treated with standard medical care.
According to an oral presentation at the International Diabetes Federation world congress, patients treated with gastric banding also required much less medication to achieve reductions in hemoglobin A1c.
"In the surgical group, we had a large number continuing metformin but basically very few taking other therapies, and the four people taking insulin all came off insulin by 2 years, whereas in the medical arm we had intensification of sulfonylurea, exenatide, insulin, and even gliptin therapy," said Dr. John Wentworth, an endocrinologist and research fellow at the Monash University Centre for Obesity Research and Education, Melbourne.
The study also found significant improvements in physical quality of life measures among the gastric banding group compared with the medical care group.
"Part of it was that people lost weight and they were pleased about it, but I think the other part was that they used less medication," Dr. Wentworth said in an interview.
Researchers also observed a small improvement in diastolic blood pressure, as well as significant improvements in insulin resistance and HDL levels, among patients treated with gastric banding.
The 2-year Australian study enrolled 51 overweight type 2 diabetes patients with relatively short disease duration (less than 5 years) and without underlying pancreatic pathology. Patients were randomized to either laparoscopic gastric banding or standard medical care involving regular consultations with a dietician, diabetes educator, and physician.
The study’s primary outcome was remission of diabetes at 2 years, which was defined as fasting and 2-hour glucose measurements of less than 7.0 mmol/L and less than 11.1 mmol/L, respectively, following an oral glucose challenge after at least 48 hours off medication.
Dr. Wentworth said gastric banding was a reasonable option in terms of achieving weight loss and improving glycemic outcomes with a much lower medication burden.
"Traditionally, bariatric surgery was a quite high risk procedure, looking back two or more decades, and you only targeted it to people who had very serious obesity and who had clear problems with it," Dr. Wentworth said.
"Things have become a lot safer in all types of bariatric surgery, so it becomes more of an option to offer people."
However, he stressed that the study population was carefully selected to include only people with shorter disease duration, and that gastric banding was not likely to achieve remission in patients with very long-standing and poorly controlled disease.
There were some complications in the surgical group, with one revision operation, and five episodes of esophageal obstruction in three patients, which required removal of fluid from the band.
A member of the audience pointed out that the medical care group might have achieved better results with greater use of glucagonlike peptide–1 (GLP-1) agonists, which can also have an effect on obesity. Dr. Wentworth said there was some use of the GLP-1 agonist exenatide, but it was not offered routinely to patients, and he acknowledged that this may have affected outcomes.
The Centre for Obesity Research and Education has received educational funding from Allergan, but there were no other financial conflicts of interest declared.