This article is more than 5 years old. Information may no longer be current.
Inside the endocrinologist’s armamentarium: Surgical options for type 2 diabetes
Click Here to Manage Email Alerts
The evolving role of surgery for treating type 2 diabetes has become an important topic for physicians and patients during the past several years, in light of some important recent studies.
Philip Schauer
We know that diabetes is traditionally treated with lifestyle intervention and medical therapy. Although there have been advances in these avenues, there’s still a wide gap between good efficacy and what patients are expecting. A recent study involving National Health and Nutrition Examination Survey data demonstrated that only a small percentage of patients — about 18% — are actually meeting the three important targets of therapy: glycemic control, blood pressure control and LDL cholesterol. Only about half of those are at glycemic control, and this is utilizing modern drug therapy. Now we have an opportunity for surgery to help physicians and patients meet those targets much more effectively.
In the past decade or so, a number of observational studies have been conducted, and a recent meta-analysis published 2 to 3 years ago in Archives of Internal Medicine demonstrated that a variety of bariatric procedures — including the gastric bypass operation, gastric banding and the longer bypass procedures such as biliopancreatic diversion — can be effective at achieving remission. That is, getting the patient to normal blood sugar HbA1c of 6.5% or less without medication. This was shown in a high percentage, about 65% to 85%, of patients, with durability up to 2 years and sometimes beyond.
What has been lacking in the literature, however, are randomized control comparisons with modern medical therapy. Now we have three randomized control trials (RCTs), one of which was published 4 to 5 years ago and compared gastric banding with medical management of type 2 diabetes; it showed that banding was superior to medical management.
STAMPEDE trial
In 2012, two studies were simultaneously published in The New England Journal of Medicine. I was involved with one of those studies called the STAMPEDE trial — a randomized trial comparing intensive medical therapy with two types of surgery: sleeve gastrectomy and gastric bypass. Our study involved 150 patients who were randomly assigned to one of three arms; last year we reported results at 1 year. At the beginning of the trial, patients had fairly advanced type 2 diabetes. On average, they were aged in their late 40s to 50s, with diabetes duration of about 8 years; most patients were on at least three drugs, and half of them were on insulin. The average HbA1c at the start of the study was close to 9% in all three groups. After 1 year, we looked at the percentage of patients who actually achieved a remission, defined as an HbA1c of 6% or less. In the medical group, about 12% were able to reach that target with intensive medical therapy, whereas a much higher percentage, 42%, reached that target after gastric bypass, and about 35% reached that target after the sleeve gastrectomy. It is interesting to note that all of the patients who had gastric bypass that reached an HbA1c of 6% or less did so without the use of any diabetic medical therapies; that was complete remission.
We also saw benefits in other areas; fasting blood sugar was much better controlled in the surgical groups. There were also benefits in terms of reduction in dyslipidemia; dependency on BP medication was improved in the surgical patients as well. Other important cardiovascular markers of disease also were evaluated, including C-reactive protein, which is a very good marker of CV risk. It was dramatically reduced in the surgical group by about 80% compared with a more modest reduction in the medical group.
Obviously, this raises larger questions as to what is driving the benefit. Clearly there was a major decrease in body weight by about 10 BMI points; the BMI dropped from about 36 to 26 in both surgical groups, whereas there was a modest drop in body weight in the medical group of about 2 BMI points. But there may be other factors driving this benefit as well. What is interesting is that in the surgical patients most of that HbA1c improvement, which is about a 3% drop — from 9% down to about 6% — happens in that first 3 months before there is a significant amount of weight loss. This suggests that perhaps there are other factors than weight loss alone that may be driving this benefit.
In the same issue of The New England Journal of Medicine, another study corroborated these findings. A group out of Italy led by Geltrude Mingrone, MD, and senior author Francesco Rubino, MD, conducted a randomized trial that compared conventional medical therapy with two types of surgical therapy: the Roux-en-y gastric bypass and biliary pancreatic diversion. The study, which had a total population of 60 patients, demonstrated that after 2 years both surgical therapies were superior in terms of glycemic control. Approximately 70% of the patients who had gastric bypass achieved a remission, defined as HbA1c less than 6.5%. Additionally, more than 80% of patients reached that target after the biliary pancreatic diversion, whereas a much smaller percentage of patients who had conventional treatment were able to achieve glycemic control. In addition, similar to the STAMPEDE study, they also saw benefits favoring surgery with respect to BP management and dyslipidemia. In June, an RCT by Sayeed Ikramuddin, MD, and colleagues comparing intense medical treatment with gastric bypass was published in JAMA. It also showed that surgery was superior to intense medical therapy for diabetes at 1-year follow-up.
In summary, with this recent data we now have four short-term RCTs on top of dozens of observational studies that all are consistent in showing that patients with type 2 diabetes are not often well controlled with medical management alone, and that surgical therapy with medical therapy is superior not only at achieving glycemic control, but also providing many other CV benefits.
Discuss with patients
The take-home message for endocrinologists now is that you should have a serious discussion about surgical options with your patients with type 2 diabetes and obesity (BMI .30) who are not well managed with conventional medical therapy. We all know the consequences of poorly controlled type 2 diabetes, as well as the high likelihood of microvascular and macrovascular complications and premature mortality. Surgery is another tool, a powerful tool in your toolbox, that you should be utilizing when appropriate.