This past March, the International Diabetes Federation released a position statement supporting bariatric surgery as an appropriate therapy for patients with type 2 diabetes who do not achieve their recommended treatment targets with medical therapy, particularly if they also have obesity-related comorbidities.
The statement acknowledged that bariatric surgery should be an accepted option in patients with type 2 diabetes and a body mass index of at least 35 kg/m2, and that it should be considered as an alternative treatment option in patients with a body mass index of 30-35 when diabetes is inadequately controlled by optimal medical regimens.
By Dr. Shanu N. Kothari
To translate this approach into practice, physicians who provide routine care to patients with type 2 diabetes – primary care physicians and endocrinologists – should inform appropriate patients that bariatric surgery is a metabolic surgical option in the treatment algorithm for diabetes. Bariatric surgeons should offer the type of bariatric surgery that best suits each patient’s individual situation. In many circumstances, these surgeons allow patients to choose the operation they believe is right for them, an approach that is unique to bariatric surgery; in most surgical consultations, patients are not offered a choice of procedures. Do patients select the procedure that will optimize their success?
To date, the best bariatric surgical procedure for achieving remission of diabetes is the duodenal switch (or biliopancreatic diversion), a procedure not widely performed in the United States. It is the most technically challenging type of bariatric surgery, especially when performed laparoscopically, and it carries a higher morbidity and mortality rate than do the more common bariatric surgical procedures.
Gastric banding is often sought by patients because it is widely marketed, potentially reversible, and comes with an excellent safety profile. But while gastric banding can result in significant weight loss, it achieves remission rates of type 2 diabetes that are lower than those of gastric bypass. Some patients consider the reversibility of gastric banding to be an advantage, but it is imperative that patients who undergo any bariatric surgical procedure be committed to long-term adherence to postoperative guidelines.
When comparing the risks of surgical complications with the benefits of diabetes remission (and other obesity-related comorbidities), I believe the best option is laparoscopic Roux-en-Y gastric bypass. This procedure is almost as effective as the duodenal switch for resolving diabetes, yet it is safer and is widely available in the United States.
Diabetes remission is often seen prior to significant weight loss in patients who have undergone laparoscopic Roux-en-Y gastric bypass. The reason for this has yet to be fully elucidated. There appears to be a multifactorial gut hormone response that is responsible for this metabolic effect, but this theory is still under intense study.
Efficacy of Gastric Bypass for Diabetes Remission
We published a study 2 years ago that documented the efficacy of gastric bypass for diabetes remission. We compared hemoglobin A1c levels for patients who had undergone laparoscopic Roux-en-Y gastric bypass with a group of morbidly obese patients treated with conventional medical therapy.
One year after surgery, 59% of the 46 patients for whom we had follow-up data had experienced full remission (Surg. Obes. Relat. Dis. 2009;5:4-10). They no longer required any diabetic medications, and their hemoglobin A1c was 6% or lower. In contrast, only 2 of the 41 patients (5%) in the conventional medical treatment group experienced remission.
Full remission of diabetes is very difficult to achieve with medications and lifestyle modification. Bariatric surgery – more appropriately termed "metabolic surgery" – presents an unrivaled opportunity for patients with type 2 diabetes to experience full remission. It also often resolves hypertension, lowers hypercholesterolemia, and substantially improves other obesity-related comorbidities, including obstructive sleep apnea, gastroesophageal reflux disease, and osteoarthritis.
The time has come to move away from arbitrary BMI cutoffs and insurance-mandated criteria to determine whether patients with diabetes are candidates for bariatric surgery. The primary determinant should be the severity and duration of the patient’s diabetes and obesity-related comorbidities, and whether a reasonable trial of medical and lifestyle management has failed.
Results from several studies have documented that the cost of bariatric surgery for patients who are not adequately managed by their medical regimen are recouped within 2-4 years by reduced drug costs and reduced costs for managing the complications of poorly controlled diabetes (Am. J. Manag. Care 2008;14:589-96; Surg. Obes. Relat. Dis. 2011 May 27 [doi:10.1016/j.soard.2011.05.009].
Many physicians regard bariatric surgery as dangerous, and it is held to an unreasonably high standard of success. Even though gastric bypass will produce remission in about 60% of patients with diabetes and significant benefits for another 20%-30%, it is criticized for having a 10% failure rate. Many other procedures routinely used in appropriate patients do not work in 100% of patients.