What is the role of bariatric surgery in treating Type 2 diabetes?

Weight matters in Type 2 diabetes. Being overweight is not only a risk factor for diabetic complications but can also make it more difficult to treat other risk factors such as HbA1c, LDL cholesterol, and blood pressure.

Weight loss is part of managing diabetes and developing a healthy lifestyle. A balanced diet with an emphasis on fresh fruits and vegetables, and regular physical activity are very important in reducing the risk of diabetes.

Weight loss itself can also contribute to reducing the risk of cardiovascular disease and other complications. People with Type 2 diabetes who are overweight can significantly improve their risk profile by loosing as little as 5% to 7% of their body weight, according to the CDC.  The ADA recommends moderate weight loss for patients with diabetes, especially those early in the disease process.  

Multiple weight loss procedures are available. The American Association of Clinical Endocrinologists Clinical Practice Guidelines  list the three most effective surgeries in order of degree of weight loss: Roux-en-Y Gastric Bypass (RYGBP), sleeve gastrectomy, and biliopancreatic bypass.

Recommendation 35 states that patients with Type 2 diabetes and BMI>/=30 should be considered for surgery if they fail to reach target outcomes with lifestyle and medical treatment. Target outcomes include the American Diabetes Association (ADA) targets for A1c (<7), LDL (<100), and systolic blood pressure (<130).

Results of surgery for weight loss

RYGB has been shown to result in better outcomes at three years than medical and lifestyle management alone. In a study published in Diabetes Care in June,

patients treated with RYGBP had a 17% full remission rate vs. 0% for the lifestyle/medical management only group.

Additionally, 28% of the RYGBP group achieved the triple goals of target A1c, LDL, and systolic blood pressure vs. 9% of the lifestyle/medical management group.  

In another study, RYGBP has resulted in an average reduction in BMI from 52.2 to 35.7 and A1c from 7.07 to 5.7.

Another study published in Diabetes Care comparing remission rates for RYGBP and Laparoscopic Gastric Banding (LAGB) demonstrated a remission rate of 68.7% for RYGBP and 30.2% for LAGB.

The cumulative findings of these and other studies have contributed to including the use of metabolic or bariatric surgery as a management tool for the treatment of diabetes, and inclusion of metabolic surgery into clinical guidelines or algorithms for the management of Type 2 diabetes.  

Some studies have suggested that early treatment is better, and that benefits are not restricted to those who are markedly obese. However, this is not yet clear and most guidelines are more cautious in their recommendations.

Next: A broader movement

A broader movement

Several international diabetes organizations have recently agreed to a joint statement on the role of metabolic surgery in the treatment of Type 2 Diabetes that was published in a recent issue of Diabetes Care.

The Joint Statement suggests that surgery should be available for patients with Type 2 diabetes and BMI>/=40 or those not in good control with BMI of 35-39.9.

Conclusions

Caution is always advised when considering a surgical option. The study referenced above that was published in Diabetes Care in June and found that patients treated with RYGBP had a 17% full remission rate, also cites an adverse event rate of 51 in the RYGBP group vs. 24 in the lifestyle/medical management group. 

In addition, it is recognized that some weight gain may recur and that not all patients benefit from the same degree from surgery.

Still, there is increasing evidence that metabolic surgery can benefit patients with Type 2 diabetes by decreasing weight, increasing success in reaching the ADA triple outcome, and reducing the risk of diabetic complications. Some patients achieve remission but caution should be taken because of the complications of the surgical intervention.

Edmund Pezalla, MD, MPH, is vice president and national medical director for pharmaceutical policy and strategy, Aetna.