Surgery for Diabetes – No Longer Sugaring the Pill
Bariatric surgery was originally designed to induce weight loss and treat severe obesity in patients – most of whom have been young females with a relatively low prevalence of Type 2 diabetes (T2D). The aim of the surgery is to reduce the risk of future cardiovascular complications or metabolic disease. While this approach is enshrined in national clinical practice guidelines, adhering to them delays treatment for individuals who already have metabolic disease.
However, a joint statement by international diabetes organizations argues for a paradigm shift for bariatric procedures, labeling them instead as "metabolic surgery". Published in June 2016, the statement claims evidence showing that bariatric surgery significantly improves blood sugar levels (glycemic control) and reduces cardiovascular complication rates.1
This paradigm shift means doctors may now consider surgery when treating people with diabetes, including individuals who are mildly obese and those who fail to respond to conventional treatment.2
Until now patients undergoing metabolic surgery, although as obese as individuals referred for bariatric surgery, have been typically older, male and with more severe T2D and coronary artery disease by the time of surgery.
These differences significantly influence surgical outcomes. The best results are achieved when disease duration is shortest because the body’s natural glucose regulation is still relatively intact. Delaying surgery reduces the health benefits and cost effectiveness.
Surgery appears to show impressive results in this group – with a median reduction of 2% in HbA1c (a measure of glycemic control) for surgery vs. 0.5% for conventional management. The “surgery” groups did better regardless of the baseline level of HbA1c. Sustained T2D remission is achieved in 30%-63% of patients, with a median disease-free period of 8.3 years. Whilst up to half of these may see a recurrence, the benefits can be sustained for 20 years.
There are a number of procedures available to the metabolic surgeon to help achieve glycemic control, but efficacy is inversely related to safety. Simple gastric banding is relatively safe but the least effective procedure, whilst more invasive surgery carries greater risk, particularly in the obese but has better long-term metabolic outcomes. The Roux-en-Y gastric bypass is recommended as providing the best risk/benefit profile. Mortality rates with bariatric/metabolic operations are typically 0.1%-0.5%, similar to cholecystectomy or hysterectomy. Morbidity has also dramatically declined with laparoscopic approaches. Major complications rates are 2%-6%, with minor complications in up to 15% of patients, comparing favorably with other commonly performed elective operations.
The cost effectiveness of these procedures is vital as each operation consumes significant resources at a specific time, whereas chronic disease management is typically achieved at relatively low cost over a long period until significant complications arise. Modeling studies suggest an economic benefit from the surgery.
Seeing surgery as a disease-modifying intervention changes the indicators for surgical intervention. The decision to operate is no longer solely based on the patient’s BMI. Surgery is recommended for almost everyone with a BMI above 30 and expedited at 40 or higher. Surgery should be considered for those with a lower BMI if optimal lifestyle and medical treatments fail to produce adequate glycemic control, and for BMI between 35 and 39 even if glycemic control is achieved.
Insurers may begin to see a rise in the number of applicants who have undergone "metabolic" as opposed to "bariatric" surgery if health professionals follow the new recommendations of the international diabetes organizations.
You can also read Matthew Ramjan and Lyn Franks' article on bariatric surgery for more.
- Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations, Diabetes Care 2016;39:861–877 | DOI: 10.2337/dc16-0236, http://care.diabetesjournals.org/content/39/6/861.