Experts Now Promote Surgery for Treatment of Diabesity

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During the past several years, we've benefited from unprecedented advances in our understanding of diabetes pathology, monitoring, management, and treatment. These advances include a better understanding of the microvascular and macrovascular complications of this disease—"microvascular" refers to small blood vessels and "macrovascular" refers to big blood vessels, such as those found in the heart and brain—as well as continuous ("intelligent") glucose monitoring and even a new class of diabetes drugs: sodium-glucose co-transporter 2 (SGLT2) inhibitors (think Invokana).

However, all these advances mean little to many people with this disease. Despite better treatments and management, fewer than 50 percent of those with type 2 diabetes experience adequate blood sugar control and can still be at risk for diabetes complications, and a whopping 80 percent of people with type 2 diabetes experience heart disease complications. 

Ever since the late 1980s, researchers and clinicians alike have noticed that many people with morbid obesity and diabetes, or people with diabesity, who receive metabolic, or bariatric, surgery experience sustained improvements in glycemic control and a decrease in cardiovascular risk. Moreover, some people who receive metabolic surgery experience flat-out remission and no longer need to take any medications! Nevertheless despite these observations, experts have been reluctant to recommend consensus clinical guideline recommendations regarding the place of surgery in the treatment of type 2 diabetes...

that is, until the completion of the Diabetes Surgery Summit (DSS-II) in September 2015.

Of note, although often used interchangeably, bariatric surgery simply refers to weight-loss surgery; whereas, metabolic surgery refers to surgery performed to improve diabetes and metabolic disease.

At DSS-II, experts from all over the world in collaboration with 45 leading medical societies, including the six leading diabetes organizations: the American Diabetes Association, International Diabetes Federation, Chinese Diabetes Society, European Association for the Study of Diabetes Diabetes India, and Diabetes UK, reviewed all available evidence and made transformative global recommendations regarding the integration of surgical and medical treatments in the treatment of diabetes.

They also provided much-needed guidance concerning the selection of surgical candidates as well as both pre and postoperative follow-up recommendations.

4 Types of Metabolic Surgery

Weight-loss surgery has received a lot of press over the years. Thus you probably have some idea of what some of these procedures entail. Nevertheless, let's do a quick refresher covering the four main types of metabolic surgery.

  • Roux-en-Y gastric bypass. This procedure is the most common bariatric procedure performed throughout the world. This surgery is performed laporoscopically, or by minimally invasive means, and results in significant weight loss and improvements in diabetes. Roux-en-Y gastric bypass involves creating a stomach pouch out of a portion of the stomach and then attaching this small pouch directly to the intestine thus bypassing a large swathe of the stomach and intestine.

    The combined effects of this intervention not only decrease stomach surface area and result in earlier satiety, or a feeling of fullness, but also drastically decrease fat absorption. Of note, bariatric procedures that alter stomach size are called restrictive; whereas, those that mess with the intestine and alter absorption are called malabsorptive.

    More than 75 percent of people with diabetes who undergo the Roux-en-Y gastric bypass procedure will experience remission. Furthermore, more than 90 percent of these patients will experience improvements in other biomarkers of metabolic disease, including decreases in lipid (cholesterol and triglyceride) levels. To boot, people receiving this surgery also claim cessation of GERD (heartburn) as well as amelioration of joint pain, depression, infertility issues, stress incontinence, self-esteem and overall quality of life.
  • Laparoscopic sleeve gastrectomy: This relatively new procedure is rapidly becoming very popular in the United States. During this procedure, surgeons remove between 75 and 80 percent of the stomach while leaving the rest of the gut intact.

    Initially, experts thought this procedure was merely restrictive; however, recent research suggests that this procedure also increases the release of incretins, or hormones which stimulate the release of insulin by the pancreas. Although more research needs to be done investigating the benefits of sleeve gastrectomy, it appears that sleeve gastrectomy is comparable to Roux-en-Y gastric bypass in terms of weight-loss and metabolic effects, with similar rates of diabetes remission and reduction of diabetes complications and risk factors.
  • Laparoscopic adjustable banding: The gastric lap band procedure involves placing a band around the upper portion of the stomach to create a small pouch thus resulting in earlier satiety. Because the gastric lap band is much less invasive than other types of metabolic surgeries—sleeve gastrectomy and Roux-en-Y—it takes longer to result in weight loss and improvement of diabetes. Nevertheless, between 50 and 80 percent of people receiving this procedure experience remission of diabetes. Furthermore, people receiving this procedure also experience a decrease in lipid levels, albeit a bit lower than the decreases seen after other types of metabolic surgery.
  • Biliopancreatic diversion with duodenal switch (BPD/DS): Without getting into the nitty-gritty, please just keep in mind that, as can probably be inferred from its name, BPD/DS is a complex procedure that involves lots of gut rearrangement. This surgery is both restrictive and malabsorptive and intended for super obese individuals (think BMI greater than 50). Most importantly, BPD/DS results in the largest and most sustainable levels of weight loss among all the metabolic surgeries and the largest improvement in diabetes and lipid profiles.

    In fact, some studies have demonstrated that nearly 100 percent of people receiving this procedure experience diabetes remission! Furthermore, BPD/DS is notable for greatly improving sleep apnea among patients receiving it. Nevertheless in light of its drastic nature— rearranging and cutting the gut predictably causes adverse effects—people who receive this procedure are at increased risk for nutritional deficiencies, some of which are incompletely understood and can be life threatening.

In 2013, an estimated 179,000 weight-loss surgeries were performed. Here's a breakdown:

  • 42 percent were sleeve gastrectomy
  • 34 percent were gastric bypass
  • 14 percent were gastric lap band
  • 1 percent were BPD/DS
  • 6 percent were revisions

What Are the Dangers of Metabolic Surgery?

Overall, metabolic surgery is a relatively safe, especially when performed by an experienced surgeon on a patient who has prepared for the procedure and is committed to the success of the procedure. However, like all surgeries, bad things can happen after metabolic surgery. Thus, metabolic surgery is still considered second-line treatment and reserved for people who fail treatment by means of diet, exercise and medication.

Here are some adverse effects related to metabolic surgery. Please note that these adverse effects vary depending on the specific procedure performed. For example, Roux-en-Y and BPD/DS are particularly invasive and can result in many of these adverse effects; whereas, gastric lap band typically results in far fewer adverse effects unrelated to the actual intestines.

  • metabolic and nutritional deficiencies
  • ulcers
  • gastric remnant distension leading to ileus (gut obstruction)
  • cholelithiasis (gallstones)
  • hernia at the site of incision
  • adhesions (sticky areas that muck up and obstruct the bowel)
  • dumping syndrome
  • kidney failure
  • infection
  • stenosis
  • band erosion (with lap band)
  • change in bowel habits
  • reflux

This list is by no means exhaustive or specific to any one type of metabolic surgery. Please carefully research potential adverse effects of surgery before undertaking any such procedure. Additionally, discuss these adverse effects in detail with your surgeon and healthcare team. Metabolic surgery isn't a panacea that will cure all your ills without consequence. Rather, it is a balanced decision made to improve your health.

Which Patients With Diabesity Are Candidates for Metabolic Surgery?

As previously mentioned, for the first time, experts at DSS-II recommended a treatment algorithm for the treatment of diabesity using surgery. Most notably, the experts recommend that surgery be considered in people who are merely obese (BMI between 30 and 34.9) with diabetes that isn't controlled with either oral medications or insulin.

Here are the specific treatment recommendations for people with diabesity:

  • Metabolic surgery should be recommended in patients with class III obesity (BMI greater than 40) who remain uncontrolled by means of lifestyle changes (diet and exercise) as well as medical management (oral medications and insulin).
  • Similarly, metabolic surgery should be recommended in patients with class II obesity (BMI between 35 and 35.9) who remain uncontrolled despite lifestyle modification and medical management.
  • As mentioned above, metabolic surgery should be considered in people who are obese (BMI between 30 and 34.9) and are unable to achieve control of their diabetes despite changes in diet and exercise as well as medical management with oral medications and insulin.

Experts also recommend that these thresholds and cut-offs be adjusted downward for Asian people. It should be noted that although indications for the treatment of diabesity using surgery as well as the amount of weight lost by people belonging to different ethnic groups may differ, actual improvement of diabetes and remission rates after surgery are comparable among all races. In other words, surgery similarly benefits people of all races with respect to improvements in diabetes and remission of disease.

On a related note, because type 2 diabetes is no longer considered solely "adult onset" and affects an increasing and alarming number of children and adolescents, experts recommend that further research be conducted to elucidate the role of metabolic surgery in the treatment of children with diabesity. Furthermore, experts also recommend further research as to whether surgery can help severely obese people with type 1 diabetes. Specifically, in people with type 1 diabetes, bariatric surgery may facilitate better glycemic control and decreased insulin requirements as well as a reduced risk of heart disease.

How Exactly Does Metabolic Surgery Treat Diabesity?

The mechanisms by which metabolic or bariatric surgery treat diabesity are complex and interconnected. Verily, the improvement or remission of diabetes resulting from such surgery has a lot to do with calorie restriction and weight loss. However, there are likely many other factors that contribute to the treatment of diabesity including the following:

  • changes in bile acid metabolism
  • GI tract sensing and glucose utilization
  • incretin release (remember that incretins promote the release of insulin by the pancreas)
  • possible role of anti-incretins
  • changes in the gut flora (composition of bacteria that live in the gut)

Most likely, these effects and others we have yet to elucidate interact to result in diabetes improvement and remission after surgery. Furthermore, some of these mechanism depend on the type of surgery being performed.

Conclusion

If you or a loved one has diabesity that's uncontrolled by diet, exercise, and medication, you may want to discuss the benefits of metabolic surgery with your physician. Although such surgery is never first-line treatment, such surgery may help you avoid diabetic complications and suffering.

Just because conventional and noninvasive measures may not treat your diabetes, that doesn't mean that your situation is hopeless or your quality of life will never improve. Please keep in mind that metabolic surgery is a generally safe procedure that has a myriad of health benefits including treatment of type 2 diabetes. Please also keep in mind, however, that metabolic surgery is a process which requires lots of preparation, thought, motivation and commitment. Such surgery is never a quick or easy fix and requires a lifetime of dedicated health maintenance and informed decision making.

Sources:

Batterham RL and Cummings DE. Mechanisms of Diabetes Improvement Following Bariatric/Metabolic Surgery. Diabetes Care 2016 Jun; 39(6): 861-877.

Cefalu WT, Rubino F and Cummings DE. Metabolic Surgery for Type 2 Diabetes: Changing the Landscape of Diabetes Care. Diabetes Care 2016 Jun; 39(6): 857-860.

Ellsmere JC, Jones D and Chen W. Late complications of bariatric surgical operations. UpToDate 2016. Accessed May 30, 2016.

Rubino F, Nathan DM, Eckel RH, et al. Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations. Diabetes Care 2016 Jun; 39(6): 861-877. Accessed May 25, 2016.

Schauer PR, Schirmer B. The Surgical Management of Obesity. In: Brunicardi F, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, Pollock RE. eds. Schwartz's Principles of Surgery, 10e. New York, NY: McGraw-Hill; 2014. Accessed May 25, 2016.

Wu JJ, Perugini RA. Chapter 68. Common Surgical Options for Treatment of Obesity. In: McKean SC, Ross JJ, Dressler DD, Brotman DJ, Ginsberg JS. eds. Principles and Practice of Hospital Medicine. New York, NY: McGraw-Hill; 2012. Accessed May 25, 2016.

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