Five Minutes with… Walter Pories, MD, FACS, on Bariatric Surgery as an Option to Treat Diabetes

| January 21, 2010

Bariatric Times. 2010;7(1):8–9

In November of 2009, the 2009 Diabetes Surgery Summit (DSS) published its findings and recommendations on bariatric surgery in the online edition of Annals of Surgery.[1] In its position statement, the DSS said that bariatric surgery may be appropriate for treatment of people with mild-to-moderate obesity (body mass index (BMI) of 30–35 kg/m2). This goes beyond parameters established by the National Institutes of Health (NIH) for bariatric surgery in 1991, which limited bariatric surgery to people with a BMI of 35kg/m2 or more and an obesity-related condition or a BMI of 40kg/m2 or more with or without an obesity-related condition—parameters still adhered to by most insurance companies in determining coverage of the surgery.

The 2009 Summit group called for more research on the nonmorbidly obese population in the form of randomized, controlled, clinical trials and the development of standards for measuring clinical and physiological outcomes of bariatric surgery to further improve the quality of medical evidence and help in clinical decision-making. The statement also said novel and emerging surgical techniques, including sleeve gastrectomy, duodenal-jejunal bypass operations, and endoluminal sleeves show promising results for the treatment of diabetes, but should only be used in Institutional Review Board (IRB)-approved and registered trials.

According to the American Society for Metabolic and Bariatric Surgery (ASMBS), about 220,000 bariatric or metabolic procedures were performed last year in the United States.[2] The ADA reports 23.6 million children and adults or 7.8 percent of the United States population have diabetes and another 57 million have pre-diabetes.[2] The World Health Organization estimates that 220 million people worldwide have diabetes with 90 percent affected by type 2 diabetes.[2]

Dr. Walter J. Pories, Professor of Surgery, Biochemistry, Exercise and Sport Science at East Carolina University, Greenville North Carolina, is Principal Investigator for the East Carolina University Longitudinal Assessment of Bariatric Surgery (LABS).

Dr. Pories was the first person to describe full remission of diabetes following the gastric bypass and to propose and define the role of the gut in the pathogenesis of the disease. He has made many contributions to the research of bariatric surgery as an option to treat diabetes, including a paper reporting that gastric bypass patients not only experienced significant weight loss, but that 83 percent of the patients with diabetes had normal blood sugar control after 14 years.[3]

He participated as a voting delegate in the 2009 DSS and was on the international organizing committee for the event.

The staff at Bariatric Times interviewed Dr. Pories to get his opinion on the debate and the DSS’s recent concensus to lower the recommended BMI for patients having bariatric surgery to treat their diabetes.

What are some differences between performing surgery on a patient with a BMI greater than 30 and BMI greater than 40? Are there different factors to consider in the surgical preoperative and postoperative period when treating diabetes with surgery in these patients?

Curiously, a higher BMI does not necessarily offer greater technical challenges. For example, a woman with a BMI of 65kg/mg2 and a “pear-shaped” body composition, i.e. primarily subcutaneous deposits of fat in her hips, thighs, and breasts, may require less effort and skill than a muscular male with a BMI of 32kg/mg2 whose fat is primarily visceral in distribution. The pre- and postoperative care has to be meticulous in bariatric patients, no matter what their BMI. In general, patients with a lower BMI have fewer comorbidities but factors such as gender, race, age, nutrition, level of adherence with instructions, socio-economic status, educational levels, and degree of follow up may all outweigh the influence of BMI alone.

A core issue in this topic is whether surgery should be considered a primary treatment for diabetes or a treatment of last resort. Do you think there will ever be an agreed-upon answer to this? In your opinion, should surgery be considered as a primary treatment for the control/resolution of diabetes?

I doubt that we’ll ever have “agreed-upon” answers on any therapy, and I hope that never changes. We must continue to review all of our therapies, no matter how sacred. If we did not, we would still be bleeding patients with the croup (the treatment given George Washington), pouring boiling oil to cauterize amputations, or treating wounds with a solution of egg yolk, oil of roses, and turpentine like the French surgeon Ambroise Paré.

Yes, surgery should and will be considered as the primary care of some patients with type 2 diabetes. I am pleased that good prospective, controlled, randomized studies by Dr. Phillip Schauer at the Cleveland Clinic, Cleveland, Ohio, and Dr. Anita Courculas at Magee-Womens Hospital of University of Pittsburgh Medical Center (UPMC), Pittsburgh, Pennsylvania are already underway to provide us the answers we need before we decide the best approaches. Even so, I have no doubt that if I had a daughter with type 2 diabetes, I would strongly urge her to consider a metabolic surgical intervention within an approved protocol. When an operation that takes about an hour is able to return a patient to euglycemia, stop the need for insulin injections, and prevent the complications of blindness, renal failure, and amputation, such an approach just makes good sense with the caveat that we have to wait, perhaps impatiently, for the results of the studies.

What is the risk/benefit relationship in using bariatric surgery to treat diabetes? Do the risks vary depending on different groups of patients?

While we know the risks of bariatric surgery with a 90-day surgical mortality of 0.3 percent based on Bariatric Outcomes Longitudinal Database (BOLD),[4] Dr. Henry Buchwald’s meta-analysis and American College of Surgeons National Surgical Quality Improvement Program (NSQIP),[5] and long-term data of improved survival from our data at East Carolina, Utah, and Sweden, we have remarkably little information about the risk/benefits of medical therapy.6 Based on the data we now have, I believe it is far safer to treat the diabetes with surgery. Along with every bariatric surgeon, however, I am eager to see the results of the prospective studies before urging surgery for our patients.

Risks do vary with different groups of patients. Dr. Eric DeMaria’s contributions in terms of risk assessment7 and the comorbidity scale[8,9] have already advanced our ability to predict and improve outcomes. The Surgical Review Corporation’s BOLD, with more than 200,000 patients, is now being analyzed to sharpen our understanding of the operative risks and prediction of outcome benefits.

With so many different types of bariatric surgery procedures—gastric bypass, sleeve gastrectomy, enterectomy, omenectomy, intraluminal duodenal sleves)—what types of surgery would be optimal in the treatment of diabetes?

The ideal operation for the treatment of diabetes remains to be defined. Currently, two procedures appear to be the most effective in the United States for the control of type 2 diabetes, Roux-en-Y gastric bypass and pancreatico-bilibary bypass with a duodenal switch.[10] The gastric band is less effective in terms of full recovery and requires much longer to produce full euglycemia.[11] Personally, I don’t see much future for enterectomy, omentectomy, and intraluminal duodenal sleeves, but that’s just my opinion.

During the 2007 Diabetes Surgery Summit, which you atteneded, there was a debate about what to call a surgery used for the treatment of diabetes. Do you think the 2009 Summit has resolved this debate by calling it “diabetes surgery?” In your opinion, is there a need to rename procedures once considered bariatric to fit the term diabetes surgery? Do you think in the future we will see the creation of a new specialist to perform these procedures?

For the present, we are stuck with the name bariatric surgery, even though it reflects only on the control of weight. The best name, at present, appears to be metabolic surgery, but that terminology has not been widely adopted. I don’t think that diabetes surgery is any better. It fails to recognize the other effects of the operations, i.e. control of obesity, pseudotumor cerebri, hypertension, hyperlipidemia, infertility, and polycystic ovary disease.

We already have such specialists. We call them bariatric surgeons…. at least for now, until we get a better name.

With the progress made during the 2009 Diabetes Surgery Summit, what is your prediction for the future? Where would you like to see the debate on this topic go?

As Yogi Berra said, “It’s tough to make predictions, especially about the future.”

My prediction would be that the demand for metabolic surgery will increase annually as patients and referring colleagues see that the procedures are effective and safe. My concern is that we will not have adequate surgical manpower to meet this demand. In time, however, perhaps over the next 5 to 10 years, as we gain better understanding of the metabolic effects of bariatric surgery, the procedures will be reproduced by pharmaceuticals. The debate should be based on data. To get that information, we need far better support for clinical and basic research and we need it soon before obesity and diabetes overwhelm our economy.

Time’s up!

1.     Rubino F, Kaplan LM, Schauer PR, Cummings DE; On Behalf of the Diabetes Surgery Summit Delegates. The Diabetes Surgery Summit Consensus Conference: Recommendations for the Evaluation and Use of Gastrointestinal Surgery to Treat Type 2 Diabetes Mellitus. Ann Surg. 2009 Nov 19. [Epub ahead of print]
2.    ASMBS Fact Sheet on Metabolic and Bariatric Surgery.
media/asmbs_fs_surgery.pdf. Accessed on 12/30/2009.
3.    Pories WJ, Swanson MS, MacDonald KG, et al. Who would have thought it? An operation proves to be the most effective therapy for adult-onset diabetes mellitus. Ann Surg. 1995;222(3):339–350; discussion 350–352.
4.    Hughes G, Pratt GM, Sugerman H, et al. Bariatric Outcomes Longitudinal Database (BOLD): A national uniform database for quality control of bariatric surgery. Poster. The Obesity Society Annual Scientific Meeting, Phoenix, Arizona, 2008.
5.    Buchwald H, Estok R, Fahrbach K, et al. Weight and type 2 diabetes after bariatric surgery: systematic review and meta-analysis. Am J Med. 2009;122(3):248–256.e5. Review.
6.    MacDonald KG Jr, Long SD, Swanson MS, et al. The gastric bypass operation reduces the progression and mortality of non-insulin-dependent diabetes mellitus. J Gastrointest Surg. 1997;1(3):213–220; discussion 220
7.    American College of Surgeons: National Surgical Quality Improvement Program.
default.aspx. Accessed 12/29/09
8.    Portenier D, DeMaria EJ. Risk scoring systems for weight loss surgery. Adv Surg. 2008;42:313–320.
9.    Ali MR, Maguire MB, Wolfe BM. Assessment of obesity-related comorbidities: a novel scheme for evaluating bariatric surgical patients. J Am Coll Surg. 2006;202(1):70–77.
10.    Sjöström L. Bariatric surgery and reduction in morbidity and mortality: experiences from the SOS study. Int J Obes (Lond). 2008;32 Suppl 7:S93–97. Review.
11.    Adams TD, Stroup AM, Gress RE, et al. Cancer incidence and mortality after gastric bypass surgery. Obesity (Silver Spring). 2009;17(4):796–802. Epub 2009 Jan 15

Author information:
Dr. Pories is Professor of Surgery, Biochemistry, Exercise and Sport Science as well as Principal Investigator for the East Carolina University Longitudinal Assessment of Bariatric Surgery (LABS) funded by the National Institutes of Health (NIH)/The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) as well as other grants from Johnson & Johnson and GlaxoSmithKline addressing insulin action and  the molecular effects of bariatric surgery. He the first to describe full remission of diabetes following the gastric bypass and to propose and define the role of the gut in the pathogenesis of the disease.

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