Type 2 Diabetes: A Surgical Disease?
The ongoing diabetes epidemic, the impressive effectiveness of bariatric surgical procedures in treating type 2 diabetic patients, and the lines of evidence suggesting weight-independent effects of these procedures on glycemia, considered together, have resulted in substantial enthusiasm in the surgical community for lowering the minimal BMI criteria for bariatric surgical candidates with type 2 diabetes. This would in effect be the first step in making type 2 diabetes a surgically treated disease, and this proposal has been the subject of two recent international consensus conferences.[30]
However, treating type 2 diabetes with bariatric surgery remains highly controversial in the endocrinology community.[12] First, it must be emphasized that the evidence suggesting that bariatric surgical procedures may have direct effects on glycemia independent of weight loss include very few randomized controlled trials, and most surgical outcomes are from uncontrolled case series with considerable missing data.[9] In one meta-analysis, a large number of studies did not report enrolling consecutive patients, and less than half reported the number of patients available for follow-up.[7] To date, the only prospective randomized controlled trial on the subject evaluated the effects of the LAGB, a procedure generally thought to not have weight-independent effects on glycemia.[6] Thus, the substantial lack of level 1 evidence precludes achieving a consensus across specialties.
Second, concurrent to the advances in the surgical treatment of type 2 diabetes, there have been significant advances in the medical management of the disease. Since 1995 there have been multiple new drugs approved by the Food and Drug Administration for the treatment of hyperglycemia in patients with type 2 diabetes, including the biguanide metformin, α-glucosidase inhibitors, thiazolidinediones, glinides, GLP-1 analogs, amylin analogs, dipeptidyl peptidase-IV inhibitors,[31] a bile acid sequestrant,[32] and most recently a dopamine receptor agonist.[33] In addition, multiple insulin analogs are now available[34] with improved kinetics and safer dosing profiles permitting more individualized and safer regimens compared with prior preparations. Novel pharmacologic agents to promote weight loss are also under development.[35,36] Together these agents hold great promise for generating improved health outcomes for type 2 diabetic patients, and with them more patients are achieving metabolic targets. However, long-term safety remains incompletely understood, and some agents may impart undesirable risks for adverse outcomes, such as the potential for cardiovascular risk with rosiglitazone[37] or pancreatitis with exenatide.[38] Optimal treatment strategies and glycemic goals for patients with type 2 diabetes remain incompletely understood, and very tight glycemic control may not reduce cardiovascular event rates, and may even lead to increased mortality.[39] Thus, just as with surgical therapy of the disease, further study is needed on the effects of current combination and long-term medical therapeutic regimens on type 2 diabetes. Understanding the long-term safety and efficacy of pharmacologic weight loss agents will likewise be important to consider.[36,40]
A growing number of investigators have initiated efforts to provide level 1 data relevant to determining optimal treatment regimens for type 2 diabetes given the current equipoise for the clinician to recommend surgical or medical interventions. There are currently 11 studies registered on Clinicaltrials.gov comparing various bariatric and medical interventions (Table 1) (clinicaltrials.gov, accessed 20 September 2010). The National Institute of Diabetes and Digestive and Kidney Diseases has funded four prospective pilot and feasibility trials in the past year, possibly in consideration of a larger nationally based outcome trial to follow. With the societal imperative to provide optimal care for the growing population of patients with diabetes, the intense scientific focus on medical and surgical option effectiveness, and such a rapid expansion of clinical trials on the matter, a number of relevant issues are brought to bear by those designing, conducting, reviewing, and ultimately interpreting such trials.
Diabetes Care. 2011;34(3):763-770. © 2011 American Diabetes Association, Inc.
Cite this: The Great Debate: Medicine or Surgery - Medscape - Mar 01, 2011.
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