Metabolic Surgery for Type 2 Diabetes: Appraisal of Clinical Evidence and Review of Randomized Controlled Clinical Trials Comparing Surgery with Medical Therapy
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Bariatric surgical procedures were originally developed to treat morbid obesity where their benefits certainly outweigh their potential side effects. Although they are very beneficial in improving metabolic control in type 2 diabetes, there are many medical treatments that are also effective. The role of bariatric surgery as primary therapy for type 2 diabetes depends on whether the benefit exceeds the surgical and nutritional complications, which are significant. The ultimate role for bariatric surgery in treating type 2 diabetes can only be determined by large, long-term randomized clinical trials which compare clinical outcomes of bariatric surgery with those of current intensive medical treatment. The four reported small, mostly 1-year trials have shown superior glycemic control by surgery as compared with medical treatment, but at the expense of significant surgical complications and unknown nutritional liability. They show that future trials will have to be much larger and last for at least 5–10 years.
KeywordsBariatric surgery Type 2 diabetes Metabolic control Mortality Surgical complications Nutritional disturbances Randomized clinical trials Medical therapy
Conflict of Interest
Harold E. Lebovitz is a scientific advisory board member of Biocon, Amylin Pharma, Intarcia Pharma, Janssen Pharmaceuticals, Metacure, and Poxel Pharma. He has received payment for the development of educational material for AstraZenica and Bristol Myers Squibb. He owns stock shares in Abbott, Abbvie and Merck.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by the author.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
- 6.• Lee W-J, Hur KY, Lakadawala M, et al. Gastrointestinal metabolic surgery for treatment of diabetic patients: a multiinstitutional international study. J Gastrointest Surg. 2012;16:45–52. Two hundred patients with poorly controlled type 2 diabetes and BMI below 35 kg/m 2 underwent bariatric surgery. Of 87 patients followed up at 1 year, 72.4 % had remission of their diabetes. A better diabetes remission rate was achieved in patients with shorter duration of diabetes (less than 5 years), higher BMI (greater than 30 kg/m 2 ), and gastric bypass surgery as compared with restrictive procedures.PubMedCrossRefGoogle Scholar
- 9.•• Brethauer SA, Aminian A, Romero-Talamas H, et al. Can diabetes be surgically cured? Long-term metabolic effects of bariatric surgery in obese patients with type 2 diabetes mellitus. Ann Surg. 2013;258:628–37. This is an analysis of 217 patients with type 2 diabetes treated by bariatric surgery with a median follow-up of 6 years. The long-term complete remission rate was 24 %. Mean excess weight loss was 55 % and the mean reduction in HbA1c level fell from 7.5 to 6.5 %. The rate of recurrence of diabetes after initial remission was 19 %.PubMedGoogle Scholar
- 13.•• Schuaer PR, Kashyap SR, Wolski K, et al. Bariatric surgery versus intensive medical therapy in obese patients with diabetes. N Engl J Med. 2012;366:1567–76. This was a randomized controlled trial comparing medical therapy with gastric bypass or sleeve gastrectomy in the treatment of 150 poorly controlled type 2 diabetic patients. Follow-up was 1 year. Remission of the diabetes (HbA1c level below 6 %) occurred in 12 % of the medically treated group, 42 % of the gastric bypass group, and 37 % of the sleeve gastrectomy group.CrossRefGoogle Scholar
- 14.• Mingrone G, Panunzi S, De Gaetario A, et al. Bariatric surgery versus conventional medical therapy for type 2 diabetes. N Engl J Med. 2012;366:1577–85. This was a single-center randomized trial of 60 poorly controlled type 2 diabetic patients undergoing conventional medical therapy, gastric bypass surgery, or biliopancreatic diversion. At 2 years, remission of the diabetes (HbA1c level below 6.5 % and fasting blood glucose level below 100 mg/dl) occurred in 75 % of the gastric bypass patients, 95 % of the biliopancreatic diversion patients, and 0 % of the medically treated patients.PubMedCrossRefGoogle Scholar
- 15.•• Ikramuddin S, Korner J, Lee W-J, et al. Roux-en-Y gastric bypass vs intensive medical management for the control of type 2 diabetes, hypertension, and hyperlipidemia. The Diabetes Surgery Study randomized clinical trial. JAMA. 2013;309:2240–9. This was a 12-month randomized trial comparing gastric bypass surgery with intensive lifestyle–medical management in 120 type 2 diabetic patients. Forty-nine percent of the bariatric surgery group and 19 % of the medically treated group achieved the primary end point of HbA1c level below 7 %, LDL cholesterol level below 100 mg/dl, and systolic blood pressure below 130 mmHg. Four perioperative and six late postoperative complications occurred in the surgical group. Nutritional deficiencies occurred in 34 surgical patients and 12 medically treated patients.PubMedCrossRefGoogle Scholar
- 19.DeMaria EJ, Winegar DA, Pate VW, et al. Early postoperative outcomes of metabolic surgery to treat diabetes from sites participating in the ASMBS bariatric surgery center of excellence program as reported in the bariatric outcomes longitudinal database. Ann Surg. 2010;252:559–67.PubMedGoogle Scholar
- 22.•• Bal BS, Finelli FC, Shope TR, et al. Nutritional deficiencies after bariatric surgery. Nat Rev Endocrinol. 2012;8:544–56. This is an extensive review which summarizes the current knowledge of nutritional deficiencies that can occur in patients after bariatric surgery. It highlights the symptoms, frequencies, follow-up, and treatment options for the macronutrient and micronutrient disorders that occur following bariatric surgery.PubMedCrossRefGoogle Scholar
- 23.Clements RH, Katasani VG, Palepu R, et al. Incidence of vitamin deficiency after laparoscopic Roux-en-Y gastric bypass in a university hospital setting. Am Surg. 2006;72:1196–204.Google Scholar
- 28.Mechanick JI, Youdim A, Jones DB, et al. Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient—2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic and Bariatric Surgery. Surg Obes Relat Dis. 2013;9:159–91.PubMedCrossRefGoogle Scholar
- 34.Treating diabetes with bariatric surgery. BMJ. 2013;346:f3710.Google Scholar