Bariatric Surgery for DM2 Remission

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Lucas G Hill
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Bariatric Surgery for DM2 Remission
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Authors


Marilyn L. Mootz | PharmD Candidate 2017
Lucas G. Hill, PharmD, BCPS | Clinical Assistant Professor
The University of Texas at Austin College of Pharmacy

 

Citation


Courcoulas AP, Belle SH, Neiberg RH, et al. Three-year outcomes of bariatric surgery vs lifestyle intervention for type 2 diabetes mellitus treatment: a randomized clinical trial. JAMA Surg 2015;150(10):931-40. (http://1.usa.gov/1Td3tW2)

 

Background


The worldwide prevalence of diabetes was recently estimated at 9.5%.1 Prevalence in the U.S. is similar at 9.3%, with 30% of these individuals undiagnosed. The burden of diabetes mellitus type 2 (DM2) is projected to rise as 37% of U.S. adults over the age of 20 years have prediabetes.2 Global and domestic trends in obesity, a well-known risk factor for the development of insulin resistance and DM2, are also discouraging.3 The prevalence of obesity in the U.S. outpaces the rest of the world with 36% of adults 25 years and older having a body mass index (BMI) > 30 kg/m2.4

 

Opinions are divided regarding the most effective strategy to address obesity in patients with DM2, as experts favor varying combinations of medication therapy, bariatric surgery, and therapeutic lifestyle changes. While several medications have recently been approved for long-term weight management, the current options generally induce only modest weight loss.5 The authors of a recent clinical practice guideline regarding bariatric surgery note only 1% of eligible patients receive surgical treatment for obesity.6 A team from the University of Pittsburgh Medical Center Department of Surgery sought to investigate the impact of bariatric surgery on DM2 remission with funding from a National Institutes of Health grant.

 

Trial Description


Patients aged 25-55 years with DM2 and BMI = 30-40 kg/m2 were allocated to one of three treatment groups: Roux-en-Y gastric bypass surgery (RYGB), laparoscopic adjustable gastric banding surgery (LAGB), or intensive lifestyle intervention (ILI). Baseline demographics varied somewhat between the three groups with RYGB patients having more severe and long-standing diabetes, and higher levels of total cholesterol and low-density lipoprotein. The study population was predominantly caucasian (79%) and female (82%).

 

Table 1. Primary Outcomes
  DM2 Meds HbA1c FPG
Complete Remission None < 5.7 % < 100 mg/dL
Partial Remission None < 6.5 % < 125 mg/dL

 

667 patients were assessed for study eligibility, 69 patients were initially randomized to the three treatment arms, and 52 patients were available at 36 months for inclusion in the final analysis. All patients received a limited lifestyle intervention (LLI), consisting of twice monthly contact focused on behavioral topics related to weight loss, for entire study duration. LLI was initiated after surgery in the RYGB and LAGB groups, and in the second year in the ILI group.

 

Patients in the RYGB group were most likely to achieve complete or partial remission at 36 months. The authors reported a single p-value without a confidence interval for each primary outcome but did not explain which groups were compared to generate these values. A smaller proportion of patients in the LAGB group achieved complete or partial remission, while no patients in the ILI group satisfied remission criteria. The RYGB group saw improvements in every secondary outcome, including weight, BMI, cholesterol, and other cardiometabolic factors. Smaller and less uniform improvements occurred in the LAGB and ILI groups. This section of the results was also littered with objectionable p-values.

 

Table 2. Trial Results
 
RYGB (n=18)
LAGB (n=20)
ILI (n=14)
Complete Remission
15% (3)
5% (1)
0% (0)
Any Remission
40% (8)
29% (6)
0% (0)

 

Discussion


Bariatric surgery shows great promise in achieving complete or partial disease remission in patients with DM2 and BMI = 30-40 kg/m2. RYGB seems more likely than LAGB to help patients attain remission and uniform improvements in other cardiometabolic parameters. ILI alone may not assist a substantial portion of patients in obtaining clinically meaningful weight loss. While the long-term impact of DM2 remission after bariatric surgery on mortality is unclear, there is no doubt that disease remission is a patient-oriented outcome. Ambulatory care pharmacists should begin screening obese patients with DM2 for surgical intervention referral. Patients with BMI > 35 kg/m2 should be given priority, but those with BMI > 30 kg/m2 may also be considered.

 

Forum Prompts

  1. Study Design: Do you believe the methodology of this study to be sound? If so, do you find the results compelling?
  2. Risks vs. Benefit: Do the risks of surgical treatment (RYGB, LAGB) outweigh the benefit of achieving DM2 remission, decreasing risk of cardiovascular events, and accelerating weight loss for this patient population?
  3. Pharmacists’ Role: Do you agree that clinical pharmacists should be screening patients for bariatric surgery referral? Why or why not? How does this debate fit into the greater context of ambulatory care pharmacy services?
  4. Patient Eligibility: What BMI threshold should clinicians utilize when referring DM2 patients for surgical treatment? How should other comorbidities be weighed in this calculation?
 

References


  1. Danaei G, Finucane MM, Lu Y, et al. National, regional, and global trends in fasting plasma glucose and diabetes prevention since 1980: systematic analysis of health examination surveys and epidemiological studies with 370 country-years and 2.7 million participants. Lancet. 2011;378(9785):31.
  2. Centers for Disease Control and Prevention. National diabetes statistics report: estimates of diabetes and its burden in the United States, 2014. Atlanta, GA: U.S. Department of Health and Human Services; 2014.

  3. Ng M, Fleming T, Robinson M, et al. Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2014;384(9945):766.

  4. Yang L, Colditz GA. Prevalence of overweight and obesity in the United States, 2007-2012. JAMA Intern Med. 2015;175(8):1412.

  5. PL Detail-Document, Drugs for Weight Loss. Pharmacist’s Letter/Prescriber’s Letter. November 2014.

  6. 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 the American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery. Obesity. 2013;21(01):S1-27.