A Cure for Diabetes?

Can Bariatric Surgery ‘Cure’ Diabetes?

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According to two new studies published in the New England Journal of Medicine, obese patients with diabetes had better glycemic control following bariatric surgery plus intensive medical management than a control group who received intensive medical management alone.

In the STAMPEDE trial,[1] a total of 150 patients with a mean body mass index (BMI) of 36 were randomized to one of three treatment groups: intensive medical therapy only (IMT; n=41); medical therapy plus Roux-en-Y gastric bypass (n=50); or medical therapy plus sleeve gastrectomy (n=49). IMT was defined as a combination of counseling, lifestyle changes, and medications. The primary endpoint of the study was the percentage of patients who achieved a hemoglobin A1c (HbA1c) level of ≤6.0. At 12 months, glycemic control had improved in all three groups with a mean HbA1c of 7.5% (IMT), 6.4% (gastric bypass), and 6.6% (sleeve gastrectomy). While there was no significant difference in the HbA1c improvement between the two surgery groups, 27% of the patients in the sleeve gastrectomy group required medications to achieve the targeted HbA1c levels compared with none in the gastric bypass group.

Overall, weight loss was fivefold greater in the gastric bypass group (-29.4 lbs) and the sleeve gastrectomy group (-25.1 lbs) compared with IMT (-5.4 lbs). Patients in both surgical groups required significantly fewer hypoglycemic medications following surgery; in comparison, the IMT group generally required more medications.

The second study[2] enrolled 60 obese patients between the ages of 30 and 60 with a BMI of at least 35. Patients had diabetes for at least five years and HbA1c of at least 7.0%. Patients were evenly randomized to IMT, gastric surgery via biliopancreatic diversion (BPD), or Roux-en-Y gastric bypass. The primary endpoint was the percentage of patients who achieved remission, defined as HbA1c ≤6.5%. In the two surgical groups, 75% (Roux-en-Y) and 95% (BPD) achieved remission, compared with no patients in the IMT group. Glycemic control improved in all three groups from a mean HbA1c of 8.65% to a mean of 7.69% (IMT), 6.35% (Roux-en-Y) and 4.95% (BPD). Of note is that baseline BMI, age, duration of diabetes, and weight changes did not predict HbA1c levels at months one and three or diabetes remission at two years. Because the study was small, it did not have the power to analyze safety or to detect differences in mortality rates or cardiovascular events.

While these are intriguing results, bariatric surgery is not likely to be a universal panacea for patients with type 2 diabetes—at least not yet. The overall quality of published evidence is weak to moderate, because the studies have included only small numbers of patients and relatively short follow-up periods. Perioperative surgical risks exist, particularly with BPD—a difficult procedure that is done much less frequently than the Roux-en-Y. Some patients may also develop micronutrient deficiencies or psychological problems after gastric bypass surgery. Despite these reservations, bariatric surgery is likely to see increasing prominence in diabetes management, particularly given its dramatic effect on glycemic control independent of weight loss. In fact, such procedures might well be considered earlier in the treatment of obese patients with type 2 diabetes.[3]

To help patients who may wonder if they’re good candidates for weight loss surgery or have general questions about the procedure itself, we’ve provided the following FAQ:

Who is an appropriate candidate for weight loss surgery?

  • Adults aged 18 to 60 who have a BMI over 40 (more than 100 pounds overweight)
  • Adults with a BMI between 35 and 40 (75 lbs overweight) and who have obesity-related medical complications, such as diabetes, heart disease, or sleep apnea
  • In early 2011, the FDA approved the use of gastric banding surgery in those with a BMI[4] of 30 or higher who have at least one obesity-related condition, such as diabetes
  • Those who have failed to lose weight by nonsurgical means (weight loss programs, diets, etc). Some insurance companies may require documentation of participation in at least one weight loss program
  • Those willing to commit to a lifelong change of proper diet, exercise, and medical follow up

What are the different types of surgeries?

Restrictive Procedures

Adjustable gastric banding. The least invasive surgery is adjustable gastric banding, which restricts the amount of food people can eat. A silicone gastric band with an inflatable inner collar (Lap-Band System; Realize Band) is placed around the upper stomach to restrict food intake. This creates a small pouch and a narrow passage to the lower stomach. This small passage delays the emptying of food from the pouch and causes a feeling of fullness. The band is connected by tubing to a reservoir, which is placed under the skin during surgery. After the operation, the surgeon can tighten or loosen the band over time by entering the reservoir with a fine needle through the skin.

Gastric banding physically restricts the amount of food people can take in at a meal. Most people can eat only a half to one cup of soft or well-chewed food before feeling too full or sick. Patients can generally expect to lose 50% of their excess weight over two years, but may have up to a 50% failure rate over the long term.[5]

Malabsorptive Procedures

Roux-en-Y. The Roux-en-Y gastric bypass is the most frequently performed of the malabsorptive weight loss surgeries in the United States and is considered the ‘gold standard’ of this type of procedure.[6]

In the Roux-en-Y procedure, the volume of the stomach is mechanically reduced. The intestines are rerouted and a small stomach pouch is created by stapling off the main body of the stomach. Food flows through this pouch, bypassing the main portion of the stomach and empties slowly into the small intestine where it is absorbed. The result of gastric bypass surgery is restricted food intake and reduced hunger to promote healthy weight loss.

Roux-en-Y offers the best balance between weight loss and risk of complications. On average, weight loss can average 65% to 80% of excess body weight 18 months after surgery and they should be able to maintain the weight loss for at least five years.

Gastric sleeve. In gastric sleeve surgery, about 60% of the stomach is removed, leaving behind a sleeve of stomach. This smaller stomach restricts the amount of food a patient can eat and leads to significant weight loss.

In some patients, the gastric sleeve procedure is performed instead of gastric banding or gastric bypass surgery. In others, especially those at higher surgical risk, it is offered as the first part of a two-stage surgical plan. As weight is lost following the gastric sleeve procedure—and patients become healthier—they can safely undergo either gastric bypass or gastric band for additional weight loss. Patients can expect to lose 60% to 70% of their excess weight at two years. In a fourth procedure—biliopancreatic diversion—portions of the stomach are removed and the bypass is attached to the distal ilium. This procedure is complicated and less widely used, because there is greater risk of nutritional deficiencies.

Most of the bariatric procedures are now done laparoscopically, which reduces the number and size of scars, healing time, hospital stay, and the risk of wound infection.

After surgery, can the patient eat whatever he or she wants?

Bariatric surgery is not a license to eat at will. The amount of food that patients can eat changes significantly. At maximum capacity (12-18 months after surgery), the ‘pouch’ can hold between 4 to 6 oz. of food, compared with approximately 4 cups of food prior to the surgery. Portions and serving sizes still count and a dietitian or nutritionist can suggest appropriate serving sizes. Patients should eat slowly and chew each bite very slowly and completely and swallow food only when it is smooth. Food that is not chewed well can block the small opening between the new stomach pouch and the intestines. You can advise your patients to follow these guidelines:

  • Eat six small meals throughout the day instead of three big meals. Do not snack between meals.
  • Take at least 30 minutes to eat a meal. Stop eating as soon as you are full.
  • To suppress hunger, eat foods with protein, rather than fat or carbohydrates.
  • Drink up to 8 cups of water or other calorie-free beverages.
  • Avoid foods that are high in calories.
  • Do NOT drink much alcohol.
  • Avoid beverages that have sugar, fructose, or corn syrup in them, or that are carbonated.

Is bariatric surgery approved for kids?

Mounting evidence suggests that bariatric surgery can favorably change both the weight and health of youth with extreme obesity.[7,8] However, experts in childhood obesity and bariatric surgery suggest that families consider surgery only after the child has tried for at least six months to lose weight and has not had success.

Candidates should meet the following criteria:

  • Have extreme obesity (BMI ≥40)
  • Be their adult height
  • Have serious health problems linked to weight—such as type 2 diabetes or sleep apnea—that may improve with bariatric surgery

In addition, young patients and their parents should be assessed for emotional readiness and the lifestyle changes they will need to make. They should also be referred to special youth bariatric surgery centers that focus on meeting the unique needs of youth.

Over the years, gastric bypass surgery has been the main operation used to treat extreme obesity in youth. A review of short-term data from the largest inpatient database in the United States suggests that these surgeries are at least as safe for youth as adults.[9] As of yet, gastric banding has not been approved for use in the United States for people younger than age 18. However, favorable weight loss outcomes after adjustable gastric banding for youth have been reported abroad.

Will medications need to change?

Some medications—such as those for diabetes and hypertension—may not be necessary in the months following surgery. The procedure will not affect the absorption of other medications and no dose change is typically required.

What does it cost?

Bariatric procedures, on average, cost from $20,000 to $25,000.[10] Medical insurance coverage varies by state and insurance provider, including Medicare. Bariatric surgery may be covered under these conditions:

  • If the patient has at least one health problem linked to obesity
  • If the procedure is suitable for the patient’s medical condition
  • If approved surgeons and facilities are involved

Have your patients can contact staff at their regional Medicare, Medicaid, or health insurance office to find out if the procedure is covered and to obtain facts about options.


Jill Shuman, MS, ELS
Published April 10, 2012



  1. Schauer PR, Kashyap SR, Wolski K, et al. Bariatric surgery versus intensive medical therapy in obese patients with diabetes [published online ahead of print March 26, 2012]. N Engl J Med. doi: 10.1056/NEJMoa1200225. http://www.nejm.org/doi/full/10.1056/NEJMoa1200225?query=featured_home.
  2. Mingrone G, Panunzi S, De Gaetano A, et al. Bariatric surgery versus conventional medical therapy for type 2 diabetes [published online ahead of print March 26, 2012]. N Engl J Med. 2012. doi: 10.1056/NEJMoa1200111. http://www.nejm.org/doi/full/10.1056/NEJMoa1200111.
  3. Inabnet WB III, Winegar DA, Sherif B, Sarr MG. Early outcomes of bariatric surgery in patients with metabolic syndrome: an analysis of the bariatric outcomes longitudinal database. J Am Coll Surg. 2012;214(4):550-556.
  4. FDA News Release: FDA expands use of banding system for weight loss. U.S. Food and Drug Administration Website. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm245617.htm. Updated March 3, 2011. Accessed April 12, 2012.
  5. Spivak H, Abdelmelek MF, Beltran OR, et al. Long-term outcomes of laparoscopic adjustable gastric banding and laparoscopic Roux-en-Y gastric bypass in the United States [published online ahead of print January 5, 2012]. Surg Endosc. doi: 10.1007/s00464-011-2125-z.
  6. Heber D, Greenway FL, Kaplan LM, et al. Endocrine and nutritional management of the post-bariatric surgery patient: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2010;95(11):4823-4843.
  7. Inge TH, Krebs NF, Garcia VF, et al. Bariatric surgery for severely overweight adolescents: concerns and recommendations. Pediatrics. 2004;114(1):217-223.
  8. Michalsky M, Reichard K, Inge T, et al. ASMBS pediatric committee best practice guidelines. Surg Obes Relat Dis. 2012;8(1):1-7.
  9. Tsai WS, Inge TH, Burd RS. Bariatric surgery in adolescents: recent national trends in use and in-hospital outcomes. Arch Pediatr Adolesc Med. 2007;161(3):217-221.
  10. Weight-control Information Network. Bariatric Surgery for Severe Obesity. Bethesda, MD: U.S. Department of Health and Human Services; Updated June 2011. NIH Pub No. 08-4006. http://win.niddk.nih.gov/publications/PDFs/Bariatric_Surgery_508.pdf.