Bariatric weight-reduction surgery, long considered a treatment option largely reserved for severe obesity cases, may also be a safe and effective option for the treatment of uncontrolled type 2 diabetes in persons who are overweight or have mild to moderate obesity, according to researchers at the Cleveland Clinic in Cleveland, Ohio.

The Cleveland Clinic investigators’ findings were presented at ObesityWeek 2015, the largest international event focused on the basic science, clinical application, and prevention and treatment of obesity, held in Los Angeles, California, November 2–7, and reported in an American Society for Metabolic and Bariatric Surgery (ASMBS) paper entitled “Bariatric surgery is safe option for managing type 2 diabetes in overweight or mildly obese patients“ in the Nov. 5, 2015, edition of ScienceDaily.

The annual ObesityWeek conference is hosted by the American Society for Metabolic and Bariatric Surgery (ASMBS) — the largest organization for bariatric surgeons in America — and The Obesity Society (TOS).

The Cleveland Clinic scientists say this study is the largest ever-published series on bariatric surgery in patients with type 2 diabetes and body mass index (BMI) of 35 kg/m2 or less. The researchers studied 1,003 patients from North America with BMIs of between 25 and 35, with an average BMI among study participants of 33.5 kg/m2. Forty-six patients had a BMI of 30 or less. All had weight-loss surgery, or what is known as bariatric or metabolic surgery, between 2005 and 2013. Four-in-10 patients were taking insulin injections and 60 percent were on oral medications for diabetes prior to undergoing surgery. Data was obtained from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.

“Bariatric surgery is emerging as a safe and effective option for managing type 2 diabetes in patients with mild obesity,” says lead study author Ali Aminian, MD, a Laparoscopic and Bariatric Surgeon at the Cleveland Clinic Digestive Disease Institute in an ASMBS release. “We are seeing significant improvement or remission of type 2 diabetes in most lower BMI patients. Current evidence suggests that baseline BMI is unrelated to diabetes remission following bariatric and metabolic surgery. Our data, which is from a large sample size of patients with type 2 diabetes, shows a modest early morbidity (4%) and low mortality (0.2%) following bariatric surgery in non-severely obese patients. These data are important because most patients with diabetes fall into this BMI category.”

National Institutes of Health (NIH) guidelines categorize a person as overweight with BMI between 25 and 30, and obese with BMI of 30 or greater. The severe obesity threshold is at BMI 35 kg/m2. The NIH guidelines, which ASMBS notes have not been updated since 1991, consider surgery an option only for patients with a BMI of 35 or more accompanied by one or more obesity-related conditions such as diabetes, or a BMI of greater than 40.

The ASMBS cites Centers of Disease Control and Prevention (CDC) data estimating that more than 78 million adults were obese in 2011–12, about 24 million of whom have severe or morbid obesity. They note that individuals with a BMI greater than 30 have a 50 to 100 percent increased risk of premature death compared to healthy weight individuals, as well as an increased risk of developing more than 40 obesity-related diseases and conditions, including type 2 diabetes, heart disease and cancer.

Dr. Aminian observes that the field of bariatric surgery has significantly evolved over the last quarter-century, with the introduction of new, less-invasive surgical approaches (e.g., laparoscopic surgery) and surgical procedures (e.g., sleeve gastrectomy) that have led to an improved safety profile for the surgery.

The Cleveland Clinic study showed bariatric and metabolic surgery having a high degree of safety in lower BMI patients in operations that included gastric bypass (57%), gastric banding (23%), sleeve gastrectomy (19%) and duodenal switch (1%). The 30-day postoperative mortality rate was 0.2 percent and the cumulative rate of 16 postoperative adverse events was 4 percent. The surgical procedures averaged about two hours in duration with patients discharged from hospital within two days.

“A two-hour operation and a two-day hospital stay has the potential to resolve or improve what is a chronic, progressive and dangerous disease,” says John M. Morton, president of the ASMBS and Chief of Bariatric and Minimally Invasive Surgery at Stanford University School of Medicine in Palo Alto, California, who was not involved in the study. “The risk-benefit profile that has emerged for bariatric surgery in people with type 2 diabetes and low BMIs is very favorable and should be considered as a treatment option in carefully selected patients.”

Last year, Cleveland Clinic researchers presented another study (Published in the Diabetes, Obesity & Metabolism journal 2015; 17(2):198-201) finding a 30-day complication rate associated with metabolic surgery, specifically gastric bypass in patients with type 2 diabetes and BMIs of 35 or more, of 3.4 percent — about the same rate as with laparoscopic cholecystectomy (gallbladder surgery) and hysterectomy. Hospital stays and readmission rates were similar to laparoscopic appendectomy. The monthlong mortality rate for metabolic or diabetes surgery was 0.3 percent, similar to that of total knee replacement, and about one-tenth the risk of death after cardiovascular surgery.

The ASMBS release notes that previous studies have shown that metabolic and bariatric surgery improves type 2 diabetes in nearly 90 percent of patients and diabetes goes into remission in up to 50 percent.

In addition to Dr. Aminian, study authors of the abstract entitled, “A Nationwide Safety Analysis of Bariatric Surgery in Nonmorbidly Obese Patients with Type 2 Diabetes” include John Kirwan, PhD; Bartolome Burguera, MD, PhD; Stacy Brethauer, MD; and Philip Schauer, MD, all from Cleveland Clinic.

For more information, visit:
http://www.asmbs.org

Other resources:

Prevalence of Obesity Among Adults: United States, 20112012. Center for Disease Control and Prevention. (October 2013). http://www.cdc.gov/nchs/data/databriefs/db131.htm

Office of the Surgeon General U.S. Department of Health and Human Services. Overweight and obesity: health consequences. http://www.surgeongeneral.gov/topics/obesity/calltoaction/fact_consequences.html

Kaplan, L. M. (2003). Body weight regulation and obesity. Journal of Gastrointestinal Surgery. 7(4) pp. 443-51. Doi:10.1016/S1091-255X(03)00047-7.

Poirier, P., Cornier, M. A., Mazzone, T., et al. (2011). Bariatric surgery and cardiovascular risk factors. Circulation: Journal of the American Heart Association. 123 pp. 1-19. http://circ.ahajournals.org/content/123/15/1683.full.pdf

Flum, D. R. et al. (2009). Perioperative safety in the longitudinal assessment of bariatric surgery. New England Journal of Medicine. 361 pp.445-454. http://content.nejm.org/cgi/content/full/361/5/445

Sources:
ASMBS
Cleveland Clinic
ObesityWeek 2015