According to a study published in an online edition of the New England Journal Medicine (NEJM), bariatric surgery is significantly more effective at treating individuals with severe type 2 diabetes than standard medical treatment.

The study, the first of its kind, was conducted by researchers from the Catholic University/Policlinico Gemelli in Rome, Italy, and NewYork-Presbyterian/Weill Cornell Medical Center.

The researchers found that the majority of study participants who were randomly assigned to receive bariatric surgery were able to stop using diabetes medications, and also maintained disease remission for the two-year study period, compared with 0 participants in the standard medical treatment group.

Senior author Dr. Francesco Rubino, chief of Gastrointestinal Metabolic Surgery and director of the Metabolic and Diabetes Surgery Center at NewYork-Presbyterian/Weill Cornell and associate professor of surgery at Weill Cornell Medical College, explained:

“Although bariatric surgery was initially conceived as a treatment for weight loss, it is now clear that surgery is an excellent approach for the treatment of diabetes and metabolic disease.”

Treating obese patients who have type 2 diabetes can be challenging as insulin therapy as well as other hypoglycemic medications frequently result in further weight gain. In this study, the majority of participants saw improvements in blood sugar levels, improved HDL-cholesterol concentrations, as well as decreased total cholesterol and triglycerides. These results indicate that bariatric surgery for the treatment of diabetes may lower a patient’s cardiovascular risk.

Lead author of the study, Dr. Geltrude Mingrone, chief of the Division of Obesity and Metabolic Diseases and professor of medicine at Catholic University in Rome, said:

“The unique ability of surgery to improve blood sugar levels and cholesterol levels as well as reduce weight makes it an ideal approach for obese patients with type 2 diabetes.”

The researchers conducted the study in order to assess remission of diabetes in 60 severely obese patients (those with a body mass index [BMI] greater than 35) with advanced diabetes. The 60 participants were aged between 30 to 60 years.

They randomly assigned participants to one of three groups:

  • One group of participants received Roux-en Y gastric bypass (RYGB)
  • One group underwent bilopancreatic diversion (BPD)
  • The standard therapy group – they received tailored medication treatment and were monitored rigorously

Since the start of the study, no participants in the medical-therapy group has gone into remission. Remission is defined as fasting glucose lower than 100 mg and hemoglobin A1c (HbA1c) of less than 6.5% for at least one year. The researchers found that diabetes remission occurred and has been maintained in 75% of participants receiving RYGB and 95% of patients who underwent BPD.

According to the researchers age, gender, duration of diabetes, preoperative BMI as well as weight-loss after surgery were not predictors of diabetes remission.

Dr. Mingrone, explained:

“These findings confirm that the effects of bariatric surgery on type 2 diabetes may be attributed to the mechanisms of surgery rather than the consequences of weight loss. Studying the actual mechanisms by which surgery improves diabetes may help understand the disease better.”

At present, the majority of bariatric operations throughout the world are performed according to 1991 U.S. National Institutes of Health guideline’s. The guideline’s indicate that the surgery should not be performed on individuals with type 2 diabetes who have a BMI greater than 35 kg m-2.

Dr. Rubino, said:

“BMI is correlated with the risk of developing diabetes in the general population; in an individual, however, BMI does not tell much about the severity of diabetes, its potential to cause complications or the mechanisms of disease.

The study confirms that using strict cut-off BMI levels to define eligibility for surgery in patients with diabetes is medically inappropriate and that there is an urgent need to define better criteria for patient selection.”

Results from earlier studies conducted by Dr. Rubino support the use of surgery as a diabetes treatment, including in patients who are less obese, as gastronintestinal bypass procedures, such as BPD and RYGB, trigger direct, weight-independent mechanisms of diabetes control.

At NewYork-Presbyterian/Weill Cornell Medical Center, researchers are currently conducting a randomized trial comparing gastric bypass surgery and best medical treatment in participants with BMI between 26 to 35.

Written by Grace Rattue