Patients with severe type 2 diabetes who undergo bariatric surgery have considerably better outcomes than those on standard medical treatment for the chronic disease, researchers from Italy and the USA reported in NEJM (New England Journal of Medicine). The authors added that the majority of bariatric surgery patients eventually did not need diabetes drugs, and went into complete remission for the 24-month duration of the study. This did not occur to any of those on standard medical treatment for diabetes type 2.

Senior author, Dr. Francesco Rubino, from NewYork-Presbyterian/Weill Cornell and Weill Cornell Medical College, said:

“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.”

Insulin therapy, as well as other hypoglycemic drugs, tend to make the patient put on weight; experts say this makes standard therapy “challenging”.

The researchers reported that the vast majority of the patients who underwent surgery had improvements in HDL-cholesterol concentrations, triglyceride and total cholesterol levels, as well as blood sugar levels, indicating that bariatric surgery reduces a diabetes type 2 patient’s cardiovascular risk.

Lead author Dr. Geltrude Mingrone, from the Catholic University, 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.”

In this study, 60 severely obese individuals, aged between 30 and 60 years, were randomly selected into three groups:

  • The RYGB (Roux-en-Y gastric bypass) group
    Roux-en-Y gastric bypass
    Diagram of a Roux-en-Y gastric bypass
  • The BPD (biliopancreatic diversion) group
    Biliopancreatic diversion
    Diagram of a biliopancreatic diversion
  • The Standard Care group (they had conventional individualized medication, strict dietary monitoring, as well as supervised lifestyle modification)

Since the beginning of the study, nobody in the Standard Care group has gone into remission, compared to 95% of those in the BPD group, and 75% in the RYGB group.

The researchers define remission as (at least one year of..):

  • Fasting glucose of under 100 mg
  • HbA1c (hemoglobin A1c) of less than 6.5%

The authors added that the following were NOT diabetes remission predictors: weight-loss after surgery, diabetes duration, BMI before surgery, sex, and age.

Dr. Mingrone said:

“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.”

Current bariatric surgery procedures among patients with diabetes type 2 are limited for those whose BMIs are greater than 35.

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.”

According to previous studies led by Dr. Rubino, gastrointestinal bypass surgeries, such as BPD and RYGB “activate direct, weight-independent mechanisms of diabetes control, supporting the use of surgery as a diabetes treatment, including in less obese patients.”

A currently ongoing study, being carried out at NewYork-Presbyterian/Weill Cornell Medical Center, is comparing best medical treatment with gastric bypass surgery for individuals with a BMI of 26 to 35.

It is estimated by WHO (World Health Organization) that approximately 8.3% of adults worldwide have diabetes type 2. Over the next two decades they say the prevalence will probably rise to nearly 10%. Over one-fifth of morbidly obese adults have diabetes type 2.

Diabetes type 2 represents a large and growing part of health care systems’ expenditures. Previous studies indicate that bariatric surgery may not only provide health solutions, but economic ones as well for health systems.

The authors explain that, unfortunately, access to these types of surgeries is very limited, as are the criteria for eligibility. In the USA, less than 2% of eligible individuals have access to bariatric/metabolic surgery – in other parts of the world the percentage is even lower.

Hopefully, this study will change the general perception of bariatric surgery.

Written by Christian Nordqvist