Bariatric Surgery To Prevent Type 2 Diabetes: Good Medicine?

A study appearing in the 23 August 2012 issue of the New England Journal of Medicine is sure to incite some debate about the value and the ethical considerations of surgical intervention as a preventive measure with regard to type 2 diabetes.

In the study, Swedish researchers investigated the effects of bariatric surgery on the prevention of type 2 diabetes. This was a non-randomized but case-matched, prospective study that began in 1987. It initially included 1,658 patients who underwent bariatric surgery and 1,771 obese matched controls. None of the participants had diabetes at baseline.

Patients who had bariatric surgery had one of three types:

• Banding (19%)
• Vertical banded gastroplasty (69%)
• Gastric bypass (12%)

All participants were between 37 and 60 years old.

In Men, the body-mass index was at least 34.
In women, it was at least 38.

At the first 15 year follow-up, a sizeable number of participants had dropped out (over 36%) and another 30 percent had enrolled later, causing them to not yet have reached the time to follow-up.

Nonetheless, the results were startling: During the follow-up period, type 2 diabetes developed in 392 people who were in the control group.

It developed in just 110 people in the bariatric-surgery group.

Researchers conclude that "Bariatric surgery appears to be markedly more efficient than usual care in the prevention of type 2 diabetes in obese persons."

Accompanying Editorial: "Don't Get Too Excited."

Results such as this inevitably call forth the accompanying editorial, and in this case it is provided by Dr. Danny Jacobs, a surgeon at Duke University (Bariatric Surgery—From Treatment of Disease to Prevention? N Engl J Med 2012;367:764-765.).

He notes that this study defied at least one of the criteria set forth for bariatric surgery by the National Institutes of Health (NIH)—notably, that the patients have a BMI of at least 40, although patients whose BMI was 35 but who had existing medical issues could be considered as well. The criteria established weren't pulled from nowhere; they were designed to acknowledge the health risks associated with obesity—coronary artery disease, sleep apnea, and type 2 diabetes, to name a few.

However, while admitting that the results of this study are "provocative and exciting", he has a far more measured conclusion:

"…it remains impractical and unjustified to contemplate the performance of bariatric surgery in the millions of eligible obese adults. And to be certain, the authors do not suggest such an approach. Rather, the current study should provide an impetus to develop a more complete understanding of the mechanisms by which the various bariatric procedures exert their beneficial effects. Such understanding will be important because it will enable the identification of the persons who are the most appropriate candidates for surgery. The cause of type 2 diabetes is multifactorial, and this long-term study shows that surgery did not prevent the development of diabetes in all patients. Furthermore, it is possible that interventions that are even less invasive may accomplish the very desirable goal of decreasing the incidence of type 2 diabetes and its attendant complications."

What do you think? Is bariatric surgery a reasonable way to prevent type 2 diabetes, or is it too risky?