Obesity Surgery in Diabetes Mellitus: A Three Year Trial Shows High "Cure Rates." The Implications for Population Health

In case there is any doubt about the long-term efficacy of obesity surgery for diabetes, check out this three year study that was just published by the New England Journal of Medicine. 150 persons between the ages of 20 and 60 years with an A1c greater than the recommended target of 7% and a BMI greater than 27 were randomly assigned to either gastric bypass, sleeve gastrectomy or intensive medical therapy. 8 persons dropped out after being assigned to medical therapy and one patient had their surgery cancelled. Over the next 3 years, 4 persons were lost to follow up.

Of the remaining participants, two thirds were women and three quarters were white. The mean age was 48 years, the average BMI was a prodigious 36 and the mean A1c was a poor 9.3%, with an average duration of diabetes of just over 8 years. 

Of the 40 medical patients, 5% ended up with an A1c of 6%, versus 38% of the 48 bypass and 24% of the 49 sleeve patients.  The average weight loss was 4.3 kg in the medical patients vs. 26 and 21 kg in the bypass and sleeve patients. While only 2% of medically treated patients were able to stop their diabetes medications, 69% and 43% of the bypass and sleeve patients were able to do so. Only four patients in the surgery groups required additional surgery for the treatment of complications.  None died.

The Population Health Blog finds the results compelling enough to believe that the surgical option for obesity-related diabetes mellitus may be turning out to be a first line option.  The complication rate is acceptably low and the "cure" rate of up to 70% (if defined as not having to take medications) is likely to be welcomed by patients facing a lifetime of otherwise chronic illness.

Criticisms?

Critics may worry that any long-term economic benefits at a population-based level may be cancelled by the cost of surgery.  The PHB understands that, but doesn't believe that obesity surgery should be viewed through a "return-on-investment" lens.  Rather, the value assessment of "outcome" (in terms of diabetes and obesity cure) per unit of cost (dollars spent) is a as good as an investment compared to, say, coronary artery bypass grafting or a knee replacement.

Critics may also worry that obesity surgery is more of a symptom of an overfed society and that our national treasure would be better spent on understanding our dietary dysfunctions.  The Population Health Blog cannot disagree, but doubts that our national health spending can be wired so that every dollar spent on the promotion of nutritional wisdom will reduce the near-term health care cost crisis from diabetes.  We need to be prepared to invest in both.

Implications for Population Health

It appears to the PHB that this was a single site "efficacy" study involving an academic medical center.  We don't know if the low complication rate observed here is typical of other hospitals that offer obesity surgery.  In addition, this study did not examine the impact of the more popular approach of banding surgery.  That being said, this three year trial suggests that bariatric surgery should be offered in the suite of options for persons meeting the criteria above.

The good news is that shared decision making has already been evaluated in this setting.  While the majority of participants are more likely to chose conservative treatment, the point is that a 40-70% chance of cure over three years should be raised in the course of patient-centric coaching.  Population health vendors in the diabetes-obesity "space" should be prepared to engage patients on this treatment option and help them decide if surgery is the right choice for them.

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