Tuesday, January 10, 2017

What's in a name? Obesity, ABCD, and prediabetes

- Kenny Lin, MD, MPH

A recent position statement from the American Association of Clinical Endocrinologists and the American College of Endocrinology proposed replacing obesity with the term "adiposity-based chronic disease," or ABCD for short. The authors argued that this new term emphasizes that most persons with obesity will struggle with weight gain for their entire lives; encourages a complications-centric as opposed to body mass index-based management approach; and "avoids the stigmata [sic] and confusion" associated with obesity in popular culture. They also asserted that ABCD is more amenable to interventions based on the Chronic Care Model, which explicitly recognizes that screening and office-based management need to be adapted to the patient's unique environment.

None of these concepts should surprise family physicians, though, and after reading through the AACE/ACE statement, I was not sold on the benefits of the new term. Some patients with body mass indexes above 30 don't like the obesity label, but would they respond any more positively to the disease acronym ABCD? There are potential harms to consider, too. One of my AFP physician colleagues felt that the new term was "intimidating" and "not at all patient centered," while another thought that it "only hides the issue [of obesity] instead of confronting it."

This discussion brought to mind another medical term often associated with overweight and obese patients: prediabetes. On one hand, being classified as "prediabetic" or at risk for this exceptionally common diagnosis may motivate obese patients to lose weight through improved diet and physical activity. On the other, the term prediabetes is misleading: many of these patients will not develop diabetes, and the diagnostic accuracy of the most common screening tests (hemoglobin A1c and fasting glucose levels) is poor, according to a systematic review published in the BMJ. Due to the tests' low sensitivity and specificity, some persons are incorrectly diagnosed with prediabetes, and others who might actually benefit from interventions to prevent diabetes are falsely reassured. Therefore, the review authors concluded, "'screen and treat' policies alone are unlikely to have substantial impact on the worsening epidemic of type 2 diabetes."

For all its limitations, obesity is a diagnosis with well-established clinical utility. It is less clear how many patients have been helped (or harmed) by being diagnosed with prediabetes. With more study, adiposity-based chronic disease might someday become a useful term, but the current case for more widespread use is unconvincing.