Miriam E. Tucker

May 17, 2014

LAS VEGAS, Nevada — A new definition of obesity that takes complications into account, along with body mass index (BMI), has been proposed by the American Association of Clinical Endocrinologists (AACE) and the American College of Endocrinology (ACE).

The 2014 Advanced Framework for a New Diagnosis of Obesity as a Chronic Disease was presented in a symposium here at the American Association of Clinical Endocrinologists (AACE) 23rd Annual Scientific and Clinical Congress.

"Regarding obesity as simply a number reflecting BMI to then dictate the way you manage it may be a good reason why, after so many years, the prevalence rates of overweight and obesity haven't changed much....What we're doing is rebooting the system, essentially," AACE president Jeffrey I. Mechanick, MD, clinical professor of medicine at Mt. Sinai School of Medicine, New York, said at a press briefing.

The framework is the latest step in an ongoing process to develop new approaches to obesity, based on the American Medical Association's June 2013 designation of it as a chronic disease, which originated with a proposal from the AACE. The need for a new obesity definition was among the major ideas to emerge from a consensus conference on the subject, held in March 2014, which involved participants from healthcare, research, science, government, industry, insurers, and advocacy, Dr. Mechanick said.

The new AACE white paper, which will now be sent to the consensus conference participants for input prior to publication, calls for staging patients on the basis of both BMI and number of obesity-related complications, then recommends a treatment approach based on that stage. The model includes use of the AACE obesity treatment algorithm that was published in April 2013 as part of the AACE diabetes algorithm.

"We're using weight-loss therapy to treat the complications of obesity in a medical model that's really designed to treat disease. It's not so much the additional BMI that's of primary importance, it's the degree to which that weight gain has impacted the health of the individual in terms of the presence and severity of obesity-related complications," W. Timothy Garvey, chair of the AACE/ACE Consensus Conference on Obesity and Obesity Scientific Committee and author of the AACE/ACE Obesity Consensus Statement, said at the briefing.

Setting the Stage: 5 Categories Proposed

The new approach involves classifying people into 1 of 5 categories:

  1. Normal weight (BMI < 25).

  2. Overweight (BMI 25–29.9, no obesity-related complications).

  3. Obesity stage 0 (BMI 30 or greater and no obesity-related complications).

  4. Obesity stage 1 (BMI 25 or greater* and the presence of 1 or more mild to moderate obesity-related complications).

  5. Obesity stage 2 (BMI 25 or greater* and the presence of 1 or more severe obesity-related complications).

*BMI 23–25 and elevated waist circumference in certain ethnic groups

Obesity-related complications include the following: metabolic syndrome; prediabetes; type 2 diabetes; dyslipidemia; hypertension; nonalcoholic fatty liver disease; polycystic ovary syndrome; sleep apnea; osteoarthritis; gastroesophageal reflux disease; and disability/immobility.

Recommended treatments include lifestyle modification for obesity stage 0; intensive lifestyle modification and behavior therapy, with or without medications, for obesity for stage 1; and intensive lifestyle modification/behavior therapy and medications, with consideration of bariatric surgery, for obesity stage 2.

"Our objectives were to create an actionable and medically meaningful diagnosis of obesity, something that would tell you what we are treating and why are we treating it," Dr. Garvey said.

Wide-Ranging vs Narrower Takes on the Same Problem

The new framework comes on the heels of the November 2013 publication of the 2013 Report on the Management of Overweight and Obesity in Adults from the US National Heart, Lung, and Blood Institute (NHLBI) — recommendations that were issued via the American College of Cardiology (ACC), the American Heart Association (AHA), and the Obesity Society (TOS).

Although there are similarities, the 2 differ in 2 main ways: the NHLBI AHA/ACC/TOS approach still relies on BMI for defining obesity and is strictly based on level 1 evidence, whereas the AACE's framework derives from varying levels of evidence and also expert opinion.

The 2 cochairs of the AHA/ACC/TOS writing committee largely praised the AACE's new proposal in a joint statement provided to Medscape Medical News.

"What’s good about this effort from AACE is that it also acknowledges the limitations of using BMI alone to assess health risks and urges physicians to consider whether the patient is suffering impacts of excess weight manifesting as chronic diseases," said Donna H. Ryan, MD, professor emerita at Louisiana State University's Pennington Biomedical Research Center, Baton Rouge, and Michael D. Jensen, MD, professor of medicine at the Mayo Clinic, Rochester, Minnesota.

They added that the AACE framework is concordant with the AHA/ACC/TOS guideline, "which clearly positions BMI as a screening tool and recommends more aggressive weight-loss efforts only for those overweight persons who have health risk factors or comorbidities."

Dr. Ryan and Dr. Jensen called the AACE's attempt to refocus attention from body size to overall health effects of excess body fat "a good thing; healthcare providers need to accept that good (or bad) health can come in a variety of body sizes and become more competent in helping patients succeed when they need to lose weight for health reasons. It's all about improving how people feel, function, and their health risk, not how they look."

However, they also noted the strengths of the guidelines they coauthored, which were based on an evidence review as recommended by the US Institute of Medicine.

"This was a stringent methodology designed to encourage rigor and eliminate bias to result in authoritative statements around a limited number of critical questions....The overwhelming strength of [the AHA/ACC/TOS guideline] is the authoritative information in 5 areas where healthcare providers need it and can help direct our public policy."

The AACE approach is wider ranging, they said, "and it therefore relies heavily on expert opinion to make such broad and comprehensive recommendations. [The AHA/ACC/TOS guideline] is much narrower in scope but speaks with great authority."

"Complications-Centric" vs "BMI-Centric"

Asked to comment on the AHA/ACC/TOS guidelines, Dr. Mechanick told Medscape Medical News that they represented "a BMI-centric approach, whereas AACE espouses a complications-centric approach....So, although we agree that obesity is a disease, we disagree that the basis of that definition should be a number. It should be a pathophysiologic correlate, like a risk for complication or stage of complication."

"They could only use level 1 evidence from prospective randomized trials. If you limit your conclusions to that much more contracted body of evidence, the conclusions are going to be substantively different than the way AACE does it. We look at an entire information base," he added.

During the briefing, Dr. Mechanick said that once this new AACE framework has been published, the next step will be to work on implementation.

"Our hope is that we can actually make a difference....Maybe the [American Medical Association] will buy into it, maybe Congress will buy into it with more antiobesity legislative acts. Once you get a critical mass with all this action, then a complex disease is managed in a complex fashion and you see a difference. We believe that obesity is a complex disease and is not effectively managed with simple solutions."

Dr. Mechanick has received honoraria from Abbott Nutrition for lectures and program development. Dr. Garvey reported consulting for Daiichi Sankyo, Liposcience, Takeda, Vivus, Boehringer Ingelheim, Janssen, Eisai, and Novo Nordisk and has received research funding from Merck, AstraZeneca, Weight Watchers, Eisai, and Sanofi. Dr. Ryan reports consulting for the following companies between 2008 and 2012: Alere Wellbeing, Amylin, Arena Pharmaceuticals, Eisai, Novo Nordisk, Nutrisystem, Orexigen, Takeda, and Vivus. During 2013, she consulted for Arena Pharmaceuticals, Eisai, Novo Nordisk, Takeda, and Vivus. Dr. Jensen has disclosed no relevant financial relationships for the period 2008–2012. In 2013, he consulted for Eisai, Novo Nordisk, and Vivus.

American Association of Clinical Endocrinologists (AACE) 23rd Annual Scientific and Clinical Congress. Presented May 16, 2014.


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