New diagnostic name for stigmatizing term obesity
The American Association of Clinical Endocrinologists (AACE) and American College of Endocrinology (ACE) proposed Adiposity-Based Chronic Disease (ABCD) is a new diagnostic term for obesity that explicitly identifies a chronic disease, alludes to a precise pathophysiological basis, and avoids the stigmata and confusion related to the differential use and multiple meanings of the term “obesity”.
The Obesity Problem.
The United States is in the midst of an obesity epidemic. This problem is complicated, prevalent, and not adequately addressed by current interventions (1-3). Pragmatically, the management of obesity, both for individuals and the population at large, can be approached by addressing three principal characteristics of obesity intervention: 1. Impact on Health: due to clinically relevant and progressive adiposity-based complications in many but not all patients; 2. Sustainability: related to costly, disease-oriented, fragmented, and varying health care infrastructures and the high prevalence of obesity; and 3. Therapeutic Nihilism: on the part of both health care professionals (HCP) and the general public, based on beliefs that patients with obesity will have poor responses to current efforts because obesity is solely a lifestyle choice rather than a chronic disease with important behavioral components. In this position paper, the American Association of Clinical Endocrinologists (AACE) and American College of Endocrinology (ACE) further evolve their blueprint to improve obesity care by presenting a new diagnostic term and conceptual framework.
Obesity as an Adiposity-Based Chronic Disease (ABCD).
“Obesity” is currently applied by most HCP, regulators, and third-party payers to any person with a body mass index (BMI) of 30 kg/m2 or greater. For the most part, the general public, and indeed most HCP, are confused about this definition and the related health implications of obesity since the diagnosis is based solely on an anthropometric measurement. In fact, in the 2014 AACE/ACE Consensus Conference on Obesity, participants representing four stakeholder pillars (biomedical; government/regulatory; health industry and economics; and professional organizations, education, and research) were unable to embrace “obesity” as an actionable term because the relationship of the term to the health of individuals was obscure (4).
Furthermore, the term obesity carries with it a great deal of stigmatization in the public domain that has negative implications pertaining to the personal character of patients with the disease, even after obesity was recognized as a disease state in 2012 (5). Patients with excess adiposity often harbor guilt from being overweight or obese (6). Indeed, the predominant sentiment associated with the term obesity in social media is derogatory and often cloaked in disparaging humor, invariably pointing to weight bias (7). Although the diagnosis of obesity is typically interpreted as being “bad” for one’s health, few recognize the far-reaching integrative physiology centering on body fat and affecting quality of life and longevity. The word “obesity” itself conveys little about the conditions associated with excess adiposity. Scientifically, BMI can be used as an office screening tool to estimate adiposity, but it is an anthropometric measure that clearly underperforms as a predictor of health and sole guide for clinical decision-making (8-10). Objections to the exclusive use of BMI as a screening tool or diagnostic term include, but are not limited to, varying cut-offs with different ethnicities, effect of increased or decreased muscle mass, and independent cardio-metabolic risks associated with waist circumference (WC). AACE/ACE has promoted a “complications-centric” approach to the diagnosis and management of patients with obesity (3,8,11).
However, a new nomenclature is warranted that conceptualizes obesity as a chronic disease state leading to characteristic adiposity-based complications, and encompasses a specific medical diagnostic term reflecting the adiposity-based pathophysiological process. The term “adiposity” directly refers to adipocytes and adipose tissue, which in the context of ABCD, incorporates an impact on health that can relate to quantity, distribution, and/or function of adipose tissue. The quantity of body fat mass can correlate with certain adverse clinical endpoints, or adiposity-based complications, but is inadequately reflected by BMI (8-10). Advanced body imaging promises a better means to assess adiposity, and investigational studies are underway (10,12).
The distribution of body fat also correlates with relevant pathophysiology, such as insulin resistance and inflammation. For example the relative accumulation of fat in the intra-abdominal depot, and accumulation of lipid within hepatocytes (i.e., non-alcoholic fatty liver and muscle cells, is linked to insulin resistance, development of type-2 diabetes, and cardiovascular disease. On the other hand, gluteo-femoral fat accumulation is independently associated with a protective effect on glucose- and lipid-related cardiometabolic risk (13-15). The functional attributes of fat are governed by the adipocyte secretome, as well as involving other cytokine, hormonal, and humoral factors, and will be delineated by emerging technologies in genetic/genomic analyses (16). Dysregulated secretion of these factors can affect multiple organ systems that correlate with adiposity-based complications. In short, adiposity is an encompassing term that offers advantages in health messaging and scientific research. A disease state results when the severity of abnormal adiposity translates into a physiological process and symptom burden through definable mechanisms.
Chronic disease occurs when a disease state persists for more than three months (defined by the National Center for Health Statistics ), and is characterized by adaptive and maladaptive processes, interacting and evolving toward a steady state, which may not be reached and which can obfuscate the primary etiology (18). For example, subtle changes in adiposity distribution can drive events that lead to metabolic syndrome, increased body weight, vascular inflammation, heart disease, and cognitive changes, eventually creating a complex medical state that conceals the initial problems with fat deposition. Hence, what has been generally termed obesity can now be reconsidered as an Adiposity-Based Chronic Disease (ABCD) based upon a preponderance of evidence (Figure 1) (3,4,8). This new terminology of obesity offers distinct opportunities to demystify the imprecise term “obesity” with a diagnostic term that describes the disease state. The clinical use of ABCD has the potential to promote improvements in patient care, appropriate screening for associated health co-morbidities, and structured treatment protocols. We propose that the term ABCD be used for medical diagnostic purposes and precise reference to the chronic disease state, with related disease stages, divested from the stigmata and ambiguity associated with the word obesity in the general public sphere.
The Central Role for Lifestyle Medicine.
By its very nature, chronic disease is complex and can be configured as a biological network of interactions and relationships (18). Obesity interventions targeting single pathways or mechanisms may be able to cause some scientifically predictable changes (19) but durable benefits are frequently elusive. The current treatment paradigm for obesity is to focus on weight loss (reducing the BMI and/or WC), and to identify and specifically treat adiposity-based complications. This is executed with often-meager attempts at achieving long-term healthy eating patterns and increased physical activity, as well as inconsistent use of pharmacotherapy and poorly defined clinician/patient thresholds for bariatric procedures. Lifestyle medicine is the non-pharmacological, non-surgical/ procedural management of chronic disease (Table 1) (18). With reference to the ABCD term in a complications-centric framework of care, lifestyle medicine offers the advantage of exerting a broad set of network based interventions. However, the optimal application of lifestyle medicine in clinical practice requires scientific study and validation, much more effort in HCP education and training for standardized evidence-based protocols, and clinical implementation and monitoring with fair reimbursement strategies. Lifestyle medicine will need to address the classic prevention stages of chronic disease management: primordial (decreasing disease risk on a population level), primary (decreasing disease in patients at-risk), secondary (decreasing complications in patients with early disease), and tertiary (decreasing morbidity and mortality in patients with complications and/or late disease) (3). Furthermore, the conversational message of lifestyle medicine is framed positively as promoting “health”, can be applied to all patients with any disease type or stage, includes human behavior, social reform, and environmental change, and should be adopted by an entire HCP team (20,21). C. Standardization of ABCD Complications-Centric Protocols.
The AACE/ACE obesity chronic care model
The model consists of four main parts: contextualization (healthy environment and reformed health care system), a prepared obesity practice, a motivated or “activated” patient, and assessment of outcomes (individual and population-based with subsequent innovations) (3). Pragmatically, there are several key actions for comprehensive patient care using the ABCD term. First, the patient must be “activated” for change by implementing proven behavioral medicine skills. Patient activation is the linchpin for managing ABCD as a complex clinical problem, and this aspect of behavioral medicine needs to be a focus of medical education. Next, the relevant drivers and associated abnormalities in adipose tissue need to be identified pertaining to mass, distribution, and function (e.g., increased fat mass [history and physical examination], insulin resistance and ectopic lipid [using available biochemical testing and imaging], and adipose tissue inflammation and abnormal secretory function affecting cardiovascular and metabolic disease risk [may require laboratory testing not widely available]). In addition, an evaluation of the risk, presence, and severity of adiposity-based complications within the AACE/ACE framework ) should be performed (i.e., stage 0 ABCD has no identifiable adiposity-based complications, stage 1 has mild to moderate adiposity-based complications, and stage 2 has severe adiposity-based complications). And lastly, an individualized care plan needs be designed that always includes structured lifestyle change, and can include pharmacotherapy, endoscopic procedures, or bariatric surgery based on the presence and severity of adiposity-based complications, as well as the degree of weight loss needed to ameliorate adiposity-based complications (ranging from at least 3% to over 15% depending on the specific adiposity-based complications ).
Unfortunately, evidence-based protocols to specifically address ectopic lipid and an abnormal adipocyte secretome are currently lacking (AACE/ACE has published management recommendations for lipodystrophy, which is related to ABCD based on the hypothesis that dysfunctional fat deposition with decreased or absent areas of adipose tissue increases the risk for ectopic lipid deposition, insulin resistance, and the metabolic syndrome ). Subtle, evidence-based decision-making for specific adiposity-based complications in various real-life settings is provided in the AACE/ACE obesity CPG (3); however, portfolios of more specific ABCD protocols will need to be standardized. that they can have the desired broad and significant impact on both individual and population based health promotion. The translation of specific abnormalities of adipose tissue into the clinical presentation and care plan requires intermediation or contextualization (Figure 1) taking into account both the physical (“built” or human-made) and nonphysical (e.g., culture, beliefs, customs, and sociopolitical-economic) environment (Table 2). Realistically, in order for standardized, evidence based protocols to be implemented successfully, they must be adapted for the patient within their unique context. In fact, the transculturalization process, which adapts evidence-based recommendations from one culture and/or ethnicity to another, and recently implemented by AACE/ACE in Latin America (23), is inherently part of personalized/precision medicine, and will be included in care strategies using the ABCD term. D. Strategies and Tactics for Successful ABCD Implementation.
The approach to care of patients with obesity has made enormous strides forward in recent years, but current management is still sub-optimal, perhaps due to poor coordination of medical care with the legislative-regulatory environment, as well as problems with public education, health care access, and stigmatization (24). AACE/ACE is dedicated to advancing preventive and therapeutic practices for obesity that improve health for all people, and believe that the adoption of ABCD as a precise pathophysiological term referring to the medical diagnosis of obesity and importance of addressing body fat and related adiposity-based complications will advance this goal. Strategically, this ABCD conceptual approach is not a rebranding of obesity per se, but a novel approach that incorporates better health messaging for HCP and patients. This approach spans primordial/primary prevention to decrease the risks and adverse effects of abnormal adiposity mass, distribution, and/or function, to secondary/tertiary prevention to decrease the risks and adverse effects of adiposity-based complications. For instance, special populations, such as children, adolescents, and young adults who are metabolically healthy will need to be screened for adiposity derangements so appropriate protocols can be initialized to prevent adiposity-based complications.
The ABCD approach includes formal behavioral science and is in adherence with the AACE/ACE obesity chronic care model and CPG, which prioritize patient activation for change, practice preparedness, protocol formulation with standardization, and relevant contextual adaptions. AACE/ACE also endorses a continued, concerted, and vigorous effort regarding health policy and the legislative agenda pertaining to reimbursement for structured lifestyle medicine and indeed all evidence-based therapeutic modalities for patients with ABCD. Tactically, to continue to address the obesity epidemic beyond CPG, AACE/ACE is developing varied and enduring educational materials (e.g., web-based, printed, and face-to-face) and conferences, and with its partner professional organizations, continues to press on with legislative and regulatory initiatives at the local, state, and federal levels (see www.aace.com). More specifically, AACE/ACE will spearhead clear definition and positioning of ABCD in the human disease ontology database (25) and then creation of relevant complication-based ICD-10 coding to facilitate HCP reimbursements, routine implementation, and realizable quality metrics.
However, a major challenge to using the ABCD term is identification of appropriate, available, and affordable markers/metrics reflecting the impact of adiposity on health. To be clear, the ABCD approach does not eliminate BMI as this computation still confers value for many patients with excess adiposity. However, further research is needed that can now focus on specific tools to quantitate derangements in adiposity mass, distribution, and function. Overall, to combat this prevalent, chronic, and injurious disease, HCP will need to incorporate a conceptual approach to management that goes beyond a singular focus on BMI. The adoption of the new ABCD diagnostic term is a clear step forward.
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