Sarcopenic obesity (SO)…you’ve probably heard of it. But can you define it? If you’re struggling to think of the diagnostic criteria for sarcopenic obesity, you’re not the only one. In fact, we’ve gone without a formal definition or diagnostic criteria for quite some time.
Obesity is characterized by the presence of a high body fat percentage. On the other hand, sarcopenia is characterized by low skeletal muscle mass accompanied by low muscle function. Both of these conditions have a bidirectional interaction with each other but are clinically different.
What is sarcopenic obesity?
Sarcopenic obesity is, as the name suggests, the coexistence of excess adiposity and low muscle mass and function. When these conditions coexist, negative interactions may lead to a synergistically higher risk for metabolic disease and functional impairment compared to those caused by each condition separately. SO has consistently been shown to be a strong risk factor for frailty, comorbidities, and mortality.
While sarcopenic obesity has been shown to negatively impact health, the lack of a universally accepted definition and diagnostic criteria has slowed progress on prevention and treatment strategies. The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) recently tried to close this gap with their consensus statement published in 2022. They proposed that sarcopenic obesity be simply defined as the coexistence of obesity and sarcopenia. They additionally gave recommendations on how to screen and diagnose sarcopenic obesity in hopes to guide future research and prevention strategies.
Based on the definition, screening should occur in individuals with a suspected concomitant presence of excess adiposity and decreased muscle mass. Excess adipose tissue can present as an elevated body mass index (BMI) or waist circumference, as defined by the World Health Organization and National Institute of Health cutoff points, respectively.
Clinical symptoms are used to screen for the presence of sarcopenia and can include any report of decreased muscle mass or function or risk factors known to lead to decreased muscle mass or function. Examples include repeated falls, reports of limited mobility, recent acute diseases impacting a patient’s nutrition status, or chronic inflammatory disease states. This information can be gathered from discussion with your patient and chart review. Alternatively, a validated questionnaire such as SARC-F can be used.
Diagnosis and Staging
Following a positive screening result in both categories, diagnosis to confirm SO should be conducted. Skeletal muscle strength can be tested by handgrip strength, knee extensor strength, or a chair-stand test. Body composition analysis can be completed by dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), or computerized tomography (CT).
If both altered body composition and altered skeletal muscle function parameters are present, a diagnosis of sarcopenic obesity is confirmed and can be staged as follows:
- Stage 1: no complications present
- Stage 2: presence of at least one complication attributable to SO. This can include metabolic diseases, cardiovascular disease, respiratory disease, functional disabilities, etc.
The new consensus statement from ESPEN and EASO will help shape clinical efforts directed toward managing sarcopenic obesity. Talk with your healthcare facility about what can be done to identify and treat patients with sarcopenic obesity.
With a new definition in place and diagnostic criteria established, progress can be made on further treatment and prevention strategies. Of course, there is still more to be done. Validated reference parameters for many of the diagnostic categories need to be established and universally accepted, and further research is needed to detail how to effectively treat sarcopenic obesity. Nevertheless, dietitians will undoubtedly be an integral part in the treatment plan through personalized nutrition interventions.
Lyncoln Nardo, MS, RD, LD, CNSC is a clinical dietitian from Virginia. She has over six years of experience caring for surgical patients, where her passion is providing enteral and parenteral nutrition support to critically ill patients. Beyond patient care, she enjoys working with dietetic interns and healthcare providers via classes, conferences, and creating nutrition protocols to facilitate best-care practices.
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Donini LM, Busetto L, Bischoff SC, et al. Definition and diagnostic criteria for Sarcopenic Obesity: Espen and EASO consensus statement. Obesity Facts. 2022;15(3):321-335. doi:10.1159/000521241