Background: Body mass index (BMI) is the most widely used measure to diagnose obesity. However, the accuracy of BMI in detecting excess body adiposity in the adult general population is largely unknown. Methods: A cross-sectional design of 13 601 subjects (age 20-79.9 years; 49% men) from the Third National Health and Nutrition Examination Survey. Bioelectrical impedance analysis was used to estimate body fat percent (BF%). We assessed the diagnostic performance of BMI using the World Health Organization reference standard for obesity of BF%425% in men and435% in women. We tested the correlation between BMI and both BF% and lean mass by sex and age groups adjusted for race. Results: BMI-defined obesity (X30 kg m À2 ) was present in 19.1% of men and 24.7% of women, while BF%-defined obesity was present in 43.9% of men and 52.3% of women. A BMIX30 had a high specificity (men ¼ 95%, 95% confidence interval (CI), 94-96 and women ¼ 99%, 95% CI, 98-100), but a poor sensitivity (men ¼ 36%, 95% CI, 35-37 and women ¼ 49%, 95% CI, 48-50) to detect BF%-defined obesity. The diagnostic performance of BMI diminished as age increased. In men, BMI had a better correlation with lean mass than with BF%, while in women BMI correlated better with BF% than with lean mass. However, in the intermediate range of BMI (25-29.9 kg m À2 ), BMI failed to discriminate between BF% and lean mass in both sexes. Conclusions: The accuracy of BMI in diagnosing obesity is limited, particularly for individuals in the intermediate BMI ranges, in men and in the elderly. A BMI cutoff ofX30 kg m À2 has good specificity but misses more than half of people with excess fat. These results may help to explain the unexpected better survival in overweight/mild obese patients.

The prevalence of obesity in combination with sarcopenia (the age-related loss of muscle mass and strength or physical function) is increasing in adults aged 65 years and older. A major subset of adults over the age of 65 is now classified as having sarcopenic obesity, a high-risk geriatric syndrome predominantly observed in an ageing population that is at risk of synergistic complications from both sarcopenia and obesity. This Review discusses pathways and mechanisms leading to muscle impairment in older adults with obesity. We explore sex-specific hormonal changes, inflammatory pathways and myocellular mechanisms leading to the development of sarcopenic obesity. We discuss the evolution, controversies and challenges in defining sarcopenic obesity and present current body composition modalities used to assess this condition. Epidemiological surveys form the basis of defining its prevalence and consequences beyond comorbidity and mortality. Current treatment strategies, and the evidence supporting them, are outlined, with a focus on calorie restriction, protein supplementation and aerobic and resistance exercises. We also describe weight loss-induced complications in patients with sarcopenic obesity that are relevant to clinical management. Finally, we review novel and potential future therapies including testosterone, selective androgen receptor modulators, myostatin inhibitors, ghrelin analogues, vitamin K and mesenchymal stem cell therapy.

Older women with sarcopenia have an increased all-cause mortality risk independent of obesity.

Prevalence of sarcopenic obesity in older adults varies up to 26-fold depending on current research definitions. Such a high degree of variability suggests the need to establish consensus criteria that can be reliably applied across clinical and research settings.

Background Body composition changes with aging lead to increased adiposity and decreased muscle mass, making the diagnosis of obesity challenging. Conventional anthropometry, including body mass index (BMI), while easy to use clinically may misrepresent adiposity. We determined the diagnostic accuracy of BMI using dual energy x-ray absorptiometry (DEXA) in assessing the degree of obesity in older adults. Methods The National Health and Nutrition Examination Surveys 1999–2004 were used to identify adults aged ≥60years with DEXA measures. They were categorized (yes/no) as having elevated body fat by gender (men≥25%; females ≥35%) and by body mass index (BMI) ≥25 and ≥30kg/m2. The diagnostic performance of BMI was assessed. Metabolic characteristics were compared in discordant cases of BMI/body fat. Weighting and analyses were performed per NHANES guidelines. Results We identified 4,984 subjects (men:2,453; female:2,531). Mean BMI and % body fat was 28.0kg/m2 and 30.8% in men, and 28.5kg/m2 and 42.1% in females. A BMI ≥30kg/m2 had a low sensitivity and moderately high specificity (men:32.9% and 80.8%, concordance index 0.66; females:38.5% and 78.5%, concordance 0.69) correctly classifying 41.0 and 45.1% of obese subjects. A BMI ≥25kg/m2 had a moderately high sensitivity and specificity (men:80.7% and 99.6%, concordance 0.81;females:76.9% and 98.8%, concordance 0.84) correctly classifying 80.8 and 78.5% of obese subjects. In subjects with BMI<30kg/m2 body fat was considered elevated in 67.1% and 61.5% of males and females, respectively. For a BMI≥30kg/m2, sensitivity drops from 40.3 to 14.5% and 44.5 to 23.4%, while specificity remains elevated (>98%),in males and females, respectively in those 60–69.9years to subjects aged ≥80years. Correct classification of obesity using a cutoff of 30kg/m2 drops from 48.1 to 23.9% and 49.0 to 19.6%, in males and females in these two age groups. Conclusions Traditional measures poorly identify obesity in the elderly. In older adults, BMI may be a suboptimal marker for adiposity.

<b><i>Introduction:</i></b> Loss of skeletal muscle mass and function (sarcopenia) is common in individuals with obesity due to metabolic changes associated with a sedentary lifestyle, adipose tissue derangements, comorbidities (acute and chronic diseases) and during the ageing process. Co-existence of excess adiposity and low muscle mass/function is referred to as sarcopenic obesity (SO), a condition increasingly recognized for its clinical and functional features that negatively influence important patient-centred outcomes. Effective prevention and treatment strategies for SO are urgently needed, but efforts are hampered by the lack of a universally established SO definition and diagnostic criteria. Resulting inconsistencies in the literature also negatively affect the ability to define prevalence as well as clinical relevance of SO for negative health outcomes. <b><i>Aims and Methods:</i></b> The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) launched an initiative to reach expert consensus on a definition and diagnostic criteria for SO. The jointly appointed international expert panel proposes that SO is defined as the co-existence of excess adiposity and low muscle mass/function. The diagnosis of SO should be considered in at-risk individuals who screen positive for a co-occurring elevated body mass index or waist circumference, and markers of low skeletal muscle mass and function (risk factors, clinical symptoms, or validated questionnaires). Diagnostic procedures should initially include assessment of skeletal muscle function, followed by assessment of body composition where presence of excess adiposity and low skeletal muscle mass or related body compartments confirm the diagnosis of SO. Individuals with SO should be further stratified into stage I in the absence of clinical complications or stage II if cases are associated with complications linked to altered body composition or skeletal muscle dysfunction. <b><i>Conclusions:</i></b> ESPEN and EASO, as well as the expert international panel, advocate that the proposed SO definition and diagnostic criteria be implemented into routine clinical practice. The panel also encourages prospective studies in addition to secondary analysis of existing data sets, to study the predictive value, treatment efficacy and clinical impact of this SO definition.

BACKGROUND Disparities in healthcare access and delivery, caused by transportation and health workforce difficulties, negatively impact individuals living in rural areas. These challenges are especially prominent in older adults. DESIGN We systematically evaluated the feasibility, acceptability, and effectiveness in providing telemedicine (TMed), searching the English‐language literature for studies (January 2012 to July 2018) in the following databases: Medline (PubMed); Cochrane Library (Wiley); Web of Science; CINAHL; EMBASE (Ovid); and PsycINFO (EBSCO). PARTICIPANTS Older adults (mean age = 65 years or older, and none were younger than 60 years). INTERVENTIONS Interventions consisted of live, synchronous, two‐way videoconferencing communication in nonhospital settings. All medical interventions were included. MEASUREMENTS Quality assessment, using the Cochrane Collaboration's Risk‐of‐Bias Tool, was applied on all included articles, including a qualitative summary of all articles. RESULTS Of 6616 citations, we reviewed the full text of 1173 articles, excluding 1047 that did not meet criteria. Of the 17 randomized controlled trials, the United States was the country with the most trials (6 [35%]), with cohort sizes ranging from 3 to 844 (median = 35) participants. Risk of bias among included studies varied from low to high. Our qualitative analysis suggests that TMed can improve health outcomes in older adults and that it could be used in this population. CONCLUSIONS TMed is feasible and acceptable in delivering care to older adults. Research should focus on well‐designed randomized trials to overcome the high degree of bias observed in our synthesis. Clinicians should consider using TMed in routine practice to overcome barriers of distance and access to care. J Am Geriatr Soc 67:1737–1749, 2019

The Foundation for the NIH (FNIH) Sarcopenia Project validated cutpoints for appendicular lean mass (ALM) to identify individuals with functional impairment. We hypothesized the prevalence of sarcopenia and sarcopenic obesity would be similar based on the different FNIH criteria, increase with age, and be associated with risk of impairment limitations. We identified 4,984 subjects ≥60 years from the National Health and Nutrition Examination Surveys 1999–2004. Sarcopenia was defined using: ALM (males<19.75kg; females<15.02kg), and ALM adjusted for body mass index (BMI) (males<0.789; females<0.512). Sarcopenic obesity is defined as subjects fulfilling criteria for sarcopenia and obesity by body fat (men≥25%; females≥35%). Prevalence rates of both sarcopenia and sarcopenic obesity were evaluated with respect to sex, age category (60–69, 70–79, >80years) and race. We assessed the association of physical limitations, basic and instrumental activities of daily living (ADL) and sarcopenia status. The mean age was 70.5 years in males and 71.6 years in females. Half (50.8%, n=2,531) were female, and mean BMI was 28kg/m2 in both sexes. ALM was higher in males than in females (24.1 vs. 16.3; p<0.001) but fat mass was lower (30.9 vs. 42.0;p<0.001). In males, sarcopenia prevalence was 16.0% and 27.8% using the ALM and ALM/BMI criteria. In females, prevalence was 40.5% and 19.3% using the ALM and ALM/BMI criteria. Sarcopenia was associated with a 1.10 [0.86,1.41] and 0.93 [0.74,1.16], and 1.46 [1.10,1.94] and 2.13 [1.41,3.20], risk of physical limitations using the ALM and ALM/BMI definitions in males and females, respectively. Prevalence of sarcopenia and sarcopenic obesity vary greatly, and a uniform definition is needed to identify and characterize these high risk populations.