title: Sarcopenia, sarcopenic obesity and mortality in older adults: results from the National Health and Nutrition Examination Survey III.
abstract: BACKGROUND
  Sarcopenia is defined as the loss of skeletal muscle mass and quality, which accelerates with aging and is associated with functional decline. Rising obesity prevalence has led to a high-risk group with both disorders. We assessed mortality risk associated with sarcopenia and sarcopenic obesity in elders.
  
  
  METHODS
  A subsample of 4652 subjects ≥60 years of age was identified from the National Health and Nutrition Examination Survey III (1988-1994), a cross-sectional survey of non-institutionalized adults. National Death Index data were linked to this data set. Sarcopenia was defined using a bioelectrical impedance formula validated using magnetic resonance imaging-measured skeletal mass by Janssen et al. Cutoffs for total skeletal muscle mass adjusted for height(2) were sex-specific (men: ≤5.75 kg/m(2); females ≤10.75 kg/m(2)). Obesity was based on % body fat (males: ≥27%, females: ≥38%). Modeling assessed mortality adjusting for age, sex, ethnicity (model 1), comorbidities (hypertension, diabetes, congestive heart failure, osteoporosis, cancer, coronary artery disease and arthritis), smoking, physical activity, self-reported health (model 2) and mobility limitations (model 3).
  
  
  RESULTS
  Mean age was 70.6±0.2 years and 57.2% were female. Median follow-up was 14.3 years (interquartile range: 12.5-16.1). Overall prevalence of sarcopenia was 35.4% in women and 75.5% in men, which increased with age. Prevalence of obesity was 60.8% in women and 54.4% in men. Sarcopenic obesity prevalence was 18.1% in women and 42.9% in men. There were 2782 (61.7%) deaths, of which 39.0% were cardiovascular. Women with sarcopenia and sarcopenic obesity had a higher mortality risk than those without sarcopenia or obesity after adjustment (model 2, hazard ratio (HR): 1.35 (1.05-1.74) and 1.29 (1.03-1.60)). After adjusting for mobility limitations (model 3), sarcopenia alone (HR: 1.32 ((1.04-1.69) but not sarcopenia with obesity (HR: 1.25 (0.99-1.58)) was associated with mortality. For men, the risk of death with sarcopenia and sarcopenic obesity was nonsignificant in both model-2 (HR: 0.98 (0.77-1.25), and HR: 0.99 (0.79-1.23)) and model 3 (HR: 0.98 (0.77-1.24) and HR: 0.98 (0.79-1.22)).
  
  
  CONCLUSIONS
  Older women with sarcopenia have an increased all-cause mortality risk independent of obesity.
authors: 1] Section of General Internal Medicine, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA [2] Geisel School of Medicine at Dartmouth, Hanover, NH, USA [3] Centers for Aging and Aging Research, Dartmouth College, Hanover, NH, USA.
authors: J A
authors: JA
authors: Batsis
authors: Geisel School of Medicine at Dartmouth, Hanover, NH, USA.
authors: T A
authors: TA
authors: Mackenzie
authors: 1] Geisel School of Medicine at Dartmouth, Hanover, NH, USA [2] Centers for Aging and Aging Research, Dartmouth College, Hanover, NH, USA.
authors: L K
authors: LK
authors: Barre
authors: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors: F
authors: F
authors: Lopez-Jimenez
authors: 1] Geisel School of Medicine at Dartmouth, Hanover, NH, USA [2] Centers for Aging and Aging Research, Dartmouth College, Hanover, NH, USA.
authors: S J
authors: SJ
authors: Bartels
mesh_terms: D000273:Adipose Tissue; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D002318:Cardiovascular Diseases / Q000401:mortality; D002423:Cause of Death; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal; D009749:Nutrition Surveys; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000401:mortality*; D015995:Prevalence; D012016:Reference Values; D012307:Risk Factors; D055948:Sarcopenia / Q000150:complications / Q000453:epidemiology / Q000401:mortality*; D012737:Sex Factors