title: Association of low muscle mass and combined low muscle mass and visceral obesity with low cardiorespiratory fitness.
abstract: OBJECTIVE
  Previous studies have shown that low cardiorespiratory fitness (CRF), visceral obesity and low muscle mass may share pathophysiological mechanisms, such as insulin resistance and chronic inflammation. In this study, we investigated whether low CRF is associated with low muscle mass, visceral obesity, and visceral obesity combined with low muscle mass.
  
  
  METHODS
  The associations between CRF and low muscle mass and combined low muscle mass and visceral obesity were examined in 298 apparently healthy adults aged 20-70 years. Low muscle mass was defined using a skeletal muscle mass index (SMI) that was calculated using dual energy X-ray absorptiometry. Visceral obesity was defined as a visceral fat area (VFA) exceeding 100 cm2 in women and 130 cm2 in men. We classified the participants into 4 low muscle mass/visceral obesity groups according to SMI and VFA. CRF was measured using a cycle ergometer test.
  
  
  RESULTS
  CRF level correlated positively with SMI and negatively with VFA. Individuals with low muscle mass had lower CRF values than those without low muscle mass. After adjustment for age, sex, lifestyle factors, and markers for insulin resistance and inflammation, participants in the lowest quartile of CRF had an odds ratio (OR) for low muscle mass of 4.98 compared with those in the highest quartile (95% confidence interval (CI) = 1.19-12.99; P for trend = 0.001) and an OR for combined low muscle mass and visceral obesity of 31.46 (95% CI = 4.31-229.68; P for trend = 0.001).
  
  
  CONCLUSIONS
  Individuals with lower CRF exhibited increased risk of low muscle mass and combined low muscle mass and visceral obesity. These results suggest that low CRF may be a potential indicator for low muscle mass and combined low muscle mass and visceral obesity in Korean adults.
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea; Division of Endocrinology and Metabolism, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea.
authors.forename: Tae Nyun
authors.initials: TN
authors.lastname: Kim
authors.affiliation: Department of Statistics, College of Natural Sciences, Sungshin Women's University, Seoul, Korea.
authors.forename: Man Sik
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
authors.forename: You Jeong
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea; Division of Endocrinology and Metabolism, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea; Division of Endocrinology and Metabolism, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Ko
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea; Division of Endocrinology and Metabolism, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea.
authors.forename: Byoung Doo
authors.initials: BD
authors.lastname: Rhee
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea; Division of Endocrinology and Metabolism, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea.
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Won
mesh_terms: D000328:Adult; D000368:Aged; D002320:Cardiovascular Physiological Phenomena; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D056128:Obesity, Abdominal / Q000209:etiology* / Q000473:pathology; D012307:Risk Factors; D055948:Sarcopenia / Q000150:complications / Q000503:physiopathology*; D055815:Young Adult