title: Reference Values of Skeletal Muscle Mass for Korean Children and Adolescents Using Data from the Korean National Health and Nutrition Examination Survey 2009-2011.
abstract: BACKGROUND
  Skeletal muscle mass (SMM) plays a crucial role in systemic glucose metabolism.
  
  
  OBJECTIVE
  To obtain reference data on absolute and relative values of SMM for Korean children and adolescents.
  
  
  METHODS
  Cross-sectional results from 1919 children and adolescents (1024 boys) aged 10-18 years that underwent dual-energy X-ray absorptiometry (DXA) during the Korean National Health and Nutrition Examination Survey 2009-2011 were analyzed. SMMs were evaluated as follows; absolute SMM (appendicular skeletal muscle mass [ASM]) and relative SMMs, namely, height-adjusted skeletal muscle index (SMI; ASM/height2), %SMM (ASM/weight x 100), and skeletal muscle-to-body fat ratio (MFR; ASM/body fat mass).
  
  
  RESULTS
  Percentile curves illustrated the developmental patterns of the SMMs of Korean children and adolescents. ASM and SMI increased with age in both genders, and increased from age 10 throughout adolescence in boys, whereas in girls, they increased until age 13 and then stabilized. In boys, %SMM and MFR were highest at age 15 and then slowly stabilized or decreased, whereas in girls, they peaked at age 10 to 11 and then decreased through adolescence. Cut-off values for low MFR were identified and a significant association was found between a low MFR and high risk of metabolic syndrome. However, this association was found to be dependent on gender and the level of BMI.
  
  
  CONCLUSIONS
  This study provides reference values of absolute and relative SMM for Korean children and adolescents. Detailed body composition analyses including skeletal muscle and fat mass might provide improved measures of metabolic risk.
authors.affiliation: Department of Food Science and Nutrition, Dankook University, Yongin, Republic of Korea.
authors.forename: Kirang
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Endocrinology and Metabolism, Hanyang University Guri Hospital, Gyeonggi-do, Republic of Korea.
authors.forename: Sangmo
authors.initials: S
authors.lastname: Hong
authors.affiliation: Department of Radiology, Gachon University Gil Hospital, Incheon, Republic of Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology*; D009929:Organ Size / Q000502:physiology; D012016:Reference Values; D056910:Republic of Korea