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

BackgroundSkeletal muscle mass (SMM) plays a crucial role in systemic glucose metabolism.ObjectiveTo obtain reference data on absolute and relative values of SMM for Korean children and adolescents.MethodsCross-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).ResultsPercentile 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.ConclusionThis 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.

Pediatric Sarcopenia: A Paradigm in the Overall Definition of Malnutrition in Children?

“…The European Working Group on Sarcopenia in Older People defined sarcopenia as reduced SMM and muscle function . In studies that used DEXA (n = 5), SMM was determined from appendicular lean mass (ALM) in 3 studies, and 2 studies used ALM and lean muscle mass as a direct indicator of sarcopenia . Even though there is a direct relationship between whole body SMM and ALM (sum of lean mass in arms and legs), use of ALM without consideration of pubertal stage may overestimate sarcopenia in males and underestimate sarcopenia in females .…”

“…Of the 12 studies, n = 8 (67%) characterized sarcopenia, 6,[8][9][10][11][18][19][20] whereas n = 4 (33%) demonstrated the presence of SO in childhood. 17,[21][22][23] More than half (n = 7/12; 58%) of the studies were done retrospectively. 6,[8][9][10][18][19][20] The sample size ranged from 29 to 1919, with subjects aged between 6 months and 19.6 years.…”

“…A total of 12 articles published between 2013 and 2018 met the inclusion criteria. 6,[8][9][10][11][17][18][19][20][21][22][23] The majority of these articles (n = 10/12; 83%) were published in the last 2 years, 6,8,10,11,[17][18][19][20][21][22][23] indicating growing interest of sarcopenia research in the pediatric populations. Details on study design, study population, body composition measurements, definition of sarcopenia, and clinical outcomes associated with sarcopenia were extracted in Table 1.…”

Skeletal muscle reference for Chinese children and adolescents

“…Among them, DXA has been recommended as the preferred detection technology for assessing skeletal muscle loss due to its low radiation, accuracy and strong clinical feasibility . Several reference curves for skeletal muscle for youths have been established in UK and South Korea . However, these reference values are limited by their small sample sizes and absence of data for individuals with age <5 years.…”

“…11,12 Several reference curves for skeletal muscle for youths have been established in UK 13 and South Korea. 14 However, these reference values are limited by their small sample sizes and absence of data for individuals with age <5 years. To date, there is no reference data of skeletal muscle mass for Chinese youths.…”