Reference ranges for midupper arm circumference, upper arm muscle area, and upper arm fat area in US children and adolescents aged 1-20 y.
Midupper arm circumference (MUAC) has long been used in anthropometric assessments of nutritional status in field settings, especially in emergency situations, but percentile ranges for healthy, well-nourished children are currently unavailable.



We developed reference curves for MUAC and derived measures of arm muscle area (AMA) and arm fat area (AFA) on the basis of the population used in the current CDC body mass index growth charts.



We analyzed cross-sectional MUAC and triceps (triceps skinfold thickness) data from 32,952 US children aged 1-20 y. Generalized additive models for location, scale, and shape were used to calculate semiparametric smoothed percentiles and L, M, and S coefficients needed for z-score estimation by age and sex. Equations were developed with the use of the height-for-age z score (HAZ) to adjust for the associations of stature with upper arm measures.



MUAC increased with age steadily throughout the growing period. For children <5 y old, lower percentile ranges varied markedly across age and sex such that the single cutoff (<11.5 or 12.5 cm) for field screening of acute malnutrition did not track along the same percentile. AFA and AMA growth patterns exhibited sex-specific trends including multiple distinct age-related inflections that were more pronounced in males for AFA-for-age than in females. HAZ and age were substantially and independently related with all arm measures.



The new reference percentile ranges for midupper arm measures for healthy children provide a useful nutritional assessment tool in a wide variety of settings. Height status (HAZ) has complex independent associations with arm measures irrespective of the distributional ranking by age and sex. Prediction equations that account for these effects further extend the practical use of the new curves.
Emory University Rollins School of Public Health and Global Health Institute, Atlanta, GA; yaw.addo@emory.edu.
O Yaw
0000-0003-1269-759X
OY
Addo
University of Minnesota, School of Public Health, Minneapolis, MN; and.
John H
JH
Himes
The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.
Babette S
BS
Zemel
D000273:Adipose Tissue; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000886:Anthropometry / Q000379:methods; D001132:Arm; D001823:Body Composition; D001827:Body Height; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D044342:Malnutrition; D018482:Muscle, Skeletal; D015596:Nutrition Assessment; D009752:Nutritional Status; D012016:Reference Values; D012737:Sex Factors; D012885:Skinfold Thickness; D014481:United States; D055815:Young Adult
arm; nutritional assessment; percentiles; references; stature