Construction of Lambda, Mu, Sigma Values for Determining Mid-Upper Arm Circumference z Scores in U.S. Children Aged 2 Months Through 18 Years

Nutr Clin Pract. 2017 Feb;32(1):68-76. doi: 10.1177/0884533616676597. Epub 2016 Nov 19.


Background: Mid-upper arm circumference (MUAC) has proven highly predictive of morbidity and mortality associated with malnutrition better, in some cases, than other growth indicators, including body mass index (BMI) z scores and weight-for-height z scores. A recent consensus statement recommended the inclusion of MUAC and MUAC z scores in the nutrition assessment of children in the United States; however, the requisite data to permit z score calculations for children aged >5 years have not been published.

Objective: This investigation was designed to generate lambda mu sigma (LMS) values to permit the calculation of MUAC z scores in U.S. children 2 months through 18 years of age.

Design: Anthropometric data from the Centers for Disease Control and Prevention (CDC) National Health and Nutrition Examination Survey (1999-2012) were used for model development (n = 28,995). Smoothed centiles were constructed and compared with previously described CDC percentiles. Independently collected MUAC data from 2 different U.S. studies were used for external validation (n = 1438).

Statistical analyses: Goodness-of-fit was assessed visually and statistically by examining detrended quantile-quantile plots, Q statistics, and the distribution of z scores.

Results: The curves generated in this investigation fit the raw data well with no systematic bias and no sacrifice in fit for children aged <12 months. The curves were consistent with those published by the CDC, and the distribution z scores approximated 0 ± 1 in all age groups.

Conclusions: These LMS values derived in this investigation can be used by clinicians to generate MUAC z scores for U.S. children.

Keywords: adolescent; child; growth curve; infant; malnutrition; nutrition assessment.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Adolescent
  • Adolescent Development
  • Adolescent Nutritional Physiological Phenomena*
  • Arm
  • Body Size
  • Child
  • Child Development
  • Child Nutritional Physiological Phenomena*
  • Child, Preschool
  • Cohort Studies
  • Female
  • Growth Charts*
  • Humans
  • Infant
  • Infant Nutritional Physiological Phenomena*
  • Male
  • Models, Biological*
  • Nutrition Assessment*
  • Nutrition Surveys
  • Nutritional Status*
  • Sex Characteristics
  • United States