Reference percentiles for mid-upper arm circumference, upper arm muscle and fat areas of Nigerian children and adolescent population aged 0 – 19 years

INTRODUCTION: Mid-upper arm circumference (MUAC) has commonly been used for many years as an alternative nutritional status index in field settings, yet estimates of percentile range for healthy children and adolescents have not been documented in Nigeria. We construct reference curves for MUAC and its derived measures of upper arm muscle area (UAMA), upper arm fat area (UAFA) and present sex- and age-specific MUAC, UAMA and UAFA values for children and adolescents. METHODS: Natural cubic splines were fitted by maximum penalized likelihood to develop centile curves for MUAC, UAMA and UAFA and the LMS coefficients necessary to estimate the z-score specific to each age and gender were presented. MUAC, UAMA and UAFA reference curves of US children and adolescents were used for comparison. RESULTS: The centiles of MUAC, UAMA and UAFA increased with age. However, these centile curves show significant sex-specific differences for boys and girls aged ≥ 10, ≥ 14.5 and ≥ 4.5 years of age, respectively. Compared to the US reference, the percentiles of MUAC, UAMA and MUAC are generally lower. CONCLUSION: In this study, we have presented a reference set of curves and tables for MUAC and its measures for healthy children and adolescents.