relationship between mid-upper arm circumference (muac) and body mass index (bmi) in children aged 6 - 12 years: a cross-sectional study

Background: obesity has become one of the most important health problems worldwide. body mass index (bmi) is a clinical assessment of overweight and obesity in children, although mid-upper arm circumference (muac) assessment is more straightforward, especially for parents. objectives: this study aimed to investigate the relationship between muac and bmi in children aged 6 - 12 years. methods: this cross-sectional study was performed on 455 elementary school children aged 6 - 12, including 278 girls and 177 boys with a mean age of 8.8 ± 1.8 years selected using the census method. our researcher was trained for anthropometric data collection. data were analyzed by spss version 25 software using mann-whitney, kolmogorov-smirnov, and kruskal-wallis tests. results: the mean age was 9.19 ± 1.8 years, the mean height was 135 ± 12 cm, the mean weight was 31.85 ± 11 kg, the mean muac was 21 ± 3.1 cm, and the mean bmi was 17 ± 3.6 kg/m 2. there was a significant correlation between muac and bmi in both sexes, but it was stronger in girls than in boys (p-value < 0.05). the muac cutoff point was 23.75 cm (77% sensitivity and 80% specificity) and 24.75 cm (93% sensitivity and 88% specificity) for overweigh and obesity in girls, respectively. also, it was 23.25 cm (88% sensitivity and 83% specificity) and 25.25 cm (87% sensitivity and 90% specificity) for overweigh and obesity in boys, respectively. conclusions: we recommend muac as a predictor of early diagnosis of overweight and obesity.