Measurement of Neck Circumference and Its Correlation with Body Composition in a Sample of Students in São Paulo, Brazil

Purpose: The purpose of this study was to verify the correlation between neck circumference (NC) and body mass index (BMI) in children, and to determine NC percentiles for Brazilian children. Methods: The subjects of this cross-sectional study were students between the ages of 6 and 19 years from five schools in São Paulo, Brazil. Clinical and anthropometric data were collected from the students from April 2011 to June 2012. NC was measured at the level of the cricoid cartilage. We calculated Pearson correlation coefficients between NC and other indices of obesity with Sigma Stat 3.5. NC percentiles were produced using the LMS (lambda, mu, and sigma) method (STATA 12.0). Results: Among 2,794 students, 49.9% were male. NC was significantly correlated with age, BMI, waist circumference (WC), and body fat percentage (%BF). The NC of boys was greater than that of girls. The NC curves of smoothed 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were constructed by age and sex. Conclusions: NC can be used in the assessment of obesity in childhood. There was a positive correlation between NC and BMI, WC and %BF. This study was the first to provide NC percentiles for children in Brazil.