Neck circumference - A simple and valid screening tool for obesity in school children

Background/Aim: Childhood obesity is on a rise worldwide with an estimated prevalence of over 8% and 6% in boys and girls, respectively. Being a forerunner of adult obesity and its consequences, this has to be detected earlier and appropriate interventions instituted timely for better health outcomes. Neck Circumference is a simple screening tool for detecting obesity. This study aimed to find out the correlation between neck circumference and body mass index (BMI) and measures of central obesity like waist circumference (WC), hip circumference (HC), and waist-hip ratio (WHR). It also tried to find out the age and gender-specific cut-off values for overweight and obesity in schoolchildren aged 6 to 16 years. Methods: This was a cross-sectional observational study conducted in the primary and secondary schools of a sub-urban region of south Kerala, India. The anthropometric measurements, including weight, height, neck circumference, waist and hip circumferences of children aged 6-16 years who satisfied the inclusion criteria were obtained by health professionals, and their BMIs were compared with WHO standards to detect overweight and obesity. The correlation between BMI and NC, sensitivity, and specificity of NC in detecting overweight and obesity, and age-related cut-off values of NC were calculated using appropriate statistical methods. The correlation of NC with indicators of central obesity like waist circumference, hip circumference, and waist-hip ratio were also determined. Results: A total of 1797 students were studied. Neck circumference showed a significant positive correlation (r = +0.6 to +0.8, P<0.001) with body mass index, waist circumference, and hip circumference but not with waist-hip ratio (r =+.3 to -.2). In ROC analysis, age-specific cut-off values of NC for obesity and overweight were obtained age-and gender-wise, with sensitivities of 87.5% and 100%, and specificities of 52.2% -88.9%, respectively. Conclusion: Neck circumference is a valid and simple tool to detect overweight and obesity in schoolchildren. It is also an indicator of the central distribution of fat in children aged 6 to 16 years.