Association of neck circumference and pulmonary function in children

Background Childhood obesity leads to many complications including impaired respiratory function. There are various anthropometric parameters related to obesity. Objective To investigate the correlation between anthropometric indices and pulmonary function test results in children without asthma. Methods Children without any respiratory disorders were enrolled in this study. Anthropometric measurements, such as height, weight, neck circumference (NC), and waist circumference, were obtained from the enrollees and body mass index was calculated. Afterward, pulmonary function tests were performed using spirometry. Results A total of 178 children (106 boys, 59.5%) with a mean age of 9.7 years were included the study. NC was above the 90th percentile in 65 children. Importantly, pulmonary parameters, such as forced expiratory volume during the first second (FEV₁) and the ratio of FEV₁ to forced vital capacity (FVC), were lower in subjects with a large NC. Similarly, waist circumference was above the 90th percentile in 67 children, and FEV₁/FVC was significantly lower in children with a large waist circumference. Moreover, there was a statistically significant negative correlation among FEV₁, FEV₁/FVC, and body mass index SD score. Also, multivariable linear regression analysis showed that an NC above the 90th percentile was associated with lower FEV₁ and FEV₁/FVC values. Conclusion We identified NC as a novel anthropometric index that is strongly correlated with respiratory functions in children. Therefore, close monitoring of respiratory symptoms, particularly in children with obesity and a large NC, could help with early and prompt determination of respiratory complications of obesity.