Association of Neck Circumference with Pulse Pressure Among School-Aged Children in Ibadan, Nigeria: A Cross-Sectional Study

Background: Neck circumference is a simple marker of upper-body adiposity, but its relationship with pulse pressure in African children has received limited attention. Objectives: To determine whether increasing neck circumference is associated with higher pulse pressure among school-aged children in Ibadan, Nigeria. Methods: This school-based, cross-sectional study analysed 402 children aged 5-12 years selected by multistage stratified random sampling technique from public and private primary schools in Ibadan North Local Government Area. Height, weight, Body Mass Index (BMI), neck circumference and blood pressure were measured using standard procedures. Pulse pressure was calculated as systolic minus diastolic blood pressure and averaged across two readings. Associations were examined using Spearman correlation, sex-stratified summaries and heteroskedasticity-robust linear regression. Results: The mean age was 8.5±1.8 years, and 216 (53.7%) participants were girls. The mean neck circumference was 26.8±1.8 cm, and the mean pulse pressure was 39.1±7.7 mmHg. Boys had a statistically higher mean neck circumference than girls, although the absolute difference was small (27.1±1.6 cm versus 26.7±1.9 cm; t = 2.20; p = 0.028). Mean pulse pressure was 38.9 ± 7.9 mmHg in boys vs. 39.3 ± 7.5 mmHg in girls (p = 0.584). Neck circumference correlated positively with pulse pressure overall (r = 0.428; p<0.001), in boys (r = 0.431; p<0.001) and in girls (r = 0.435; p<0.001). In the fully adjusted model, each 1.0 cm increase in neck circumference was associated with 1.50 mmHg higher pulse pressure (95% Confidence Interval 0.81 to 2.19; p<0.001). The association between neck circumference and pulse pressure did not differ significantly by sex (interaction p = 0.456). Conclusion: Increasing neck circumference was independently associated with higher pulse pressure. This low-cost measurement may support school-based cardiovascular risk screening when used alongside routine blood pressure and body-size assessment.