RT Journal Article SR Electronic T1 Neck circumference and clustered cardiovascular risk factors in children and adolescents: cross-sectional study JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e016048 DO 10.1136/bmjopen-2017-016048 VO 7 IS 9 A1 Castro-Piñero, José A1 Delgado-Alfonso, Alvaro A1 Gracia-Marco, Luis A1 Gómez-Martínez, Sonia A1 Esteban-Cornejo, Irene A1 Veiga, Oscar L A1 Marcos, Ascensión A1 Segura-Jiménez, Víctor A1 YR 2017 UL http://bmjopen.bmj.com/content/7/9/e016048.abstract AB Objective Early detection of cardiovascular disease (CVD) risk factors, such as obesity, is crucial to prevent adverse long-term effects on individuals’ health. Therefore, the aims were: (1) to explore the robustness of neck circumference (NC) as a predictor of CVD and examine its association with numerous anthropometric and body composition indices and (2) to release sex and age-specific NC cut-off values to classify youths as overweight/obese.Design Cross-sectional study.Setting 23 primary schools and 17 secondary schools from Spain.Participants 2198 students (1060 girls), grades 1–4 and 7–10.Measures Pubertal development, anthropometric and body composition indices, systolic and diastolic blood pressure (SBP and DBP, respectively), cardiorespiratory fitness, blood sampling triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), glucose and inflammatory markers. Homoeostasis model assessment (HOMA-IR) and cluster of CVD risk factors were calculated.Results NC was positively correlated with all anthropometric and body composition indices. NC was negatively associated with maximum oxygen consumption (R2=0.231, p<0.001 for boys; R2=0.018, p<0.001 for girls) and positively associated with SBP, DBP, TC/HDL-c, TG, HOMA, complement factors C-3 and C-4, leptin, adiponectin and clustered CVD risk factor in both sexes (R2 from 0.035 to 0.353, p<0.01 for boys; R2 from 0.024 to 0.215, p<0.001 for girls). Moreover, NC was positively associated with serum C reactive protein, LDL-c and visfatin only in boys (R2 from 0.013 to 0.107, p<0.05).Conclusion NC is a simple, low-cost and practical screening tool of excess of upper body obesity and CVD risk factors in children and adolescents. Paediatricians can easily use it as a screening tool for overweight/obesity in children and adolescents. For this purpose, sex and age-specific thresholds to classify children and adolescents as normal weight or overweight/obese are provided.