Prediction of cardiometabolic risk by BMI and waist circumference

Background: Evidence suggests that puberty is associated with a clustering of cardiometabolic risk factors (CMRFs) in adolescents and in later life. Few research has explored the possibly interaction effect of pubertal stage on the prediction of cardiometabolic risk by body mass index (BMI) or waist circumference (WC). We aimed to examine the associations between pubertal stage and CMRFs and the effect of pubertal stage on the prediction of cardiometabolic risk by BMI and WC. Methods: A cross-sectional school-based study was conducted among 1985(95.1%) students aged 6 to 18 years. Fasting lipid profile and plasma glucose, blood pressure (BP), body weight (BW), body height (BH) and WC were measured. A self-reported pubertal stage questionnaire was used to collect pubertal stage of participants. Two cardiometabolic risk scores alpha and beta were constructed to quantify the cardiometabolic risk of the participants. Results: The interaction of WC Z-score(ZWC) and pubertal stage demonstrated a significant increase in variance explained in cardiometabolic risk score alpha in boys(0.6%, p=0.010) and girls(0.4%, p=0.035) and in cardiometabolic risk score beta in boys(1%, p=0.008) but not in girls(0.5%, p=0.071). The interaction of BMI Z-score (ZBMI) and pubertal stage demonstrated a significant increase in variance explained in cardiometabolic risk score alpha in boys(0.5%, p=0.024) and girls(0.7%, p=0.006) and in cardiometabolic risk score beta in boys(0.8%, p=0.030) but not in girls(0.5%, p=0.051). Conclusions: Pubertal stage has a moderator effect of pubertal stage on the prediction of cardiometabolic risk by both WC and BMI in boys and may have a similar but lesser effect in girls