Aim: It has been shown that compared with healthyweight children, overweight and obese primary school-aged children have a higher incidence of hyperinsulinism, dyslipidaemia and hypertension. It is therefore important to investigate clinically relevant markers of cardiovascular risk in children. Waist circumference is a simple, non-invasive anthropometric measure, but its association with cardiovascular risk profile in young Australian children is not clear.
Methods: This study presents cross-sectional data from the Growth and Development Study. The sample included 70 healthy weight children, 50 overweight children and 28 obese children (n = 148, 9.6 +/- 1.9 years). All children had a medical assessment which included a physical examination (waist circumference, blood pressure), and investigations including glycated haemoglobin, total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, insulin, glucose and total homocysteine levels. An oral glucose tolerance test was performed in a subgroup of children (n = 119). Body mass index (BMI) was determined and BMI Z-scores calculated.
Results: In a multilevel model, waist circumference was the only significant anthropometric predictor of lipid profile (high-density lipoprotein beta = -0.01, P < 0.05; triglycerides beta = 0.01, P < 0.005), systolic blood pressure (beta = 0.29, P < 0.05), fasting insulin (beta = 0.16, P < 0.005), insulin concentrations throughout the oral glucose tolerance (60 min beta = 1.07, P < 0.005; 120 min beta = 1.42, P < 0.001) and insulin resistance (homeostasis model assessment (HOMA-IR): beta = 0.03, P < 0.05), with increasing waist circumference associated with increasing cardiovascular risk. In contrast, BMI Z-score was only predictive of 120-min glucose concentrations during the OGTT (beta = 0.34, P < 0.05).
Conclusions: Waist circumference is a better anthropometric indicator than BMI Z-score of cardiovascular risk in Australian primary school-aged children. Even in young children, measurement of waist circumference represents a simple, non-invasive screening tool to identify children with an increased cardiovascular risk profile.