Are age references for waist circumference, hip circumference and waist-hip ratio in Dutch children useful in clinical practice?

The aim of this study was to present age references for waist circumference (WC), hip circumference (HC), and waist/hip ratio (WHR) in Dutch children. Cross-sectional data were obtained from 14,500 children of Dutch origin in the age range 0-21 years. National references were constructed with the LMS method. This method summarises the distribution by three smooth curves representing skewness (L curve), the median (M curve), and coefficient of variation (S curve). The correlations between body mass index-standard deviation score (BMI-SDS), the circumferences and their ratio, and demographic variables were assessed by (multiple) regression analysis for three age groups: 0- < 5 years (1), 5- < 12.5 years (2), and 12.5- < 21 years (3). A cut-off for clinical use was suggested based on the International Obesity Task Force criteria for BMI. Mean WC and HC values increased with age. Mean WC was slightly higher in boys than in girls, and this difference was statistically significant from 11 years of age onwards. In contrast, HC was significantly higher in girls than in boys from 9 years onwards. The correlation between WC-SDS and BMI-SDS (r=0.73, P < 0.01) and between HC and BMI-SDS (r=0.67, P < 0.01) increased with age. With regard to WHR-SDS, a low correlation was found for 12.5-20 years of age (r=0.2, P < 0.01). WC-SDS correlated positively with height SDS (r=0.35, P < 0.01). Conclusion: Waist circumferences can be used to screen for increased abdominal fat mass in children, whereby a cut-off point of 1.3 standard deviation score seems most suitable.