Waist circumference percentiles for Portuguese children and adolescents aged 10 to 18 years

The purposes of this study were to develop age- and sex-specific waist circumference reference data for Portuguese children and adolescents aged 10–18 years and to compare them with those from other countries. This was a school-based study performed in Portugal. A total of 22,003 children and adolescents aged 10–18 years were included in the study. Smoothed sex- and age-specific 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile curves of waist circumference were estimated using Cole's lambda–mu–sigma method. Waist circumference values increased with age in both boys and girls, and boys had higher values than girls at every age and percentile. In both sexes, the Portuguese values in the 90th percentile were closer to the Bolivian values and considerably lower than those of the American children for all age groups. Conclusion: The data presented provide information for abdominal risk assessment and clinical and lifestyle intervention; our results also provide useful baseline data information for the implementation of a surveillance system required to monitor trends and factors associated with abdominal obesity in children and adolescents.