Waist circumference percentile criteria for the pediatric metabolic syndrome in Korean adolescents.

This study aimed to determine valid waist circumference (WC) thresholds using receiver operating characteristic (ROC) curves for pediatric metabolic syndrome (MS) prediction and to compare validities between the thresholds derived from ROC curves and the WC cut-offs defined by International Diabetes Federation (IDF). Four hundred and sixty four males and 415 females, 10-18 years, who participated in the KNHNES 2005 were included. Subjects were classified as having pediatric MS when a high WC and > or = 2 of the risk factors defined by IDF were present. High WC was defined using either IDF criterion (> or =90th percentile for age and sex-specific WC based on Korean reference in adolescents 10-15 years of age, > or =90cm in males and > or =80cm in females 16-18 years of age) or age-adjusted WC thresholds derived from the ROC curves predicting > or = 2 abnormal risk factors. The AUCs were 0.71-0.81 (sensitivity 74-100%, specificity 52-65%) among males and 0.63-0.76 (sensitivity 71-90%, specificity 37-87%) among females for WC thresholds (55th and 32th percentile for males and females 10-15 years of age, 73cm and 76cm for males and females 16-18 years of age), while the AUCs were 0.65-0.66 (sensitivity 39-45%, specificity 84-93%) among males and 0.53-0.76 (sensitivity 20-57%, specificity 86-96%) among females for IDF-defined WC cut-offs. The prevalence of MS using IDF definition for WC was 4% in males and 2% in females, while those using WC thresholds were 8% and 5%, respectively. The IDF's definition of abdominal obesity may be less sensitive in screening adolescents with pediatric MS compared to WC thresholds.