Validity of a Continuous Metabolic Risk Score as an Index for Modeling Metabolic Syndrome in Adolescents

PURPOSE: Although continuous values of metabolic syndrome risk scores (cMetS) has been suggested for modeling the association between potential risk factors and metabolic syndrome (MetS) in young people, the construct validity of cMetS has not been sufficiently examined in a representative sample of youngsters. This study examined: (i) sex and race/ethnic-specific optimal cut-off points of cMetS that are associated with MetS and (ii) the construct validity of cMetS in 12-to 19-year old non-Hispanic white (NHW), non-Hispanic black (NHB), and Mexican-American (MA) subjects. METHODS: Data (n = 1239) from the 2003 to 2004 and 2005 to 2006 National Health and Nutrition Examination Surveys were used in this study. cMetS was derived by aggregating age-and sex-standardized residuals of arterial blood pressure, triglycerides, glucose, waist circumference, and high-density lipoprotein cholesterol. Receiver operating characteristics analysis was used to determine the validity and performance of cMetS. The overall performance of the receiver operating characteristics test was quantified with area under the curve (AUC). RESULTS: A graded relationship between cMetS and increased number of MetS factors was observed, with MetS factors of 3 or greater yielding the greatest cMetS. In male adolescents, the optimal cMetS cut-off points of cMetS that are associated with MetS in NHW, NHB, and MA were 2.01, 2.45, and 2.34, respectively. The corresponding values in female adolescents for NBW, NHB, and MA were 1.93, 2.12, and 2.23, respectively. The construct validity of cMetS for MetS was high (AUC >= 0.885; sensitivity >= 66.7; specificity >= 74.8%). CONCLUSIONS: cMetS appears to be a suitable index for investigating the association between potential risk factors and MetS in adolescents. An understanding of the role of genetic and environmental risk factors in MetS in children may be enhanced with the use of cMetS. Ann Epidemiol 2010;20:843-851. (C) 2010 Elsevier Inc. All rights reserved.