Continuous metabolic syndrome risk score validity for Danish children and adolescents

Abstract

A study performed in children (Eisenmann, Laurson, DuBose, Smith, & Donnelly, 2010) showed that a continuous metabolic syndrome risk (cMSr) score, derived from principal component analysis (PCA), was higher in those with the metabolic syndrome (MS) and that the cMSr score raised progressively with the number of adverse risk factors, validating the cMSr score in 7-9 years old children. Their study suggests the application of such approach to validate a cMSr score for older youth. Our study aims to assess the validity of a cMSr score for Danish children and adolescents. Data included 1812 youth between 9.0-15.99 years old who participated in the European Youth Heart Study (EYHS) framework in Denmark (Riddoch et al., 2005). The cMSr was calculated based on the risk factors considered by the current International Diabetes Federation (IDF) definition for children and adolescents (Zimmet et al., 2007), involving three steps: a) all variables were normalized (log10) because of their non-normal distribution; b) PCA with orthogonal (varimax) rotation was applied, and variables with a factor loading ≥ 0.4, which share at least 15% of variance, were used. Analysis revealed three principal components with eigenvalue ≥ 1.0 for girls and two principal components for boys; c) cMSr was computed by summing the individual principal component scores, each weighted for the relative contribution of the principal components to the explained variance. The cMSr score increased progressively with the number of adverse risk factors, being lowest in the group without risk factors (-0.35 ± 1.4), higher (p < 0.001) in the group with one risk factor (0.78 ± 1.6), even higher (p < 0.001) in the group with two risk factors (1.98 ± 1.2) and highest in those possessing the MS according to IDF criteria for youth (3.17