Validity of a single-factor model underlying the metabolic syndrome in children: a confirmatory factor analysis.

OBJECTIVE: We used confirmatory factor analysis to test whether a single factor might explain the clustering of the metabolic syndrome (MS) components in children. RESEARCH DESIGN AND METHODS: We studied 1,020 children aged 10-13 years from 20 schools in Cuenca, Spain. The single-factor model included: waist circumference (WC), fasting insulin, triglyceride to HDL cholesterol ratio (Triglyl/HDL-C), and mean arterial pressure (MAP). The standardized scores of the four variables in the model were used to develop a continuous MS index. RESULTS: Factor loadings were 0.67 for WC, 0.68 for fasting insulin, 0.57 for Triglyl/HDL-C, and 0.37 for MAP. The single-factor model also showed a good fit to the data. As compared with Adult Treatment Panel III criteria, the MS index showed strong validity in the diagnosis of MS (area under the receiver operating characteristic curve = 0.98, 95% CI 0.96-0.99). CONCLUSIONS: A single underlying factor has acceptable validity to represent MS in children.

Association of adiposity measures with blood lipids and blood pressure in children aged 8-11 years.

AIM: To examine the association of body mass index (BMI), triceps skinfold thickness (TST) and percentage body fat (%BF) from bioelectrical impedance analysis (BIA) with blood lipids, systolic blood pressure (SBP) and diastolic blood pressure (DBP) in children. METHODS: Cross-sectional study was conducted on 1280 schoolchildren aged 8-11 years from the Cuenca province (Spain). Data collection was conducted under standardized conditions, taking several measurements of each variable to enhance accuracy. Analyses were performed using age-adjusted correlation coefficients, and multiple linear regression adjusted for age, BMI, TST and %BF. RESULTS: Correlations between %BF and apolipoprotein (apo) B, total cholesterol, low-density lipoprotein cholesterol (LDL-c), total cholesterol/HDL-c ratio and DBP were higher than those for BMI and TST. In contrast, the correlations between BMI, and apo A-I and SBP were higher than those for %BF and TST. The results were similar across the sexes. The correlations between each of the three measures of body fatness, and blood lipids and blood pressure were highest in children with greatest BMI and %BF. When analyses were adjusted for the three body fatness measures, %BF showed stronger associations than did BMI or TST with blood lipids and blood pressure, with the exception of apo A-I and SBP, which were more closely associated with BMI. CONCLUSION: %BF from BIA is more strongly associated than either BMI or TST with most of the blood lipid fractions in schoolchildren aged 8-11 years.