title: Is there a single underlying factor for the metabolic syndrome in adolescents? A confirmatory factor analysis.
abstract: OBJECTIVE
  The lack of a universally applicable model for the metabolic syndrome in the pediatric population makes it difficult to define this syndrome and compare its prevalence across studies and diverse populations. We sought to assess whether a single underlying factor could represent the metabolic syndrome in adolescents.
  
  
  METHODS
  Using data from the National Health and Nutrition Examination Survey (1999-2002), we conducted a confirmatory factor analysis to assess the validity of waist circumference, triglycerides, fasting insulin, and systolic blood pressure (SBP) as potential phenotypic traits for the metabolic syndrome in adolescents aged 12-17 years (n = 1,262). A multiple-group approach was used to test the invariance in factor loadings across sex and race/ethnicity.
  
  
  RESULTS
  The estimates of factor loadings for the total sample were 0.76, 0.46, 0.81, and 0.42 for waist circumference, triglycerides, fasting insulin, and SBP, respectively. The goodness-of-fit indexes were adequate for the total sample (comparative fit index, 0.99; standardized root mean square residual, 0.02), Caucasian boys (1.0; 0.01), African-American boys (0.99; 0.03), Mexican-American boys (1.0; 0.01), Mexican-American girls (1.0; 0.01), and Caucasian girls (0.95; 0.04) and acceptable for African-American girls (0.94; 0.05). There were no significant differences in factor loadings of the four measured variables between boys and girls and among the three racial or ethnic subgroups.
  
  
  CONCLUSIONS
  The metabolic syndrome as a single underlying factor for the four simple phenotypic traits may be plausible in adolescents. The proposed model appears to be generalizable across sex and race/ethnicity.
authors.affiliation: Division of Adult and Community Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. cli@cdc.gov
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Li
authors.forename: Earl S
authors.initials: ES
authors.lastname: Ford
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D049628:Body Size; D002648:Child; D005163:Factor Analysis, Statistical; D005260:Female; D006306:Health Surveys; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D014481:United States / Q000453:epidemiology
chemical_list: D007328:Insulin; D014280:Triglycerides