title: General versus central adiposity and relationship to pediatric metabolic risk.
abstract: BACKGROUND
  The influence of moderate-to-vigorous physical activity (MVPA) and general versus central adiposity on pediatric metabolic risk is not well described.
  
  
  METHODS
  Secondary analyses on pediatric participants from the National Health and Nutrition Examination Survey, 2003-2006 (n=2,155). MVPA (min/day) and adherence to MVPA recommendations were assessed objectively by accelerometers. Body mass index (BMI) z-score and waist circumference (WC) were measured by standard protocols. The main dependent variables included an overall metabolic risk score and clinical tests related to metabolic risk. A series of linear regression analyses were used to examine BMI z-score versus WC as a mediator of the relationship between MVPA and the metabolic risk score or the individual components, controlling for sociodemographic covariates. All analyses with BMI z-score as an independent variable controlled for WC and vice versa. The product-of-coefficients method was used to test for mediation.
  
  
  RESULTS
  MVPA adherence was inversely associated and WC was positively associated with the metabolic risk score (all P<0.05). MVPA was inversely associated with systolic blood pressure and positively associated with high-density lipoprotein cholesterol (HDL-C) (all P<0.05). WC was inversely associated with HDL-C and positively associated with C-reactive protein (CRP), glycohemoglobin, fasting triglycerides, and fasting insulin (all P<0.05). WC mediated the relationship between MVPA and CRP or HDL-C (both P<0.05).
  
  
  CONCLUSIONS
  MVPA correlated with pediatric metabolic risk and this relationship was mediated by central adiposity for CRP and HDL-C. This finding suggests the need for programs to screen for and improve children's MVPA and WC.
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, USA. jason.mendoza@bcm.edu
authors.forename: Jason A
authors.initials: JA
authors.lastname: Mendoza
authors.forename: Theresa A
authors.initials: TA
authors.lastname: Nicklas
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Janice
authors.initials: J
authors.lastname: Stuff
authors.forename: Tom
authors.initials: T
authors.lastname: Baranowski
mesh_terms: D056044:Actigraphy; D050154:Adiposity / Q000502:physiology*; D000293:Adolescent; D017668:Age of Onset; D050218:Body Fat Distribution; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D002648:Child; D005260:Female; D006801:Humans; D008075:Lipoproteins, HDL / Q000032:analysis / Q000097:blood; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology / Q000209:etiology*; D008954:Models, Biological; D009749:Nutrition Surveys; D056128:Obesity, Abdominal / Q000150:complications / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D055105:Waist Circumference / Q000502:physiology; D055815:Young Adult
chemical_list: D008075:Lipoproteins, HDL; D002097:C-Reactive Protein