title: Intra-abdominal adiposity and individual components of the metabolic syndrome in adolescence: sex differences and underlying mechanisms.
abstract: OBJECTIVE
  To investigate the association between intra-abdominal adiposity and individual components of the metabolic syndrome (MS) in adolescent males and females.
  
  
  METHODS
  Cross-sectional study of a population-based cohort.
  
  
  METHODS
  Saguenay Youth Study, Quebec, Canada.
  
  
  METHODS
  A total of 324 adolescents, aged 12 to 18 years.
  
  
  METHODS
  Measures were compared between males and females with "high" or "low" intra-abdominal fat (IAF).
  
  
  METHODS
  Intra-abdominal fat was quantified with magnetic resonance imaging. Primary outcome measures were blood pressure (BP) and fasting serum glucose, insulin, lipids, and C-reactive protein levels. Secondary mechanistic measures were cardiovascular variability indexes of autonomic nervous system function, pubertal development, and serum levels of cortisol, leptin, and sex hormones.
  
  
  RESULTS
  The MS was completely absent in adolescents with low IAF and was present in 13.8% of males and 8.3% of females with high IAF. Excess IAF was associated with a higher homeostasis model assessment index (0.5 [95% confidence interval (CI), 0.3 to 0.8]; P < .001) and triglycerides level (17.7 mg/dL [to convert to millimoles per liter, multiply by 0.0113] [95% CI, 9.7 to 25.7 mg/dL]; P < .001), lower high-density lipoprotein cholesterol level (-3.9 mg/dL [to convert to millimoles per liter, multiply by 0.0259] [95% CI, -6.2 to -1.5 mg/dL]; P = .003), and higher C-reactive protein level (0.03 mg/L [to convert to nanomoles per liter, multiply by 9.524] [95% CI, 0.01 to 0.05 mg/L]; P = .003). High IAF was associated with elevations of BP and sympathetic activity in males only (higher systolic BP, 6 mm Hg [95% CI, 1 to 11 mm Hg]; P = .02 and low-frequency power of diastolic BP, 629 mm Hg2 [95% CI, 37 to 1222 mm Hg2]; P = .04).
  
  
  CONCLUSIONS
  Our results suggest that, already in adolescence, accumulation of IAF may promote development of the MS, affecting the metabolic and inflammatory components similarly in both sexes but influencing BP adversely only in males. The latter may be attributed, in part, to the augmentation of sympathetic activity also seen only in males.
authors.affiliation: Brain and Body Centre, University of Nottingham, Nottingham, England.
authors.forename: Catriona
authors.initials: C
authors.lastname: Syme
authors.forename: Michal
authors.initials: M
authors.lastname: Abrahamowicz
authors.forename: Gabriel T
authors.initials: GT
authors.lastname: Leonard
authors.forename: Michel
authors.initials: M
authors.lastname: Perron
authors.forename: Alain
authors.initials: A
authors.lastname: Pitiot
authors.forename: Xi
authors.initials: X
authors.lastname: Qiu
authors.forename: Louis
authors.initials: L
authors.lastname: Richer
authors.forename: John
authors.initials: J
authors.lastname: Totman
authors.forename: Suzanne
authors.initials: S
authors.lastname: Veillette
authors.forename: Yongling
authors.initials: Y
authors.lastname: Xiao
authors.forename: Daniel
authors.initials: D
authors.lastname: Gaudet
authors.forename: Tomas
authors.initials: T
authors.lastname: Paus
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Pausova
mesh_terms: D050153:Abdominal Fat; D050154:Adiposity; D000293:Adolescent; D001341:Autonomic Nervous System / Q000502:physiology; D001794:Blood Pressure; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications*; D009765:Obesity / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D012727:Sex Characteristics