title: Association of cardiorespiratory fitness and adiposity with inflammatory biomarkers in young adults.
abstract: OBJECTIVE
  Cardiorespiratory fitness (fitness) has been inversely associated with inflammation, but whether the association is attributed to fitness itself or lower levels of adiposity remains uncertain in young adults. The purpose of this study was to determine the association of fitness and adiposity with inflammation in young adults.
  
  
  METHODS
  A cross-sectional study was conducted with 88 participants aged 20-34 years. Fitness was assessed by a submaximal treadmill walking test. Adiposity was assessed by body mass index (BMI) and waist circumference (WC). Inflammation was measured by plasma C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) levels using immunoassays. Biological data were log10transformed. A separate multiple regression analysis was conducted with each inflammatory biomarker as a dependent variable. Covariates (sex, oral contraceptive use, and education level) were adjusted.
  
  
  RESULTS
  Fitness was inversely associated with log10CRP after adjustment for covariates but not after adjusting for BMI or WC. Fitness was inversely associated with log10IL-6 after adjustment for WC and covariates (β = -0.341, P = .049) but not after adjusting for BMI. Fitness × WC interaction (partial eta2= 0.056, P = .033) indicated that high fitness was more strongly associated with low log10IL-6 in young adults with high WC than those with low WC.
  
  
  CONCLUSIONS
  Although adiposity has a stronger association than fitness with CRP and IL-6, higher levels of fitness could be essential for maintaining low levels of IL-6, especially in the presence of high levels of central adiposity.
authors.affiliation: School of Nursing, The University of Texas Health Science Center at Houston, , Houston, Texas, 77030.
authors.forename: Eunduck
authors.initials: E
authors.lastname: Park
authors.affiliation: School of Nursing, The University of Texas Health Science Center at Houston, , Houston, Texas, 77030.|School of Public Health, The University of Texas Health Science Center at Houston, Houston, Texas, 77030.
authors.forename: Janet C
authors.initials: JC
authors.lastname: Meininger
authors.affiliation: School of Nursing, The University of Texas Health Science Center at Houston, , Houston, Texas, 77030.
authors.forename: Duck-Hee
authors.initials: DH
authors.lastname: Kang
authors.affiliation: School of Public Health-Austin Campus, The University of Texas Health Science Center at Houston, Austin, Texas, 78701.
authors.forename: Kelley Pettee
authors.initials: KP
authors.lastname: Gabriel
authors.affiliation: School of Nursing, The University of Texas Health Science Center at Houston, , Houston, Texas, 77030.
authors.forename: Nikhil S
authors.initials: NS
authors.lastname: Padhye
mesh_terms: D050154:Adiposity; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D000072599:Cardiorespiratory Fitness; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D055105:Waist Circumference; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein