title: Objectively-measured and self-reported physical activity and fitness in relation to inflammatory markers in European adolescents: the HELENA Study.
abstract: OBJECTIVE
  Atherogenesis involves an inflammatory process that occurs early in life even though clinical symptoms are not observed until adulthood. Two important protective factors for low-grade inflammation may be physical activity (PA) and fitness. We examined the independent associations of objective and subjective measurements of PA and fitness with low-grade inflammation in European adolescents.
  
  
  METHODS
  A total of 1045 adolescents, aged from 12.5 to 17.5 years old from 10 European cities, were selected from the HELENA-Cross-Sectional Study. Objectively-measured and self-reported PA variables were obtained by accelerometry and the International PA Questionnaire for Adolescents, respectively. Overall, cardiorespiratory, muscular and motor fitness variables were assessed by standardized field-based fitness tests and the International Fitness Scale. C-reactive protein (CRP), complement factors 3 (C3) and 4 (C4), interleukin-6 and TNF-α inflammatory markers were measured.
  
  
  RESULTS
  Objectively-measured vigorous PA was inversely associated with C3 (β=-0.094, P=0.021) but it did not remain significant after any objective fitness indicator was included in the model. Other objectively measured or self-reported assessments of PA were not significantly associated with inflammatory markers. All objective measures of fitness were inversely associated with CRP, C3 and C4, whereas only self-reported motor fitness remained significantly associated with C3, C4 and TNF-α. All these observations were independent of age, sex, city and body mass index or waist circumference.
  
  
  CONCLUSIONS
  High PA in adolescence may play an indirect role on lessening low-grade inflammation through improvements in fitness.
authors.affiliation: Immunonutrition Research Group, Department of Metabolism and Nutrition, Institute of Food Science, Technology and Nutrition, Spanish National Research Council, Calle José Antonio Novais 10, 28040 Madrid, Spain. d.martinez@uam.es
authors.forename: David
authors.initials: D
authors.lastname: Martinez-Gomez
authors.forename: Sonia
authors.initials: S
authors.lastname: Gomez-Martinez
authors.forename: Jonatan R
authors.initials: JR
authors.lastname: Ruiz
authors.forename: Ligia Esperanza
authors.initials: LE
authors.lastname: Diaz
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Ortega
authors.forename: Kurt
authors.initials: K
authors.lastname: Widhalm
authors.forename: Magdalena
authors.initials: M
authors.lastname: Cuenca-Garcia
authors.forename: Yannis
authors.initials: Y
authors.lastname: Manios
authors.forename: Tineke
authors.initials: T
authors.lastname: De Vriendt
authors.forename: Denes
authors.initials: D
authors.lastname: Molnar
authors.forename: Inge
authors.initials: I
authors.lastname: Huybrechts
authors.forename: Christina
authors.initials: C
authors.lastname: Breidenassel
authors.forename: Frederic
authors.initials: F
authors.lastname: Gottrand
authors.forename: Maria
authors.initials: M
authors.lastname: Plada
authors.forename: Sara
authors.initials: S
authors.lastname: Moreno
authors.forename: Marika
authors.initials: M
authors.lastname: Ferrari
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.forename: Michael
authors.initials: M
authors.lastname: Sjöström
authors.forename: Ascension
authors.initials: A
authors.lastname: Marcos
mesh_terms: D056044:Actigraphy; D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D002097:C-Reactive Protein / Q000032:analysis; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D003430:Cross-Sectional Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D009043:Motor Activity; D010809:Physical Fitness; D012044:Regression Analysis; D057566:Self Report; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: C038245:C3 protein, human; D003176:Complement C3; D003181:Complement C4; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein