title: Associations of low-grade inflammation with physical activity, fitness and fatness in prepubertal children; the European Youth Heart Study.
abstract: OBJECTIVE
  To examine the associations of low-grade inflammation with objectively measured physical activity, cardiovascular fitness (CVF) and fatness in prepubertal children.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  One hundred and forty-two children (74 boys and 68 girls) aged 9-10 years (pubertal stage I and II) from the Swedish part of the European Youth Heart Study.
  
  
  METHODS
  Total physical activity and its intensity levels (moderate, vigorous, moderate + vigorous) were measured by accelerometry. CVF was measured with a maximal ergometer bike test. Body fat was derived from the sum of five skinfold thicknesses. The measured low-grade inflammatory markers include C-reactive protein, fibrinogen, complement factors C3 and C4.
  
  
  RESULTS
  C-reactive protein and C3 were negatively associated with CVF (beta=-0.254 and -0.267, respectively, P<0.05) and positively associated with body fat (beta=0.439 and 0.446, respectively, P<0.001), after controlling for sex, age and pubertal development. C-reactive protein and C3 were not significantly associated with CVF once body fat was in the model. Low-grade inflammation was not associated with physical activity, but physical activity was associated with CVF.
  
  
  CONCLUSIONS
  The results showed that low-grade inflammatory markers were negatively associated with CVF and positively associated with body fat in prepubertal children. For most of the variables, the influence of fatness was slightly higher than the influence of CVF. The findings suggest that the potential beneficial effects of physical activity on low-grade inflammation may be explained by its association with CVF. Understanding the interplay between physical activity, CVF and fatness may be of importance to reducing cardiovascular disease risk in young people.
authors.affiliation: Unit for Preventive Nutrition, Department of Biosciences and Nutrition at NOVUM, Karolinska Institutet, 14157 Huddinge, Sweden.
authors.forename: J R
authors.initials: JR
authors.lastname: Ruiz
authors.forename: F B
authors.initials: FB
authors.lastname: Ortega
authors.forename: J
authors.initials: J
authors.lastname: Warnberg
authors.forename: M
authors.initials: M
authors.lastname: Sjöström
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001823:Body Composition / Q000502:physiology*; D002097:C-Reactive Protein / Q000378:metabolism*; D002320:Cardiovascular Physiological Phenomena; D002648:Child; D003176:Complement C3 / Q000378:metabolism; D003181:Complement C4 / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009765:Obesity / Q000097:blood*; D010809:Physical Fitness / Q000502:physiology*
chemical_list: D015415:Biomarkers; D003176:Complement C3; D003181:Complement C4; D002097:C-Reactive Protein