title: Cross-Sectional and Prospective Associations between Physical Activity and C-Reactive Protein in Males.
abstract: BACKGROUND
  There is conflicting evidence about the association between physical activity and inflammatory markers. Few prospective studies are available, particularly from low and middle-income countries. This study was aimed at assessing the cross-sectional and prospective associations between physical activity and C-reactive protein (CRP) levels in males belonging to the 1982 Pelotas (Brazil) Birth Cohort Study.
  
  
  METHODS
  The sample comprised 2,213 males followed up at the ages of 18 and 23 years. We performed high sensitivity CRP assays; we used a cut-off of 3 mg/L in categorical analyses. We measured physical activity by self-report at ages 18 and 23 years. Body mass index and waist circumference were studies as possible mediators.
  
  
  RESULTS
  CRP levels above the 3mg/L cut-off were found in 13.3% (95%CI: 11.7; 14.8) of the individuals. We found no evidence for an association between physical activity (leisure-time or all-domains) and either continuous (geometrical mean) or categorical CRP. We confirmed these null findings in (a) prospective and cross-sectional analyses; (b) trajectories analyses.
  
  
  CONCLUSIONS
  There was no association between CRP levels and physical activity levels in early adulthood in a large birth cohort. Little variability in CRP at this early age is the likely explanation for these null findings.
authors.affiliation: Post-Graduate Program in Physical Education. Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Aírton J
authors.initials: AJ
authors.lastname: Rombaldi
authors.affiliation: Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil; Institute of Cardiology of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Lúcia C
authors.initials: LC
authors.lastname: Pellanda
authors.affiliation: Post-Graduate Program in Epidemiology. Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Renata M
authors.initials: RM
authors.lastname: Bielemann
authors.affiliation: Post-Graduate Program in Epidemiology. Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Denise P
authors.initials: DP
authors.lastname: Gigante
authors.affiliation: Post-Graduate Program in Physical Education. Federal University of Pelotas, Pelotas, Brazil; Post-Graduate Program in Epidemiology. Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Hallal
authors.affiliation: Post-Graduate Program in Epidemiology. Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Bernardo L
authors.initials: BL
authors.lastname: Horta
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D015992:Body Mass Index; D001938:Brazil; D002097:C-Reactive Protein / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009043:Motor Activity; D011446:Prospective Studies; D055105:Waist Circumference; D055815:Young Adult
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein