title: Objectively measured physical activity and sedentary-time are associated with arterial stiffness in Brazilian young adults.
abstract: OBJECTIVE
  To examine the associations between objectively measured physical activity and sedentary time with pulse wave velocity (PWV) in Brazilian young adults.
  
  
  METHODS
  Cross-sectional analysis with participants of the 1982 Pelotas (Brazil) Birth Cohort who were followed-up from birth to 30 years of age. Overall physical activity (PA) assessed as the average acceleration (mg), time spent in moderate-to-vigorous physical activity (MVPA - min/day) and sedentary time (min/day) were calculated from acceleration data. Carotid-femoral PWV (m/s) was assessed using a portable ultrasound. Systolic and diastolic blood pressure (SBP/DBP), waist circumference (WC) and body mass index (BMI) were analyzed as possible mediators. Multiple linear regression and g-computation formula were used in the analyses.
  
  
  RESULTS
  Complete data were available for 1241 individuals. PWV was significantly lower in the two highest quartiles of overall PA (0.26 m/s) compared with the lowest quartile. Participants in the highest quartile of sedentary time had 0.39 m/s higher PWV (95%CI: 0.20; 0.57) than those in the lowest quartile. Individuals achieving ≥30 min/day in MVPA had lower PWV (β = -0.35; 95%CI: -0.56; -0.14). Mutually adjusted analyses between MVPA and sedentary time and PWV changed the coefficients, although results from sedentary time remained more consistent. WC captured 44% of the association between MVPA and PWV. DBP explained 46% of the association between acceleration and PWV.
  
  
  CONCLUSIONS
  Physical activity was inversely related to PWV in young adults, whereas sedentary time was positively associated. Such associations were only partially mediated by WC and DBP.
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Brazil.
authors.forename: Bernardo Lessa
authors.initials: BL
authors.lastname: Horta
authors.affiliation: EndocrineDivision, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Department of Internal Medicine, Facultyof Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: beatrizschaan@gmail.com.
authors.forename: Beatriz D
authors.initials: BD
authors.lastname: Schaan
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Brazil; Department of Nutrition, Federal University of Pelotas, Brazil.
authors.forename: Renata Moraes
authors.initials: RM
authors.lastname: Bielemann
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Brazil.
authors.forename: Carolina Ávila
authors.initials: CÁ
authors.lastname: Vianna
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Brazil.
authors.forename: Denise Petrucci
authors.initials: DP
authors.lastname: Gigante
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Brazil.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Barros
authors.affiliation: Medical Research Council, Epidemiology Unit, University of Cambridge, United Kingdom; Department of Sport Medicine, Norwegian School of Sport Sciences, Oslo, Norway.
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Brazil.
authors.forename: Pedro Curi
authors.initials: PC
authors.lastname: Hallal
mesh_terms: D000054:Acceleration; D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D001938:Brazil; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D009043:Motor Activity; D063177:Pulse Wave Analysis; D057185:Sedentary Behavior; D014463:Ultrasonography; D059289:Vascular Stiffness; D055105:Waist Circumference; D055815:Young Adult
keywords: Cohort studies; Physical activity; Vascular stiffness