title: Vascular endothelial function and leisure-time physical activity in adolescents.
abstract: BACKGROUND
  Exercise training improves endothelial function in high-risk adolescents, but the influence of habitual leisure-time physical activity on endothelial function in healthy adolescents is unknown.
  
  
  RESULTS
  Brachial artery flow-mediated endothelial function and physical activity habits were assessed in 483 adolescents (13 years of age) participating in an atherosclerosis prevention study (Special Turku Coronary Risk Factor Intervention Project for Children [STRIP]). Endothelial function was examined with ultrasound; physical activity was assessed with self-administered questionnaires. A leisure-time physical activity index was calculated by multiplying mean weekly leisure-time exercise intensity, duration, and frequency [boys, 31.2 +/- 23.0 MET h/wk (mean +/- SD); girls, 24.0 +/- 20.9 MET h/wk; P for gender difference=0.0003]. Maximum flow-mediated dilatation (FMD) and total FMD response (the area under the dilatation curve 40 to 180 seconds after hyperemia) were calculated. In boys, maximum FMD and area under the dilatation curve 40 to 180 seconds after hyperemia were directly associated with leisure-time physical activity index in regression analyses adjusted for brachial artery diameter (maximum FMD, P=0.020; area under the dilatation curve 40 to 180 seconds after hyperemia, P=0.0055). These associations remained significant after further adjustments for body mass index, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein, and systolic blood pressure. A difference of approximately 50 MET h/wk corresponding to approximately 10 hours of moderate intensity activity weekly between sedentary and active boys was associated with an approximately 1% unit difference in maximum FMD.
  
  
  CONCLUSIONS
  Leisure-time physical activity is directly associated with brachial artery FMD responses in 13-year-old boys, providing evidence that physical activity beneficially influences endothelial function in healthy male adolescents. Lack of association in girls may reflect their overall lower physical activity level.
authors.affiliation: University of Turku, Research Centre of Applied and Preventive Cardiovascular Medicine, Turku, Finland. katja.pahkala@utu.fi
authors.forename: Katja
authors.initials: K
authors.lastname: Pahkala
authors.forename: Olli J
authors.initials: OJ
authors.lastname: Heinonen
authors.forename: Hanna
authors.initials: H
authors.lastname: Lagström
authors.forename: Paula
authors.initials: P
authors.lastname: Hakala
authors.forename: Olli
authors.initials: O
authors.lastname: Simell
authors.forename: Jorma S A
authors.initials: JS
authors.lastname: Viikari
authors.forename: Tapani
authors.initials: T
authors.lastname: Rönnemaa
authors.forename: Miika
authors.initials: M
authors.lastname: Hernelahti
authors.forename: Lauri
authors.initials: L
authors.lastname: Sillanmäki
authors.forename: Olli T
authors.initials: OT
authors.lastname: Raitakari
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D001916:Brachial Artery / Q000502:physiology; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D006940:Hyperemia; D007899:Leisure Activities; D008055:Lipids / Q000097:blood; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014463:Ultrasonography; D014664:Vasodilation
chemical_list: D008055:Lipids