title: Physical Activity, Physical Fitness, and Leukocyte Telomere Length: The Cardiovascular Health Study.
abstract: BACKGROUND
  The influence of physical activity (PA) and physical fitness (PF) at older ages on changes in telomere length (TL)--repetitive DNA sequences that may mark biologic aging--is not well-established. Few prior studies (mainly cross-sectional) have been conducted in older adults, and few studies have evaluated PF.
  
  
  METHODS
  We investigated cross-sectional and prospective associations of PA and PF with leukocyte TL among 582 older adults (mean ± SD age, 73 ± 5 yr at baseline) in the Cardiovascular Health Study, with serial TL measures and PA and PF assessed multiple times. Cross-sectional associations were assessed using multivariable repeated-measures regression, in which cumulatively averaged PA and PF measures were related to TL. Longitudinal analyses assessed cumulatively averaged PA and PF against later changes in TL, and changes in cumulatively averaged PA and PF against changes in TL.
  
  
  RESULTS
  Cross-sectionally, greater walking distance and chair test performance, but not other PA and PF measures, were each associated with longer TL (P trend = 0.007 and 0.04, respectively). In longitudinal analyses, no significant associations of baseline PA and PF with change in TL were observed. In contrast, changes in leisure-time activity and chair test performance were each inversely associated with changes in TL.
  
  
  CONCLUSIONS
  Cross-sectional analyses suggest that greater PA and PF are associated with longer TL. Prospective analyses show that changes in PA and PF are associated with differences in changes in TL. Even later in life, changes in certain PA and PF measures are associated with changes in TL, suggesting that leisure-time activity and fitness could reduce leukocyte telomere attrition among older adults.
authors.affiliation: 1Research Center in Physical Activity Health and Leisure, Faculty of Sport, University of Porto, Porto, PORTUGAL; 2MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UNITED KINGDOM; 3New York Academy of Medicine, New York, NY; 4Department of Epidemiology, University of Washington, Seattle, WA; 5Department of Pathology, University of Vermont College of Medicine, Burlington, VT; and 6Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA.
authors.forename: Luisa
authors.initials: L
authors.lastname: Soares-Miranda
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Imamura
authors.forename: David
authors.initials: D
authors.lastname: Siscovick
authors.forename: Nancy Swords
authors.initials: NS
authors.lastname: Jenny
authors.forename: Annette L
authors.initials: AL
authors.lastname: Fitzpatrick
authors.forename: Dariush
authors.initials: D
authors.lastname: Mozaffarian
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D018737:Hand Strength; D006801:Humans; D007962:Leukocytes / Q000166:cytology*; D008297:Male; D009043:Motor Activity; D010809:Physical Fitness; D011446:Prospective Studies; D059505:Telomere Homeostasis; D016138:Walking / Q000502:physiology