title: Physical fitness and telomere length in patients with coronary heart disease: findings from the Heart and Soul Study.
abstract: BACKGROUND
  Short telomere length (TL) is an independent predictor of mortality in patients with coronary heart disease (CHD). However, the relationship between physical fitness and TL has not been explored in these patients.
  
  
  METHODS
  In a cross sectional study of 944 outpatients with stable CHD, we performed exercise treadmill testing, assessed self-reported physical activity, and measured leukocyte TL using a quantitative PCR assay. We used generalized linear models to calculate mean TL (T/S ratio), and logistic regression models to compare the proportion of patients with short TL (defined as the lowest quartile), among participants with low, medium and high physical fitness, based on metabolic equivalent tasks achieved (METs).
  
  
  RESULTS
  229 participants had low physical fitness (<5 METS), 334 had moderate physical fitness (5-7 METS), and 381 had high physical fitness (>7 METS). Mean ± T/S ratio ranged from 0.86±0.21 (5349±3781 base pairs) in those with low physical fitness to 0.95±0.23 (5566±3829 base pairs) in those with high physical fitness (p<.001). This association remained strong after adjustment for numerous patient characteristics, including measures of cardiac disease severity and physical inactivity (p = 0.005). Compared with participants with high physical fitness, those with low physical fitness had 2-fold greater odds of having TL in the lowest quartile (OR 2.39, 95% CI 1.60-3.55; p<.001). This association was similar after multivariable adjustment (OR 1.94, 95%CI, 1.18-3.20; p = 0.009). Self-reported physical inactivity was associated with shorter TL in unadjusted analyses, but not after multivariable adjustment.
  
  
  CONCLUSIONS
  We found that worse objectively-assessed physical fitness is associated with shorter leukocyte telomere length in patients with CHD. The clinical implications of this association deserve further study.
authors.affiliation: School of Medicine, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Krauss
authors.forename: Ramin
authors.initials: R
authors.lastname: Farzaneh-Far
authors.forename: Eli
authors.initials: E
authors.lastname: Puterman
authors.forename: Beeya
authors.initials: B
authors.lastname: Na
authors.forename: Jue
authors.initials: J
authors.lastname: Lin
authors.forename: Elissa
authors.initials: E
authors.lastname: Epel
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Blackburn
authors.forename: Mary A
authors.initials: MA
authors.lastname: Whooley
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003327:Coronary Disease / Q000235:genetics*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D016615:Telomere / Q000235:genetics*
references.citation: J Cell Sci. 2004 May 1;117(Pt 11):2417-26
references.pmid: 15126641
references.citation: Arch Intern Med. 2008 Jan 28;168(2):154-8
references.pmid: 18227361
references.citation: Arterioscler Thromb Vasc Biol. 2003 May 1;23(5):842-6
references.pmid: 12649083
references.citation: Biol Psychiatry. 2010 Mar 15;67(6):531-4
references.pmid: 19828140
references.citation: Mech Ageing Dev. 2008 May;129(5):254-60
references.pmid: 18295822
references.citation: J Am Coll Cardiol. 2007 Apr 3;49(13):1459-64
references.pmid: 17397675
references.citation: Hypertension. 2004 Feb;43(2):182-5
references.pmid: 14732735
references.citation: Arterioscler Thromb Vasc Biol. 2008 Jul;28(7):1379-84
references.pmid: 18467646
references.citation: JAMA. 2008 Nov 26;300(20):2379-88
references.pmid: 19033588
references.citation: Free Radic Biol Med. 2008 Jan 15;44(2):126-31
references.pmid: 18191748
references.citation: Am J Clin Nutr. 2008 Nov;88(5):1405-12
references.pmid: 18996878
references.citation: Lancet. 2007 Jan 13;369(9556):107-14
references.pmid: 17223473
references.citation: Lancet. 2001 Aug 11;358(9280):472-3
references.pmid: 11513915
references.citation: Circulation. 2009 Dec 15;120(24):2438-47
references.pmid: 19948976
references.citation: J Clin Endocrinol Metab. 2006 Feb;91(2):635-40
references.pmid: 16303830
references.citation: Cell. 2001 Sep 21;106(6):661-73
references.pmid: 11572773
references.citation: Clin Chim Acta. 2009 May;403(1-2):139-41
references.pmid: 19217888
references.citation: Circ Res. 2006 Nov 24;99(11):1167-80
references.pmid: 17122447
references.citation: Eur Heart J. 2007 Jan;28(2):172-6
references.pmid: 17215319
references.citation: Arterioscler Thromb Vasc Biol. 2008 Jun;28(6):1165-71
references.pmid: 18388332
references.citation: Biochem Biophys Res Commun. 2006 Sep 22;348(2):669-72
references.pmid: 16890917
references.citation: Nucleic Acids Res. 2002 May 15;30(10):e47
references.pmid: 12000852
references.citation: J Am Coll Cardiol. 2008 Aug 5;52(6):470-82
references.pmid: 18672169
references.citation: Eur J Vasc Endovasc Surg. 2010 May;39(5):559-64
references.pmid: 20172749
references.citation: Exp Cell Res. 1995 Sep;220(1):186-93
references.pmid: 7664835
references.citation: Nature. 1991 Apr 18;350(6319):569-73
references.pmid: 1708110
references.citation: PLoS One. 2010 Jan 08;5(1):e8612
references.pmid: 20072607
references.citation: Am J Cardiol. 2010 Sep 1;106(5):659-63
references.pmid: 20723641
references.citation: Ann N Y Acad Sci. 2000 Jun;908:99-110
references.pmid: 10911951
references.citation: Aging Cell. 2007 Oct;6(5):639-47
references.pmid: 17874998
references.citation: J Hypertens. 2007 Nov;25(11):2185-92
references.pmid: 17921808
references.citation: N Engl J Med. 2002 Mar 14;346(11):793-801
references.pmid: 11893790
references.citation: Circ Res. 2004 Apr 2;94(6):768-75
references.pmid: 14963003
references.citation: Diabetes Care. 2006 Feb;29(2):283-9
references.pmid: 16443874
references.citation: FEBS Lett. 1999 Jun 25;453(3):365-8
references.pmid: 10405177
references.citation: J Immunol Methods. 2010 Jan 31;352(1-2):71-80
references.pmid: 19837074
references.citation: Lancet. 2003 Feb 1;361(9355):393-5
references.pmid: 12573379
references.citation: Mech Ageing Dev. 2010 Feb;131(2):165-7
references.pmid: 20064545
references.citation: Biogerontology. 2005;6(1):71-5
references.pmid: 15834665
references.citation: Public Health Nutr. 1998 Dec;1(4):265-71
references.pmid: 10933427
references.citation: Med Sci Sports Exerc. 2008 Oct;40(10):1764-71
references.pmid: 18799986
references.citation: Atherosclerosis. 2003 Apr;167(2):327-34
references.pmid: 12818416
references.citation: Circ Res. 2006 Jul 21;99(2):156-64
references.pmid: 16794190
references.citation: J Appl Physiol (1985). 2005 Apr;98(4):1154-62
references.pmid: 15772055
references.citation: Circulation. 2001 Oct 2;104(14):1694-740
references.pmid: 11581152
references.citation: PLoS One. 2010 May 26;5(5):e10837
references.pmid: 20520771
references.citation: Circulation. 2005 May 3;111(17):2171-7
references.pmid: 15851602
references.citation: Proc Natl Acad Sci U S A. 2004 Dec 7;101(49):17312-5
references.pmid: 15574496
references.citation: Aging Cell. 2006 Aug;5(4):325-30
references.pmid: 16913878
references.citation: J Gen Intern Med. 2001 Sep;16(9):606-13
references.pmid: 11556941
references.citation: Physiol Rev. 2008 Apr;88(2):557-79
references.pmid: 18391173
references.citation: Mol Biotechnol. 2004 Jun;27(2):169-72
references.pmid: 15208457
references.citation: Br J Sports Med. 2003 Jun;37(3):197-206; discussion 206
references.pmid: 12782543
references.citation: Arch Intern Med. 2008 Oct 27;168(19):2163-4
references.pmid: 18955647