Sex-Specific and Time-Varying Associations Between Cigarette Smoking and Telomere Length Among Older Adults

Am J Epidemiol. 2016 Dec 15;184(12):922-932. doi: 10.1093/aje/kww102. Epub 2016 Nov 17.


Inconsistent associations between smoking and telomere length (TL) have been reported in epidemiologic studies, perhaps because of the time-varying nature of smoking behaviors. We estimated the associations of TL, which was measured by quantitative polymerase chain reaction using saliva DNA, with concurrent and past smoking status reported biennially for up to 16 years before TL measurement in 5,624 participants in the Health and Retirement Study (1992-2008). Smoking was associated with reduced TL when we used prospective data on smoking statuses among men and women, but the association was strongly attenuated among men in cross-sectional analyses. This attenuation was largely due to a higher rate of smoking cessation during the study period among men with shorter TL than among men with longer TL. Short TL was also associated with poorer overall health in men, which suggests that male smokers with short TL were more likely to quit smoking because of poor health. Analyses of years since cessation, smoking duration, and pack-years of smoking all support the hypothesis that increased cigarette use shortens TL. Our results provide a potential explanation for the inconsistent associations between smoking and TL reported in previous cross-sectional studies. Time-varying associations should be considered in future studies of smoking behavior, TL, aging, and disease risk.

Keywords: Health and Retirement Study; aging; sex; smoking; smoking cessation; telomere length.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / blood
  • Aging / drug effects
  • Biomarkers / blood
  • DNA / analysis
  • Female
  • Health Status
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Oxidative Stress / drug effects
  • Polymerase Chain Reaction
  • Prospective Studies
  • Saliva / chemistry*
  • Sex Distribution
  • Smoking / adverse effects*
  • Smoking / blood
  • Smoking / genetics
  • Smoking Cessation / statistics & numerical data*
  • Telomere Shortening / drug effects*
  • Telomere Shortening / genetics


  • Biomarkers
  • DNA