Longitudinal changes in leukocyte telomere length and mortality in humans

Abstract

Background. Leukocyte telomere length (LTL) ostensibly shortens with age and has been moderately associated with mortality. In humans, these fndings have come almost solely from cross-sectional studies. Only recently has LTL shortening within individuals been analyzed in longitudinal studies. Such studies are relevant to establish LTL dynamics as biomarkers of mortality as well as to disentangle the causality of telomeres on aging. Methods. We present a large longitudinal study on LTL and human mortality, where the 10-year change of LTL is analyzed in 1,356 individuals aged 30-70 years. Results. We fnd age, smoking status, and alcohol consumption to be associated with LTL attrition and confrm a strong association with baseline LTL. The latter association might be an epiphenomenon of regression to the mean. We do not fnd an association of mortality with either absolute LTL or LTL attrition. Further, we show that DNA quality has an impact on TS ratios. Conclusions. This study establishes that certain lifestyle factors infuence LTL dynamics. However, it questions the applicability of LTL dynamics as a predictor of mortality. We suggest cautiousness when assessing actual LTL attrition due to the need for high-quality DNA and the phenomena of regression to the mean. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America.