Abstract P417: Physical Activity, Physical Fitness and Leukocyte Telomere Length: The Cardiovascular Health Study

Abstract

Background The influence of physical activity (PA) and fitness (PF) at older ages on changes in telomere length (TL), repetitive DNA sequences that may mark biologic aging, are not well established. Prior studies in older adults were cross-sectional, and few evaluated PF. Aim To investigate both cross-sectional and prospective associations of PA and PF with Leukocyte TL in older adults. Methods Among 582 adults age 73±5 y at baseline in CHS having serial LTL measures (leucocyte mean terminal restriction length) in 1992 and 1997, PA (walking pace, blocks, combined walking score; leisure time activity) and PF (15-ft walk, chair stands, grip strength) were assessed multiple times from 1989 to 1997. Cross-sectional associations were assessed using multivariable repeated-measures regression of cumulative average serial PA and PF measures from 1989 to 1992 against LTL in 1992; and cumulative averaged PA and PF from 1993 to 1997 against LTL in 1997. Longitudinal analyses assessed cumulative averaged PA and PF from 1989-92 against later changes in LTL from 1992-97; and changes in cumulative averaged PA and PF from 1989-92 to 1993-97 against changes in LTL from 1992-97. We evaluated all subjects, those without poor/fair self-reported health, and those without limited ADLs. Results Cross-sectionally, greater walking distance and chair test performance, but not other PA and PF measures, each associated with longer LTL ( P trend 0.007, 0.04 respectively). Lab measures of DNA integrity suggested measurable degradation that markedly attenuates ability to detect differences in LTL changes over time, especially over only 5 y. For example, baseline PA and PF from 1989-92 were unassociated with later changes in LTL. In contrast, changes in leisure time activity and chair test performance from 1992-97 were each inversely associated with LTL shortening. Conclusions Even late in life, certain PA and PF metrics are associated with longer LTL cross-sectionally and, even with likely substantial measurement error, with less LTL shortening over time.