Physical activity and telomere length in American Indians: the Strong Heart Study
Telomere length, a marker of biological aging, has been associated with many chronic diseases, but its relations with physical activity remains unclear. The purpose of this study was to examine the association of objectively measured ambulatory activity with leukocyte telomere length (LTL), a marker of biological aging, among American Indians. This cross-sectional study included 2312 AI participants from the Strong Heart Family Study. Steps per day were measured using Accusplit AE120 pedometers. Quantitative PCR was used to measure LTL. Generalized estimating equations were used to examine the associations of steps per day with LTL. The median steps per day over a 1 week period was 5118 steps (interquartile range = 3163–7576 steps). Compared to participants in the lowest quartile of steps per day, participants in the upper three quartiles of steps per day had longer LTL: beta ± SE = 0.0195 ± 0.0144, 0.0273 ± 0.0139, and 0.0375 ± 0.0143 T/S ratio units longer (p trend = 0.010) after adjustment for potential confounders. These data suggest that ambulatory activity is associated with LTL. Further studies are needed to determine the mechanism by which ambulatory activity influences LTL.
KeywordsPhysical activity Telomeres American Indians Pedometer
The Strong Heart Family Study (SHFS) is supported by the National Institutes of Health Grants R01DK091369, K01AG034259, R21HL092363, and cooperative agreement Grants U01 HL65520, U01HL41642, U01HL41652, U01HL41654, and U01HL65521. Amanda M. Fretts is also supported by KL2TR000421. The authors acknowledge the assistance and cooperation of the participating tribes, the Indian Health Service hospitals and clinics at each center, the directors of the Strong Heart Study clinics, the field coordinators, and their staffs. The opinions expressed in this article are those of the authors and do not necessarily reflect the views of the Indian Health Service.
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Conflict of interest
The authors report no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.