Leukocyte Telomere Dynamics: Longitudinal Findings Among Young Adults in the Bogalusa Heart Study

摘要

Leukocyte telomere length (LTL) is ostensibly a biomarker of human aging. Cross-sectional analyses have foundnthat LTL is relatively short in a host of aging-related diseases. These studies have also provided indirect estimatesnof age-dependent LTL shortening. In this paper, the authors report findings of the first comprehensive longitudinalnstudy of 450 whites and 185 African Americans in Louisiana (aged 31.4 and 37.4 years at baseline (1995–1996)nand follow-up (2001–2006) examinations, respectively) participating in the Bogalusa Heart Study. Rate of changenin LTL was highly variable among individuals, with some displaying a paradoxical gain in LTL during the follow-upnperiod. The most striking observation was that age-dependent LTL shortening was proportional to LTL at baselinenexamination. At both baseline and follow-up examinations, African Americans had longer LTLs than whites, andnsmokers had shorter LTLs than nonsmokers. The longer LTL in African Americans than in whites explained in partnthe faster rate of LTL shortening observed among African Americans. These findings underscore the complexity ofnleukocyte telomere dynamics in vivo and suggest that determinants in addition to the ‘‘end-replication problem’’ncontribute to telomere shortening in vivo.