Determinants of Leukocyte Telomere Length at Birth

描述（由申请人提供）：造血干细胞储备的消耗，表现为白细胞端粒长度（LTL）的缩短，限制了寿命，增加了心血管疾病的风险。到目前为止，几乎所有关于LTL的研究都集中在成年人身上。然而，最近的证据表明，从受孕到出生影响LTL的因素可能与在生命过程中影响LTL的因素一样重要。出生时LTL的个体间差异是如此之大，以至于它可以与整个成年生命过程中LTL的平均缩短相媲美。此外，父亲受孕时的年龄也较高

DESCRIPTION (provided by applicant): Depletion of hematopoietic stem cell reserves, expressed as the shortening of leukocyte telomere length (LTL), sets a limit on longevity and increases the risk of cardiovascular disease. Until now, almost all research on LTL has focused on adults. Recent evidence suggests, however, that the factors which influence LTL from conception to birth could be as important as those which influence LTL over the remainder of the life course. The inter-individual variation in LTL at birth is so large that it rivals the averge shortening of LTL over the entire adult life course. In addition, higher paternal age at conception is associated with longer LTL in adult offspring, and since this effect must derive from the paternal germ line, it may be evident by the time of birth. However, no rigorous study has been done of the determinants of LTL at birth. This prospective investigation of the determinants of LTL at birth is an "ancillary study" which builds on a multisite NICHD-funded "parent study" of nulliparous women. The ancillary study will be done in 1,000 trios of mother, father, and baby. It will add to the rich array of data in the parent study in several ways, including the collection of paternal blood samples and the measurement of LTL in mothers, fathers, and babies for the 1,000 trios. The Aims of the study are to: 1) examine the relation of paternal age at conception (PAC) to LTL at birth, 2) examine whether maternal exposures and conditions are determinants of LTL at birth, 3) compare LTL at birth across sex, race/ethnicity and socioeconomic status, and 4) explore the relation of fetal growth rate to LTL at birth. This study will build a platform or further investigations including genetic and epigenetic influences on LTL at birth and changes in LTL during early childhood years. By identifying the determinants of LTL at birth, this research will provide a foundation for linking experience from conception to birth with health and longevity in later life. Moreover, this research has the potential to transform understanding of population health by opening novel investigations of the pathways through which intra-uterine experiences are biologically embedded in the individual's constitution, and might be reflected in risk factors for disease which emerge in childhood and evolve thereafter. PUBLIC HEALTH RELEVANCE: Much is known about telomere length (measured by leukocyte telomere length or LTL) in adults, and its important role in cardiovascular disease and longevity, but very little is known about LTL at birth. We do know, however, that individuals vary widely in LTL at birth, and this study examines whether exposures before birth (such as maternal exposures and paternal age at conception) explain the variation in LTL at birth. The results will help us understand whether interventions early in life (even as early as prenatal care) could improve the health of the population in later life.