Telomere dynamics across the early life course: Findings from a longitudinal study in children

Abstract

Telomeres are protective caps on chromosome ends that shorten with each cell division. Telomere length (TL) predicts the onset of cellular senescence and correlates with longevity and age-related disease risk. Previous research suggests that adults display fixed ranking and tracking of TL by age 20 years, supporting the importance of TL at birth and attrition during childhood. However, longitudinal research examining telomere dynamics during early life is sparse. Here, we used monochrome multiplex quantitative polymerase chain reaction to measure relative TL in leukocytes isolated from cord blood and child blood collected at ages 3, 5, 7, and 9 years among 224 minority children enrolled in a New York City-based birth cohort. We also measured maternal TL at delivery in a subset of 197 participants with a biobanked blood sample. TL decreased most rapidly in the first years of life (birth to 3 years), followed by a period of maintenance into the pre-puberty period. Mothers with longer telomeres gave birth to newborns with longer telomeres that remained longer across childhood, suggesting that the fixed ranking and tracking of TL observed among adults may extend to early childhood or even the prenatal period with a potential transgenerational basis. We did not find significant sex differences in the pattern of child TL change across development. These findings emphasize the need to understand factors and mechanisms that determine TL during early childhood.

Keywords: Childhood; Development; Epidemiology; Prenatal; Telomere length.

Figure 1.

Relative leukocyte telomere length across age (n=224) predicted from a mixed effects model with a cubic spline. Individual lines correspond to children and the black line reflects the population-level mean. Storage duration is fixed at the mean for all samples and all follow-up ages.

Figure 2.

Relationship between maternal and cord blood relative leukocyte telomere length (rLTL) among 197 mother-newborn pairs. Shading reflects 95% confidence interval around the predicted line.

Figure 3.

Child relative leukocyte telomere length across age (n=224) predicted from a cubic spline mixed effects model stratified by high vs. low maternal rLTL at delivery based on dichotomization at the maternal rLTL median. Individual lines correspond to children and the bold lines reflects the population-level means for each group. Storage duration is fixed at the mean for all samples and all follow-up ages.

Figure 4.

Associations between participant characteristics and relative leukocyte telomere length (rLTL) in maternal and cord blood collected after delivery. All models are adjusted for sample storage duration. Bars around each marker reflect 95% confidence intervals.

Figure 5.

Child relative leukocyte telomere length (rLTL) across age (n=224) predicted from a cubic spline mixed effects model stratified by child sex. Individual lines correspond to children and the bold lines reflects the population-level change for each group. Storage duration is fixed at the mean for all samples and all follow-up ages.