Telomere Length and Change Among Infants Growing up in Low- to Mid-Income Households.

Telomere biology is a molecular mechanism that may underlie relationships between stress and health outcomes and has been shown to vary across racial and ethnic groups. Telomere length may also be susceptible to the deleterious impacts of stress during early development. However, limited research has examined these associations in diverse samples using repeated measures in infancy. This study assessed longitudinal change in telomere length across three time points in the first year of life (n = 90) in a diverse sample of infants (53.3% female, 30% Black, and 35.6% Hispanic) from low- to middle-income backgrounds. We also examined associations between maternal psychological stress, sociodemographic characteristics, COVID-19 pandemic onset, and infant telomere length. In this sample, female infants had longer telomeres than male infants. Additionally, visit timepoint significantly predicted infant telomere length, showing nonlinear patterns of change over time. Maternal psychological distress, sociodemographic characteristics, and the onset of the COVID-19 pandemic were not associated with infant telomere length. Overall, these findings suggest that infant telomere length is dynamic in the first year of life, although larger and more socioeconomically heterogeneous samples may be needed to detect the effects of stress on infant telomere length.