Telomere length and early severe social deprivation: linking early adversity and cellular aging

Abstract

Accelerated telomere length attrition has been associated with psychological stress and early adversity in adults; however, no studies have examined whether telomere length in childhood is associated with early experiences. The Bucharest Early Intervention Project is a unique randomized controlled trial of foster care placement compared with continued care in institutions. As a result of the study design, participants were exposed to a quantified range of time in institutional care, and represented an ideal population in which to examine the association between a specific early adversity, institutional care and telomere length. We examined the association between average relative telomere length, telomere repeat copy number to single gene copy number (T/S) ratio and exposure to institutional care quantified as the percent of time at baseline (mean age 22 months) and at 54 months of age that each child lived in the institution. A significant negative correlation between T/S ratio and percentage of time was observed. Children with greater exposure to institutional care had significantly shorter relative telomere length in middle childhood. Gender modified this main effect. The percentage of time in institutional care at baseline significantly predicted telomere length in females, whereas the percentage of institutional care at 54 months was strongly predictive of telomere length in males. This is the first study to demonstrate an association between telomere length and institutionalization, the first study to find an association between adversity and telomere length in children, and contributes to the growing literature linking telomere length and early adversity.

Figure 1

Flow of participants in the Bucharest Early Intervention Project: ever institutionalized. This consort diagram presents the placement and movement of the participants in the Bucharest Early Intervention Project study, from assessment through 54 months of age. Although original group designation at baseline to either continued institutional care (CAUG) compared with newly created MacArthur foster care (FCG) was random, note that significant placement changes occurred in both groups by 54 months of age.

Figure 2

Percent institution at baseline by gender. Adjusted robust regression line plotted to demonstrate the association between percent of time a child had been in institutional care at baseline, by gender and telomere length.

Figure 3

Percent institution at 54 months by gender. Adjusted robust regression line plotted to demonstrate the association between percent of time a child had been in institutional care at 54 months of age, by gender and telomere length.