The Biological Embedding of Community and Household Level Stress in Children
To enhance the understanding of biological mechanisms connecting early adversity and negative health, we examine the association between community and household stressors and telomere length (TL) in youth. These specific exposures were selected due to their established links with negative health consequences across the life-course.
METHODS:
Children age 4-14 from 87 neighborhoods were recruited through five urban schools in New Orleans, Louisiana, U.S. Cross-sectional data were collected at the level of the child, family/household, and neighborhood. DNA was obtained from saliva and buccal swabs using commercially available kits and TL was determined for 104 children using quantitative PCR.
RESULTS:
The mean TL value was 7.4 T/S ratio units (± 2.4, range=2.5-18.0), and 4.7% of the variance in TL was attributed to differences across neighborhoods. We observed a wide range of environmental impacts on cellular stress. Children living in neighborhoods characterized by high disorder had an TL value 3.2 units lower than children not living in high disordered environments (p<0.05) and their odds of having low relative TL values was 3.43 times that of children not living in high disorder environments (adjusted OR=3.43, 95% CI=1.22, 9.62). 18% of children had prenatal tobacco smoke exposure (PTE), defined as either maternal smoking during pregnancy or smoke exposure in the home during pregnancy. Mean TL was significantly lower among children with PTE (6.4 vs. 7.5, p < 0.05). Finally, cumulative exposure to interpersonal violence and family disruption was correlated with TL in a sex-dependent manner and TL was significantly shorter in children with higher exposure to family violence and disruption.
CONCLUSIONS:
Our findings are consistent with previous studies in adults demonstrating a strong link between psychosocial stress and TL and offer support for the hypothesis that TL represents a biological indicator of environmental and psychosocial stress exposure, with detectable differences even in children.