Tulane University of Louisiana
Telomere Length as a Biological Marker of Allostatic Load in Children
Katherine P. Theall
The goal of this research is to evaluate the validity of telomere length as a biomarker of physiological dysregulation or allostatic load (AL) in children. AL describes the cumulative wear and tear on physiological systems and organs due to environmental exposures or other adverse conditions. An assortment of biomarkers currently exists to measure components of AL across a variety of different physiological systems.
Each of these measures has limitations in collection and interpretation, especially in children whose biologic response to AL may not yet be detectable. Consequently, very few studies have focused on biological risk of AL in children. Furthermore, many traditional AL biomarkers may not be appropriate for younger age groups given their developmental stage. These factors make identifying and validating a biomarker for AL that is objective, distinct from disease or risk state, and amenable to longitudinal, noninvasive collection would represent a significant and innovative contribution to research on AL and health disparities.
Telomere length is a known marker of the cellular aging process and a potential biomarker of AL that is truly cumulative, given increasing evidence linking psychosocial stress and shortened telomere length. Our research takes advantage of a unique opportunity to validate telomere length as a biomarker of AL among children by using DNA samples already obtained. These samples come from a community-based sample of 260 African American children ages 4 to 14 years from inner-city New Orleans neighborhoods whose cumulative risk and/or stress exposure can be characterized at the individual, household, school and neighborhood levels.
For this study, we have established a longitudinal cohort that allows tracking of telomere length and other AL biomarkers in relation to cumulative risk exposure derived from multiple levels (i.e., individual, household, school, and neighborhood). To accomplish this broad goal, our work addresses the following specific aims:
- Establishing a sex and age matched cohort of 260 children from 87 census tracts for which saliva and traditional AL markers as well as psychosocial and environmental measures of stress characterized at multiple levels (i.e. individual, household, and neighborhood). These samples are combined with baseline data to include repeated samples of telomere length, for the first time, across a varied age range of children.
- Evaluating the validity of telomere length as a biomarker of AL. The longitudinal design also permits exploration of whether earlier versus concurrent stress exposure and whether distal versus more proximal stress exposure are associated with telomere length changes.