Demographic and health predictors of telomere length during adolescence

Abstract

Telomere length (TL) is proposed to play a mechanistic role in how the exposome affects health outcomes. Little is known about TL during adolescence, a developmental period during which precursors of adult‐onset health problems often emerge. We examined health and demographic sources of variation in TL in 899 youth aged 11–17. Demographic and health information included age, sex, race, household income, caregiver age and marital status, youth tobacco exposure, body mass index, pubertal status, health problems, medication use, and season of data collection. Genomic DNA was extracted from saliva, and T/S ratios were computed following qPCR. Age, race, season of data collection, and household income were associated with the telomere to single copy (T/S) ratio. We found that T/S ratios were larger at younger ages, among Black youth, for saliva collected during autumn and winter, and among households with higher income. Analyses stratified by race revealed that the association between age and T/S ratio was present for Black youth, that season of collection was present across races, but that family demographic associations with T/S ratio varied by race. The results provide information for future telomere research and highlight adolescence as a potentially important developmental phase for racial disparities in telomere shortening and health.

The Social Environment Matters for Telomere Length and Internalizing Problems During Adolescence

“…The date of salivary DNA collection was used to create an indicator of season. Based on prior research indicating seasonal variation in telomere length (Kertes et al, 2022 ), season was dichotomized as autumn/winter (September-February) and spring/summer (March-August) for inclusion in analyses.…”

“…Conceptually, the relative average telomere length for an individual participant is generated such that the telomere signal is normalized to the signal from a single copy gene to generate a T/S ratio. Telomere length assay protocols are reported in detail in Kertes et al ( 2022 ). In brief, genomic DNA telomere length was assessed via quantitative polymerase chain reactions (qPCR) using telomere and single-copy gene albumin primers (Eurofins Genomics, Louisville, Kentucky) run in triplicate with HeLa genomic DNA (New England BioLabs, Ipswich, Massachusetts) to create a 5-point standard curve (1.56 to 25 ng/µL).…”

“…The effects of age, sex, and season of data collection were controlled for by assigning them a prior likelihood of 1 (i.e., must be included as factors in the model). This was done to compensate for the effects of demographic and seasonal influences demonstrated in prior work in our cohort and others to covary with telomere length (Kertes et al, 2022 ; Ly et al, 2019 ).…”