Socioeconomic Disadvantage and the Pace of Biological Aging in Children

Abstract

Background and objectives: Children who grow up in socioeconomic disadvantage face increased burden of disease and disability throughout their lives. One hypothesized mechanism for this increased burden is that early-life disadvantage accelerates biological processes of aging, increasing vulnerability to subsequent disease. To evaluate this hypothesis and the potential impact of preventive interventions, measures are needed that can quantify early acceleration of biological aging in childhood.

Methods: Saliva DNA methylation and socioeconomic circumstances were measured in N = 600 children and adolescents aged 8 to 18 years (48% female) participating in the Texas Twin Project. We measured pace of biological aging using the DunedinPoAm DNA methylation algorithm, developed to quantify the pace-of-aging-related decline in system integrity. We tested if children in more disadvantaged families and neighborhoods exhibited a faster pace of aging as compared with children in more affluent contexts.

Results: Children living in more disadvantaged families and neighborhoods exhibited a faster DunedinPoAm-measured pace of aging (r = 0.18; P = .001 for both). Latinx-identifying children exhibited a faster DunedinPoAm-measured pace of aging compared with both White- and Latinx White-identifying children, consistent with higher levels of disadvantage in this group. Children with more advanced pubertal development, higher BMI, and more tobacco exposure exhibited faster a faster DunedinPoAm-measured pace of aging. However, DunedinPoAm-measured pace of aging associations with socioeconomic disadvantage were robust to control for these factors.

Conclusions: Children growing up under conditions of socioeconomic disadvantage exhibit a faster pace of biological aging. DNA methylation pace of aging might be useful as a surrogate end point in evaluation of programs and policies to address the childhood social determinants of lifelong health disparities.

FIGURE 1

Associations between family- and neighborhood-level socioeconomic disadvantage and DunedinPoAm-measured pace of aging. DunedinPoAm-measured pace of aging and socioeconomic disadvantage values are in SD units. Higher values indicate a methylation profile of faster biological aging. Regression is estimated from a linear mixed-effects model that accounts for nesting of children within families. The shaded areas represent the smoothed lower and upper 95% CIs.

FIGURE 2

DunedinPoAm-measured pace of aging in children identifying as White, Latinx, and Latinx-White. DunedinPoAm-measured pace of aging values are in SD units. Higher values indicate a methylation profile of faster biological aging. Regression is estimated from linear mixed-effects model that accounts for nesting of children within families. The boxplot reveals group differences in the mean DunedinPoAm-measured pace of aging (black circle), SEs of the mean (error bars), and the first and third quartiles (lower and upper hinges). Group differences were significant at the α = .05 threshold, without adjustment for differences in socioeconomic disadvantage between groups (left panel), but were no longer significantly different from 0 when controlling for family- and neighborhood-level disadvantage (right panel).