Residential exposure to deadly gun violence and accelerated biological aging in a national sample of U.S. adolescents.

Background: Gun violence is a traumatic and pervasive neighborhood stressor with far-reaching consequences for population health. However, less is known about how gun violence exposure becomes biologically embedded during adolescence, a sensitive period for shaping aging trajectories. We examined whether residential exposure to deadly gun violence is associated with accelerated biological aging in a diverse sample of U.S. adolescents. Methods: The sample included 1,781 15-year-olds in the Future of Families and Child Well-being Study (2014-2017). Neighborhood-level gun violence was defined as the count of fatal shootings within 1600 m (∼1 mile) of respondents' homes in the prior year. Accelerated biological aging was measured using a composite of three epigenetic clocks (GrimAge, PhenoAge, DunedinPACE). Propensity score matching balanced exposed and unexposed adolescents on race/ethnicity, socioeconomic characteristics, and area-level crime; weighted linear regression models targeting the average treatment effect on the treated then estimated associations between exposure counts and biological aging in the matched sample (n = 499). Results: Approximately half of adolescents (51.3%) lived near at least one deadly shooting in the prior year. Among exposed adolescents in the matched sample (n = 265), the mean exposure count was 3.24 (SD = 3.50). Greater exposure to deadly gun violence was associated with accelerated biological aging (β = 0.033; 95% CI, 0.003 to 0.064). Conclusions: Adolescent exposure to deadly gun violence may be linked to epigenetic markers of aging-related health risk, suggesting that chronic early-life exposure may have lasting implications for long-term health and aging.