Accelerated Epigenetic Aging in Veterans Exposed to Blast.

OBJECTIVE

To determine whether lifetime blast exposure severity is independently associated with accelerated biological aging among post-9/11 Veterans.

SETTING

Veterans Affairs medical centers in the southeastern United States.

PARTICIPANTS

In total, 114 post-9/11 combat Veterans (43.0 ± 9.6 years; 88.6% male) who completed detailed clinical interviews and provided whole-blood DNA samples were included.

DESIGN

Cross-sectional analysis of participants enrolled in 2 coordinated VA research protocols: the Chronic Effects of Neurotrauma Consortium Study 34 and the Post-Deployment Mental Health Study.

MAIN MEASURES: Lifetime blast exposure severity (Salisbury Blast Interview), posttraumatic stress disorder (PTSD) diagnosis (Clinician-Administered PTSD Scale for DSM-5), and mild traumatic brain injury (TBI) history (Mid-Atlantic MIRECC Assessment of TBI) were assessed with clinical interviews. Biological aging was measured using DunedinPACE , an epigenetic biomarker of the pace of aging derived from whole-blood DNA methylation data. Hierarchical linear regression tested additive and interactive effects of blast exposure, PTSD, and TBI, adjusting for demographic and technical covariates.

RESULTS

Greater blast exposure severity was significantly associated with faster DunedinPACE scores (B = 0.12; P = .042), indicating accelerated biological aging. Mild TBI history was also independently associated with faster aging (B = 0.50; P = .036), whereas PTSD diagnosis was not (B = 0.01; P = .970). No significant interaction effects were observed. Exploratory analyses suggested that higher-intensity and more frequent blast exposures contributed to faster accelerated aging.

CONCLUSIONS

Lifetime blast exposure severity was independently associated with accelerated epigenetic aging in post-9/11 Veterans, even after accounting for PTSD and TBI. These findings suggest that blast exposure may promote biological aging processes contributing to long-term health decline. Accelerated biological aging may represent a pathway linking blast exposure to increased vulnerability for age-related disease and could inform early identification of at-risk Veterans through biomarkers such as DunedinPACE .