Associations of post-traumatic stress disorder and metabolic syndrome with accelerated brain aging in South African adults: A case-control study

Post-traumatic stress disorder (PTSD) and metabolic syndrome (MetS) are both associated with childhood trauma (CT) and accelerated brain aging. We examined the putative moderating effects of CT exposure on the associations of PTSD diagnosis and MetS status with brain aging in cases (n = 97) compared to trauma-exposed controls (n = 87). Brain age predictions were generated from T1-weighted magnetic resonance image scans using a pre-trained machine learning pipeline (brainageR). A measure of relative brain aging known as "predicted age difference" (PAD) was calculated by subtracting chronological age from the predicted brain age. Results showed that increased waist circumference was associated with a higher PAD, while CAPS-5 scores were associated with a lower PAD. MetS status was also associated with increased PAD in adults with lower CT exposure. The association between higher brain age difference scores and CT were more pronounced in participants with lower triglyceride levels. We found that increased waist circumference correlated with an increased PAD, independent of PTSD diagnosis. Future research should elucidate the possible mechanisms of accelerated brain aging and the protective factors that may slow its progression.