Time-dependent associations between early high-sensitivity C-reactive protein levels and post-traumatic stress disorder after physical injury.

High-sensitivity C-reactive protein (hsCRP) is a widely used marker of systemic inflammation, yet longitudinal evidence for its association with post-traumatic stress disorder (PTSD) is limited and mixed. We investigated whether early post-injury hsCRP is associated with PTSD across two years. Adults hospitalized for moderate-to-severe physical injuries were consecutively enrolled at a single trauma center. Within one month of hospitalization, fasting morning blood was collected for hsCRP (Tina-quant high-sensitivity assay), and sociodemographic and clinical covariates were assessed. PTSD was determined at 3, 6, 12, and 24 months using structured telephone interviews with the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5). Analyses included participants with ≥1 follow-up. Multivariable regression models adjusted for age, sex, injury severity, education, marital status, psychiatric history, prior trauma, smoking, depression, and heart rate. Bonferroni correction set α=0.01 for five comparisons (any PTSD and four time points). Of 1,002 enrollees with baseline blood, 923 (92.1%) had ≥1 follow-up; 112 (12.1%) developed PTSD over 24 months (prevalence: 8.8% at 3 months, 7.6% at 6 months, 4.8% at 12 months, 3.7% at 24 months). Median baseline hsCRP was 18.9 mg/L. Higher baseline hsCRP was significantly associated with PTSD at 3 and 6 months after covariate adjustment and multiplicity control (α=0.01), but not at 12 or 24 months; the association with "any PTSD" attenuated after correction. Early post-injury hsCRP is associated with short-term PTSD risk (3-6 months) but not with later PTSD (12-24 months), supporting a time-limited inflammatory window and the pragmatic use of hsCRP for short-term risk stratification after trauma.