Acute Endocrine Alterations After Traumatic Brain Injury and 6‐Month Functional Outcome
Biao Xu, Peng Guo, Rui Pan, Zhenghao Wang, Jingchao Zhou, Pengcheng Zhang, Xingzhe Zhang, Qinghua Zhang, Haibin Ma, Zhanfeng NiuABSTRACT
Objective
Acute multi‐axis endocrine alterations after traumatic brain injury (TBI) remain incompletely characterized. This study aimed to examine their temporal patterns and explore their associations with 6‐month functional outcome and early inflammatory markers.
Methods
We conducted a single‐center prospective observational cohort study of hospitalized adults with traumatic brain injury. Among 130 enrolled patients, 125 with complete 6‐month Glasgow Outcome Scale‐Extended follow‐up were included. Blood samples were collected on Day 1, 7, and 14 after injury to assess hypothalamic–pituitary–adrenal, thyroid, gonadal, and growth hormone axes. Day‐1 inflammatory markers were measured. Associations of individual biomarkers with unfavorable 6‐month outcome were evaluated using separate Firth penalized logistic regression models adjusted for admission Glasgow Coma Scale (GCS).
Results
Serum cortisol levels at 08:00 and 16:00 decreased significantly over time (Kendall's W = 0.205 [95% CI 0.085–0.388] and 0.239 [95% CI 0.126–0.408], respectively; both p < 0.001), whereas triiodothyronine, free triiodothyronine, and thyroid‐stimulating hormone increased during the acute phase. Patients with unfavorable 6‐month outcome had higher day‐1 interleukin‐6, neutrophil count, and procalcitonin levels and lower day‐1 triiodothyronine and free triiodothyronine levels than those with favorable outcome. After adjustment for admission GCS in separate Firth models, interleukin‐6, white blood cell count, neutrophil count, procalcitonin, day‐1 triiodothyronine, and day‐1 free triiodothyronine were not significantly associated with unfavorable 6‐month outcome.
Interpretation
Endocrine alterations after acute TBI were heterogeneous across injury severity groups and time points. Although selected day‐1 inflammatory and thyroid‐axis measures differed between outcome groups, their associations with unfavorable 6‐month functional outcome were not statistically significant after adjustment for admission GCS. These outcome‐related findings require validation in larger cohorts.