Endocrine Sequelae of Mild Traumatic Brain Injury in Patients Admitted to the Emergency Department: A 12-Month Study

Background/Objectives: Over the last two decades, there has been a substantial change in the understanding of post-traumatic hypopituitarism (PTHP), which is no longer regarded as a marginal phenomenon. Clinical manifestations of pituitary hormone deficiency are frequently nonspecific, with fatigue and cognitive dysfunction predominating. Given that head injuries currently constitute a global burden for healthcare systems, the aim of the present study was to determine whether self-reported post-mild traumatic brain injury (mTBI) symptoms that may indicate hypopituitarism reflect true pituitary insufficiency or are attributable to other hormonal aberrations. The study aimed to assess the relationship between self-reported symptoms of PTHP and hormonal test results following mTBI. Setting: Patients were recruited from a tertiary trauma center Emergency Department (ED) in northern Poland from January 2023 to October 2025. Participants: The participants were adult (18 > y.o.) individuals with mTBI who met the inclusion criteria. Design: This was a prospective cohort study. During their post-head injury admission to the ED, patients had a blood sample taken. The procedure was repeated consecutively after 3, 6 and 12 months. After 6 and 12 months, patients were asked to complete a questionnaire. Methods: Pituitary and thyroid hormones were measured using the chemiluminescence immunoassay method and the heterogenous immunochemiluminescence method. The questionnaire used, Questionnaire for the Assessment of Symptoms of Anterior Pituitary Insufficiency in Patients After Mild Traumatic Brain Injury (mTBI) Hospitalized in the Emergency Department, was designed for the purposes of this study. Results: Self-reported symptoms suggestive of anterior pituitary dysfunction following mTBI were not confirmed by laboratory assessment of pituitary hormones. However, after 6 months, a statistically significant correlation was found between the number of reported symptoms and prolactin levels (ρ = 0.730; p = 0.0013), whereas after 12 months a downward trend in free triiodothyronine (fT3) levels was observed compared with the baseline. Conclusions: Persistent symptoms reported by patients following mTBI at 6 and 12 months, particularly fatigue and impaired concentration, showed statistical associations with prolactin levels at 6 months and lower fT3 levels at 12 months. These findings reflect correlations identified in the statistical analysis and do not support inferences regarding causality or the presence of true PTHP.