Dynamics of anterior pituitary function in the acute phase of traumatic brain injury: a prospective cohort

Objective  Traumatic brain injury leads to disruption of the hypothalamic-pituitary axis. The aim of this study was to evaluate anterior pituitary gland function in the acute phase following traumatic brain injury and its relationship with patient outcomes.

Methods  This was a prospective cohort of traumatic brain injury patients admitted to the intensive care unit. The levels of adrenocorticotropic hormone, growth hormone, and thyroid-stimulating hormone on Days 0, 3 and 7 after the injury were measured. The Glasgow Outcome Scale-Extended (GOSE) was used for 6-month outcomes.

Results  A total of 88 traumatic brain injury patients (79% male, 41 ± 19 years old) who were admitted to the intensive care unit were studied. The frequencies of hormone levels below the range were as follows: adrenocorticotropic hormone, 81% on Day 0, 75% on Day 3, and 68% on Day 7; growth hormone, 76% on Day 0, 65% on Day 3, and 61% on Day 7; and thyroid-stimulating hormone, 42% on Day 0, 41% on Day 3, and 14% on Day 7. Traumatic brain injury severity was associated with Day 0 adrenocorticotropic hormone (p = 0.03) and Day 7 growth hormone (p = 0.03) levels and inversely associated with Day 3 thyroid-stimulating hormone (p = 0.03) levels. Glial fibrillary astrocytic protein was directly associated with Day 3 adrenocorticotropic hormone (OR 1.02, 95%CI 1.01 - 1.03; p < 0.001) and inversely associated with Day 7 thyroid-stimulating hormone (OR 1.02, 95%CI: 1.02 - 1.03; p = 0.04) levels. There was no significant association between hormone levels and mortality or the 6-month Glasgow Outcome Scale-Extended score.

Conclusion  Anterior pituitary hormone disturbances are common following a traumatic brain injury, and the degree of dysfunction is related to the injury severity. No associations were found with mortality or disability. Further investigations are warranted to standardize the measurement of pituitary function after traumatic brain injury and clarify its prognostic/therapeutic role.

Keywords:
Brain injuries, traumatic; Hypophysis; Pituitary gland; Pituitary diseases; Intensive care