Pituitary dysfunction in traumatic brain injury: Is evaluation in the acute phase worthwhile?

Introduction: Traumatic brain injury (TBI) is an under-recognized cause of hypopituitarism. According to recent data, it could be more frequent than previously known. However, there is a scarcity of data in Indian population.

Aims: The main aim of the study was to determine the prevalence of pituitary hormone deficiencies in the acute phase of TBI. The secondary objectives were to correlate the severity of trauma with basal hormone levels and to determine whether initial hormone deficiencies predict mortality.

Subjects and methods: Forty-nine TBI patients (41 men and 8 women) were included in this study. Pituitary functions were evaluated within 24 h of admission.

Results: Gonadotropin deficiency was found in 65.3% patient while 46.9% had low insulin-like growth factor-1, 12.24% had cortisol level <7 mcg/dl. Cortisol and prolactin level were positively correlated with the severity of TBI suggestive of stress response. Free triiodothyronine (fT3) and free thyroxine were significantly lower in patients with increasing severity of tuberculosis. Logistic regression analysis revealed that mortality after TBI was unrelated to the basal pituitary hormone levels except low T3 level, which was found to be positively related to mortality.

Conclusions: Pituitary dysfunction is common after TBI and the most commonly affected axes are growth hormone and gonadotropin axis. Low fT3 correlates best with mortality. During the acute phase of TBI, at least an assessment of cortisol is vital as undetected cortisol deficiency can be life-threatening.