Predictors of Hypopituitarism in Patients with Traumatic Brain Injury

Hypopituitarism may often occur in association with traumatic brain injury (TBI). Identification of reliable predictors of pituitary dysfunction is of importance in order to establish a rational testing approach. We searched the records of patients with TBI, who underwent neuroendocrine evaluation in our institution between 2007 and 2013. One hundred sixty-six adults (70% men) with TBI (median age: 41.6 years; range: 18-76) were evaluated at a median interval of 40.4 months (0.2-430.4).Of these, 31% had ≥1 pituitary deficiency, including 29% of patients with mild TBI and 35% with moderate/severe TBI. Growth hormone deficiency was the most common deficiency (21%); when body mass index (BMI)-dependent cutpoints were used, this was reduced to 15%. Central hypoadrenalism occurred in10%, who were more likely to have suffered a motor vehicle accident (MVA, p = 0.04), experienced post-traumatic seizures (p = 0.04), demonstrated any intracranial hemorrhage (p = 0.05), petechial brain hemorrhages (p = 0.017), or focal cortical parenchymal contusions (p = 0.02). Central hypothyroidism occurred in 8% and central hypogonadism in 12%; the latter subgroup had higher BMI (p = 0.03), were less likely to be working after TBI (p = 0.002), and had lower Global Assessment of Functioning (GAF) scores (p = 0.03). Central diabetes insipidus (DI) occurred in 6%, who were more likely to have experienced MVA (p < 0.001) or sustained moderate/severe TBI (p < 0.001). Patients with MVA and those with post-traumatic seizures, intracranial hemorrhage, petechial brain hemorrhages, and/or focal cortical contusions are at particular risk for serious pituitary dysfunction, including adrenal insufficiency and DI, and should be referred for neuroendocrine testing. However, a substantial proportion of patients without these risk factors also developed hypopituitarism.