Endocrine Abstracts

There is growing evidence that pituitary failure is a common complication of traumatic brain injury. However, prevalence of hypopituitarism following traumatic brain injury varies between 25 and 69% in the literature. Moreover, the pattern of involved hypothalamic/pituitary axes differs considerably in the published trials. This might be due to small and inhomogeneous series of patients and different test methods in previous studies. The aim of our study was therefore to investigate a large cohort of patients using the gold standard insulin tolerance test (ITT). We included 90 patients at least 12 months after traumatic brain injury aged between 18 and 60 years in our trial. Patients were recruited from an out-patient clinic specialized in neuro-rehabilitation. At baseline, beside physical examination and routine laboratory testings, endocrine evaluation includes basal measurement of LH, FSH, TSH, fT3, fT4, prolactin, IGF-I, testosterone in males and estradiol in females. In addition an ITT with intravenous administration of 0.1 IU/kg body weight of regular insulin was performed in each patient. Blood samples for measurement of glucose, growth hormone (GH), ACTH and cortisol were drawn at −15, 0, 30, 45, 60 and 90 min. There was no complication during any test although all patients achieved adequate hypoglycemia. The prevalence of pituitary insufficiency is summarized in the following Table:

We conclude that an ITT is a safe diagnostic tool in patients after traumatic brain injury. In 52% of these patients at least one pituitary axis deficiency was newly diagnosed. In contrast to previous studies, the predominant pituitary failure was an ACTH-deficiency followed by GH insufficiency.

We conclude that an ITT is also a safe diagnostic tool in patients after traumatic brain injury. In 52% of these patients at least one pituitary axis deficiency was newly diagnosed. In contrast to previous studies, the predominant pituitary failure was an ACTH-deficiency.