GHD is the most common pituitary deficit 12 months after TBI, and 50.9% of the patients had at least one anterior pituitary hormone deficiency. Pituitary function may improve or worsen in a considerable number of patients over 12 months.

GH deficiency (GHD) was the most common pituitary deficit at 12 months after SAH and the majority of the patients (87.5%) had isolated GHD. During the 12-month follow-up, pituitary function was found to either improve or worsen in a considerable number of patients.

GH deficiency is the most common pituitary deficit 1 and 3 years after TBI. In patients with mild and moderate TBI, pituitary function improves over time in a considerable number of patients, but it may also worsen rarely over the 3-year period. In patients with severe TBI, ACTH and GH deficiencies at 1st year evaluation persist at 3rd year.

Objective: Traumatic brain injury (TBI) is a devastating public health problem that may result in hypopituitarism. However, the mechanisms responsible for hypothalamic-pituitary dysfunction due to TBI are still unclear. Although the antibodies against neurons have been demonstrated in injured animal studies, investigations regarding the occurrence of antipituitary antibodies (APAs) in patients with TBI are lacking in the literature. In order to investigate whether autoimmune mechanisms could play a role in the pituitary dysfunction after TBI, we have planned this study aimed at investigating the presence of APA at the third year of TBI and association between the TBI-induced hypopituitarism and APA. Patients and design: Twenty-nine (25 males and 4 females; age 36.5G2.3 years) patients who had completed a 3-year follow-up after TBI were included in the present study. APA and pituitary function were evaluated in all the patients 3 years after TBI; moreover, APAs were tested also in sera of 60 age-/sexmatched normal controls. The APAs were investigated by an indirect immunofluorescence method. Results: APAs were detected in 13 out of the 29 TBI patients (44.8%), but in none of the normal controls. Pituitary dysfunction development ratio was significantly higher in APA-positive patients (46.2%) when compared with APA-negative ones (12.5%; PZ0.04). There was a significant association between APA positivity and hypopituitarism due to TBI (odds ratio: 2.25, 95% confidence intervals 1.1-4.6). Moreover, there was a significant positive correlation (rZ0.74, PZ0.004) between APA titer ratio and peak GH response to GHRHCGH related peptide (GHRP)-6 test, suggesting that high APA titers were associated with low GH response to GHRHCGHRP-6 test. Conclusions: This study shows for the first time the presence of the APA in TBI patients 3 years after head trauma. Moreover, present investigation indicates preliminary evidence that APA may be associated with the development of TBI-induced pituitary dysfunction, thus suggesting that autoimmunity may contribute in the development of TBI-induced hypopituitarism. The presence of the association between APA and TBIinduced hypopituitarism may provide a new point of view in this field and promote further clinical and experimental studies.European Journal of Endocrinology 159 7-13

Present data clearly demonstrate for the first time that amateur kickboxing is a novel cause of hypopituitarism and kickboxers are at a risk for hypopituitarism especially isolated GH deficiency. Therefore, participants of the combative sports who were exposed to chronic repetitive head trauma need to be screened.