Endocrine Abstracts

Objective: Impaired cognitive function has been demonstrated in adults with GH deficiency (GHD) by using different neuropsychological tests. P300 ERP application is a well established neurophysiological approach in the assessment of cognitive function. Kickboxing is a novel cause of hypopituiatarism due to sports related traumatic brain injury (TBI) and isolated GHD is the most common problem (1).

The present preliminary study was therefore designed to investigate the effects of sports related head trauma induced GHD on cognitive function by using P300 ERPs.

Methods: The study comprised 15 amateur kickboxers (13 male, 2 female), with a mean age of 30.0±5.9 yr. GHD was diagnosed in 6 kickboxers by using two stimulation tests (GHGH+GHRP-6 and glucagon). ERPs were recorded at the Fz (frontal), Cz (central), Pz (parietal) and Oz (occipital) electrode sites; and P300 latencies and P300 amplitudes were estimated at all electrode sites. Standard Oddball paradigm was used to evoke P300 responses.

Results: The mean P300 latencies (at all electrode sites) of the kickboxers with GHD were prolonged when compared with those of GH normal kickboxers. However the difference did not reach to a significant level. There was a significant negative correlation between IGF-I levels and latencies at Fz electrode site (r: −0.530, P: 0.04).

Conclusions: P300 latency is related to stimulus evaluation time and prolonged P300 latencies suggest an impaired cognitive function in GH deficient kickboxers. The differences did not reach to a significant level due to a small sample size. This is an objective electrophysiological evidence for cognitive dysfunction in GHD and further data with high number of kickboxers are warranted.