Growth hormone stimulation test

The growth hormone (GH) stimulation test measures the ability of the body to produce GH.

The test is performed by administering the amino acid arginine in a vein to raise hGH levels. The test measures the ability of the pituitary to secrete growth hormone in response to the arginine.

In a study in all children the pituitary hormones basal levels were assessed at least five years post-TBI. Growth hormone stimulation tests were performed 3-4 years post-TBI in children with Growth hormone deficiency (GHD) 1-year post-TBI and in all children with low height velocity (〈-1 DS) or low IGF-1 (〈-2 DS). Central precocious puberty (CPP) was confirmed by GnRH stimulation test.

61/66 children were followed-up 7 [5-10] years post-TBI (median; [range]); 17/61 children had GHD 1-year post-TBI, GHD was confirmed in 5/17 patients. For one boy, with normal pituitary function 1-year post-TBI, GHD was diagnosed 6.5 years post-TBI. 4/61 patients developed CPP, 5.7 [2.4-6.1] years post-TBI. Having a pituitary dysfunction 1-year post-TBI was significantly associated with pituitary dysfunction or CPP more than five years post-TBI.

Severe traumatic brain injury in childhood can lead to permanent pituitary dysfunction; Growth hormone deficiency and Central precocious puberty may appear after many years. Dassa et al., recommended systematic hormonal assessment in children one-year after severe TBI and a prolonged monitoring of growth and pubertal maturation. Recommendations should be elaborated for the families and treating physicians ¹⁾.