Evaluation of the growth hormone insulin-like growth factor-I axis in children with familial growth hormone deficiency

الملخص EN

Growth hormone deficiency (GHD) as a cause for short stature have to be carefully searched for because of its therapeutic consequences.

In the present study, two GH provocative tests (clonidine and ITT) were evaluated in a cohort of children with familial GHD.

Members of the growth hormone insulin growth factor-1 axis, namely insulin like growth factor-1 (IGF-1) and insulin growth factor binding protein-3 (1GFBP-3), were also evaluated to asses their reliability in detecting GHD by studying their concentration in relation to anthropometric measurements and GH values.

The study included 50 (36 males, 14 females) children and adolescents (mean age 8.46 ± 5.2 yrs, range 0.59-21.16) with the clinical and anthropometric criteria of GH deficiency and a positive family history for such a disorder as well.

All patients were subjected to a meticulous auxological evaluation besides assessment of the GH-1GF-1 axis.

To diagnose cases of multiple pituitary hormone deficiencies basal levels of free thyroxin, TSH, prolactin, LH and FSH after LHRH stimulation and cortisol in ITT were also measured.

The results of GH testing using both methods (clonidine and ITT) were concordant in cases of GHD and non-GHD.

In patients with GHD higher peak values and mean stimulated values were obtained after clonidine than after ITT (P<0.0001, P<0.001 respectively).

Results have also shown that GH peak value correlated positively to height and weight and with IGFBP-3, but not with other anthropometric variables or IGF-1.

IGF-1 correlated negatively with delay in bone age and not with other anthropometric parameters or IGFBP-3.

IGFBP-3 showed a Positive correlation with height and weight and a negative correlation with bone age delay, but none with other parameters.

We support the use of clonidine test being superior to ITT giving Slgnificantly higher GH values.

IGFBP-3 estimation is superior to IGF-1 in the evaluation of GH status because it is more consistently decreased in GHD patients and its levels correlate more with both anthropometry and GH levels.