Growth Hormone and Cortisol Responses to Insulin Stimuli in Children with Short Stature

Kim, Hwa In; Oh, Jae Hwa; Choi, Du Young; Kim, Jong Duck

Abstract

PURPOSE
For evaluation of the growth hormone and cortisol responses to insulin stimuli in children with short stature, the human growth hormone secretion and cortisol level was monitored 30 and 60 minutes after insulin infusion by intravenousely.
METHODS
The inclusion criteria of children for this study were that the height was below 3 percentile compare with the same sex and age children, bone age was younger more than one year of chronologic age, and insulin and L-dopa induced growth hormone secretion was below 10ng/mL. There were 10 children compatible with this criteria(group A) and 11 children was selected for control group(group B). Serum concentration of growth hormone was determined just before intravenous infusion of 0.1U/kg insulin and then 30 and 60 minutes after insulin infusion. Serum level of cortisol was determined simultaneously with the growth hormone but skip the level of the 30 minutes after insulin infusion. Serum glucose level was monitored on every time sampling the blood for determined growth hormone and cortisol level. Serum level of growth hormone and cortisol were determined by radioimmunoassay.
RESULTS
:The serum glucose concentration were decrease to under 50% of baseline level on 30 minutes after insulin infusion in A and B group. The serum growth hormone level before insulin infusion was 2.5+/-1.78ng/mL and changed to 2.2+/-1.69 ng/mL on 60 minutes after insulin infusion in group A. In group B, the serum growth hormone level alteration before and on 60 minutes after insulin infusion was from 5.5+/-6.67ng/mL to 12.6+/-7.91ng/mL. The serum concentration of cortisol was changed from baseline level 10.7+/-7.10, 7.9+/-3.98microg/dL to 16.7+/-11.47, 26.1+/-3.59microg/ dL on 60 minutes after insulin infusion in group A and B respectively, but some cases in group A show a little increase in cortisol level.
CONCLUSION
On the basis of this study, it is suggested that the deficiency of growth hormone secretion is related to cortisol concentration in peripheral blood. But for more detailed assessment of this association, follow up studies will be needed in more cases.