Low dose of insulin for assessment of growth hormone and cortisol release in short children.
OBJECTIVE
In 55 prepubertal children with growth failure, aged 8.62 +/- 2.89 years, we evaluated the efficacy of a test using only half the usual dose of insulin by comparing the results with those obtained during a classical arginine tolerance test, performed separately.


METHODS
The patients were randomly divided into two groups: group A consisting of 37 children received 0.05 U/kg insulin, while group B consisting of 18 patients received 0.1 U/kg insulin. Each child received the same dose of arginine per kg during the second test.


RESULTS
Serum growth hormone (GH) peak levels were significantly (p < 0.01) lower in children of group A (6.59 +/- 4.10 ng/ml) than in those of group B (10.12 +/- 5.80 ng/ml). No differences of GH peak levels were found in patients of the two groups after arginine infusion. The injection of 0.05 U/kg insulin induced a significantly (p < 0.0001) lower percent decrease of serum glucose than 0.1 U/kg. No difference of the percent increase of serum cortisol induced by insulin at 0.05 U/kg and 0.1 U/kg was observed.


CONCLUSIONS
The diagnosis of GH deficiency in children can be supported by a blunted GH response after two or more pharmacological stimuli including hypoglycaemia induced by only half the usual dose of insulin.
Bozzola
Mauro
M
Pediatric Department, University of Pavia, Italy. mauro.bozzola@unipv.it
Comoli
Patrizia
P
Bozzola
Elena
E
Tinelli
Carmine
C
Marello
Annalisa
A
Stabile
Milena
M
Mazzola
Alessandra
A
Locatelli
Vittorio
V
D001120:Arginine; D002648:Child; D005260:Female; D006130:Growth Disorders / Q000175:diagnosis*; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism; D007003:Hypoglycemia; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007328:Insulin / Q000008:administration & dosage; D008297:Male; D012680:Sensitivity and Specificity
D007004:Hypoglycemic Agents; D007328:Insulin; D019382:Human Growth Hormone; D001120:Arginine; D006854:Hydrocortisone