Variabilidad de respuesta de hormona de crecimiento a pruebas de estímulo reiteradas en niños de talla normal. / [Variability of growth hormone response to repeated stimulation tests in children of normal height]

ABSTRACT

The presence of false negatives in the evaluation of patients with short stature and the variability of 24 hour growth hormone (GH) physiological studies in the normal population are well known. Therefore the reproducibility of two widely used pharmacological test was studied in normal children. Forty prepuberal children were evaluated (34 boys and 6 girls), with chronological ages ranging from 2 years 11 months to 12 years 11 months (mean 9 years 1 month), bone ages from 3 years 2 months to 12 years 6 months (mean 8 years 4 months) and with normal stature and growth velocity (SDS > -2) and normal body mass index (BMI < 25). Clonidine test was performed (100 micrograms/m2 surface) measuring GH (ng/ml) 0,06 and 90 min in 20 patients (Group I). Exercise-Propranolol test was performed (0,5 mg/kg weight) with basal and post-exercise GH measurements in 20 patients (Groups II). The tests were repeated at one week intervals and each child was his own control. Group I showed (mean +/- SD) 1st test B = 1.78 +/- 1.59, Max Resp = 13.16 +/- 8.34; 2nd test B = 1.17 +/- 0.51, Max Resp = 15.12 +/- 8.09. Group II showed (mean +/- SD) 1st test B = 1.38 +/- 0.58, Max Resp 16.97 +/- 9.69; 2nd test B = 1.54 +/- 1.16, Max Resp = 13.49 +/- 7.81. Wilcoxons test did not show significant differences when comparing B vs B and Max Resp vs Max Resp in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)