Decreased Growth Hormone Response to Dexamethasone Stimulation Test in Obese Children

Acute administration of glucocorticoids is a recently described stimulus for growth hormone secretion. The aim of the present study was the assessment of dexamethasone-induced growth hormone secretion in obese children. Dexamethasone iv tests were carried out in 14 normal control and 8 obese children. Growth hormone was measured by radioimmunoassay up to 5 h after dexamethasone administration. Dexamethasone elicited clear growth hormone secretion in normal children (mean peak 12.3 +/- 1.6; area under the curve 682.3 +/- 74.3). In the obese children, dexamethasone induced a slight but significant (p < 0.01) increase in growth hormone over basal values. However, the growth hormone response in this group was significantly lower than in the normal controls, when comparing both mean peak (5.5 +/- 2.3, mean +/- SEM) (p < 0.01) and area under the curve (306.8 +/- 44.5) (p < 0.001).