Simultaneous Assessment of Growth Hormone and ACTH Reserve In Children Pretreated with Diethylstilbestrol

Abstract

Plasma growth hormone (GH) and cortisol responses to insulin-induced hypoglycemia were evaluated in children with growth retardation of various etiologies before and after 3 days of diethylstilbestrol (DES) therapy. It was found that DES not only enhances peak GH responses (mean concentrations were 11.5 ng/ml vs. 19 ng/ml at 60 minutes) but that 4 out of 5 children with absent or blunted GH responses before DES had normal responses after DES. When plasma cortisol concentrations were measured simultaneously, it was found that baseline and 60 minute levels were elevated following DES. However, the 60 minute cortisol response to insulin-hypoglycemia, measured during GH testing, could still be used to assess ACTH reserve. Twentynine children with normal GH responses all achieved 60 minute plasma cortisol values of 40 μg/100 ml or greater, while 5 children with GH deficiency secondary to organic pituitary disease had significantly lower levels. Four patients with idiopathic GH deficiency were tested and 2 had diminished plasma cortisol responses. The effects of DES pretreatment for 3 days on the response to iv metyrapone were also studied. Before DES, 9 normal children had a mean 8 hour compound S value of 10.4 μg/100 ml, while following DES, these same children had a blunted response (mean 4.7 μg/100 ml). DES pretreatment has been shown to be a useful and necessary adjunct in testing for GH reserve in prepubertal children. Although it affects plasma cortisol levels, it does not impair the value of using the cortisol response to insulin-hypoglycemia to assess ACTH reserve.