Transdermal estradiol priming during clonidine stimulation test in non-growth hormone deficient children with short stature: A pilot study

The diagnosis of growth hormone (GH) deficiency is strongly influenced by age, body mass index and presence of gonadal steroids. Priming with oral estradiol (E-2) is one possible way to overcome the impact of variable levels of sex steroids. We describe the effects of transdermal estradiol (E-2-t) priming on GH response after clonidine stimulation. in prepubertal children with familial short stature (group 1, n = 12) or constitutional growth delay (group 2, n = 22). All patients underwent A clonidine test (0.1 mg/m(2), p.o.) followed by a clonidine plus E-2-t test (50 mu g/day) with a 7-day interval. Before E-2-t, basal GH and insulin-like growth factor-I (IGF-I) values were similar in the two groups. After E-2-t priming, basal GH was significantly higher only in group 2. When compared with group 1, patients from group 2 had a significant increase of GH peak response when submitted to E-2-t. The number of patients in both groups with adequate GH peak response was higher after E-2-t priming. We conclude that E-2-t priming is able to increase GH peak response after clonidine stimulation and also improves the accuracy of the clonidine test in the diagnosis of GH deficiency. Compared to oral administration, E-2-t delivery can prevent liver toxicity, providing a more physiological mechanism of GH secretion.Santa Casa Sao Paulo, Pediat Endocrinol Unit, Dept Pediat, Fac Med Sci, Sao Paulo, BrazilWeb of Scienc