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Transdermal estradiol priming during clonidine stimulation test in non-growth hormone deficient children with short
M M S Borghi1, C A Longui, L E Calliari
1Pediatric Endocrinology Unit, Pediatric Department, Santa Casa de São Paulo, Faculty of Medical Sciences, Brasil.
Insights
Transdermal estradiol (E2-t) priming enhances growth hormone (GH) response to clonidine stimulation in children. This method improves the accuracy of diagnosing GH deficiency, offering a safer alternative to oral estradiol.
Area of Science:
- Pediatric Endocrinology
- Growth Hormone Physiology
Background:
- Growth hormone (GH) deficiency diagnosis is complex, influenced by age, BMI, and sex steroids.
- Oral estradiol (E2) priming is used to mitigate variable sex steroid levels.
- Transdermal estradiol (E2-t) offers a potentially safer alternative to oral administration.
Purpose of the Study:
- To evaluate the effect of transdermal estradiol (E2-t) priming on clonidine-stimulated GH response in prepubertal children.
- To compare the efficacy of E2-t priming in children with familial short stature versus constitutional growth delay.
Main Methods:
- Prepubertal children with familial short stature (n=12) or constitutional growth delay (n=22) received a clonidine stimulation test.
- A second clonidine test was performed after 7 days of transdermal estradiol (E2-t) priming (50 microg/day).
- Basal GH, IGF-I, and peak GH responses were measured and compared between groups and conditions.
Main Results:
- After E2-t priming, basal GH significantly increased only in the constitutional growth delay group.
- Children with constitutional growth delay showed a significant increase in peak GH response post-E2-t priming compared to the familial short stature group.
- A higher proportion of patients in both groups achieved an adequate GH peak response after E2-t priming.
Conclusions:
- Transdermal estradiol (E2-t) priming effectively enhances GH peak response to clonidine stimulation.
- E2-t priming improves the diagnostic accuracy of the clonidine test for GH deficiency.
- Transdermal delivery of estradiol avoids liver toxicity associated with oral administration, promoting a more physiological GH secretion pattern.
Abstract:
The diagnosis of growth hormone (GH) deficiency is strongly influenced by age, body mass index and presence of gonadal steroids. Priming with oral estradiol (E2) is one possible way to overcome the impact of variable levels of sex steroids. We describe the effects of transdermal estradiol (E2-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/m2, p.o.) followed by a clonidine plus E2-t test (50 microg/day) with a 7-day interval. Before E2-t, basal GH and insulin-like growth factor-I (IGF-I) values were similar in the two groups. After E2-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 E2-t. The number of patients in both groups with adequate GH peak response was higher after E2-t priming. We conclude that E2-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, E2-t delivery can prevent liver toxicity, providing a more physiological mechanism of GH secretion.
