The effect of Letrozole on bone age progression, predicted adult heights and adrenal gland function. WV Karmazin, J Moore, J Popovic, JD Jacobson. Children's Mercy Hospital, University of Missouri Kansas City School of Medicine, USA.
A common problem in pediatric endocrinology is limited growth potential resulting from advanced bone ages. GnRH agonists, which are frequently used in such situations, can be associated with injection site pain, psychological consequences of delayed puberty, and deleterious effects on bone mineral density. Several studies have shown that some boys with constitutional delay of puberty do not exploit their genetic growth potential. In these boys, androgen treatment does not increase adult height. As evidence for the role of estrogens in epiphyseal closure seems unequivocal, it has been postulated that boys with constitutional delay of puberty would attain greater adult height if estrogen action were suppressed [Wickman, 2001 #56; Wickman, 2003 #55]. Dr Popovic, Children's Mercy Hospital, University of Missouri Kansas City School of Medicine, USA, presented evidence that letrozole, a third generation aromatase inhibitor, would be safe and effective in increasing predicted adult height in a population of adolescent males. In this study, male patients who were taking letrozole at the time of their visits to clinic were eligible for enrolment in two separate studies. The efficacy study involved a retrospective chart review of auxologic parameters and bone age progression. Of 60 patients enrolled in the efficacy study, 34 subjects had sufficient data for analysis. 6 were excluded because they had received prior treatment with Depot-Lupron, radiation therapy, a different aromatase inhibitor, or had syndromes associated with short stature. The remaining 28 patients included 6 patients treated with androgen, who were analyzed separately. In the safety study, low-dose ACTH stimulation tests were performed on 15 patients taking letrozole for a period ? 6 months. The efficacy study demonstrated a decrease in bone age progression from 1.53 ? 0.13 to 0.65 ? 0.09 bone age years per year after starting letrozole therapy (p < 0.001). In addition there was an increase in predicted adult height from 169.7 ? 1.1 cm prior to starting letrozole to 173.7 ? 1.0 cm after a mean duration of treatment of 14 months (p=0.01). Similar results were noted in the 6 androgen-treated patients. The safety arm revealed that 26.7% of patients displayed subnormal responsiveness to ACTH. These results showed that aramatose inhibitor. Thus whereas letrozole may cause mild adrenal suppression, it is extremely effective in increasing final height prediction in boys at risk for compromised adult height.
Thats a bit of the information from the link that I wanted to show you guys.
For those of you who dont know what letrozole is,it is an aramatose inhibitor (estrogen blocker).
You might not get all of it I dont get a few of things of what they are talking about either but to simplify they are stating that letrozole has been shown to slow down plate fusion by alot.
