Where can I read about that? Google didnt pull up to much. Care to breifly explain?
Horm Res. 2009 Jan;71 Suppl 1:57-63. Epub 2009 Jan 21. Links
Update on the role of aromatase inhibitors in growth disorders.Dunkel L.
Kuopio University Hospital and University of Kuopio, Kuopio, Finland.
[email protected]
Background: Without oestrogen action, the fusion of the growth plates is postponed and longitudinal growth continues for an exceptionally long period of time. Aromatase inhibitors that block oestrogen biosynthesis have therefore emerged as a new potential treatment option for children with short stature. Results from three prospective randomised controlled trials using potent third-generation aromatase inhibitors have recently been published.
These studies all show that treatment with the aromatase inhibitors letrozole and anastrozole effectively delays bone maturation and increases predicted adult height in boys with constitutional delay of growth and puberty (CDGP), idiopathic short stature and growth hormone deficiency. Long-term follow-up data from the study in which boys with CDGP were treated with letrozole for 1 year during adolescence suggest that the achieved gain in predicted adult height also results in taller final adult height. Conclusions: Until the safety profile of aromatase inhibitors, particularly their qualitative effects on bone development, is established, use of these agents must be considered experimental in treating short stature. Copyright 2009 S. Karger AG, Basel.
J Clin Endocrinol Metab. 2005 Dec;90(12):6396-402. Epub 2005 Sep 27. Links
Inhibition of estrogen biosynthesis with a potent aromatase inhibitor increases predicted adult height in boys with idiopathic short stature: a randomized controlled trial.Hero M, Norjavaara E, Dunkel L.
Hospital for Children and Adolescents, University of Helsinki, Finland.
CONTEXT: In males as well as in females, estrogen is an essential regulator of bone maturation, growth plate fusion, and cessation of longitudinal growth. Therefore, an increase in predicted adult height (PAH) may be achieved in short boys by blocking estrogen biosynthesis. OBJECTIVE: We tested the hypothesis that a decrease in the rate of bone maturation and an increase in PAH can be achieved in boys with idiopathic short stature (ISS) by the method of blocking estrogen biosynthesis with an aromatase inhibitor. Secondarily, we investigated the effects of aromatase inhibition on bone mineralization. DESIGN: This was a prospective, double-blind, randomized, placebo (Pl)-controlled clinical study. SETTING: The study was performed at a university hospital out-patient clinic. PATIENTS: Thirty-one boys, aged 9.0-14.5 yr, with ISS were studied. INTERVENTION: The boys were treated with the aromatase inhibitor letrozole (Lz; 2.5 mg/d) or Pl for 2 yr. MAIN OUTCOME MEASURE: The main outcome measure was the change in PAH after 24 months of treatment.
RESULTS: PAH increased by 5.9 cm (P < 0.0001), and height SD score for bone age increased by 0.7 SD score (P < 0.0001) in the Lz-treated boys, whereas no changes occurred in the respective measures in Pl-treated boys. Areal bone mineral density of the lumbar spine and femoral neck, assessed by dual-energy x-ray absorptiometry, increased in a similar fashion in both groups during the treatment, whereas bone mineral apparent density increased only in those taking Lz (median increase, 4.3%; P = 0.009). CONCLUSIONS: Treatment with the aromatase inhibitor Lz delays bone maturation and improves PAH in boys with ISS. No adverse effects on bone mineralization were evident after 2 yr of treatment.
J Steroid Biochem Mol Biol. 2003 Sep;86(3-5):345-56. Links
Novel treatment of short stature with aromatase inhibitors.Dunkel L, Wickman S.
Hospital for Children and Adolescents, University of Helsinki, PO Box 281, Helsinki 00029 HUS, Finland.
[email protected]
Estrogens have an essential role in the regulation of bone maturation and importantly in the closure of growth plates in both sexes. This prospective, randomized, placebo-controlled study was undertaken to evaluate whether suppression of estrogen synthesis in pubertal boys delays bone maturation and ultimately results in increased adult height. A total of 23 boys with constitutional delay of puberty (CDP) received a conventional, low-dose testosterone treatment for inducing progression of puberty. Eleven of these 23 boys were randomized to receive a specific and potent P450-aromatase inhibitor, letrozole, for suppression of estrogen action, and 12 boys were randomized to receive placebo. Estradiol concentrations in the letrozole-treated boys remained at the pretreatment level during the administration of letrozole, whereas the concentrations increased during the treatment with testosterone alone and during spontaneous progression of puberty. Testosterone concentrations increased in all groups, but during the letrozole treatment, the increase was more than fivefold higher than in the group treated with testosterone alone. The inhibition of estrogen synthesis delayed bone maturation. The slower bone maturation in the boys treated with testosterone and letrozole, despite higher androgen concentrations, than in the boys treated with testosterone indicate that estrogens are more important than androgens in regulation of bone maturation in pubertal boys.
During the 18 months follow-up, an increase of 5.1 cm in predicted adult height was observed in the boys who received testosterone and letrozole, but no change was seen in the boys who received testosterone alone or in the untreated boys. This finding indicates that an increase in adult height can be attained in growing
