Update on the Role of Aromatase Inhibitors in Growth Disorders

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 (C) 2009 S. Karger AG, Basel