Aromatase Inhibitors and Growth Disorders

Abstract

Without estrogen action, the fusion of the growth plates is postponed and height growth continues for exceptionally long period of time. Aromatase inhibitors, blockers of estrogen biosynthesis, have therefore emerged as a new potential option for treatment of children with short stature. Currently three prospective randomised controlled trials using potent third-generation aromatase inhibitors have been published. These reports all show that treatment with the aromatase inhibitor letrozole or anastozole effectively delays bone maturation and increase predicted adult height in boys with constitutional delay of growth and puberty (CDGP) (Wickman and Kajantie, 2003), idiopathic short stature (ISS) (Hero et al., 2005), and GHD (Mauras et al. 2008). Long-term follow-up data of boys with constitutional delay of puberty, treated with letrozole for 1 year during adolescence, suggest that the achieved gain in predicted adult height also results in taller adult height. However, before the safety of the treatment is better established, particularly as regards bone architecture and vertebral morphology, treatment of short stature with aromatase inhibitors must be considered experimental.