ESPE Abstracts

Background: Estrogen is an essential regulator of bone maturation, growth plate fusion, and cessation of longitudinal growth. Aromatase inhibitors (AI) block the conversion of androgens to estrogens, and can be used to delay bone maturation in males.

Objective and hypotheses: We sought to determine whether the blockage of estrogen biosynthesis due to the use of the AI Anastrazole increases the Predicted Adult Height (PAH) in boys with short stature.

Method: Twenty-eight boys (13.6 years), used oral Anastrazole 1 mg/day for 1 year. Eighteen received GH therapy (‘GH’ group) and 10 did not (‘ØGH’ group). PAH was calculated based on Bayley/Pinneau formula.

Results: Basal PAH was statistically below the TH (−2.9 cm, P=0.008), and after 1 year of treatment with Anastrazole it was above the TH (+3.4 cm, P=0.008) and above the Basal PAH (+6.3 cm, P<0.001). For the ‘GH’ group the increase in PAH after 1 year was +3.6 cm comparing to TH (P=0.01) and +6.3 cm for Basal PAH (P<0,001). For the ‘ØGH’ group, the increase in PAH after 1 year was +3.1 cm comparing to TH (P=0.06) and +6.2 cm for Basal PAH (P<0.002) Table 1.

Conclusion: One year use of anatrazole in boys with short PAH can improve PAH in ‘GH’ and ‘ØGH’ groups. The complete follow up until adulthood will determine if this increase in PAH will reflect in better final adult height.