Aromatase Inhibitor Growth Study: Letrozole vs. Anastrozole

Randomization to Letrozole vs. Anastrozole in Short Pubertal Males

The purpose of the study is to determine if there are differences in the final height or hormone profile of short pubertal boys placed on different forms of aromatase inhibitor now routinely used to increase stature: Anastrozole and Letrozole. It also should determine if there are differences in the side effect profiles of the two drugs to be used.

Inclusion Criteria:

• Current height less than 5th percentile AND/OR
• Predicted adult height (based on bone age) more than 10 cm below target height (mid parental height)
• Evidence of puberty: physical signs and serum luteinizing hormone > 0.3 IU/L and testosterone > 15 ng/dl

Exclusion Criteria:

• Bone age reading more than 14.0 years
• Follicle stimulating hormone > 20 IU/L