Treatment with the aromatase inhibitor letrozole during adolescence increases near-final height in boys with constitutional delay of puberty.
OBJECTIVE
We investigated whether inhibition of oestrogen biosynthesis with the aromatase inhibitor, letrozole, during adolescence improves near-final height in boys with constitutional delay of puberty.


METHODS
Seventeen boys with constitutional delay of puberty were randomized to receive testosterone (T) enanthate (1 mg/kg i.m.) every 4 weeks for 6 months in combination with placebo (Pl, n = 8), or the aromatase inhibitor letrozole (Lz, 2.5 mg/day orally) (n = 9), for 12 months. After treatment, patients were followed up until near-final height. Height discrepancy was calculated as near-final height minus mid-parental target height.


METHODS
The primary end point was the difference in near-final height between the groups treated either with T + Pl or T + Lz. Secondarily, height discrepancy and gain in height standard deviation score (SDS) were analysed in both groups.


RESULTS
Boys treated with T + Lz reached a higher mean near-final height than did boys on T + Pl (175.8 vs. 169.1 cm, respectively, P = 0.04). In T + Lz-treated boys, mean near-final height did not differ from their mid-parental target height (175.8 vs. 177.1 cm, P = 0.38), whereas in T + Pl-treated boys, mean near-final height was lower than mid-parental target height (169.1 vs. 173.9 cm, P = 0.007). T + Lz-treated boys had a greater increment in height SDS over the pretreatment height SDS than T + Pl-treated boys (+1.4 SDS vs.+0.8 SDS, P = 0.03).


CONCLUSIONS
Our findings indicate that in adolescent boys an increase in adult height can be attained by use of aromatase inhibitors.
Hero
Matti
M
Hospital for Children and Adolescents, Helsinki University Central Hospital, Helsinki, Finland.
Wickman
Sanna
S
Dunkel
Leo
L
D000293:Adolescent; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001827:Body Height / Q000187:drug effects*; D004958:Estradiol / Q000097:blood; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D000077289:Letrozole; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D009570:Nitriles / Q000627:therapeutic use*; D011446:Prospective Studies; D011628:Puberty, Delayed / Q000097:blood / Q000188:drug therapy*; D013739:Testosterone / Q000097:blood; D013997:Time Factors; D014230:Triazoles / Q000627:therapeutic use*
D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D013739:Testosterone; D004958:Estradiol; D000077289:Letrozole; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone