Testosterone treatment of excessively tall boys

Twenty-nine tall boys with a mean height prediction of 198 cm were treated for serious psychosocial reasons with high doses of a long-acting testosterone preparation (500 mg/m2/month). Their ages at the start of treatment ranged from 9.8 to 16.9 years, and the mean duration of treatment was 1.2 years. Bone age was assessed according to the Tanner-Whitehouse II (RUS) method, and height predictions were calculated using the age-specific regression equations of Tanner and colleagues. On the basis of bone age at the start of treatment, three groups were formed (bone age 12.1 to 14, 14.1 to 15, and greater than 15 years), and the results were assessed separately. In the whole series, adult height was reduced by 5.4 cm; the best results (8cm) were achieved in the youngest bone age group. Under treatment, bone maturation was accelerated (1.8 years per year) and growth velocity increased (youngest bone age group) or was normal (older bone age groups). Testicular volume remained prepubertal in young patients and decreased in older ones. After discontinuation of treatment, testicular volume and sperm count became normal again after a mean period of 1.5 years, but in a few cases recovery was slower. It is concluded that adult height in tall boys may be effectively reduced by testosterone, that the results are best if treatment is started in early puberty, and that the suppressing effects on pituitary and testicular function are fully reversible. Since the indication for treatment is a psychosocial one, the patients should be carefully selected, taking into account not only growth but also psychological and familial factors.