Testosterone treatment of constitutional delay in growth and development: effect of dose on predicted versus definitive height.

The outcome of treatment in 3 groups of boys with constitutional delay in growth and development given monthly intramuscular injections of testosterone enanthate 200 mg (22 subjects) 100 mg (10 subjects) and 50 mg (12 subjects) was compared with the outcome in a control group (14 subjects) without treatment. The 4 groups were similar in chronological age, height, height age, bone age, height age/bone age ratio, pubertal development and had similar predicted adult heights. All treated subjects achieved an excellent growth response with growth velocities reflecting androgen dose. Bone age advanced commensurate with height age in all the treated groups and delta height age/delta bone age ratios at the end of therapy did not differ significantly. Nor was there a significant difference in the height prediction by the RWT method before and at the end of treatment. However, the year following treatment, growth velocities reversed so that those who received the largest steroid dose and had grown the fastest, decelerated the most and eventually ended up significantly shorter than their predicted adult height. In contrast the control group and those treated with smaller doses of testosterone achieved their predicted heights. The present study confirms that large doses of androgens compromise adult height and are contraindicated in the treatment of constitutional delay in growth and development. Testosterone enanthate 50 mg/mo did not affect predicted adult height adversely, but to the contrary, permitted it to be fully realised. The data caution against drawing conclusions based on changes observed during androgen therapy in the absence of extended follow-up.