Androgen therapy in constitutional delay of growth

Two modalities of androgen therapy prevail in the treatment of constitutional delay of growth (CDG): monthly injections of testosterone or daily tablets of the non-aromatizable oxandrolone. The present study was undertaken to prospectively compare both compounds and dose.

Thirty patients with CDG were the subjects of this study. The protocol required that they all be at age 12-14 years with a bone age delay of more than 2 'years', height less than -2 SDS and growth velocity less than -0.5 SDS. The subjects were at a Tanner stage 1 or 2 and testicular volume were no larger than 4 ml. They were randomly assigned into 3 treatment groups: group 1 patients received monthly injections of 25 mg testosterone propionate-enanthate; group 2 patients received monthly injections of 50 mg testosterone propionate-enanthate; group 3 patients received oral oxandrolone at a weekly dose of 0.7 mg/kg. Treatment was given for a period of 6 months and follow-up commenced 6 months later and yearly thereafter for 2 years.

Height velocity and height increased significantly only in groups 2 and 3. Bone age advanced most in group 2. Puberty progressed faster in that group as compared with group 3. The predicted adult height before and 2 years after completion of treatment remained unchanged in the two testosterone groups. It increased significantly in the oxandrolone group from a mean 169.8 cm before therapy to a mean 177.5 cm 2 years after completion of therapy. Peak GH levels were significantly higher on both testosterone 50 mg and oxandrolone, as compared to pretreatment levels. The increment was significantly greater in group 2 as was the increment in serum IGF-1 and IGFBP3.

These results imply that 6 months of testosterone injections at a dose of 50 mg, but not 25 mg, is an effective and safe treatment for patients with CDG, with no considerable impact on final height prediction. On the other hand, daily oxandrolone treatment, starting at age 12-14 years, may increase the predicted final adult height.