GROWTH-HORMONE SUBSTITUTION IN ADULT GROWTH HORMONE-DEFICIENT MEN AUGMENTS ANDROGEN EFFECTS ON THE SKIN

OBJECTIVE To assess whether growth hormone (GH) administration to adul t GH-deficient men leads to increased sexual hair. The sexual hair sco res are subnormal in these patients, even in the presence of normal se rum androgen levels. PATIENTS Forty-six adult men with childhood-onset of GH deficiency of whom 25 were androgen deficient and received repl acement. DESIGN Double-blind and placebo-controlled. Of the 46 patient s, 33 started immediately with GH administration; the remaining 13 rec eived placebo for the first 6 months followed by GH for the next 6 mon ths. Sixty-one age-matched healthy men with normal height and serum co ncentrations of IGF-I served as a comparison group. MEASUREMENT Hair s cores at 13 defined body regions were assessed before, and after 6 and 12 months of the intervention, At the same time levels of IGF-I, dehy droepiandrosterone sulphate, androstenedione, dihydrotestosterone (DHT ), testosterone and sex hormone binding globulin (SHBG) were measured. From the latter two, the free androgen index (FAI) was calculated. RE SULTS Before GH administration, hair scores in the GH deficient patien ts were lower than in the comparison group. In the 33 men treated with GH from the beginning, there was an increase in hair scores after 6 m onths. The increase in hairscores was not seen during 6 months of plac ebo treatment. When the placebo group switched to GH administration, t heir hair scores had also significantly increased after 6 months of GH substitution therapy. Upon GH administration both levels of SHBG and testosterone/DHT declined while the FAI remained unchanged. CONCLUSION GH substitution therapy to GH deficient men has an auxiliary effect o n androgen action in the skin without an increase of the FAI.