Combined use of growth hormone and gonadotropin-releasing hormone analogue in short normal adolescent girls: a survey from Iran

Abstract

Combined therapy with gonadotropin-releasing hormone (GnRH) analogue and growth hormone (GH) has been used to increase the height of adolescents who are not GH deficient and who have normally timed puberty. Its use, however, is still controversial. For 2 years simultaneously, we treated eight healthy girls with very low predicted adult height (PAH < 145 cm) who were entering into normally timed puberty. The GnRH analogue triptorelin pamoate (Decapeptyl, 100 microg/kg intramuscularly every 4 weeks) and GH (0.1 IU/kg/day subcutaneously, 6 days/week) were administered. The mean chronologic age (CA) of our patients was 11.01 +/- 0.95 years, and mean bone age (BA) was 12.25 +/- 1.13 years. With a height of 131.50 +/- 5.83 cm (-2.37 +/- 0.35 SD below the mean) and PAH of 140.87 +/- 3.53 cm, they were all in Tanner stage 2-3 of puberty (except one patient in stage 4). In all cases, GH and thyroid hormone deficiency were ruled out before the study began. Height and BA were measured immediately after discontinuation of therapy. PAH was determined before and at the end of therapy. Combined treatment resulted in a 4.13 +/- 1.19 cm increase in PAH (p < 0.01). Height increased significantly to 142.66 +/- 3.54 cm at the end of treatment (p < 0.01). Height standard deviation score for CA increased from -2.37 +/- 0.35 to -2.32 +/- 0.67, showing no significant improvement (p = 0.5). Height age (HA)/BA ratio and BA/CA ratio both demonstrated significant growth during the treatment (p < 0.03 and p < 0.01, respectively), whereas HA/CA ratio did not improve significantly (p < 0.32). During treatment, puberty was completely suppressed in all cases. Combination therapy with GnRH analogue and GH resulted in significant improvement in height and PAH during therapy. Additional, and perhaps more long-term, studies are required to show whether this kind of treatment is effective in improving final adult height. The cost-benefit of such therapies should also be taken into account.