Background: Short-term studies have demonstrated acceleration of growth rate following administration of biosynthetic human growth hormone (r-hGH) to short normal children. We describe the effect of such treatment on final height.
Methods: This was an open study of consecutive referrals to a growth disorder clinic from which 16 short children (height standard deviation score [SDS] -2.17 [range -1.8 to -3.3]; height velocity SDS -0.44 [0.33]; peak serum GH response to stimulation 27.9 mU/L [9.2] were treated with r-hGH, and 7 short children who declined treatment (height SDS -2.34 [0.61]; height velocity SDS -0.36 [0.28]; peak serum GH response 28.2 mU/L [6.8]) acted as an observation group. Subcutaneous r-hGH dose ranged between 12.2 and 21.0 U/m2 per week (0.02-0.04 mg/kg per day) for the first 2 years of treatment and 20 U/m2 per week thereafter, 3 untreated children were lost to long-term follow-up.
Findings: r-hGH significantly increased the difference in final height compared with pretreatment predicted height (+0.42 SDS [0.79], p = 0.03) but this change was not significantly greater than that of the observation group (+0.16 SDS [0.20]). Treatment had no effect on the timing of puberty. Boys progressed slightly faster through puberty, associated with an acceleration in bone-age maturation. No untoward effects on glucose metabolism were observed. Long-term therapy did not alter body-fat distribution or blood pressure.
Interpretation: Long-term therapy in this group of children appears safe but the small increment in final height, approximately 2.8 cm in boys and 2.5 cm in girls, does not justify the widespread use of r-hGH for short normal children.