NEW YORK (Reuters Health) – In a randomized, controlled long-term study of children with idiopathic short stature who were not growth hormone (GH) deficient, GH treatment, started as late as near the start of puberty, significantly increased final height.

In this population of children, GH treatment led to a mean gain of “more than three inches, with some cases seeing a gain of nearly eight inches,” Dr. Kerstin Albertsson-Wikland noted in a statement issued by the Endocrine Society, which published the study in the November issue of the Journal of Clinical Endocrinology and Metabolism.

In their article, Dr. Albertsson-Wikland, from Goteborg Pediatric Growth Research Center at the University of Gothenburg, and colleagues report efficacy data for 151 short children — defined as height below -2 standard deviation score (SDS), according to the Swedish population-based reference. The children’s chronological age was 8 to 13 years for girls and 10 to 15 for boys, corresponding to a bone age of no more than 11 years in girls and no more than 13 years in boys.

These non-GH deficient children were randomly assigned to no treatment or to low-dose GH therapy (33 µg/kg per day) or high-dose GH therapy (67 µg/kg per day). Treatment lasted 5.9 years (+/- 1.1 year) and the children were followed until final height was reached.

“Although there was variation in the growth response owing to individual GH responsiveness, most individuals receiving the high-dose GH regimen reached normal adult height,” the investigators report.

The GH effect was dose-dependent, and the children with parents of normal heights responded best, “their mean final height being -1.2 SDS and only 0.2 SDS below midparental height after a gain of 1.5 SDS (approximately 9 centimeters),” they further note.

In contrast, the final height of untreated children was -2.4 SDS, and -1.0 SDS from their parents after a gain of only 0.2 SDS from the start of the study.

“Notably,” the investigators write, one third of children on the high GH dose and one fifth of those on the low GH dose reached a final height above -1 SDS versus none of the controls.

GH therapy was safe in this population of children and had no impact on the time until onset of puberty.

Dr. Albertsson-Wikland and colleagues caution that the finding of a significant height gain with GH treatment “does not mean that such treatment is recommended for all children with idiopathic short stature.”

“On the contrary, it should be recommended to those predicted to have a good growth response, and only after thorough discussions with the subjects and parents to determine, on a case-by-case basis, those who suffer substantially from their short stature, thus justifying this long-term therapy,” they conclude.

Reference:
J Clin Endocrinol Metab 2008;93:4342-4350.