The Growth Pattern and Final Height of Girls With Turner Syndrome With and Without Human Growth Hormone Treatment

Abstract

Background. Shortness is the most frequent and quite disturbing characteristic of girls with Turner syndrome (TS). Human growth hormone administration (hGH) to girls with TS increases growth velocity (GV), but a favorable effect on final height (FH) has not been documented. The aim of this study was to evaluate the effect of hGH administration on the growth pattern and FH in girls with TS. Methods. The study group was comprised of 123 girls with TS who were cared for in our center. Eighty-two of these girls received hGH (mean dose, 0.78 ± 0.12 IU/kg/week), given subcutaneously 5 to 7 times per week for a period of 2.2 ± 1.2 years (hGH group). The mean chronological age (CA) and bone age (BA) at hGH initiation were 11.5 ± 2.5 years and 9.7 ± 2.3 years, respectively. The remaining 41 girls did not receive hGH and are designated as the untreated control group. In both groups, gonadal steroids were given for pubertal initiation and maintenance. Results. The GV during the first year of hGH therapy (GV1) was higher than the year before hGH (6.3 cm/year vs 4.0 cm/year) and higher than the GV of the untreated group at a similar CA (4.4 cm/year). The GVs during the second (GV2) and third (GV3) year of hGH treatment (5.4 and 4.9 cm/year, respectively) were lower, but still higher in the hGH group, in comparison with the untreated group (GV2, 4.2 cm/year; GV3, 3.4 cm/year). GV1, GV2, and GV3 were negatively related to age and to BA at hGH initiation. The FH of the 35 hGH-treated girls was not significantly different from the FH of the 27 untreated girls (146.1 cm vs 144.0 cm). The Δ target height-FH was not significantly different in the two groups. The FH standard deviation score of the hGH-treated group was positively related to height standard deviation score for CA at treatment initiation (r = +0.73), maternal height (r = +0.57), target height (r = + 0.66), and birth weight (r = +0.54), but was unrelated to CA or BA at start of therapy or to hGH dose. Conclusions. hGH therapy in girls with TS, in the dose and duration of treatment applied in this study, significantly accelerated GV but did not significantly improve FH.