Comparison of the effectiveness of prepubertal growth hormone treatment on height and predicted adult height in children with short stature born small for gestational age vs. with a growth hormone deficiency.

Objectives: We compared the effects of growth hormone (GH) treatment on height and predicted adult height in children with short stature born small for gestational age (SGA-SS) vs. with a growth hormone deficiency (GHD).

Methods: This retrospective study analyzed the background and clinical characteristics of children who presented to Tanaka Growth Clinic for short stature and were diagnosed with either SGA-SS or GHD and underwent treatment with GH. We compared differences in height, height velocity, GH dose increases, insulin-like growth factor-1 levels, and bone-age/chronological-age ratio between the two groups.

Results: Out of these children, 33 SGA-SS and 54 GHD children started GH treatment before the age of 8 years, with a mean dose of 0.25 mg/kg/week and 0.20 mg/kg/week, respectively. At treatment initiation, the age and height standard deviation scores (SDS) of the SGA-SS group were significantly lower than those of the GHD group. The height velocity was significantly greater in the SGA-SS group for 3 years owing to higher GH doses and younger age. No notable differences in puberty onset height or predicted adult height were observed between the two groups for boys or girls. The increase in height SDS from the start of GH treatment until the onset of puberty was substantially greater in the SGA-SS group than in the GHD group for both sexes.

Conclusions: Adult height of patients with SGA-SS is expected to resemble that of patients with GHD but may not reach the -1.0 SD achieved with GH treatment of those patients in Western countries.