The aim was to investigate the clinical characteristics and responses to growth hormone (GH) therapy in children with attenuated growth who showed normal GH responses to GH stimulation tests (GHST).

The study included 39 patients with height velocity (HV) of less than 4 cm/yr and normal GHST results. Clinical characteristics of patients were analyzed retrospectively.

Eleven were born as small for gestational age (SGA) and 28 as appropriate for age (AGA). In the SGA group, the standard deviation score (SDS) of age and height measured at their first visit was significantly low. Sixteen patients were treated with GH and six of 23 without GH therapy were followed for 1 year after GHST. The mean (range) of HV was 7.7 (4.9 to 11.1) cm/yr in patients with GH therapy and 3.7 (2.7 to 4.5) cm/yr in those without GH therapy, which was statistically significant ( P <0.001). In the GH-treated group, HV and difference in height SDS during the treatment increased significantly ( P <0.001; P <0.001, respectively). HV increased after 1 year of GH therapy in the SGA and AGA groups (SGA, P =0.043; AGA, P =0.003). The level of Insulin-like growth factor-I was significantly lower in GH-treated patients with height SDS <-3 than those with ≥3 ( P =0.023).

In children with growth failure and normal GHST, HV increases significantly by short-term GH therapy. The assessment of long-term effects of GH therapy is necessary. Moreover, further studies should be considered to evaluate the GH-IGF-I axis due to the possibility of GH insensitivity syndrome.