Long-term efficacy and safety of two doses of growth hormone in short Japanese children born small for gestational age.

BACKGROUND/AIMS To investigate the long-term efficacy and safety of two doses (33 and 67 μg/kg/day) of growth hormone (GH) in short Japanese children born small for gestational age (SGA). METHODS 96 children born SGA (age 3 to <8 years) were randomized to GH at 33 or 67 μg/kg/day for 104 weeks, or to an untreated control (UC) group for 52 weeks. After 52 weeks, the UC group was randomized to GH at a dose of 33 or 67 μg/kg/day for a 156-week extension study. Initial treatment groups continued unchanged for the extension phase. Efficacy was evaluated by change in height SDS for chronological age from baseline to 208/260 weeks. RESULTS After 208 weeks, change in height SDS from baseline (least square (LS) means (SE)) was 1.01 (0.47) and 1.99 (0.67) in the UC 33 and UC 67 μg/kg/day groups, respectively. After 260 weeks, change in height SDS from baseline was 1.22 (0.51) and 2.01 (0.64) in the 33 and 67 μg/kg/day groups, respectively. Insulin-like growth factor-1 levels were significantly higher in the groups receiving 67 μg/kg/day but largely remained within normal limits (-2 to +2 SDS). CONCLUSION Long-term continuous GH treatment was well tolerated and effective in improving height SDS. Improvements were dose-dependent and significantly higher at 67 than 33 μg/kg/day.