Growth hormone treatment in short Japanese children born small for gestational age

Recent reports have shown that high-dose growth hormone (GH) treatment in short children born with small for gestational age (SGA) resulted in a pronounced acceleration of linear growth. We describe the results of multicenter trials of recombinant human GH (rhGH) treatment in short SGA children in Japan. Two clinical studies were performed and the results were combined. Study 1 comprised 104 SGA children and study 2 comprised 61 SGA children. The patients were divided into three groups: group 1 consisted of 20 patients (13 boys and 7 girls) who received rhGH 25 microg/kg per day six or seven times per week in the first year and 50 microg/kg per day in the second year and thereafter; group 2 consisted of 48 patients (28 boys, 20 girls) who received rhGH 45/50 microg/kg per day; group 3 consisted of 44 patients (28 boys, 16 girls) who received 90/100 microg/kg per day. The mean increments in height SDS were 0.46, 0.67 and 0.94 SD in boys and 0.49, 0.79 and 0.93 SD in girls in groups 1, 2 and 3, respectively. The mean increment in height SDS at 2 years in group 3 was significantly greater than that in group 1, but it was not significantly different from that in group 2 in boys and girls. Our data demonstrated that high-dose GH administration significantly improved height velocity and height SDS in short SGA children. Additional studies are necessary to optimize a long-term GH treatment regimen and combined luteinizing hormone releasing hormone analog treatment for final height. Careful observation is also necessary to assess the metabolic effects of high-dose GH, especially on carbohydrate metabolism.