When and how to combine growth hormone with a luteinizing hormone-releasing hormone analogue.

Abstract

The effect of combined treatment with growth hormone (GH) and a luteinizing hormone-releasing hormone (LHRH) analogue, or GH alone, on pubertal height gain was assessed in an uncontrolled study in 15 boys and 10 girls with GH deficiency (GHD). Seven boys and six girls were treated with GH alone (group 1), and eight boys and four girls were treated with a combination of GH and an LHRH analogue during puberty (group 2). Mean ages (+/- SD) at the start of GH treatment and at the onset of puberty were significantly lower in group 2 (8.0 +/- 3.3 years and 11.2 +/- 0.8 years, respectively, in boys, and 6.3 +/- 1.6 years and 10.8 +/- 0.7 years in girls) than in group 1 (12.8 +/- 1.9 years and 13.7 +/- 1.4 years in boys, and 11.2 +/- 1.0 years and 12.5 +/- 1.2 years in girls). Height at the onset of puberty was less in group 2 than in group 1, but the difference was significant only for the boys. Combination treatment was started at a mean age of 11.7 +/- 1.2 years in boys and 11.5 +/- 1.0 years in girls. The duration of the combination treatment was 5.1 +/- 1.5 years in boys and 2.3 +/- 0.7 years in girls. The duration of the period between the onset of puberty and the end of GH treatment was significantly longer in group 2 (6.8 +/- 1.2 years in boys and 5.5 +/- 1.0 years in girls) than in group 1 (4.3 +/- 1.6 years in boys and 3.6 +/- 1.4 years in girls). The pubertal height gain was also significantly greater in group 2 (36.7 +/- 6.5 cm in boys and 29.0 +/- 8.3 cm in girls) than in group 1 (21.9 +/- 4.1 cm in boys and 18.6 +/- 4.1 cm in girls). Final height was significantly greater in group 2 than in group 1 in boys. Although there was no significant difference in final height between groups in the girls, the change in height SDS from the start of GH treatment until final height was significantly greater in group 2 (2.7 +/- 1.6 in boys and 4.5 +/- 0.5 SD in girls) than in group 1 (1.0 +/- 0.8 in boys and 1.8 +/- 0.9 SD in girls), in both boys and girls. In conclusion, it appears that combination of an LHRH analogue and GH may increase the pubertal height gain and the final height of children with GHD. The improvement is attributed to the prolongation of the treatment period, permitting slow bone maturation, and to the maintenance of height velocity. This combination treatment appears to be more effective in boys than girls. To fully assess this therapeutic approach, prospective controlled studies are needed.