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

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 (gro up 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 st art 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 gr oup 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 treat ment was 5.1 +/- 1.5 years in boys and 2.3 +/- 0.7 years in girls. The dura tion 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 great er in group 2 (36.7 +/- 6.5 cm in boys and 29.0 +/- 8.3 cm in girls) than i n group 1 (21.9 +/- 4.1 cm in boys and 18.6 +/- 4.1 cm in girls). Final hei ght 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 g irls, the change in height SDS from the start of CH treatment until final h eight 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 i n girls), in both boys and girls. In conclusion, it appears that combinatio n 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 pro longation of the treatment period, permitting slow bone maturation, and to the maintenance of height velocity. This combination treatment appears to b e more effective in boys than girls. To fully assess this therapeutic appro ach, prospective controlled studies are needed.