EFFECT OF A LONG ACTING LHRH ANALOGUE AND GH ON THE SUPPRESSION OF SECONDARY SEXUAL DEVELOPMENT AND FINAL HEIGHT

Abstract

LHRH analogue therapy has been estimated as useful for suppressing secondary sexual development in cases of precocious puberty and is expected to improve final height. We studied changes in the pituitary and gonadal functions after cessation of LHRHa in patients exhibiting precocious puberty. Furthermore, we studied the effects of a combination therapy of LHRHa and growth hormone in short patients.<Patients and method> Group A; Five girls who had been diagnosed as exhibiting precocious puberty and had been treated with LHRHa(TAP-144-SR) during a period of 1.5 to 3.4years, and who were no loonger being treated. Group B; Six girls and a boy who underwent pubertal development and exhibited acceleration of bone maturation during a GH supplement for GH deficiency or short stature without GHD, were treated with LHRHa. GH was injected subcutaneously 4-6 times a week at a dosage of 0.5-0.6U/kg/w. A and B; LHRHa, 30-60 μg/ml, was administered via a subcutaneous injection every 4 weeks. Changes in secondary sexual characteristics, height velocity, bone age, height SDS for bone age, serum estradiol, serum gonadotropins and IGF-1 were observed in all patients, and serum GH was measured in group A. Height velocity/ΔBA and ΔBA/ΔCA were calculated in group B.<Results> A; After cessation of LHRHa treatment, secondary sexual characteristics began to progress within 6 months, and E2 and peak LH were elevated to the pubertal level within one year. Improvement of height SDS for BA and increase of height velocity continued at least 6 months after the off-therapy. B; After LHRHa treatment, secondary sexual characteristics were attenuated, acceleration of bone maturation was suppressed and hormonal parameters decreased to the prepubertal range in all cases. Height SDS for BA, growth velocity/ΔBA and ΔBA/ΔCA were all improved by LHRHa treatment.<Conclusion> The suppression of pubertal bone maturation by LHRHa was significant. On the other hand, secondary sexual characteristics developed promptly after the cessation of LHRHa treatment. This data suggests the possibility of improving final height without any side effects by a combination therapy consisting of GH and LHRHa.