Long-term treatment of central precocious puberty with an intranasal LHRH analogue: control of pituitary function by urinary gonadotropins

Evaluation of central precocious puberty treatment with GnRH analogue at the Triangulo Mineiro Federal University (UFTM)

OBJECTIVE

To report our experience of treating central precocious puberty (CPP) with a GnRH analogue with respect to the final heights (FH) attained in patients who completed treatment.

SUBJECTS AND METHODS

Among 105 records of children diagnosed with precocious puberty, 62 cases (54 girls and 8 boys), who were treated with leuprolide acetate/3.75 mg/monthly, were selected, and divided into 4 groups: group 1 (G1), 25 girls who attained FH; group 2 (G2), 18 girls who completed treatment but did not reach FH; group 3 (G3), 11 girls still under treatment; and group 4 (G4), 8 boys, 5 of which attained FH. Treatment was concluded at a bone age of 12 years, and follow-up continued until FH was achieved.

RESULTS

In both G1 and G2 groups, height standard deviation score (SDS), weight-SDS and percentile of body mass index (PBMI) did not show intra/intergroup differences at the beginning and at interruption of treatment, but when added, G1+G2, height-SDS and weight-SDS differed significantly (p = 0.002 and 0.0001, respectively). In G1, 19 of 25 cases attained TH, and average height gain was 16.7 cm (7.7- 27.1); there was significant difference between FH and prediction of FH at the start (PFH at start) (p = 0.0001), as well as between PFH at interruption vs TH and vs FH (p = 0.007) with FH higher than TH (p = 0.004). Significant correlation was identified between FH and height gain after treatment.

CONCLUSION

As shown by some studies, GnRH analogue treatment was effective in children with CPP reaching FH near the genetic target.

Variations in pituitary-gonadal suppression during intranasal buserelin and intramuscular depot-triptorelin therapy for central precocious puberty. Belgian Study Group for Pediatric Endocrinology

This study evaluated pubertal development, growth and pituitary-gonadal suppression in 21 patients with central precocious puberty treated with buserelin intranasally and switched after a mean of 2.1 yr to depot-triptorelin given im for 1 year. Arrest or regression of puberty was observed in 12 patients while progression of puberty during therapy was seen in 9 patients (6 on buserelin, 2 on triptorelin and 1 on both therapies). The increment in serum LH and FSH concentrations after sc injection of short-acting triptorelin was greater on buserelin than on triptorelin therapy, particularly in patients with evidence of progression of puberty. Height velocity during therapy showed a reduction which paralleled the decelerating phase of the normal pubertal growth spurt. The rate of bone maturation during therapy was inversely related to pretreatment bone age. Predicted final height showed marked individual variations which were inversely related to predicted adult height before therapy. These data indicate that differences in the nature and route of administration of Gn-RH agonist therapy for central precocious puberty can be of importance for inhibition of pituitary gonadotropin secretion and development of secondary sex characteristics. Height velocity and bone maturation are age-related and the change in predicted adult height depends on pretreatment level.

Buserelin. A review of its pharmacodynamic and pharmacokinetic properties, and clinical profile

The gonadotrophin releasing hormone (GnRH) [luteinising hormone-releasing hormone (LHRH); gonadorelin] agonist buserelin is a promising new agent in the treatment of a variety of disorders in gynaecology and andrology, paediatrics and oncology. While a single dose of buserelin stimulates the release of pituitary gonadotrophins, multiple doses produce reversible pituitary desensitisation, and this specific blockade of gonadotrophin support to the gonads provides the basis for the drug's efficacy in conditions dependent on sex hormone secretion. Thus, buserelin provides comparable efficacy to orchidectomy or high dose estrogens in the treatment of hormone-sensitive prostate cancer and exhibits a lower incidence of adverse effects. During the early phase of treatment it may be particularly useful in combination with antiandrogens. Buserelin also appears promising in hormone-sensitive premenopausal breast cancer. Extensive studies have proven the value of buserelin in endometriosis, where it produces a transient remission with gradual recurrence of the disease on cessation of treatment. Surgical intervention is necessary in severe disease after buserelin-induced involution of the lesions. In patients with uterine leiomyoma, preliminary data suggest that buserelin may be beneficial in rendering surgery more conservative by reducing fibroid size, although it appears unlikely to preclude surgical intervention. The use of buserelin to induce a state of reversible hypogonadotrophism before administration of exogenous gonadotrophins is a promising strategy in the treatment of infertility associated with polycystic ovary syndrome and other conditions of infertility with underlying ovarian dysfunction; such a strategy also clearly enhances the efficiency of in vitro fertilisation programmes. Initial studies suggest its potential usefulness as a female contraceptive when administered intermittently in conjunction with a progestogen. Buserelin represents a first-line treatment of central precocious puberty. In endometriosis the adverse effect profile of buserelin is generally favourable, with hypoestrogenic effects such as hot flushes and vaginal dryness, and decreased libido, predominating. There is no apparent detrimental effect on lipid metabolism. The potential for adverse hypoestrogenic effects on bone mineral content with long term administration remains to be clarified. Thus, the GnRH agonist buserelin represents an advance in the treatment of a variety of gynaecological and andrological as well as paediatric and oncological conditions, infertility and other sex-hormone dependent conditions, with a low incidence of adverse treatment effects.

The pathophysiology of precocious puberty

Advances in understanding of normal puberty have clarified many of the mechanisms underlying precocity and led in several instances to better therapy. The essential diagnostic task is to determine if the normal process has been triggered prematurely or if an abnormal process (usually inappropriate sex steroid secretion) has circumvented the normal physiology.