Advances in the management of precocious puberty

Screening for central precocious puberty by single basal Luteinizing Hormone levels

PURPOSE

To identify cut-off for basal LH levels and for pelvic ultrasound uterine and ovarian parameters indicating an Hypotalamic-Pituitary-Gonadal (HPG) axis activation as diagnostic of Central Precocious Puberty (CPP).

METHODS

248 girls referred for suspected precocious/early puberty who had undergone a GnRH stimulation test were enrolled and divided into three groups: Premature Idiopathic Thelarche (PIT), CPP, and Early Puberty (EA). For every patient basal serum Luteinising Hormone (LH) and Follicle Stimulating Hormone (FSH), basal LH/FSH ratio and pelvic ultrasonographic parameters were also collected. Through the use of Receiver Operating Curves (ROCs) the sensitivity (Se) and specificity (Sp) of basal LH, FSH, LH/FSH ratio and ultrasonographic parameters were evaluated at each level and Area Under the Curve (AUC) was measured.

RESULTS

Basal LH model ≥0.14 mIU/mL reached the highest predictability (90.6% and 78.2%, Se and Sp, respectively). Basal LH/FSH ratio ≥0.1 showed a sensitivity of 85.90% and a specificity of 78.14%, while basal FSH cut-off (≥2.36 mIU/mL) had the lowest predictability, with a less favourable sensitivity (71%) and specificity (70.5%). Cut-off point for uterine length as 35 mm, (83.5% and 42.9% of Se and Sp, respectively) was calculated. For ovarian volumes, ROC curves showed very low sensitivity and specificity.

CONCLUSION

A single basal LH measurement under the cut-off limit may be adequate to exclude an HPG axis activation as CPP.

[Treatment with LHRH analogues in girls with precocious puberty does not improve final height. Longitudinal study compared with a control group]

BACKGROUND

We analysed the effectiveness of therapy with LHRH analogues in girls with a puberty onset at age 8 years.

PATIENTS AND METHOD

We performed a non-randomised clinical study of 32 girls with advanced puberty. These included 16 treated with triptorelin LHRH analogue(3.75 mg/month during 1 year) and 16 control subjects. We carried out anthropometric measurements and determined the pubertal height growth (gain in height from the puberty onset up to the final height) and the pubertal duration (time in years from the puberty onset up to the age at which final height is attained).

RESULTS

Treatment with LHRH analogue delayed the menarche age (11.5 [1.46]vs 10.37 [0.67] years of age; p = 0.03), led to an involution in secondary sexual characteristics and a temporary decrease ingrowth rate, and delayed skeletal maturation. However, pubertal duration, pubertal height growth and final height were all similar in both groups. In addition, no significant differences in body fat mass were observed.

CONCLUSIONS

Treatment with LHRH analogues in advanced puberty modifies pubertal development, without modifying pubertal duration or pubertal height growth. Furthermore, this treatment does not improve final height.

When to stop GnRH analog therapy: the experience of the Italian Study Group for Physiopathology of Puberty

Data reported in this study have been recently published elsewhere. The authors retrospectively analyzed the auxological response to GnRH agonist treatment and the final height (FH) outcome in 71 girls with idiopathic and truly precocious (onset before 8 years) central puberty (CTPP), who had been treated with the same therapy protocol (Decapeptyl Depot at the dose of 60 microg/kg i.m. every 28 days) for at least 2 years (since 7.0 +/- 1.3 yr) and followed until puberty was completed and FH was reached. During the entire treatment period we observed: A) a decrease of height standard deviation scores (SDS) (from 1.5+/-1.7 to 0.9+/-1.3 SDS, p<0.01); B) a striking deceleration of BA, revealed by the subnormal deltaBA:deltaCA ratio (0.2 +/- 0.1); C) an increase of predicted adult height (from 155.6+/-7.0 to 160.7+/-6.7 cm, p<0.0005). Treatment interruption was followed by notable catchdown growth, with FH (158.4 +/- 5.8 cm) lower (p < 0.025) with respect to that predicted at the end of therapy. However FH fell within the population norm and the target range in 87.3% and 90% of patients, respectively. The tallest FH was recorded in the patients who discontinued treatment at a BA of 12.0-12.5 years. We conclude that: 1) Most girls with idiopathic CTPP treated by GnRH agonists may achieve an adult height within the population norm and/or their target range; 2) The height gain from therapy onset until FH attainment, however, is generally rather limited (on average 2.9 cm) and only few patients are able to reach their target percentile; 3) The most favorable height prognosis with respect to target height (TH) is generally observed in the patients with the tallest H2 and the lowest BA2:CA2 ratio, due to the notable deterioration of height prognosis which frequently follows therapy interruption; 4) In order to strengthen the weak therapeutic effect of GnRH agonists in CTPP, this treatment should be discontinued at a BA of 12-12.5 years.

Recent advances in the diagnosis and treatment of precocious puberty

In the last two decades, the diagnosis and treatment of precocious puberty has undergone important changes. The use of supersensitive assays to determine gonadotropins and gonadal hormones has increased the sensitivity and decreased the number of blood samples required to assess the diagnosis. The introduction of gonadotropin-releasing hormone (GnRH) agonists produced a revolution in the diagnosis and treatment of this disorder. Recently, the use of long acting GnRH agonists improved the adherence of patients to medical treatment and decreased the need for uncomfortable repeated doses. The medications in the treatment of the GnRH independent causes of precocious puberty, and the important revelations in the pathophysiology of these disorders, have advanced our knowledge and management of the affected children.

Central precocious puberty and abnormal chromosomal patterns

Central precocious puberty (PP) can be caused by chromosomal aberrations. We report three patients presenting with central PP in whom karyotype analysis demonstrated abnormal chromosomal patterns. The first patient was affected by the triple-X syndrome, commonly characterized by premature ovarian failure. The second patient, a girl with inv dup(15)(pter-->q12::q12-->pter), had a chromosomal aberration involving an imprinted region of the human genome, whose deletion is commonly associated with Prader-Willi syndrome (PWS) and hypogonadotrophic hypogonadism. The third patient was a boy carrying a rare chromosome abnormality, the duplication of chromosome 9 (q22-->qter). All patients had mental retardation, which was mild in patient 1, moderate in patient 2, and severe in case 3. They underwent treatment with luteinizing hormone releasing hormone (LHRH) analogs, which were able to stop the progression of the sexual development. We confirm that chromosomal aberrations are an important cause of central PP, and that karyotype analysis in patients with PP and mental retardation, even if mild, is necessary because chromosomal abnormalities can be present.

Central precocious puberty. An overview of diagnosis, treatment, and outcome

Central precocious puberty (CPP) is physiologically normal puberty beginning early. It is the consequence of early increased regulation of gonadotropin releasing hormone (GnRH) stimulation of pituitary gonadotropin release causing pubertal changes and accelerated growth. GnRH stimulation testing is the definitive diagnostic test--pubertal gonadotropin responses being indicative of CPP. Among patients with progressive CPP, GnRH analogue therapy is effective by decreased regulation of gonadotropin secretion. Pubertal progression is stopped, and accelerated growth rate and compromised adult height are precluded or alleviated. Outcome data have not identified unusual sequelae.

Effect of combined treatment with gonadotropin releasing hormone analogue and growth hormone in patients with central precocious puberty who had subnormal growth velocity and impaired height prognosis

Growth hormone-insulin-like growth factor-I status and response to growth hormone therapy (0.6 IU/kg/week sc, six times a week for 12 months) were evaluated in 12 girls (chronological age 9.4 +/- 1.6 years) suffering from central precocious puberty with growth velocity less than 4 cm/year and no substantial increase or decrease in predicted adult height during gonadotropin releasing hormone Bn-RH) analogue treatment (D-Trp6-LH-RH, 60 micrograms/kg im/28 days). At baseline, large variations were observed in nocturnal growth hormone (GH) means (pathological values stimulated levodopa GH peaks (pathological values (< 10.0 micrograms/l) 28.6%) and serum insulin-like growth factor-I (IGF-I) levels. Neither GH-nor IGF-I levels were correlated with growth velocity. During recombinant GH therapy, growth velocity increased significantly (baseline 3.0 +/- 0.9 cm/year; 6 months 6.4 +/- 1.9 cm/year, p < 0.001 versus baseline; 12 months 6.0 +/- 1.3 cm/year, p < 0.0001 versus baseline). There was a significant increase in height SDS for bone age (baseline -1.6 +/- 0.5 SDS; 12 months -1.04 +/- 0.6 SDS; p < 0.002) and in predicted adult height (baseline 152.0 +/- 3.6 cm; 12 months 155.9 +/- 3.4 cm; p < 0.002). Our results suggest that combined therapy with Gn-RH analogues and recombinant GH can improve growth velocity and predicted adult height in girls with central precocious puberty and impaired height prognosis during Gn-RH analogue treatment.