Human growth hormone and gonadotropin releasing hormone analog combination therapy increases predicted height in short normal girls

Efficacy and safety of a 4-year combination therapy of growth hormone and gonadotropin-releasing hormone analogue in pubertal girls with short predicted adult height

OBJECTIVES

To improve adult height in pubertal girls with a poor height prediction, treatment with growth hormone (GH) can be used in combination with a gonadotropin releasing hormone agonist (GnRHa), to delay closure of the growth plates. However, there are few studies to support this practice, and they show conflicting results. The objective of this trial is to assess the safety and efficacy of this combination treatment in early pubertal girls with a short predicted height, in comparison with matched controls.

DESIGN PATIENTS AND METHODS

We designed an open-label, multicenter, interventional case-control study. Early pubertal girls with predicted adult height (PAH) below -2.5 SDS, were recruited in tertiary care centers in Belgium. They were treated for four years with GH and GnRHa. The girls were followed until adult height (AH) was reached. AH vs PAH, AH vs Height at start, and AH vs Target Height (TH) were evaluated, as well as safety parameters. Control data were assembled from historical patient files or from patients who preferred not to participate in the study.

RESULTS

Sixteen girls with mean age ( ± SD) at start of 11.0 years (± 1.3) completed the study protocol and follow-up. Their mean height ( ± SD) increased from 131.3 ± 4.1 cm (-2.3 ± 0.7 SDS) at start of treatment to 159.8 ± 4.7 cm (-1.1 ± 0.7 SDS) at AH. In matched controls, height increased from 132.3 ± 4.2 cm (-2.4 ± 0.5 SDS) to 153.2 ± 3.4 cm (-2.1 ± 0.6 SDS) (p<0.001). AH surpassed initial PAH by 12.0 ± 2.6 cm in treated girls; and by 4.2 ± 3.6 cm in the controls (p<0.001). Most treated girls reached normal adult height (>-2SD) (87.5%) and 68.7% reached or superseded the target height (TH), which was the case in only a minority of the controls (37.5% and 6.2%, respectively) (p= 0.003 and 0.001). A serious adverse event possibly related to the treatment, was a fracture of the metatarsals.

CONCLUSION

A four-year GH/GnRHa treatment in early pubertal girls with a poor PAH seems safe and results in a clinically relevant and statistically significant increase in AH compared with matched historical controls.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT00840944.

Gonadotropin-releasing hormone analog therapy for central precocious puberty and other childhood disorders affecting growth and puberty

Gonadotropin-releasing hormone (GnRH) analog therapy relies primarily on the ability of these compounds to bind to and modulate GnRH-receptor activity. GnRH analogs have been used in pediatric patients where endogenous gonadotropin release is undesirable or potentially harmful, such as in: (i) patients with central precocious puberty (CPP); (ii) healthy short children where pubertal delay would provide an opportunity to supplement pre-pubertal linear growth; and (iii) children with malignancies and other disorders where treatment requires the use of gonadotoxic compounds. In the first two groups of patients, GnRH agonists may be used alone or in conjunction with somatropin (growth hormone [GH]) to prevent early skeletal maturation and increase the subsequent adult height, while in the latter case, GnRH agonists are used alone or in conjunction with GnRH antagonists in an attempt to preserve gonadal function.In children and adolescents with CPP, timely use of GnRH agonists alone can result in an adult height within the genetic potential of the individual (target height); however, minimal height is gained when GnRH agonist therapy is commenced after a marked advancement of skeletal age. This provides the rationale for combined therapy with GnRH agonists and somatropin in such patients, and studies have shown improved growth with this approach compared with GnRH agonists alone. Combination therapy with GnRH agonists and somatropin has also been shown to increase adult heights to a greater extent than GnRH agonists alone in pediatric patients with concomitant CPP and GH deficiency, those with idiopathic short stature, and those born small for gestational age; however, such combination therapy has shown no increased benefit over somatropin alone in pediatric patients with GH deficiency. Limited results in children and adolescents with congenital adrenal hyperplasia and chronic primary hypothyroidism have also shown increased growth rates, while no growth benefit was seen in pediatric renal transplant recipients.GnRH analogs also have potential as gonadoprotective agents; studies of GnRH agonists used alone and in combination with GnRH antagonists in women undergoing cytotoxic therapy have shown increased preservation of reproductive potential in patients who were receiving GnRH analog therapy versus those who were not.The adverse effects of GnRH analogs mainly consist of menopausal-like complaints. Increases in bodyweight and body mass index in children receiving GnRH agonist therapy have been shown; however, these increases do not persist after discontinuation of therapy. Adult bone mineral density and fertility are also not adversely affected by childhood GnRH agonist therapy.GnRH analog therapy appears to be both well tolerated and effective in pediatric patients, as it allows the preservation or improvement of adult height, and shows no longstanding negative effects on body composition, bone density, reproductive function, or endocrine physiology. These agents may also be useful for preservation of gonadal function in children and adolescents undergoing cytotoxic therapy.

Anabolic steroid and gonadotropin releasing hormone analog combined treatment increased pubertal height gain and adult height in two children who entered puberty with short stature

We studied the effect of gonadal suppression treatment in combination with anabolic steroid on pubertal height gain and adult height in two children who entered puberty with short stature. Patient 1 was a female with idiopathic short stature. She received combined treatment with an anabolic steroid (stanozolol) and a gonadotropin releasing hormone analog (leuprorelin acetate). Her pubertal height gain was 28.5 cm, which is greater than that in normal height girls (20-25 cm). Patient 2 was a male with Aarskog syndrome. Although his growth hormone (GH) secretion was normal, he received GH treatment. Since GH administration did not accelerate his growth, he received combined treatment with stanozolol and leuprorelin acetate. His pubertal height gain was 27.0 cm, which is greater than that observed in GH deficient boys treated with GH alone (21.9 cm). Combined treatment with stanozolol and leuprorelin acetate appears to be effective in increasing pubertal height gain and adult height in children who enter puberty with short stature.

Final height in a patient with Laron syndrome after long-term therapy with rhlGF-I and short-term therapy with LHRH-analogue and oxandrolone during puberty

OBJECTIVE

To report our experience on long-term treatment with recombinant-human-IGF-I (rhIGF-I) of a female patient with Laron syndrome (mutation G223G in the GH receptor gene), who received short-term treatment (1 yr) with LHRH analogue at the start of puberty and subsequently with oxandrolone.

CASE REPORT

The patient started IGF-I therapy (dose 40 microg/kg bid for 9 months, 80 microg/kg bid until 13.7 yr of age and 120 microg/kg bid thereafter) when she was 7.6 yr old (height -6 sds), and was treated for 9.4 yr until final height (cm 129.7; -5.5 sds). At first signs of puberty (age 12.7 yr; height 116.3; -5.3 sds), LHRH analogue was started (3.75 mg/28 days) and bone age progressed by 6 months in the 12-month period. Growth velocity decreased in the 6-12th month of combined treatment (0.9 cm/6 months), and treatment was suspended. At age 14.8 (height 124.5; -6.6 sds), oxandrolone was added (0.1 mg/kg/day), but after 12 months (height 128 cm; -5.7 sds) bone age increased from 11.5 to 13.5 yr and the drug was stopped. No side effects occurred during the various treatments. Body segments progressed harmonically: there was a tendency towards improvement in the upper to lower body segment ratio and in cranial growth. Only biiliac diameter did not increase during LHRH treatment. During the 9-yr period, body mass index (BMI), subscapular and triceps skinfold centiles did not show any significant variations.

CONCLUSIONS

Our patient with Laron syndrome after long-term treatment showed a final result below the initial expectations, confirming that IGF-I used with the present schedule is less effective than GH in GH-deficient patients. LHRH analogue therapy at puberty was associated with a slower bone age maturation but with an almost complete arrest of growth. On the contrary, oxandrolone sustained growth but caused an excessive maturation of bone age. Other strategies are necessary to improve final height in these patients.