Growth hormone deficiency impedes the rise in plasma insulin-like growth factor I levels associated with precocious puberty

Effect of gonadotropin-releasing hormone agonist monotherapy and combination therapy with growth hormone on final adult height in girls with central precocious puberty

This study aimed to compare clinical parameters, including final adult height (FAH), in girls with central precocious puberty treated with gonadotropin-releasing hormone agonists (GnRHa) with and without growth hormone (GH). This retrospective study reviewed data of 210 girls with precocious puberty who had reached FAH in a long-term trial of GnRHa treatment. The subjects were divided into the GnRHa treatment group (n = 188), and the combined GnRHa + GH treatment group (n = 22). Chronological age, bone age, height, height standard deviation score, predicted adult height (PAH), FAH, Tanner stage, and hormone levels were assessed during the treatment period. At the start of treatment, PAH was 156.35 ± 6.34 cm in the GnRHa monotherapy group and 150.41 ± 5.32 cm in the GnRHa + GH group (P < 0.001). At the end of treatment, PAH was 166.25 ± 5.26 cm in the GnRHa group and 164.07 ± 4.99 cm in the combined GnRHa + GH treatment group, which had increased compared to the start of treatment. The FAH in the GnRHa group and GnRHa + GH combination group were 161.07 ± 4.78 cm and 159.63 ± 3.8 6 cm, respectively, without significant difference. In addition, the height gain (FAH-PAH) was significantly higher in the GnRHa + GH group than the GnRHa group (9.22 ± 6.03 cm vs. 4.72 ± 5.01 cm, P < 0.001). In girls with central precocious puberty, the height gain in the FAH compared to PAH at the start of treatment was significantly higher with the GnRHa + GH combination treatment.

Comparing adult height gain and menarcheal age between girls with central precocious puberty treated with gonadotropin-releasing hormone agonist alone and those treated with combined growth hormone therapy

PURPOSE

This study aimed to investigate the outcomes of gonadotropin-releasing hormone agonist (GnRHa) therapy with or without growth hormone (GH) therapy for girls with idiopathic central precocious puberty (CPP).

METHODS

The medical records of 166 girls diagnosed with CPP from 2002 to 2017 were retrospectively reviewed. All included patients were treated with GnRHa for ≥36 months. Changes in height standard deviation score (SDS) for bone age, chronological age (CA), and predicted adult height (PAH) were assessed for the first three years of treatment. The final height gain SDS was calculated as the difference between the initial PAH SDS and adult height (AH) SDS; these were then compared between the GnRHa group (group A, n=135) and the combined GnRHa/GH group (group B, n=31).

RESULTS

The initial mean CA was 7.89 years. The mean menarcheal age was 13.12 years (group A, 13.1±0.99; group B, 13.18±0.58 years; P=0.755). PAH SDS at the start of GnRHa treatment and AH SDS were significantly lower in group B than in group A (PAH SDS: -2.20±0.83 vs. -3.19±0.84, P&lt;0.001; AH SDS: 0.18±084 vs. -0.30±0.66, P=0.021). The increase in PAH SDS was higher in group B than in group A for the first three years of GnRHa treatment (1.66±0.66 vs. 2.35±0.93, P&lt;0.001). The height gain SDS was significantly higher in group B than in group A (2.5±0.75 vs. 2.93±1.02, P=0.048). Younger age, higher PAH at the start of treatment, and a greater increase in PAH SDS during the first year of GnRHa treatment positively affected AH.

CONCLUSION

The combined GH group had more additional height gain than the GnRHa-alone group.

The Efficacy of GnRHa Alone or in Combination with rhGH for the Treatment of Chinese Children with Central Precocious Puberty

The addition of recombinant human growth hormone (rhGH) to GnRH agonist (GnRHa) to treat central precocious puberty (CPP) is controversial. We systemically reviewed and evaluated the efficacy and safety of the rhGH and GnRHa adjunctive therapy in Chinese children with CPP and assessed the influence of age and therapy duration on the efficacy of the combined treatment. A total of 464 patients were included from 14 studies. Compared with baseline, administration of GnRHa plus rhGH led to a significant increase in height, predicted adult height (PAH) and height standard deviation for bone age (HtSDS-BA), corresponding to a weighted mean difference (WMD) (95%CI) of 9.06 cm (6.41, 11.70), 6.5 cm (4.47, 8.52), and 0.86 (0.58, 1.14) respectively. Subgroup analysis showed the combined therapy had increased efficacy in subjects with initial treatment age younger than 10 years old or with treatment lasting over 12 months. Compared with GnRHa alone treatment, the combined treatment led to a significant increase in height, PAH and HtSDS-BA, corresponding to a WMD (95% CI) of 3.56 cm (2.54, 4.57), 3.76 cm (3.19, 4.34) and 0.56 (0.43, 0.69). The combined treatment exhibited no safety concerns. Our findings may aid clinicians in making treatment decisions for children with CPP.

Relationship between serum insulin-like growth factor-1, IGF binding protein-3 levels and body height before and after gonadotropin-releasing hormone agonist therapy

PURPOSE

The gonadotropin-releasing hormone agonist (GnRHa) is widely used to treat patients with precocious puberty. However, its effect on growth is often difficult to predict because of the diverse nature of its causes and presentation. This study aims to show the impact of GnRHa treatment on insulin-like growth factor-1 (IGF-I) and IGF binding protein-3 (IGFBP-3) secretion, growth, and on other parameters that may help estimate the height velocity.

METHODS

Data from 60 girls (mean age, 8.8±0.7 years) treated with GnRHa were analyzed. Their height, bone age (BA), serum IGF-I, and IGFBP-3 concentrations were measured at the start and after a year of GnRHa treatment. To eliminate the confounding effect of chronological age (CA), the standard deviation scores (SDSs) of their height, IGF-I, and IGFBP-3 concentrations according to their CA at the start and after a year of GnRHa treatment were calculated. We looked for possible correlations between these variables and compared the subgroups based on their height velocities and midparental heights.

RESULTS

During their one-year GnRHa therapy, height SDS for CA significantly decreased to 0.81±0.83 (P<0.001), but height SDS for BA increased to -0.28±0.68 (P<0.001). There was no significant change in serum IGF-I SDS, IGFBP-3 SDS, and IGF-I/IGFBP-3 ratio. The advanced BA was the factor most strongly correlated to the height velocity (R=0.265, P=0.041).

CONCLUSION

These findings suggest that GnRHa treatment may affect the height velocity due to mechanisms other than suppression of the IGF-I and IGFBP-3 secretory axis.

Ethinylestradiol and testosterone have divergent effects on circulating IGF system components in adolescents with constitutional tall stature

OBJECTIVE

Pharmacological doses of estrogens or testosterone are used to limit the final height of girls or boys with constitutional tall stature but the mechanism behind this growth inhibition is still debated. We therefore studied the changes in the circulating components of the insulin-like growth factor (IGF) system during high dose sex steroid therapy.

DESIGN AND METHODS

Twenty three girls and twenty boys with constitutional tall stature were treated with 100 microg ethinylestradiol per day or 250 mg testosterone ester every 14 days respectively. In 19 girls and 18 boys, the levels of IGF-I, free IGF-I, IGF-II, acid-labile subunit (ALS) and IGF binding proteins (IGFBP)-2 to -6 were measured before and 3-6 months after the start of therapy (group 1). In 18 girls and 11 boys, samples were collected at the end of therapy and 3 to 6 months afterwards (group 2). Fourteen girls and nine boys belonged to both groups. All parameters were measured by radioimmunoassay or ELISA.

RESULTS

Levels of IGF-I were decreased significantly by estrogen treatment but remained unchanged during testosterone treatment. Free IGF-I decreased during estrogen treatment but increased during testosterone therapy. Estrogens increased IGF-II and testosterone reduced it. The important reduction of IGFBP-2 during estrogen therapy is not reproduced by androgen therapy, neither is the stimulation by estrogens of IGFBP-4. IGFBP-3 is not modulated by either sex steroid. We found that IGFBP-6 is up-regulated by testosterone but not by estrogens; the reverse is true for ALS, which increased during estrogen treatment but remained unchanged during testosterone treatment.

CONCLUSIONS

Our findings demonstrate that androgens and estrogens exert differential effects on the circulating levels of several IGF components.

Neuroendocrine facets of human puberty

The unfolding of pubertal growth and maturation entails multisystem collaboration. Most notably, the outflow of gonadotropins and growth hormone (GH) proceeds both independently and jointly. The current update highlights this unique dependency in the human.

Growth retardation in premenarchial female rhesus monkeys during chronic administration of GnRH agonist (leuprolide acetate)

Leuprolide acetate in depot form (0.75 mg/kg body weight/month, i.m.) was administered to four female rhesus monkeys from 18-30 months of age, a period that includes the premenarchial growth spurt. They were compared to eight age matched controls. As anticipated, sexual maturation was blocked in the Leuprolide group and menarche did not occur. Growth was also severely retarded; no weight gain occurred during the study in the Leuprolide group as compared to a 25% weight gain (P = .044) in the control group. The Leuprolide group also lost muscle mass. Food intake normalized for body weight was not affected. Linear growth averaged 35% less in the Leuprolide group. Serum IGF-1 concentrations increased from 486 +/- 84 to 965 +/- 47 ng/mL (P = .0025) in the Leuprolide group and from 838 +/- 139 to 3,006 +/- 545 ng/mL (P = .0016) in the control group. These data suggest that premenarchial pituitary/gonadal suppression results in a distinctive pattern of growth retardation in monkeys.

Serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 levels in children with precocious puberty treated with gonadotropin-releasing hormone analog without or in combination with cyproterone acetate

In order to assess the behavior of growth hormone, insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) in girls with central precocious puberty treated with gonadotropin-releasing hormone (GnRH) analog-therapy, we studied 14 girls with this condition, the patients were subdivided into two groups, according to the therapy followed. Group A (n = 7; age 4.2-7.1 years) received GnRH analog in combination with cyproterone acetate, and Group B (n = 7; age 4.4-6.9 years) received long-acting analog alone. Before treatment, IGF-I levels were significantly increased compared to healthy age-matched children in the two groups (447 +/- 33 micrograms/l for Group A and 435 +/- 38 micrograms/l for Group B vs. control 175 +/- 78 micrograms/l; p < 0.01). Moreover, serum IGFBP-3 levels were significantly higher than the age-related reference range for IGFBP-3 (4478.2 +/- 178 micrograms/l for Group A and 4532.3 +/- 167 micrograms/l for Group B vs. control 2905 +/- 641 micrograms/l; p < 0.01). During the two years of gonadal suppression, Group A patients showed a significant decrease in IGF-I and IGFBP-3 levels, while in Group B there was no significant change in IGF-I; moreover, in Group B, IGFBP-3 levels increased significantly compared to baseline values during the first year of treatment (4532.3 +/- 167 micrograms/l vs. 5410.3 +/- 169 micrograms/l; p < 0.05) and decreased significantly at the end of the second year of treatment (3816.1 +/- 189 micrograms/l vs. 5410.3 +/- 169 micrograms/l; p < 0.01). Our study shows that the two different treatments of precocious puberty (with and without cyproterone acetate) have different effects on IGF-I and IGFBP-3, and suggests that these growth factors are under different metabolic regulation.

The pubertal spurt: effects of sex steroids on growth hormone and insulin-like growth factor I

In puberty, the growth spurt and the appearance of secondary sex characteristics occur concomitantly with an increase of sex steroids, growth hormone (GH) and insulin-like growth factor I (IGF-I). A number of experiments indicate that sex steroids exert a stimulatory action on the somatotropic axis. This effect is due to an amplifying action of oestradiol (secreted by the ovaries or after testosterone aromatization) on the neuroendocrine regulation of pulsatile GH release.

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.

Height prognosis of children with true precocious puberty and growth hormone deficiency: effect of combination therapy with gonadotropin releasing hormone agonist and growth hormone

We evaluated height prognosis and therapeutic efficacy of long-term, combination therapy with gonadotropin releasing-hormone agonist and growth hormone (GH) in five children (three girls) with coexistent precocious puberty and GH deficiency. Their clinical characteristics and growth response were compared with those of 12 girls with idiopathic true precocious puberty and eight prepubertal GH-deficient children (one girl). Precocious GH-deficient subjects were older than the precocious GH-sufficient children (9.5 +/- 1.8 years vs 6.5 +/- 1.3 years; mean +/- SD), but bone ages were comparable (12 +/- 3.7 years vs 10 +/- 0.9 years); their chronologic age was similar to that of the prepubertal GH-deficient children (9.6 +/- 2.1 years), but bone age was significantly more advanced (6.9 +/- 2.3 years). The mean height velocity of the prepubertal GH-deficient children (3.8 +/- 1.5 cm/yr) was lower than that of the precocious GH-deficient subjects (6.7 +/- 1.6 cm/yr) and the precocious GH-sufficient children (9.5 +/- 2.9 cm/yr). Baseline adult height prediction z scores were significantly lower in the precocious GH-deficient children (-3.7 +/- 1.0) than in either the precocious GH-sufficient children (-2.2 +/- 1.0) or the prepubertal GH-deficient subjects (-1.5 +/- 0.8). During therapy with gonadotropin releasing-hormone agonist, growth rates slowed to an average of 3.7 cm/yr in the precocious GH-deficient children but increased after the addition of GH to 7.4 cm during the first year of combination therapy. After 2 to 3 years of combination therapy, height predictions increased an average of 10 cm, compared with an increase of 2.8 cm in the precocious GH-sufficient group treated with gonadotropin releasing-hormone agonist alone. We conclude that combination treatment with gonadotropin releasing-hormone agonist and GH improves the height prognosis of children with coexistent true precocious puberty and GH deficiency, but falls short of achieving normal adult height potential.