J. Endocrinol. Invest. 14: 37-40,1991

Growth hormone response following growth hormone releasing hormone injection in thalassemia major: influence of pubertal development B.P. Leheup*, M. Cisternino**, M. Bozzola**, B. Dousset*, P.L. Marradi***, F. Antoniazzi***, L. Tato***, F. Severi***, D. Sommelet, and M. Pierson* *Service de Medecine Infantile 1, H6pital d'Enfants, CHR de Nancy, Vandoeuvre les Nancy, France, **Clinica Pediatrica, 2a Cattedra, Universita di Pavia, 27100 Pavia, ***Clinica Pediatrica, Facolta di Medicina e Chirurgia, Universita degli Studi di Verona, 37100 Verona, Italia layed in thalassemic patients with retarded puberty. The integrated secretion of GH during the 120-min test was slightly but not significantly reduced in these patients. The prepubertal pattern of GHRH response was restored in the patients receiving substitutive therapy by HCG or testosterone. The alteration of GH response to GHRH in thalassemic patients is likely to be only due to delayed puberty and decreased endogeneous GHRH secretion since it is corrected by androgen or gonadotropin replacement.

ABSTRACT. Thirty-five patients with thalassemia major, aged 7 to 21 years, were studied to define the relationship between the pubertal development and the growth-hormone (GH) secretion during sleep, after administration of GH-releasing factor (hpGRF 1-44), and betaxolol-glucagon or arginininsulin. Pubertal development was classified as being appropriate or delayed for chronological age. GH response to pharmacological stimuli and during sleep was not linked to the pubertal development according to the chronological age. The peak of GH secretion after GHRH injection was significantly de-

INTRODUCTION

decreased GH response to GHRH has been reported in thalassemic patients (8, 9) contrasting to a more normal pattern of response in younger patients (10). Since relationship between GHRH-induced GH secretion and pubertal development is still unknown, we have analysed this response in 35 patients with thalassemia major according to their profile of pubertal development.

Contrasting with their almost normal growth during the first ten years of life, the growth and sexual development of adolescents with beta-thalassemia major is characterized by a stunted growth and delayed puberty associated with retarded bone maturation (1). This profile is similar to the definite slowing of the growth velocity experienced by patients with idiopathic delayed puberty (lOP) (2). A stunted response of hGH to pharmacological tests was observed in thalassemic patients from South East Asia with chronic anemia (3) contrasting with the normal hGH secretion in most thalassemic patients receiving high frequency blood support therapy (4, 5). The depressed serum somatomedin C/IGF I activity, found even in the well supported patients, may explain part of the discrepancy between a normal GH secretion and a stunted growth (6, 7). A

SUBJECTS, MATERIALS AND METHODS Thirty-five patients with homozygous beta-thalassemia (24 males and 11 females), 7 to 21 years old, were studied in the three clinical centers. All patients had received regular transfusion therapy (hemoglobin levels higher than 100 gil) under sc desferrioraxime (1 to 2 g/night). None has been splenectomized during the year before the study or has any evidence of cardiac or hepatic insufficiency. Ferritin levels were above normal for all patients but one (100-5,400 ng/ml; normal values < 150 ng/ml). Physical characteristics are summarized in Table 1. Height and growth velocity were tabulated according Sempe and Pedron (11). In regard of pu-

Key-words: Thalassemia. growth hormone, puberty, growth, growth-hormone-releasing hormone. Correspondence: B.P. Leheup, Service de Medecine Infantile 1, Hopital d'Enfants, 54511 Vandoeuvre les Nancy Cedex. France.

Received November 13, 1989; accepted October 15, 1990.

37

BF Leheup, M Cisternino, M Bozzo/a, et al.

Table 1 - Physical characteristics of the study group!. N

35

Sex

24M; 11F

Age (yr)

Height

Puberty stages

Chronological

Bone

SO

13.90 ± 3.5

12.10±2.5

-1.45 ± 1.6

ABC

0

7

6

11

11

1Mean ± SO are given for the overall group. Pubertal stages: Group A: 11 patients with normal absence of puberty according to chronological age; Group B: 7 patients with normal progression of puberty; Group C 11 patients with delayed onset and progression of puberty; Group 0: 6 patients with delayed onset but present evolution of puberty either spontaneously (n=1) or after gonadal substitution (n=5).

bertal development 16 patients did not show any sign of puberty, 10 were at stage 2 of Marshal and Tanner, 4 at stage 3, and 5 have reached final stages of puberty. According to chronological age, four different groups of subjects were defined. Eleven patients were normally impubescent (Tanner stage 1) (6 males, 5 females, age range 7 - 11.8 yr) (Group A), 7 had normal onset and progression of puberty for their chronological age (Tanner's stage 2 to 5) (3 males, 4 females, aged 11.7 - 18.5 yr) (Group B), 11 had their puberty delayed or arrested (10 males, 1 female, aged 13.4 - 18.9 yr) (Group C), and 6 had history of spontaneous late onset (1 female aged 16.9 yr) or artificially induced puberty with testosterone heptylate (5 males aged 14.9 - 21 yr) (Group D). These 4 groups were referred as pubertal progression groups (PP Groups) A to D. The somatotropic secretion was evaluated by the response to pharmacological stimuli (arginin-insulin or betaxolol-glucagon), GHRH stimulation (GHRH 1-44, 2Ilg/kg, Sanofi Recherche) and sleep test (6 h, 20-min sampling). Plasma GH values were expressed in ng/ml (1 ng/ml= 2IlU/ml, RIA Pharmacia, Italy). The study protocol has been accepted by the local ethical committees and informed consents obtained from the patient parents and the young adult patients.

ng/ml in 11 patients (3 in the PP Group A, 1 in PP Group B, 4 in the PP Group C and 3 in the PP Group D). The peak response was between 5 and 12 ng/ml in 18 patients (5 in PP Group A, 4 in PP Group B, 6 in PP Group C and 3 in PP Group D). Both the sleep and pharmacological peaks were not significantly correlated with any of the studied data (chronological and bone ages, Tanner's stage of puberty, height or velocity deviation, time of treatment of the disease, plasmatic ferritin level). The pharmacological response was not correlated with the sleep response. GHRH response The basal level was identical in the 4 different PP groups. The maximal or peak response was slightly but not significantly reduced in the PP Group C (18,3 ± 5,6 ng/ml; mean ± SE) in comparison to 31.7 ± 11.3 in the Group D. The analysis of the kinetic of GH response to GHRH injection led to the demonstration of a significantly lower response in the patients of the PP Group C at the times 15, 30 and 45 min compared to the responses of the patients of the PP Groups A and D. Due to the small size of the PP Group B, the difference between PP Group C and B was significant only at 15 min. The responses at the times 60 and 120 min were not

Table 2 - Pharmacological (arginin-insulin or betaxolol-glucagon stimulation) and sleep peak GH responses (ng/ml; mean ± SE) in 35 thalassemic patients as a function of the pubertal progression.

RESULTS Pharmacological and sleep GH response (Table 2):

The arginin-insulin or betaxolol-glucagon induced responses were not significantly influenced by the Tanner's stage of puberty and PP group. Twenty patients had normal peaks above 12 ng/ml of whom 7,3,6 and 4 were respectively from the PP Groups. A, B, C and D. Only 3 patients had responses below 5 ng/ml (1 patient respectively in the PP Groups A, C and D). GH peak during sleep was found higher than 12

Puberty stage 1

Pharmacological peak

Sleep peak

A

12.6

1.7

9.6

1.9

B

13.4

2.6

7.3

1.2

C

15.6

3.2

11.6

1.9

o

15.2

3.8

11 .1

1.6

1The definition of the pubertal groups is given in the legend of the Table 1.

38

Thalassemia and GHRH response

significantly different between the various PP groups even if there was a tendency to find slightly higher response in the PP Group C at 120 min (Fig . 1). The correlation study did not find any significant relation between the GH peak to GHRH and the following independent variables: pharmacological peak response, sleep peak, ferritin level, chronological or bone ages, height or velocity deviation. A significant correlation was found between the peak and the integrated secretion during the GHRH stimulation (p < 0.001).

decreased hypothalamic secretion of GHRH. The lack of a strong relation between the sleep peak of GH and the peak of GH after GHRH and the absence of relation between nocturnal GH secretion and pubertal progression stages contrast with the recently reported increased GH secretion in a group of adult patients with isolated hypogonadotropic hypogonadism after androgen or gonadotropin replacement (13, 14). The apparent discrepancy is more likely due to methodological reasons as regards to number of patients enrolled in the reported studies and ours. The decreased response according to higher age has also been advanced in a study on children with thalassemia before puberty (10). The mechanisms underlying the modified response to GHRH are not related to the iron deposition in either the hypothalamus or the hypophysis since there was no relation between the ferritin plasmatic level and the kinetic of GH release after GHRH stimulation. Moreover the patients with androgen replacement had the highest amount of ferritin in relation with their age , and still were able to increase their individual response after induction of puberty (13) . No significant difference of the ferritin plasmatic concentration was found among the different pubertal progression groups even if the lowest value was reported among the patients with spontaneously normal pubertal progression. Such an absence of relation has been previously reported by others (1) The pattern of GH response to GHRH is influenced by delayed puberty and may

DISCUSSION

Impaired growth hormone response to GHRH injection has been previously reported in young patients with thalassemia major (8). The present study was designed to get a more precise insight of the relation between the pubertal development and the response of GH to GHRH stimulation. Delayed puberty led to a decrease GH peak value. The normal prepubertal pattern of response was fully restored in patients given androgen or undergoing spontaneous puberty. This was likely in favor of a functional alteration of the GH secretion. The hypothalamic regulation of endogenous secretion of GHRH is probably modified as suggested by the decreased GHRH response to L-Dopa stimulation in patients with idiopathic delayed puberty (12) and in a group of thalassemic patients (13) . Partial hypophyseal desensitization may be secondary to the



GH ng/ml

.. ..

.---,,.--,

40

..

fIJ

*

35

A

B

!2] C '·).i

0

30 25 20 15 10

S

0 0

15

30

45

60

Ti me (min)

39

120

0

Fig . 1 - Time-response curve of the GH response after the iv. injection of 2 /lg/kg of GHRH (GRF 1-44, Sanofi) in 35 thalassemic patients. Group A: patients with normal absence of puberty according to chronological age; Group B: patients with normal progression of puberty; Group C: patients with delayed onset and progression of puberty; Group 0: patients with late spontaneous onset (n= 1) or under androgen or gonadotropin replacement (n=5). The peak of GH secretion is significantly delayed in the group C in comparison to the time response of the 3 other groups. (*:p < 005, **:p < 0.01)

BF Leheup, M. Cisternino, M. Bozzo/a, et al.

Lack of response of non suppressible insulin-like activity to short term administration of human growth in thalassemia major. J. Clin. Endocrinol. Metab. 53: 806, 1981.

be corrected by an adequate androgen or gonadotropin replacement if required. Such a treatment is likely to restore normal growth. The place of growth hormone therapy may be also discussed on the basis of the positive effect of substitutive GH in the syndrome of constitutional delay of growth and puberty (15).

8. Pintor C., Cella S.G., Manso P., Corda R., Dessi C., Locatelli V., Muller E.E. Impaired growth hormone (GH) response to GH-releasing hormone in thalassemia major. J. Clin. Endocrinol. Metab. 62: 263, 1986.

ACKNOWLEDGMENTS

9. Loche S. Growth and sexual maturation in thalassemia. J. Pediatr. 107: 642, 1985.

This work was made possible by the precious support of Sanofi Recherche France and Italy which kindly provided hpGRF 1-44.

10. Leger J., Girot R., Crosnier H., Postel-Vi nay M.C., Rappaport R. Normal growth hormone response to GH-Releasing Hormone in children with thalassemia major before puberty: A possible age-related effect. J. Clin. Endocrinol. Metab. 69: 453,1989.

REFERENCES 1. Borgna-Pignatti C., Stefano P., Zonta L., Vullo C., De Sanctis V., Melevendi C., Naselli A., Masera G., Terzoli S., Gabutti V., Piga A. Growth and sexual maturation in thalassemia major. J. Pediatr. 106: 150,1985.

11. Sempe M., Pedron G., Roy-Pernot M.P. Auxologie. Methodes et Sequences. Theraplix, Paris, 1979.

2. Copeland K.C., Paunier L., Sizonenko P.C. The secretion of adrenal androgens and growth patterns of patients with hypogonadotropic hypogonadism and idiopathic delayed puberty. J. Pediatr. 91: 985,1977.

12. Argente J., Evain Brion D., Donnadieu M., Garnier P., Vaudry H., Job J.C. Impaired response of growth hormone-releasing hormone (GHRH) measured in plasma after L-Dopa stimulation in patients with idiopathic delayed puberty. Acta Pediatr. Scand. 76: 266, 1987.

3. Vannasaeng S., Ploybur S., Visuktul P., Tandhanand S., Suwanik R., Wasi P. Endocrine function in thalassemia Clin. Endocrinol. (Oxf.) 14: 165,1981.

13. Bozzola M., Argente J., Cisternino M., Moretta A., Valtorta A., Biscaldi I., Donnadieu M., Evain-Brion D., Severi F. Effect of human chorionic gonadotrophin on growth velocity and biological growth parameters in adolescent with thalassemia major. Eur. J. Pediatr. 148: 300,1989.

4. Canale V.C., Steinherz P., New M.I., Erlandson M. Endocrine function in thalassemia major. Ann. N.Y. Acad. Sci. USA 232: 233,1974. 5. Masala A., Meloni T., Gallisai D., Alagna S., Rovasio P.P., Rassu S., Milia A.F. Endocrine functioning in multitransfused prepubertal patients with homozygous B-thalassemia. J. Clin. Endocrinol. Metab. 58: 667, 1984.

14. Liu L., Merriam G.R., Sherins R.J. Chronic sexual steroid exposure increases mean plasma growth hormone concentration and pulse amplitude in men with isolated hypogonadotropic hypogonadism. J. Clin. Endocrinol. Metab. 64:651, 1987.

6. Saenger P., Schwartz E., Markenson A.L., Graziano J.H., Levine L.S., New M.I., Hilgartner M.w. Depressed serum somatomedin activity in B-thalassemia. J. Pediatr. 96: 214,1980.

15. Bierich J.R. Growth hormone therapy in short children without classical growth hormone deficiency. J. Endocrinol. Invest. 12: 25, 1989.

7. Werther GA, Matthews R.N., Burger H.G., Herington A.C.

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Growth hormone response following growth hormone releasing hormone injection in thalassemia major: influence of pubertal development.

Thirty-five patients with thalassemia major, aged 7 to 21 years, were studied to define the relationship between the pubertal development and the grow...
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