Metabolic parameters and adipokine profile in growth hormone deficient (GHD) children before and after 12-month GH treatment

It is a common knowledge that GH exhibits a large number of metabolic effects, involving lipid and glucose homeostasis. The aim of the study was to investigate the effect of one year GH therapy on metabolic parameters and adipokines in GH deficient (GHD) children. Sixteen prepubertal children (11 M and 5 F) with complete GHD (age range: 3.4-14.7 years) and 20 (13 M and 7 F) age and sex-matched healthy children (age range: 4.6-12.3 years) were studied. Blood was collected from patients before starting GH therapy (0.025 mg/kg/day) and one year later, and from healthy children to measure adiponectin, leptin, osteoprotegerin, resistin, interleukin (IL)-6, tumor necrosis factor (TNF)-α levels, and other glucose and lipid metabolism parameters. Adiponectin and resistin levels were significantly higher (49980 ng/ml vs. 14790 ng/ml and 11.0 pg/ml vs. 6.3, respectively) in GHD children before GH therapy than in controls. Serum IGF-I levels (p=0.0001) and height SDS (p<0.0001) significantly increased after 12 months' of GH therapy. There was a loss of body fat reflected by a significant decline in tricep (p=0.0003) and subscapular skinfold thickness SDS (p=0.0023). After 12 months, there was a significant rise in insulin (p=0.0052) and leptin levels (p=0.0048) and a significant decrease in resistin (p=0.0312) and TNF-α (p=0.0137). We observed that lipid and glucose metabolisms are only slightly affected in GHD children. Growth hormone replacement therapy affects some factors, such as leptin, resistin and fat mass, suggesting that also in children, GH treatment has a role in the regulation of factors secreted by adipose tissue.

Growth hormone deficiency in adults with thalassemia: an overview and the I-CET recommendations

This review paper provides a summary of the current state of knowledge regarding GHD provides recommendations for the diagnosis and treatment of GHD in adult patients with thalassaemia major (TM). The reported prevalence of adult GHD and /or IGF-I deficiency in TM patients varies from 8% to 44 % in different centers. Because GH treatment requires analysis of many factors, including the effect of treatment on cardiac functions, metabolic parameters and psychosocial functioning, along with safety, ethical considerations, financial cost and other burdens of therapy, stringent diagnostic criteria are needed. The authors report the diagnostic recommendations of the International Study Group of Endocrine Complications in Thalassemia (I-CET) for adult TM patients.The pros and cons of GH treatment must be discussed with each patient, after which GH doses should be individualized and titrated to maximum efficacy with minimal side effects. Prospective studies to monitor potential benefits versus possible side-effects will enable endocrinologists to define recommendations on dosage and the long term effects, particularly on cardiovascular and bone status of GH therapy in adult TM patients.

International network on endocrine complications in thalassaemia (I-CET): an opportunity to grow

Most of the endocrine complications in thalassaemia are attributable to iron overload which may be the result of economic circumstances (expense of the chelation therapy), late onset of chelation therapy or poor compliance with the iron chelation therapy. The major difficulties reported by hematologists or pediatric endocrinologists experienced in thalassaemias or thalassaemia syndromes in following growth disorders and endocrine complications were: lack of familiarity with medical treatment of endocrine complications (40%), interpretation of endocrine tests (30%), costs (65%), absence of paediatric endocrinologist for consultation on growth disorders and endocrine complications (27%), facilities (27%), other (e.g. lack of collaboration and on-time consultation between thalassaemic Centers supervised by hematologists and endocrinologists) (17%). Because any progress we make in research into growth disorders and endocrine complications in thalassaemia should be passed on to all those suffering from it, guaranteeing them the same therapeutic benefits and the same quality of life, on the 8th of May, 2009 in Ferrara (Italy), the International Network on Endocrine Complications in Thalassemia (I-CET) was founded. The I-CET group is planning to conduct, in Ferrara in May 2012, a workshop, "MRI and Endocrine Complications in Thalassaemia", and in Doha (Qatar) in September 2012, a 3-day intensive course entitled, "Growth disorders and Endocrine Complications in Thalassaemia", to provide interested pediatricians, physicians and hematologists from all over the world with an in-depth approach to the diagnosis and management of growth and endocrine disorders in thalassaemic patients.

Growth hormone/IGF-I axis and growth hormone receptor mutations in idiopathic short stature

BACKGROUND/AIMS

It was hypothesized that some children with idiopathic short stature (ISS) may have partial insensitivity to growth hormone (GH). In this study analysis of the GH/IGF-I axis as well as GH receptor (GHR) gene was done in children with ISS to determine the possible underlying factor(s) to their short stature.

METHODS

Forty-eight patients with a diagnosis of ISS were studied; 33 boys and 15 girls aged 13.6 ± 3.7 years. Molecular analysis of the GHR was performed and GH sensitivity was tested by the IGF-I generation test.

RESULTS

Basal IGF-I levels were <-2 SD in 22.9%, and 53.5% showed an IGF-I response below 40% (0-38%) to GH stimulation. GH-binding protein (GHBP) levels were below the normative mean in almost all patients. Mutations in the region of the GHR gene that codes for the extracellular domain of the receptor were found in 15.5%; one newly described mutation was recorded.

CONCLUSION

With the possible exception of the novel G62V mutation, functional studies of the other 2 heterozygous mutations found in 6 of our patients are needed in order to prove their impact on short stature.

Adrenal function in thalassemia major adolescents

BACKGROUND

Several studies reported a significant prevalence of adrenal insufficiency, ranging from 18-45%, in patients with thalassemia. Evidence for dissociation of cortisol and adrenal androgen secretion in patients with beta-thalassemia was previously reported.

AIM

We measured adrenal androgen response along with cortisol to the standard (250 mg) dose ACTH test.

METHODS

Forty five beta-thalassemia major (TM) patients were enrolled. Their ages ranged between 12 and 20 years (14.9 ± 2.2 years). All patients underwent the 250 mg cosyntropin test in the morning before blood transfusion. Blood samples for total cortisol, dehdroepiandrosterone (DHEA) and androstendione (A) measurements were collected before and 60 min after IV injection of 250 mg cosyntropin. Adrenal insufficiency was observed in 7 of 45 (15.5%) patients. Adrenal androgen levels decreased significantly with advancing Tanner stage. No difference was noted between patients with and without adrenal insufficiency regarding anthropometric and laboratory parameters.

CONCLUSION

Adrenal insufficiency is not a rare complication in thalassemia. Adrenal androgen production declines with advancing puberty in thalassemic adolescents and might explain the poor development of pubic and axillary hair observed in this condition.

A novel dysfunctional LHX4 mutation with high phenotypical variability in patients with hypopituitarism

CONTEXT

LHX4 is a LIM homeodomain transcription factor involved in pituitary ontogenesis. Only a few heterozygous LHX4 mutations have been reported to be responsible for congenital pituitary hormone deficiency.

SUBJECTS AND METHODS

A total of 136 patients with congenital hypopituitarism associated with malformations of brain structures, pituitary stalk, or posterior pituitary gland was screened for LHX4 mutations.

RESULTS

Three novel allelic variants that cause predicted changes in the protein sequence of LHX4 (2.3%) were found (p.Thr99fs, p.Thr90Met, and p.Gly370Ser). On the basis of functional studies, p.Thr99fs mutation was responsible for the patients' phenotype, whereas p.Thr90Met and p.Gly370Ser were likely polymorphisms. Patients bearing the heterozygous p.Thr99fs mutation had variable phenotypes: two brothers presented somato-lactotroph and thyrotroph deficiencies, with pituitary hypoplasia and poorly developed sella turcica; the youngest brother (propositus) also had corpus callosum hypoplasia and ectopic neurohypophysis; their father only had somatotroph deficiency and delayed puberty with pituitary hyperplasia. Functional studies showed that the mutation induced a complete loss of transcriptional activity on POU1F1 promoter and a lack of DNA binding. Cotransfection of p.Thr99fs mutant and wild-type LHX4 failed to evidence any dominant negative effect, suggesting a mechanism of haploinsufficiency. We also identified prolactin and GH promoters as potential target genes of LHX4 and found that the p.Thr99fs mutant was also unable to transactivate these promoters.

CONCLUSIONS

The present report describes three new exonic LHX4 allelic variants with at least one being responsible for congenital hypopituitarism. It also extends the phenotypical heterogeneity associated with LHX4 mutations, which includes variable anterior pituitary hormone deficits, as well as pituitary and extrapituitary abnormalities.

[Growth of anorexic adolescents]

Growth and puberty were studied in 19 children with anorexia nervosa (15 girls and 4 boys), the onset being before puberty or in its early stages. Growth retardation reached 2.04 +/- 1.39 SD, with important individual changes and for some patients a prolonged interruption of growth. Seventeen of 19 patients presented delayed puberty, and in some, hypogonadism persisted after recovery from anorexia nervosa. Endocrine investigations concerning the pituitary somatotropic (GH) and gonadotropic (FSH, LH) secretions, as well as gonadal steroids showed highly variable changes from one patient to another and even variations in the same patient from one test to another. However, no correlation could be found between the hormonal abnormalities and the degree or length of undernutrition. Some patients recovered normal endocrine function when they reached an adequate weight, others kept a lasting deficiency. The endocrine impairment in anorexia, well known in adults, is probably more severe in adolescents.

[Benign unilateral testicular hypertrophy beginning at puberty]

Two normal boys, with no previous history, were referred at the onset of puberty for unilateral testicular hypertrophy. Radiological and biological investigations, and in one case testicular biopsy, ruled out cellular proliferation or tumor. Except for FSH level slightly above normal in one case, no endocrine abnormality was found. This is a rare, and probably non pathologic event.