Growth and development in children with thalassaemia major

Ocular biometry, anterior chamber morphometry, and their relationship with serum ferritin levels in children with beta thalassemia major

Background

Ocular biometry and anterior segment evaluations are important to determine ocular development and pathological changes, especially in thalassemia patients in Mediterranean countries such as Turkey.

Objectives

The objectives of this study were to compare ocular biometry and anterior segment parameters in children with thalassemia major and healthy controls and to examine the relationship between ferritin levels, anthropometric measurements, and ocular parameters.

Design

This is a prospective case-control study.

Methods

The height, weight, body mass index, and occipitofrontal circumference values of the participants were recorded. Anterior and vitreous chamber depth, lens thickness, axial length, central corneal thickness, anterior chamber volume, iridocorneal angle, pupil diameter, and mean keratometry were measured. Measurements were compared between patients and healthy children, and between patients with ferritin levels above and below 1000 ng/mL.

Results

This study included 40 patients and 45 controls. Height, weight, and body mass index were significantly lower while ferritin level and occipitofrontal circumference were significantly higher in patients compared with the controls (p < 0.001 for all). There were no statistically significant differences in the other ocular parameters (p > 0.05). In comparisons between patients with ferritin levels below (n = 15) and above 1000 ng/mL (n = 25), there were no significant differences in age, height, weight, body mass index, occipitofrontal circumference, or ocular parameters (p > 0.05). Occipitofrontal circumference and mean keratometry value were positively correlated in patients with ferritin levels below 1000 ng/mL (r = 0.573, p = 0.025), while body mass index was negatively correlated with pupil diameter in patients with ferritin levels above 1000 ng/mL (r = -0.469, p = 0.018).

Conclusion

Children with thalassemia showed significant growth retardation and large occipitofrontal circumference but did not differ from controls in terms of biometrics and anterior segment morphology. Our results demonstrated a positive correlation between the occipitofrontal circumference and mean keratometry value in children with ferritin levels below 1000 ng/mL and a negative correlation between body mass index and pupil diameter in children with ferritin levels above 1000 ng/mL.

A Longitudinal Study of Growth and Relation With Anemia and Iron Overload in Pediatric Patients With Transfusion-dependent Thalassemia

Short stature is one of the most common endocrinopathies in transfusion-dependent thalassemia (TDT). This study aimed to determine the longitudinal pattern of growth in pediatric patients with TDT and study the relationship between growth and hemoglobin level, serum ferritin level/iron overload parameters, and other clinical factors. The interval height-for-age Z-scores (HAZ) of 50 patients with TDT, of a mean age of 13.3±2.8 years, were analyzed using linear mixed model analysis. Nineteen patients (38%) had short stature with HAZ≤-2.0. The prevalence of short stature increased with age. The estimated mean HAZ decreased by 0.19 SD per year from the age of 5 years until approximately 14 years (95% confidence interval [CI], -0.22 to -0.16, P<0.001). Male sex (estimate, -0.28; 95% CI, -0.43 to -0.14; P<0.001), mean 3-year hemoglobin level ≤8 g/dL (estimate, -0.36; 95% CI, -0.53 to -0.19; P<0.001), mean 3-year ferritin level ≥1800 ng/mL (estimate, -0.44; 95% CI, -0.59 to -0.29; P<0.001), and cardiac T2* ≤20 ms (estimate, -1.05; 95% CI, -1.34 to -0.77; P<0.001) were significantly associated with short stature. In conclusion, short stature in patients with TDT is common and relates significantly with increasing age, male sex, hemoglobin level, and iron overload status.

Iron overload detection using pituitary and hepatic MRI in thalassemic patients having short stature and hypogonadism

OBJECTIVE

to assess the growth and pubertal development among a group of patients with β-Thalassemia Major (β-TM) and to evaluate the role of the pituitary gland and liver MRI signal intensity (SI) reduction in assessing and predicting the clinical severity of growth and pubertal dysfunctions.

METHODS

Thirty-eight patients with β-TM were examined and divided into two groups: Group I patients were of normal height and puberty and Group II patients had short statures and hypogonadism. Laboratory investigations included serum ferritin, LH, FSH, prolactin, TSH, and basal and dynamic growth hormones. Pituitary and liver MRIs were performed to assess the pituitary to fat (P/F) and liver to muscle (L/M) signal intensities (SI), respectively. Fifteen healthy and sex- and age-matched subjects were included as controls.

RESULTS

Both patient groups had significantly elevated serum ferritin and significantly decreased prolactin and IGF1 compared to control subjects. Group II showed a significant reduction in LH, FSH, and IGF1 and a significant increase in ferritin in comparison with Group I and the control group, and it had a highly significant reduction in both P/F and L/M SI in comparison with Group I (p<0.001 and 0.008, respectively). The reduced P/F ratio was significantly correlated with FSH and LH, and a cutoff for a P/F ratio ≥0.94 was obtained to differentiate between Group I and II.

CONCLUSION

MRI in conjunction with the P/F signal intensity ratio is a useful and noninvasive tool for the early diagnosis of pituitary iron overload.

Patterns of physical growth and dental development in Jordanian children and adolescents with thalassemia major

Dental development and physical growth are of particular interest in pediatric dentistry and orthodontics. This study evaluated these variables in patients with thalassemia major (TM). Physical growth was assessed in 54 patients (31 males and 23 females) aged 5.5 to 18.3 years and dental development was analyzed using panoramic radiographs from 39 of the 54 patients. The Demirjian system was used to characterize dental development of the seven left mandibular permanent teeth. Chronologic age (CA) and dental age (DA) were compared using the paired t-test, and the correlation between CA and extent of delay in dental development (DA minus CA) was assessed using Pearson's correlation coefficients. Growth retardation (< 10th percentile for height and weight) was present in 75.9% of TM patients. Height less than the third percentile was noted in 41.9% (13/31) of males and 34.8% (8/23) of females. Mean (SD) body mass index was 16.5 ± 2.2 kg/m(2). The extent of growth retardation increased with advancing age. Patient radiographs revealed a delay in dental development in 31 of 39 (79.5%) of participants (mean delay, 1.12 years in males and 0.81 years in females; range, 0.1 to 2.7 years). The mean difference between CA and DA was 0.97 years (P < 0.001). CA was significant correlated with extent of dental developmental delay (r = 0.64, P < 0.01). The results show that, among children and adolescents with TM, the proportions of those who had short stature, were underweight, and had a low growth rate increased with age. In addition, participants had significant delays in dental development.

Evaluation of growth, puberty and endocrine dysfunctions in relation to iron overload in multi transfused Indian thalassemia patients

OBJECTIVE

To determine the prevalence of growth abnormality and endocrine dysfunction in a group of multi transfused thalassemic children and to correlate these with their body iron stores.

METHODS

This cross sectional study included 35 Thalassemia Major patients, aged 13 to 24 years. Growth and puberty were assessed clinically and the laboratory values of various hormone levels were stratified with their age and sexual maturity.

RESULTS

57.14% patients were short, 60% had not attained puberty, and 87.5% of the girls had primary amenorrhea. 14.29% had low FSH and 2.86% low LH levels. 89.47% of the boys had low free testosterone and 43.75% of the girls had low estradiol levels. While 20% had high TSH levels, 40% had high PTH levels, of which 92.8% had low levels of Vitamin D. Low levels of IGF-1 were noted in 51.43%.

CONCLUSIONS

In this study analysis, short stature and hypogonadism were frequent findings. These results support the need for vigilant clinical evaluation of growth and puberty, as well as appropriate hormonal evaluation in poly transfused thalassemic children in order to detect and treat endocrine dysfunction early. The authors also recommend aggressive and adequate chelation from early life so that permanent damage to the endocrine glands can be prevented.

Gonadal dysfunction and pelvic sonographic findings in females with thalassaemia major

OBJECTIVE

To investigate pubertal and menstrual problems and evaluate pelvic sonographic findings in patients with beta-thalassaemia major.

MATERIAL AND METHODS

Twenty-five female patients followed for thalassaemia major constituted the study population. Sexual maturation and hormonal status were assessed. Pubertal and menstrual problems were investigated.

RESULTS

There was one patient with delayed puberty and five patients with arrested puberty. Mean ferritin level in this group of patients was slightly but not significantly higher than patients with normal pubertal maturation (2620 +/- 994 ng/ml vs. 2409 +/- 1348 ng/ml, p > 0.05). There were 10 patients with primary amenorrhoea, three with secondary amenorrhoea, five with oligomenorrhoea and irregular menstruation and one with regular menstruation. Compared to menstruating patients, the mean uterine size was smaller (4.1 +/- 3.5 cm(3) vs. 52.8 +/- 14.5 cm(3)) in all patients with delayed and arrested puberty (p < 0.05). Ten patients were taking hormone replacement therapy (HRT). The mean uterine size in these patients was larger than that in patients with amenorrhoea who were not taking HRT, but smaller than that in menstruating patients (9.1 +/- 15.9 cm(3), 2.7 +/- 1.3 cm(3) and 52.8 +/- 14.5 cm(3), respectively) (p < 0.05).

CONCLUSION

Thalassaemia major has important side effects on the hypothaloma-pituitary-gonadal axis resulting in pubertal and menstrual abnormalities. HRT should be given to provide normal sexual maturation in these patients.

Thalassaemia and aberrations of growth and puberty

Endocrine dysfunction in Thalassaemia major (TM) is a common and disturbing complication, which requires prompt recognition and treatment. The contribution of the underlying molecular defect in TM to the development of endocrinopathies is significant because the patients with the more severe genetic defects have a greater rate of iron loading through higher red cell consumption. TM patients frequently present delay of growth and puberty with reduction of final height. The pathogenesis of growth failure is multifactorial and is mainly due to chronic anemia and hypoxia, chronic liver disease, zinc and folic acid deficiency, iron overload, intensive use of chelating agents, emotional factors, and endocrinopathies (hypogonadism, delayed puberty, hypothyroidism) and GH-IGF-1 axis dysregulation. Although appropriate iron chelation therapy can improve growth and development, TM children and adolescents treated intensively with desferrioxamine remain short as well, showing body disproportion between the upper and lower body segment. Body disproportion is independent of pubertal or prepubertal period of greater height gain. Treatment with recombinant GH (rhGH) is recommended when GH deficiency is established, and even so, the therapeutic response is often non satisfactory. Growth acceleration is mostly promoted with sex steroids in children with associated pubertal delay. Sexual complications in TM, which include Delayed Puberty, Arrested Puberty and Hypogonadism, present the commonest endocrine complication. Iron deposition on gonadotroph cells of the pituitary leads to disruption of gonadotrophin production which is proven by the poor response of FSH and LH to GnRH stimulation. In the majority of patients gonadal function is normal as most women with Amenorrhea are capable of achieving pregnancy with hormonal treatment and similarly men with azoospermia become fathers. Secondary Hypogonadism appears later in life, and is manifested in women as Secondary Amenorrhea and in men as decline in sexual drive and azzoospermia. The damage to the hypothalamus and pituitary is progressive, even when intensive chelating therapy is given and the appearance of Hypogonadism in both sexes is often unavoidable. Close follow up and proper management is crucial for every patient with TM. Early recognition of growth disturbance and prevention of hypogonadism by early and judicious chelation therapy is mandatory for the improvement of their quality of life. Patients with TM can now live a better life due to modern advances in their medical care and our better understanding in the pathogenesis, manifestation and prevention of endocrine complications.

Growth hormone secretion in adult patients with thalassaemia

BACKGROUND AND OBJECTIVES

Growth retardation and short stature are frequent clinical features of patients with beta-thalassaemia major. Dysfunction of the GH-IGF-1 axis has been described in many thalassaemic children and adolescents with short stature and reduced growth velocity. Several studies have demonstrated that recombinant GH treatment improves growth velocity in these patients, although response to the treatment is variable and not predictable. A reassessment of the GH-IGF-1 axis must be performed in young adults with childhood-onset GH deficiency (GHD), after attainment of final height, to select those who are candidates for replacement therapy as adults. To our knowledge there are no data available on retesting the GH-IGF-1 axis in adult thalassaemic patients with childhood-onset GHD. The aim of our study was to investigate GH secretion in adult thalassaemic patients with childhood-onset GHD.

DESIGN

We reassessed GH secretion in a group of adult thalassaemic patients in whom partial GHD had been diagnosed during childhood.

PATIENTS AND METHODS

We performed an arginine plus GH-releasing hormone (GHRH) stimulation test in 16 thalassaemic patients (10 males, six females) with a mean age of 24.8 +/- 3.6 years. The cut-off level for GH response was set at 9 microg/l, according to the literature. Ferritin, IGF-1, liver enzymes and lipid levels were also determined.

RESULTS

We found persisting GHD in three patients, one patient had borderline values (GH peak = 10.4 microg/l), whereas the others had a normal response. These results are in accordance with the data on GH retesting in adult patients with idiopathic partial childhood-onset GHD.

CONCLUSION

We conclude that GH status should be retested in adult thalassaemic patients with childhood-onset GHD. If the diagnosis of adult GHD is established, GH treatment may be considered as it could contribute to improve heart function and bone mineral density, which are frequently impaired in adult thalassaemic patients.

Growth of children with beta-thalassemia major

Hypertransfusion and regular chelation therapy have allowed improved survival in patients with thalassemia major (TM). Despite medical advances, growth failure and hypogonadism remain significant clinical problems in these patients in adolescence. Disproportionate truncal shortening which is common especially among adolescents with thalassemia, is due to platyspondyly resulting from a combination of factors like hemosiderosis, desferrioxamine toxicity or deficiency of trace elements. Although growth hormone (GH) deficiency and GH neurosecretory dysfunction have been described in TM patients, most short TM patients have normal GH reserve. The low serum IGF-1 and IGFBP-3 concentrations in TM patients despite having normal GH reserve and serum GH binding protein levels suggest that a state of secondary GH insensitivity exists. The pubertal growth spurt may be impaired in TM patients going through spontaneous or induced puberty and may have a negative effect on final adult height. GH therapy in dosages ranging from 0.5-1.0 IU/kg/wk has resulted in a significant improvement in growth velocity in short TM children without any adverse effects on skeletal maturation, blood pressure, glucose tolerance and serum lipids. There is limited evidence that GH treatment can result in an improved final adult height in short TM children. Careful and regular clinical and biochemical monitoring should be preformed on these patients while they are treated with GH.

Serum ferritin level as a predictor of impaired growth and puberty in thalassemia major patients

OBJECTIVE

Previous studies suggested that in patients with thalassemia major, initiating deferoxamine (DFO) therapy before puberty can prevent iron-induced failure of growth and puberty. However, early initiation of chelation has also been associated with DFO toxicity. The aim of this retrospective study was to determine the prevalence rates of endocrine complications and DFO bone toxicity in our thalassemia major patients and to correlate them with the degree of iron chelation.

METHODS

Thirty-nine patients with thalassemia major were followed for a median of 16.3 yr (range 2-28). Individual mean serum ferritin level during the study period was calculated using repeated annual measurements. Bone DFO toxicity was assessed by wrist and spine radiographs; endocrine dysfunction by anthropometric measurements and pubertal stage; and hypogonadotropic hypogonadism by lack of luteinizing hormone response to gonadotropin-releasing hormone.

RESULTS

Chelation therapy was initiated at median age 4.9 yr. Mean serum ferritin level during the study period was 2698 +/- 1444 ng/mL. Hypogonadism was noted in 59% of the patients who reached pubertal age, and short stature was found in 36% of patients who reached final height. Mean ferritin level of 2500 ng/mL during puberty was the cut-off for hypogonadism, and ferritin level of 3000 ng/mL during prepuberty was the cut-off for final short stature. None of the patients who attained final height had signs of DFO bone toxicity.

CONCLUSIONS

High serum ferritin levels during puberty are a risk factor for hypogonadism, and high serum ferritin levels during the first decade of life predict final short stature. It remains to be determined whether improving chelation by earlier initiation of DFO or by the combined use of DFO and deferiprone will lead to better growth and sexual development without DFO toxicity.

β-Thalassemia major and its effect on amino acid metabolism and growth in patients in the United Arab Emirates

BACKGROUND

There may be a marked reduction in essential amino acids in the serum of children with thalassemia major and this is related to decreased growth in affected children.

METHODS

One hundred patients with beta-thalassemia and 50 control children selected from among those who had presented with minor disorders unrelated to hematological disease were recruited. Urine and heparinized blood were collected from fasting thalassemic patients. After deproteinization and dilution, amino acid concentrations were measured using ion-exchange chromatography.

RESULTS

Isoleucine (p<0.0001), phenylalanine (p<0.05), tyrosine (p<0.0001), taurine (p<0.0001) and glutamine (p<0.01) were significantly decreased in the plasma of thalassemic patients compared to the control group. Whereas glutamate (p<0.0001), serine (p<0.05) and proline (p<0.05) were significantly higher in thalassemic patients, threonine, glycine, alanine, valine, methionine, leucine, ornithine, lysine, histidine and arginine values were not different. The essential amino acids taurine (p<0.0001), methionine (p<0.01), valine (p<0.01), phenylalanine (p<0.01) and leucine (p<0.05) were significantly decreased in urine of thalassemic patients vs. controls, but threonine and ornithine were not different. The mean urinary excretion rate of beta-aminoisobutyric acid was not different (69+/-96 in thalassemics vs. 41+/-52 in controls). However, most plasma and urinary essential amino acids were found to be lower in thalassemics. Thalassemic patients were also found to be significantly growth impaired for age, both in height and weight compared to controls.

CONCLUSION

Lower plasma values of essential amino acids and a decrease in urinary amino acids occur in thalassemic patients. Growth impairment both in height and weight also occurs in thalassemic patients compared to a control population.

Delayed puberty in chronic illness

Delayed puberty can be defined as the lack of pubertal development at an age of 2 SD above the mean, which corresponds to an age of approximately 14 years for males and 13 years for females, taking both sex and ethnic origin into consideration. Its incidence associated with chronic illnesses is unknown; however, its clinical importance is relevant due to the larger percentage of patients with chronic disorders surviving until the age of puberty. Virtually every child with any chronic disease could present with delayed puberty (due to recurrent infections, immunodeficiency, gastrointestinal disease, renal disturbances, respiratory illnesses, chronic anaemia, endocrine disease, eating disorders, exercise and a number of miscellaneous abnormalities). Pubertal delay associated with chronic illness is accompanied by a delay in growth and the pubertal growth spurt. The degree to which growth and pubertal development are affected in chronic illness depends upon the type of disease and individual factors, as well as on the age at illness onset, its duration and severity. The earlier its onset and the longer and more severe the illness, the greater the repercussions on growth and pubertal development. The mechanism that trigger the start of physiological puberty remain unknown. Although malnutrition is probably the most important mechanism responsible for delayed puberty, emotional deprivation, toxic substances, stress and the side effects of chronic therapy, among others, have been implicated in the pathophysiology of delayed puberty. Therefore, early diagnosis is essential and appropriate and specific therapy fundamental.

Final height of thalassemic patients who underwent bone marrow transplantation during childhood

We evaluated the final height achieved by 47 patients who had bone marrow transplantation (BMT) for thalassemia major. Subjects were separated into two groups: patients who received BMT before 7 years of age and patients who received BMT after 7 years of age. Parental height and genetic target height (TH) were calculated. Our data indicated a strict correlation between age at time of transplant and final adult height. The patients whose age at transplant was <7 years had a less impaired growth rate than did patients who were >7 years. Moreover, greatest loss in height was observed in subjects who had higher serum levels of transaminase and ferritin and these biochemical parameters were strictly correlated to the final adult height. Mean final adult height, however, did not differ from the genetic target height in subjects who received BMT before 7 years of age and the final height SDS corrected for TH surpasses even the TH. In contrast, the subjects who received BMT after 7 years of age, failed to achieve their full genetic potential. In conclusion, short stature is present in a significant percentage of transplanted thalassemic children. The data in this study indicate a close effect of the age at time of transplant on subsequent growth rate, but the growth impairment in these subjects remain multifactorial.

Novel application of IGF-I and IGFBP-3 generation tests in the diagnosis of growth hormone axis disturbances in children with beta-thalassaemia

OBJECTIVE

Children with beta-thalassaemia major (beta-thal) frequently have growth retardation in the presence of low serum IGF-I and a normal GH response to pharmacological stimulation suggesting that they have GH insensitivity (GHIS). This study was carried out to study the cause of their growth retardation.

DESIGN

We studied IGF-I and IGFBP-3 generation after exogenous GH administration for four days, in 15 prepubertal controls (C) and 41 prepubertal beta-thal patients divided into three groups according to their growth status: (Group 1) 15 with normal growth (N-thal) (Group 2) 16 with decelerated growth (D-thal) and (Group 3) 10 with short stature (S-thal), in order to determine whether GHIS is the cause of their growth retardation.

MEASUREMENTS

IGF-I and IGFBP-3 were measured daily, before and for 4 days after daily administration of 0.1 IU/kg hGH, in 3 groups of prepubertal beta-thal patients and normal controls.

RESULTS

N-thal and C had similar basal serum IGF-I (142 +/- 52 and 196 +/- 56 ng/ml, respectively) and IGFBP-3 concentrations (2.07 +/- 0.49 and 2.66 +/- 0.41 mg/l, respectively) as well as a similar percent increase of IGF-I (101 +/- 23% and 104 +/- 37%, respectively) and IGFBP-3 (52 +/- 36%, and 38 +/- 14%, respectively) during the generation tests. S-thal and D-thal had significantly lower basal IGF-I and IGFBP-3 concentrations (85 +/- 42 and 101 +/- 36 ng/ml; and 1.60 +/- 0.49 and 1.79 +/- 0.52 mg/l, respectively) as compared to N-thal and C (P < 0.001 and P < 0.005, respectively), and a significantly higher percent increase of IGF-I and IGFBP-3 during the generation tests (249 +/- 43 and 161 +/- 76%; and 121 +/- 99 and 73 +/- 35%, respectively) as compared to N-thal and C (P < 0.0001 and P < 0.01, respectively). Twenty-five percent of the growth retarded patients had classic GH deficiency (GHD) and percent increases of IGF-I and IGFBP-3 in the generation tests (164 +/- 86% and 80 +/- 49%, respectively) which were similar to those of the remaining growth-retarded children.

CONCLUSION

The greater percent increases of IGF-I and IGFBP-3 in the generation tests of the growth retarded beta-thal patients, both with and without GHD, strongly suggest impaired GH secretion rather than GHIS as the cause of their growth retardation. We conclude that the IGF-I and IGFBP-3 generation tests are useful tools for the study not only of GHIS but also of GH secretory disorders in patients with beta-thal and short stature that can easily be performed in an outpatient setting as an initial test to identify the patients that may benefit from GH therapy.

The effect of 3 years of recombinant growth hormone therapy on glucose metabolism in short Chinese children with beta-thalassemia major

Growth retardation and diabetes mellitus are common in children and adolescents with beta-thalassemia major despite hypertransfusion regimen and iron chelation therapy. The purpose of this study was to investigate the effects of growth hormone (GH) treatment on glucose metabolism in children with beta-thalassemia major. GH therapy for 3 years improved the height SD scores of eight short prepubertal Chinese children with beta-thalassemia major from -2.15 +/- 0.90 to -1.14 +/- 0.78 (paired t-test, p = 0.01) without excessive advancement in bone age (ABA/CA = 0.95 +/- 0.27). There was no deleterious effect on glucose metabolism with no change in fasting blood sugar, serum fructosamine, fasting and stimulated insulin to intravenous glucose infusion (sum of 1+3 min insulin, In 1+3'; incremental insulin 0-10 min area above fasting concentrations, deltaInAUC0-10'; ratio of incremental 0-10 min insulin area above fasting concentrations over glucose area above fasting concentrations, delta0-10'AUCIn/G; ratio of incremental 0-10 min insulin over peak glucose above basal 0-10 min, delta0-10'InAUC/deltaGPeak), and glucose disappearance coefficient (Kg). Short term GH therapy improves the height of children with beta-thalassemia major but the effect of treatment on final height still needs to be determined.

Growth hormone treatment in short children with beta-thalassemia major

The effect of one year recombinant human growth hormone (rhGH) treatment on growth rate and bone age was studied in ten short prepubertal children with beta-thalassemia major (age range 7.10-12.03 yr) with normal GH response to provocative stimuli. rhGH was given subcutaneously every day in a dose of 28 IU/m2/week. In the 10 children who completed 12 months of treatment the growth velocity increased from 4.22+/-0.81 cm/yr (-1.38+/-0.80 SDS for CA) to 7.61+/-1.16 cm/yr (+2.27+/-1.64 SDS for CA). IGF-I was low before treatment, 138.3 +/-38.9 ng/ml, and rose significantly to 232.2+/-122.1, 243.2+/-98.4 and 227.5+/-86.2 at 3, 6 and 12 months post-treatment, respectively (p<0.01). Bone maturation was accelerated in proportion to the increase in chronological age. The mean pre-treatment bone age in the ten children was 8.20+/-1.97 and increased to 9.55+/-1.80 yr after one year of treatment. Our data demonstrate that GH treatment of thalassemic children with normal GH reserve and low serum IGF-I concentrations with supraphysiological doses of rhGH for one year can cause a significant increase in serum IGF-I levels and growth velocity, but it remains to be elucidated whether long-term administration will affect the final height.

Recombinant human growth hormone treatment in children with thalassemia major

BACKGROUND

To evaluate the growth hormone reserve and the growth hormone response to recombinant human growth hormone (GH) in prepubertal thalassemic children with growth retardation.

METHODS

Twenty thalassemic patients with short stature and delayed bone age were studied. Patients were randomized into GH-treated (n = 10) and non-GH treated (control; n = 10) groups. The GH-treated group received recombinant human (rh)-GH (Genotropin) at the dose of 0.7 IU/kg per week for 12 months.

RESULTS

There was a significant discordance between GH response to pharmacologic stimuli and physiological secretion of GH/GHRH testing. Following the administration of rhGH, growth velocity increased from 2.47 +/- 0.48 cm/year to 6.27 +/- 0.76 cm/year (P = 0.005), whereas there was not a similar change in the non-GH-treated group. The height velocities of the two groups during the 1 year follow-up period were significantly different (6.27 +/- 0.76 vs 3.99 +/- 0.34 cm/year; P = 0.025). There were significant differences between the height velocity improvements and height velocity standard deviation scores of the two groups as well.

CONCLUSION

The present study has demonstrated that rhGH is a safe and efficacious mode of treatment in thalassemic children.

Magnetic resonance imaging evaluation of the pituitary gland and hypothalamus in thalassaemic children with elevated serum ferritin levels

OBJECTIVE

Despite modern treatment with hypertransfusion and chelation therapy, growth retardation continues to be observed in a significant proportion of thalassaemic children. The underlying reason remains unclear, but hypothalamic-pituitary axis disorder has been implicated. We aimed to assess iron overloading in the hypothalamus and pituitary gland in thalassaemic children with elevated serum ferritin, with and without growth retardation.

METHODOLOGY

Twelve thalassaemic children on hypertransfusion and chelation therapy with high serum ferritin were investigated with magnetic resonance imaging (MRI). Five children, all over 10 years of age, had growth retardation. Gradient recalled echo sequence was used to highlight any susceptibility effect that could be due to iron in the hypothalamus or pituitary gland.

RESULT

There was no evidence of abnormal hypointense signal in the hypothalamus or pituitary gland in the patients studied, regardless of the presence of growth retardation.

CONCLUSION

There was no apparent characteristic MRI appearances of iron deposition in the hypothalamus or pituitary gland in thalassaemic children with high serum ferritin.

Nutritional support and growth in thalassaemia major

Twelve thalassaemic children under 3 years of age received intensive nutritional support for one month and were discharged on a prescribed diet of locally available foods. Anthropometry, bioelectrical impedance analysis and dietary intake were longitudinally assessed. Mean energy intake was 20% greater than the recommended daily allowance during nutritional supplementation as compared with below the recommended daily allowance before and after the period of nutritional support. Weight, but not height, significantly increased during the support period and was due to increases in both fat free mass and fat mass. Body weight, fat free mass and fat mass declined in line with the reduced intake upon return home; however, height velocity accelerated and exceeded normal through the fourth month before resuming a below normal rate. It can be concluded that (1) nutritional stunting as the result of reduced nutrient intake is an important cause of growth failure in young children with thalassaemia and is responsive to nutritional support, (2) the deficit in height velocity was due to retarded truncal height growth, and (3) the bioelectrical impedance analysis method is suitable for body composition analysis of thalassaemic children.

Growth, puberty and endocrine function in beta-thalassaemia major

Although delay in onset of puberty is a common cause of growth failure in adolescent thalassaemic patients, growth retardation could also be due to iron overload, the toxic effects of desferrioxamine, or the development of other endocrinopathies such as GH insufficiency or primary hypothyroidism. Abnormal body proportions with truncal shortening are commonly seen and could be due to the disease itself, iron toxicity, delay in puberty or the toxic effects of desferrioxamine. The absence of a pubertal growth spurt during spontaneous or induced puberty is detrimental to the achievement of a normal final adult height. Low serum IGF-I and normal GH reserve in short thalassaemic children imply that a state of relative GH resistance exists. The rise in IGF-I and improvement in growth with GH therapy suggest that this GH resistance is only partial. Although the results of short-term GH therapy are encouraging, the impact of treatment on final height of non-GH deficient short thalassaemic children remains uncertain. Multiple endocrinopathies, including hypogonadism, hypothyroidism and diabetes mellitus, occur mainly in older patients who tend to have high serum ferritin levels. Prognosis for survival is greatly improved if the serum ferritin is kept below 2000 micrograms/l by regular chelation. Chelation therapy initiated early before the accumulation of a significant iron burden or dosages of desferrioxamine in excess of 50 mg/kg/day should be avoided. Serum ferritin should be checked regularly and the "toxicity index" should be used to monitor chelation therapy. In cases of delayed puberty, sexual development should be induced at an appropriate age.

Nutritional factors and thalassaemia major

Abnormal growth is a common feature of thalassaemia major in children. In an attempt to determine whether it has a nutritional cause, 12 children aged 1 to 3 years with thalassaemia major were studied under metabolic ward conditions. Nutritional status was assessed by anthropometry and biochemistry before and after an intensive nutrition regimen. Five children had wasting or stunting on admission. As a result of the nutrition intervention, mean weight for height improved significantly. The mean height increase of 0.4 cm after one month was not significant. Plasma zinc, depressed in half the children on admission, improved, as did alpha tocopherol, while copper decreased. Plasma insulin-like growth factor-I also increased commensurate with improved growth. Fat absorption was normal in all children. Undernutrition is an important cause of associated growth disturbances in children with thalassaemia major. Malnutrition was primarily caused by inadequate nutrient intake, as indicated by the capacity to gain weight appropriately when provided with nutrition support, and by the absence of intestinal malabsorption. While long term studies are required to determine if nutritional support will prevent stunting, these results underscore its central role in preventing nutritional deficiencies and in promoting normal growth in thalassaemic children.

Circadian growth hormone secretion in short multitransfused prepubertal children with thalassaemia major

Growth hormone (GH) secretion was determined by evaluating circadian GH profiles for 24 h and GH responses to clonidine stimulation test and insulin-stimulated hypoglycaemia (ITT), in nine prepubertal children with beta-thalassaemia major (TM) and 17 with non-GH deficient short stature (NGHDSS). The TM children were multitransfused and had early and intensive chelation therapy. All patients had normal hypoglycaemia to ITT, with peak GH levels of 15.71 +/- 5.86 ng/ml for children with NGHDSS and 13.91 +/- 7.20 ng/ml for children with TM. Peak GH levels during a clonidine test were 17.54 +/- 5.30 and 17.15 +/- 1.38 ng/ml, respectively. The GH peak parameters such as the number of peaks, the integrated GH concentration and the area under the curve (AUC) were similar in both groups of children and reflected the total 24-h secretion and the daily and nocturnal secretion separately. An abnormal 24-h GH profile compatible with the diagnosis of endogenous neurosecretory GH dysfunction was found in only two out of nine children with TM and in four out of seven children with NGHDSS.

CONCLUSION

Our data suggest that growth hormone neurosecretory dysfunction is not a universal finding in children with thalassaemia major but might depend on the degree of iron deposit in the pituitary.

Growth hormone treatment of short Chinese children with beta-thalassaemia major without GH deficiency

OBJECTIVE

Despite regular transfusion and desferrioxamine treatment, growth failure is commonly seen in adolescent children with beta-thalassaemia major. The growth failure has been thought to be due to GH resistance rather than GH deficiency. We investigated the effect of GH on short non-GH deficient children with beta-thalassaemia.

DESIGN

Recombinant human GH was given in a dose of 0.14 IU/kg/day subcutaneously in an open study.

PATIENTS

Fifteen prepubertal Chinese children with beta-thalassaemia major (ranging from 7.16 to 14.7 years in age) with height -1.5 SD or more below the population mean for age and a growth velocity of less than 5 cm/year were treated with growth hormone for one year. All children had peak GH response > 15mlU/l to insulin induced hypoglycaemia and normal thyroid function and adrenal reserve.

MEASUREMENTS

Anthropometric measurements were performed every 3 months. Morning urine was tested twice weekly for glycosuria. Blood count, renal and liver function tests, fasting blood glucose, IGF-I and fructosamine levels were assessed at entry and every 3 months during treatment. Fasting insulin was measured before and after 3 and 12 months of GH treatment. Skeletal maturity was assessed before and after one year of treatment.

RESULTS

Treatment was stopped in two children after 6 months because of poor growth response and noncompliance with treatment and in one child at 9 months because of bone marrow transplantation. In the 13 children, the growth velocity increased from 3.6 +/- 0.7 cm/year to 8 +/- 1.2 cm/year after one year of GH treatment (P < 0.001). IGF-I was low before treatment (10.1 +/- 2.7 nmol/l), rising significantly to 15.8 +/- 4.8, 18.4 +/- 4.6, 19.3 +/- 6.4 and 21.9 +/- 7.5 nmol/l at 3, 6, 9 and 12 months of treatment (P < 0.005). The mean pretreatment bone age in the 13 children was 9.58 +/- 1.41 years and increased to 10.53 +/- 1.43 years after one year of treatment (delta BA/CA 0.95 +/- 0.3 years). None of the patients developed glycosuria or hypertension. There was no significant change in blood count, renal and liver function, thyroid function, fasting blood glucose or insulin concentrations during treatment.

CONCLUSION

Growth failure in these children with normal GH reserve and low serum IGF-I concentrations would suggest GH insensitivity. Supraphysiological doses of exogenous GH can cause a significant increase in serum IGF-I levels and a significant improvement in short-term growth of short children with beta-thalassaemia major.

A cross-sectional study of growth, puberty and endocrine function in patients with thalassaemia major in Hong Kong

METHODOLOGY

A cross-sectional study of growth, puberty and endocrine function was performed on 35 girls and 33 boys with thalassaemia major.

RESULTS

Despite regular transfusion and chelation therapy, 75% of the girls and 62% of the boys over the age of 12 years were below the third percentile for height. Hypogonadotropic hypogonadism was found in a similar percentage of patients. Moderate to marked zinc deficiency secondary to chelation therapy was considered unlikely because normal serum zinc levels were found in all but three of our patients, but we could not exclude the possibility of a marginal status of zinc nutrition causing growth failure. Growth hormone deficiency and diabetes mellitus were sometimes encountered but hypothyroidism, hypoparathyroidism and adrenal insufficiency were rare among our patients. Most of the patients with growth failure had normal growth hormone (GH) response to insulin induced hypoglycaemia. The serum insulin-like growth factor-1 (IGF-1) levels were low in our patients and no significant difference in the serum IGF-1 levels was found between prepubertal children with or without growth failure (0.4 +/- 0.1 mU/mL vs 0.37 +/- 0.11 mU/mL, P = 0.39). Similarly, no difference in the serum IGF-1 levels was found between pubertal children with or without growth failure (0.48 +/- 0.2 U/mL vs 0.56 +/- 0.14 U/mL, P = 0.26).

CONCLUSIONS

Delayed sexual maturation and a possible defect in growth unrelated to the GH-IGF-1 axis may be responsible for the growth failure in adolescent children with thalassaemia major.