Current practice in diagnosis and treatment of growth hormone deficiency in childhood: a survey from Turkey

Growth Hormone Dosing Estimations Based on Body Weight Versus Body Surface Area

Objective

Both body weight (BW)- and body surface area (BSA)-based dosing regimens have been recommended for growth hormone (rhGH) replacement. The aim was to compare the two regimens to determine if either resulted in inadequate treatment depending on anthropometric factors.

Methods

The retrospective study included children diagnosed with idiopathic isolated growth hormone deficiency. BW-based dosing in mcg/kg/day was converted to BSA in mg/m2/day to determine the equivalent amounts of the given rhGH. Those with a BW-to-BSA ratio of more than 1 were allocated to the “relatively over-dosed group”, while the remaining patients with a ratio of less than 1 were assigned to the “relatively under-dosed” group. Patients with a height gain greater than 0.5 standard deviation score (SDS) at the end of one year were classified as the height gain at goal (HAG), whereas those with a height gain of less than 0.5 SDS were assigned as the height gain not at goal (NHAG).

Results

The study included 60 patients (18 girls, 30%). Thirty-six (60%) patients were classified as HAG. The ratio of dosing based on BW-to-BSA was positively correlated both with the ages and body mass index (BMI) levels of the patients, leveling off at the age of 11 at a BMI of 18 kg/m2. The relative dose estimations (over- and under-dosed groups) differed significantly between the patients classified as HAG or NHAG. Fifty-six percent of NHAG compared to 44% of HAG patients received relatively higher doses, while 79% of HAG compared to 21% of NHAG received relatively lower doses (p=0.006). When the patients were subdivided according to their pubertal status, higher doses were administrated mostly to the pubertal patients in both the NHAG and HAG groups. In the pre-pubertal age group, 73% of NHAG compared to 27% of HAG received relatively higher doses, while 25% of NHAG compared to 75% of HAG received relatively lower doses (p=0.01).

Conclusion

Dosing based on BW may be preferable in both prepubertal and pubertal children who do not show adequate growth responses. In prepubertal children, relatively lower doses calculated based on BW rather than BSA provide similar efficacy at lower costs.

Correlation of body mass index to Ghrelin and IGF-1 among children with short stature

OBJECTIVE

To assess the BMI among children with Growth Hormone Deficiency (GHD) and Idiopathic Short Stature (ISS) and its correlation to ghrelin, Growth Hormone (GH), and Insulin-like Growth Factor-1 (IGF-1) levels.

METHODS

A cross-sectional descriptive study in which 42 patients attending the Pediatric endocrine clinic were enrolled, allocated into two groups: group I: GHD children; group II: ISS children. Ghrelin, IGF-1 and GH in both groups were measured.

RESULTS

Ghrelin was significantly higher among GHD group (p < 0.001). Overall, there was a strong negative correlation between IGF-1 and ghrelin (r = -0.977, p-value = < 0.001) while a moderate positive correlation between ghrelin and BMI (r = 0.419, p-value = 0.006). There was a weak positive non-significant correlation between IGF-1 and BMI (r = 0.276, p-value = 0.077). In GHD group, there was a weak positive non-significant correlation between ghrelin and GH_max measurement (r = 0.052, p-value = 0.824), while a weak negative non-significant correlation between both variables in ISS group (r = -0.243, p-value = 0.288). In GHD group, there was a moderate positive correlation between ghrelin and BMI (r = 0.500, p-value = 0.021), but weak negative non-significant correlation between both variables in ISS group (r = -0.255, p-value = 0.265).

CONCLUSION

There was a negative feedback loop between ghrelin and IGF-1, whereas a positive feedback between ghrelin and BMI. BMI was more affected in the ISS group but was non-significantly correlated with ghrelin. There was no significant compensatory response of ghrelin suggesting its contribution to the pathogenesis of ISS.

The necessity of magnetic resonance imaging in the evaluation of pediatric growth hormone deficiency: Lessons from a large academic center

BACKGROUND

Current guidelines indiscriminately recommend magnetic resonance imaging (MRI) of the pituitary gland in pediatric growth hormone deficiency (GHD). The relationship between abnormal MRI, most importantly a tumor, and peak GH levels is not well known.

METHODS

In this retrospective chart review, pituitary MRI results of children, ages of 3-16 years with GHD were collected and divided into 3 groups according to peak stimulated GH levels; ≤5, 5-7.4 and 7.5-10 ng/mL, Groups A, B & C respectively. Clinical and MRI findings were compared between the groups.

RESULTS

A total of 399 children were included. Abnormal MRI was found in 36.9% of group A subjects, compared to group B (16.7%) and group C (17.0%), both p values =0.0002. Children with multiple pituitary hormonal deficiencies (MPHD) had a higher rate of abnormalities than those with isolated GHD. Children with isolated GHD were more likely to have abnormal MRI with peak GH level < 5 ng/mL compared to those with levels, 5-7.4 & 7.5-10 ng/mL. 4 children in group A had a craniopharyngioma. ROC analysis comparing peak GH levels with abnormal MRI findings showed an area under the curve (AUC) of 0.614 and 0.728 for IGHD and MPHD, respectively.

CONCLUSION

Although abnormal MRI was found in all 3 study groups, it was more likely at GH level < 5 ng/mL and in children with MPHD. To avoid missing a tumor, the importance of imaging in children with GHD and peak GH levels <5 ng/mL cannot be overemphasized.

Evaluation of the Final Adult Height and Its Determinants in Patients with Growth Hormone Deficiency: A Single-centre Experience from the South-Eastern Region of Turkey

OBJECTIVE

The aim was to determine the final adult height (FAH) achieved by recombinant human growth hormone (rhGH) treatment, the factors affecting FAH and the success of attaining the genetic potential.

METHODS

Data of 133 patients treated with rhGH therapy were reviewed retrospectively. Patients were grouped according to diagnosis, either isolated GH deficiency (IGHD) or multiple pituitary hormone deficiency (MPHD), and by sex, and pubertal status at the beginning of treatment.

RESULTS

The mean age of initiation of treatment was 12.3±2.18 years, and the mean duration of rhGH treatment was 3.65±1.5 years. The mean height standard deviation score (SDS) at diagnosis was -3.11±0.75 SD. All patients received a standardized GH dose of 0.033 mg/kg/day. Mean FAH-SDS was -1.8±0.77 and delta height-SDS (the change in height SDS between the beginning and end of treatment) was 1.28±0.94 SD. FAH-SDS was -1.79±0.86 SD in males; -1.82±0.64 in females (p=0.857); -1.94±0.71 at the beginning of treatment in pubertal patients and -1.68±0.81 in prepubertal patients (p=0.056); -1.84±0.89 in patients with IGHD and -0.47±0.2 in patients with MPHD (p˃0.05). In multiple regression analysis, First year delta height-SDS was the most predictive factor for both FAH-SDS and delta height-SDS.

CONCLUSION

The majority of our patients achieved a final height compatible with their genetic potential as well as population standards when treated with rhGH even having started at a relatively late age. First year delta height-SDS was a predictive factor for FAH.

A novel diagnostic tool for the evaluation of hypothalamic-pituitary region and diagnosis of growth hormone deficiency: pons ratio

Backgrounds Limitations in the evaluation of the pituitary size and changes according to pubertal status make its validity questionable. Recently, in a small-scale study, pons ratio (PR) has been suggested as a more sensitive tool for diagnosis and etiological evaluation of growth hormone deficiency (GHD). The aim of the study is to evaluate the diagnostic value of PR in the diagnosis of GHD. Methods We retrospectively evaluated the pituitary magnetic resonance imaging (MRI) of 133 patients with a diagnosis of GHD. Primary axis (PA) was assigned as a line crossing the mid-sagittal dorsum sella and fourth ventricle. PR was defined as the pons height above the PA divided by total pons height. The PR of patients with GHD was compared to subjects without GHD. Results Study included 133 patients with GHD and 47 controls. In total, 121 (91%) patients had isolated GHD and 12 (9%) patients had multiple pituitary hormone deficiency. The PR of the patient group (mean: 0.32 ± 0.89; range: 0.14-0.63) was significantly higher than controls (mean: 0.26 ± 0.067; range 0.19-0.44) (p: 0.000). The optimal cut-off value of PR for GHD diagnosis was 0.27 (sensitivity 71% specificity 56%). There was a negative correlation between anterior pituitary height (APH)-SDS and PR (p: 0.002; r: -0.27). APH was increased, but PR remained unchanged in pubertal patients (p: 0.089). Conclusions PR measurement is a noninvasive, practical method with a cost-benefit clinical value. As it is not affected by pubertal status, PR is potentially a more sensitive tool for evaluation of pituitary gland in GHD patients compared to APH.

Differences between patients with isolated GH deficiency based on findings in brain magnetic resonance imaging

INTRODUCTION

Protocol for prescribing hormone replacement therapy in isolated growth hormone (GH) deficiency includes magnetic resonance imaging of the brain. There is controversy on the frequency of structural pituitary abnormalities and on the importance of abnormal MRI findings on prognosis and response to GH replacement.

METHODS

A descriptive, retrospective study of children of both sexes aged 0-14 years, who had undergone brain MRI, diagnosed with isolated GH deficiency at a tertiary hospital in the past 14 years, aimed at reporting the frequency of abnormal MRI findings in isolated GH deficiency, and to establish whether differences exist in height diagnosis and evolution according to MRI findings. MRI findings were also compared with the findings reported in healthy children in order to establish incidence.

RESULTS

96 patients were studied, of whom 74/96 (77%) reached adult age. Abnormal MRI findings were seen in 11.5% of them (8/11 of pituitary origin). No brain or pituitary tumor was seen in any case. Patients with abnormal images had a mean age at treatment start of 8 years, a target height of -0.8SD, and a final height of 1.04SD, while patients with normal MRI findings had an age at treatment start of 10 years old, a target height of -1.44SD, and a final height of -1.75SD, with statistically significant differences.

CONCLUSIONS

Patients with abnormal MRI findings show a more favorable response to GH replacement therapy.

Changes in ghrelin and nesfatin-1 in children with growth hormone deficiency treated by recombinant human growth hormone

This study aims to investigate the effects of recombinant human growth hormone (rhGH) on serum nesfatin-1 and ghrelin in children with growth hormone deficiency (GHD), in order to provide a reliable basis for the effectiveness and safety of applying rhGH in treating GHD children in the clinic. A total of 30 GHD pediatric patients were selected as the observation group. According to the peak of GH, these patients were divided into two subgroups: complete absence of growth hormone (CGHD) group and partial absence of growth hormone (PGHD) group. At the same time, 20 healthy children of normal height with matching age and gender were randomly selected as a normal control group. Serum ghrelin and nesfatin-1 levels were detected in children in the control group and observation group before rhGH treatment, and at 3 and 6 months after treatment. After 3 and 6 months of treatment, the height and growth rate of children in the PGHD and CGHD groups significantly increased ( P < 0.05), but their body weights did not significantly change ( P > 0.05), compared with those before treatment. Before treatment, ghrelin was higher in the PGHD group than in the control group, while ghrelin was lower in the CGHD group than in the control group. In addition, nesfatin-1 was higher in these two subgroups, compared with that in the control group. At pretreatment, and after 3  and 6 months of treatment, ghrelin and nesfatin-1 both decreased in the PGHD group, while ghrelin increased and nesfatin-1 decreased in the CGHD group. It was confirmed that ghrelin and nesfatin-1 were closely correlated with GHD. Furthermore, rhGH has a significant effect on children with GHD, and can significantly accelerate the annual growth rate.

Comparison of the effects of the L-dopa and insulin tolerance tests on cortisol secretion

PURPOSE

The aims of the present study are to evaluate the effect of L-dopa on the secretion of cortisol and adrenocorticotropic hormone (ACTH) in short children and compare the performance of this test with the insulin tolerance test (ITT) in a large number of patients.

METHODS

A total of 29 short but otherwise healthy children [mean age 9.5 ± 3.1 years (range 3.7-14.9 years)] who had inadequate growth hormone (GH) responses to ITT, which was performed as the first test, were consecutively enrolled in this study. GH, cortisol, and ACTH levels were measured just before administration of L-dopa and then at 30-min intervals afterward over a total time of 120 min. Peak concentrations of cortisol and ACTH exceeding 18 µg/dL (496 mmol/L) and 46 pg/mL (10.2 pmol/L), respectively, were defined as an adequate response.

RESULTS

While the L-dopa test revealed that 26 of the 29 children (89.7%) had peak serum cortisol levels of > 18 µg/dL, the ITT revealed that only 23 children (79.3%) had adequate cortisol responses. The L-dopa test revealed normal ACTH responses (> 46 pg/mL) in 24 (82.8%) patients. Peak cortisol levels were higher in children with normal ACTH responses than in those with subnormal ACTH responses (25.6 ± 6.2 vs. 19.5 ± 6.4 µg/dL, p = 0.054), but the difference observed was statistically insignificant.

CONCLUSION

The results of the current study confirm that the L-dopa test is a reliable test of cortisol secretion. As such, this test may be applicable to assessments of the hypothalamic-pituitary-adrenal axis.

A Critical Appraisal of Growth Hormone Therapy in Growth Hormone Deficiency and Turner Syndrome Patients in Turkey

Early detection of abnormal growth, identification of the underlying cause, and appropriate treatment of the medical condition is an important issue for children with short stature. Growth hormone (GH) therapy is widely used in GH-deficient children and also in non-GH-deficient short stature cases who have findings conforming to certain indications. Efficacy of GH therapy has been shown in a multitude of short- and long-term studies. Age at onset of GH therapy is the most important factor for a successful treatment outcome. Optimal dosing is also essential. The aim of this review was to focus on challenges in the early diagnosis and appropriate management of short stature due to GH deficiency (GHD) and Turner syndrome. These are the most frequent two indications for GH therapy in Turkey approved by the Ministry of Health for coverage by the national insurance system.

An examination of the effects of different doses of recombinant human growth hormone on children with growth hormone deficiency

The aim of the present study was to examine the effects of different doses of recombinant human growth hormone (rhGH) on children with growth hormone deficiency (GHD) and on thyroid and glucose metabolism to identify more reasonable therapeutic doses of growth hormone (GH) for the treatment of this condition. In total, 60 prepubertal patients with GHD were randomly divided into the high-dose and low-dose groups (n=30 per group). The groups were treated with 0.1 or 0.05 U/kg for 6 months, respectively. The follow-up study focused on changes to the serum levels of insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein (IGFBP)-3, blood glucose, thyroid hormone [triiodothyronine (T3) and its prohormone, thyroxine (T4), and thyroid stimulating hormone (TSH)] and the analysis of variance of the repeated data. Changes in the height, body weight and bone age of the high-dose group were greater than those of the low-dose group. After 6 months of treatment, the difference in height between the two groups was statistically significant (P<0.05). Glucose metabolism in the two groups was consistent, but there was a statistically significant difference in the fasting blood glucose (FBG) levels of the two groups after 6 months of treatment (P<0.05). Prior to treatment, the T3, T4 and TSH values (the thyroid function tests) in the two groups, especially for the value of T3 in high-dose group were varied. However, 6 months after treatment, statistically significant differences between the two groups (P<0.05) were identified. In conclusion, 0.1 U/kg of GH is beneficial to children with GHD in attaining a satisfactory height, but it leads to insulin resistance. Thus, glucose metabolism and thyroid function should be monitored on a regular basis in a clinical setting.