Effects of Growth Hormone on Growth, Insulin Resistance and Related Hormones (Ghrelin, Leptin and Adiponectin) in Turner Syndrome

Components of the metabolic syndrome in girls with Turner syndrome treated with growth hormone in a long term prospective study

Background

Components of the metabolic syndrome are more common in patients with Turner syndrome (TS) than in the general population. Long-term growth hormone (GH) treatment also affects the parameters of carbohydrate metabolism. Therefore, all these factors should be monitored in girls with TS.

Objective

To assess the occurrence of metabolic syndrome components in TS girls before GH treatment and to monitor changes in metabolic parameters throughout GH therapy.

Patients and method

89 TS patients were enrolled in the study. Clinical and laboratory data after the 1st (V1), 3rd (V3), 5th (V5) and 10th (V10) year of GH therapy was available respectively in 60, 76, 50 and 22 patients. The patients' biochemical phenotypes were determined by glucose 0', 120', insulin 0', 120', HOMA-IR, Ins/Glu ratio, HDL-cholesterol and triglycerides (TG) concentration.

Results

Obesity was found during V0 in 7.9% of patients,V1 - 5%, V3 - 3.9%, V5 - 2%, V10 - 0%. No patient met diagnostic criteria for diabetes. A significant increase in the basal plasma glucose 0' was found in the first five years of therapy (pV0-V1 < 0.001; pV0-V3 = 0.006; pV0-V5 < 0.001). V10 glucose 120' values were significantly lower than at the onset of GH treatment (pV0-V10 = 0.046). The serum insulin 0' and 120' concentrations as well as insulin resistance increased during treatment. No statistically significant differences in serum TG and HDL-cholesterol levels during GH therapy were found.

Conclusion

The development of insulin resistance and carbohydrate metabolism impairment have the greatest manifestations during GH therapy in girls with TS. Monitoring the basic parameters of carbohydrate-lipid metabolism in girls with TS seems particularly important.

Origin of the X-chromosome influences the development and treatment outcomes of Turner syndrome

Turner syndrome (TS) affects 1/2,500 live-born female infants. In the present study, we attempted to clarify the relationship between genetic factors (especially the X-chromosome origin), clinical features, body/sexual development, and treatment outcomes. We enrolled 39 female infants aged between 3 and 14 years. General demographic and clinical features were documented, and laboratory analysis of blood samples was performed. Subject karyotype was determined by G-banding of 50 peripheral white blood cells, and the parenteral origin of the retained X-chromosome was determined. Next, growth hormone (GH) treatment was prescribed for 12 months, with follow-ups performed as determined. For patient groups separated according to X-chromosome origin, the basal height, bone age, insulin-like growth factor (IGF)-1, and insulin-like growth factor binding protein-3 (IGFBP-3) levels were comparable; however, after the 12-month treatment, significant differences in the height increase and IGF-1 levels were observed. If the X-chromosome (or chromosomes) originated from both parents, the increase in height was less substantial, with lower serum IGF-1 levels. The uterine size, prolactin level, increased weight after treatment, and bone age difference after treatment negatively correlated with the mother’s age at the time of birth. The mother’s height at the time of birth demonstrated a negative correlation with the basal bone age difference and a positive correlation with the IGF-1 level. In summary, the retained X-chromosome derived from both parents is associated with poorer response to GH therapy. The mother’s age and height at the time of birth can strongly impact the patient’s body/sexual development and the response to GH treatment. Thus, the mother’s age and height at the time of birth and the parental origin of the X-chromosome should be carefully considered before developing a treatment plan for TS.

Brain-Derived Neurotropic Factor, Vascular Endothelial Growth Factor and Matrix Metalloproteinases as Markers of Metabolic Status in Non-Growth Hormone-Treated Girls With Turner Syndrome

BACKGROUND

Turner syndrome (TS) presents a high risk of congenital heart defects and may predispose to both obesity and related metabolic complications. Hence the search for new markers as potential early predictors of the metabolic syndrome (MetS) and cardiovascular diseases appears warranted.

OBJECTIVE

To assess MMP-1 (matrix metalloproteinase-1), MMP-2 (matrix metalloproteinase-2), MMP-9 (matrix metallopeptidase-9), BDNF (brain-derived neurotrophic factor), GDNF (glial cell line-derived neurotrophic factor), and VEGF (vascular endothelial growth factor) in non-MetS TS girls not treated with growth hormone (GH) vs. healthy short stature girls, and to assess the connection with basic metabolic parameters.

METHOD

The concentrations of circulating MMP-1, MMP-2, MMP-9, BDNF, GDNF and VEGF were measured in 12 patients with TS not treated with growth hormone. The control group was composed of 17 girls with non-pathologic short stature. The patients' clinical and biochemical phenotypes were determined by weight, height, total cholesterol, HDL cholesterol, triglycerides, glucose, aminotransferases, IGF1, TSH and fT4.

RESULTS

There were no differences in mean age, weight, BMI Z-Score, or hSDS between the studied group and the controls; however, they differed in baseline values of ALT (18.2 ± 4.2 vs. 14.2 ± 4.1, p= 0.02), BDNF [29951.5 (26176.9 - 41271.9) vs. 23131.7 (18392.4 - 28313.3), p=0.01] and MMP-2 [91.8 (71.7 - 111.0) vs. 143.6 (123.7 - 244.5), p< 0.001]. BDNF correlated with ALT activity (r = 0.56 p = 0.002) and BMI Z-score (r = 0.38 p = 0.042), while MMP-2 correlated with HDL concentration (r = 0.48 p = 0.029) in all the patients. The analysis of the study group alone revealed significant positive correlations between MMP-9 and TSH (r = 0.74 p = 0.036), BDNF and both ALT (r = 0.73 p = 0.038) and TSH (r = 0.85 p = 0.008), and a negative correlation between MMP-1 and fT4 (r = -0.75 p = 0.032). The control group did not present any significant correlations.

CONCLUSION

The higher concentrations of BDNF and lower of MMP-2 found in girls with TS without MetS compared to healthy girls with short stature, could have a major impact on the future "natural" development of the metabolic status. Our findings need further studies.

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.

Dietary Energy Intake, Body Composition and Resting Energy Expenditure in Prepubertal Children with Prader-Willi Syndrome before and during Growth Hormone Treatment: A Randomized Controlled Trial

BACKGROUND/AIMS

Dietary management is a difficult but key aspect of care in children with Prader-Willi syndrome (PWS). We therefore investigated the effect of growth hormone (GH) treatment on reported energy intake in children with PWS, in relation with body composition, resting energy expenditure (REE) and hormone levels.

METHODS

In a randomized controlled GH trial including 47 children with PWS, we assessed 5-day dietary records and dual-energy X-ray absorptiometry for body composition. REE was calculated by Müller's equation, based on fat mass, fat free mass and gender.

RESULTS

Baseline energy intake of children with PWS was lower than normal daily energy requirements (p < 0.001), and decreased with age to 50% in prepubertal children. Energy intake in infants [m/f: 11/8; median (interquartile range [IQR]) age 2.7 years (1.5-3.2)] increased after 1 year of GH treatment (p = 0.008); this tended to be higher in the GH group than in the untreated group (p = 0.07). In prepubertal children [m/f: 14/14; median (IQR) age 6.8 years (5.1-8.1)], the increase in energy intake was higher in the GH group, but this was not different compared to the untreated group. REE was not different between the GH group and the untreated group. Increase in energy intake during 2 years of GH treatment was correlated with lower fat percentage standard deviation scores (p = 0.037) and higher adiponectin levels (p = 0.007).

CONCLUSION

Our study demonstrates that parents of children with PWS are very well capable of restricting energy intake up to 50% compared to daily energy requirements for age- and sex-matched healthy children. GH treatment was associated with a slight increase in energy intake, but also improved body composition and adiponectin levels, which suggests a protective effect of GH treatment.

Growth curves for Turkish Girls with Turner Syndrome: Results of the Turkish Turner Syndrome Study Group

OBJECTIVE

Children with Turner syndrome (TS) have a specific growth pattern that is quite different from that of healthy children. Many countries have population-specific growth charts for TS. Considering national and ethnic differences, we undertook this multicenter collaborative study to construct growth charts and reference values for height, weight and body mass index (BMI) from 3 years of age to adulthood for spontaneous growth of Turkish girls with TS.

METHODS

Cross-sectional height and weight data of 842 patients with TS, younger than 18 years of age and before starting any therapy, were evaluated.

RESULTS

The data were processed to calculate the 3rd, 10th, 25th, 50th, 75th, 90th and 97th percentile values for defined ages and to construct growth curves for height-for-age, weight-for-age and BMI-for-age of girls with TS. The growth pattern of TS girls in this series resembled the growth pattern of TS girls in other reports, but there were differences in height between our series and the others.

CONCLUSION

This study provides disease-specific growth charts for Turkish girls with TS. These disease-specific national growth charts will serve to improve the evaluation of growth and its management with growth-promoting therapeutic agents in TS patients.

Growth hormone effect on body composition in Turner syndrome

This study analyzes the body composition of young adult women with Turner syndrome (TS) either treated or not treated with recombinant human growth hormone (rhGH) and compares them with a group of healthy women. Fifty-two non-treated TS patients (23.0 ± 5.8 years), 30 treated with rhGH (21.5 ± 1.5 years), and 133 healthy young adult women (22.9 ± 3.2 years) were evaluated regarding height (H) and weight, body mass index (BMI), brachial perimeter and tricipital cutaneous fold (fat and lean areas at the arm), sitting height (SRH = sitting height/H × 100), leg length (leg/H), waist and hip circumferences (waist/hip), and bioimpedance (percentages of water, lean mass, and fat mass). Age at start of rhGH therapy varied from 7.8 to 15.1 years (10.0 ± 1.3 years), duration of treatment from 2.8 to 8.2 years (3.7 ± 1.5 years), and the mean dose was 0.42 mg/kg/w (from 0.32 to 0.50 mg/kg/w). Body composition (except height) did not differ between TS groups, but there were differences when compared to the control group: weight and sitting height were lower in TS patients; and BMI, SHR, and leg/H were higher. There was an association between all groups with regards to BMI, waist, SHR, and leg/H, but not in percentage of fat mass. SHR was positively correlated with BMI, waist, hip, and percentage of fat mass. This sample of TS patients (with and without rhGH therapy) did not differ in BMI or body composition. However, there were differences between patients with TS patients and normal healthy women. Regardless of rhGH therapy, TS patients should be monitored, particularly for sitting height, SHR, leg length, leg/H, and waist/hip.

Relationship of adiponectin to endogenous GH pulse secretion parameters in response to stimulation with a growth hormone releasing factor

OBJECTIVE

Obesity is associated with both reduced growth hormone (GH) and adiponectin. However, the relationship between adiponectin and parameters of endogenous GH secretion remains unknown. The aim of this study was to determine the relationship between total and high molecular weight (HMW) adiponectin and parameters of endogenous pulsatile GH secretion and the effects of tesamorelin, a synthetic GH releasing hormone (GHRH(1-44)), on total and HMW adiponectin.

DESIGN

A 2-week interventional study with tesamorelin was conducted at an academic medical center in 13 men with BMI 20-35 kg/m(2). Overnight frequent blood sampling and measurement of total and HMW adiponectin at baseline and after treatment were performed to assess the effects of augmenting endogenous pulsatile GH secretion.

RESULTS

Total, but not HMW, adiponectin was positively associated with log(10)Peak GH area (r=+0.73; P=0.005), basal GH secretion (r=+0.67; P=0.01), and total GH production (r=+0.57; P=0.04), but was not associated with the number of secretion events (P=0.85). Two-week treatment with tesamorelin increased endogenous GH release and IGF-1, but neither total (change -0.16±0.64; P=0.40), nor HMW (change +0.03±0.70; P=0.87) adiponectin changed significantly with treatment. Sub-analyses in overweight and obese men yielded similar results.

CONCLUSIONS

Our study demonstrates a strong relationship between specific parameters of endogenous GH pulsatility and adiponectin. However, short-term augmentation of GH pulsatility over 2-weeks does not change adiponectin. Therefore, the relationship between GH and adiponectin is most likely mediated by specific covariates related to adiposity or other factors.

Cord blood adiponectin and infant growth at one year

OBJECTIVE

The aim of this study was to determine the association between cord blood adiponectin and leptin and early infant growth at one year in small for gestational age (SGA) and appropriate for gestational age (AGA) infants.

STUDY DESIGN

In this prospective study adiponectin and leptin concentrations were determined in cord blood of (i) AGA newborns (n = 44) and (ii) SGA newborns (n = 24). At one year of age, height and weight were measured. Linear regression analysis was used to determine which factors were associated with anthropometric measurements at the age of one year.

RESULTS

(i) SGA neonates had a significantly lower median cord blood adiponectin and leptin than AGA neonates; (ii) among SGA neonates, cord blood adiponectin concentrations were negatively correlated with body weight at one year, weight gain after one year and with BMI at one year; and (iii) among AGA neonates cord blood adiponectin concentrations were negatively correlated with body weight at one year, weight gain after one year and with BMI at one year.

CONCLUSION

The disparity in cord blood adiponectin and leptin concentrations between SGA and AGA neonates suggests a role for adipokines in fetal growth.

Systematic review of the clinical effectiveness of Genotropin (somatropin) in children with short stature

Genotropin (somatropin) is licensed for the treatment of children with growth hormone deficiency, Prader-Willi syndrome, Turner syndrome, chronic renal insufficiency and in children born small for gestational age. This systematic review (SR) evaluated the clinical efficacy and effectiveness of Genotropin in these conditions to inform a NICE Technology Appraisal of growth hormone for the treatment of growth failure in children. Search terms were used to search seven databases, including Medline and Embase, for English language studies. Randomised controlled trials (RCTs) or observational studies investigating Genotropin in children were included. Out of 30 RCTs identified, one reported final height data. Eleven observational studies reported final height and seven were based on the Pfizer International Growth Survey (KIGS). This SR highlights the lack of long-term RCTs reporting final height data and other important qualitative outcomes, such as quality of life. Observational data, such as those from KIGS, remain vital for informing therapy.

The effect of growth hormone treatment on bone mineral density in prepubertal girls with Turner syndrome: a multicentre prospective clinical trial

BACKGROUND

Patients with Turner syndrome (TS) are treated with GH to increase adult height. Although it is well established that GH promotes longitudinal bone growth, the effects of GH treatment on bone density are less clear.

OBJECTIVE

To determine how GH treatment affects trabecular bone mineral density (BMD) in girls with TS at prepubertal ages in a prospective multicentre study.

PATIENTS AND METHOD

Twenty-two patients with TS in the prepubertal period with a mean age of 9.8 +/- 2.5 (range 3.6-12.8) years were included in the study. All girls with TS underwent measurement of areal BMD using dual-energy X-ray absorptiometry (DXA) to obtain pretreatment anteroposterior (AP) lumbar spine values at L1-L4. Patients received GH (Genotropin) subcutaneously for 1 year at a dose of 0.05 mg/kg/day. Height and weight were measured at 3-monthly intervals. The AP lumbar spine areal BMD was remeasured using the same technique after 1 year of treatment. Lumbar spine BMD Z-scores and volumetric BMD (vBMD) Z-scores were calculated using national standards.

RESULTS

The height SDS of our cases showed a significant increase with GH therapy. The pretreatment lumbar spine (L1-L4) BMD Z-score was -1.2 +/- 1.2 SD and the vBMD Z-score was -0.8 +/- 1.6 SD. There were no significant changes in these values after 1 year of GH treatment. Prepubertal TS girls more than 11 years of age had lower vBMD Z-scores (-1.7 +/- 1.7 SD) than the girls aged less than 11 (-0.1 +/- 1.0 SD) (P < 0.05) at the onset of therapy. No significant changes were observed in these values after 1 year of GH therapy.

CONCLUSIONS

Osteopaenia becomes apparent in prepubertal TS patients as they reach pubertal age. BMD evaluation may be necessary in these prepubertal TS girls at diagnosis. Short-term GH therapy in these TS patients does not have a significant effect on bone density when measured at a site with a predominance of trabecular bone.