Evaluation of IGF1/IGFBP3 Molar Ratio as an Effective Tool for Assessing the Safety of Growth Hormone Therapy in Small-for-gestational-age, Growth Hormone-Deficient and Prader-Willi Children

Efficacy, safety, and insulin-like growth factor I of weekly somapacitan in children with growth hormone deficiency: 3-year results from REAL4

OBJECTIVE

Somapacitan is a long-acting GH approved for once-weekly treatment of GH deficiency (GHD). This study aims to evaluate the efficacy and tolerability of somapacitan after 3 years of treatment and 2 years after switch from daily GH in children with GHD.

DESIGN

Randomized, multi-national, open-labelled, active-controlled parallel-group phase 3 trial, with a 52-week main phase and 3-year safety extension (NCT03811535).

METHODS

Treatment-naïve children with GHD were randomized (2:1) to continuous somapacitan (0.16 mg/kg/week; "soma/soma" group) or daily GH (Norditropin®; 0.034 mg/kg/day) followed by somapacitan (0.16 mg/kg/week; "switch" group).

RESULTS

Of 200 participants, 188 completed 3 years of treatment. Sustained growth was observed in both groups. At week 156, mean (SD) height velocity (HV) between weeks 104 and 156 was 7.4 (1.5) cm/year in the soma/soma group and 7.8 (1.4) cm/year in the switch group. At week 156, the soma/soma and switch groups had reached a mean (SD) height SD score (HSDS) of -0.95 (0.98) and -1.08 (0.93), respectively, and were approaching the mean mid-parental HSDS of -0.74 (for both groups). Mean total insulin-like growth factor I (IGF-I) SDS during year 3 was similar between groups and within normal range (-2.0 to +2.0). Bioactive IGF-I and bioactive IGF-I to IGF-I ratio were similar between groups. Somapacitan was well tolerated, with low proportions reporting injection-site reactions.

CONCLUSIONS

Sustained efficacy and tolerability were observed for continuous somapacitan treatment for 3 years, and for 2 years after the switching from daily GH treatment. HSDS in both groups was approaching mean mid-parental HSDS.

CLINICAL TRIAL REGISTRATION

NCT03811535.

Predictive value of IGF-1/IGFBP-3 ratio for thyroid nodules in type 2 diabetic mellitus

Aims

To explore the predictive value of the IGF-1/IGFBP-3 ratio for the presence of thyroid nodules in patients with type 2 diabetes mellitus (T2DM).

Methods

This observational study prospectively enrolled patients with T2DM at the Second Hospital of Jilin University between May 2021 and January 2022. Thyroid nodule (TN) status was determined by ultrasonography. Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive value of the serum IGF-1/IGFBP-3 molar ratio for TNs. Multivariable logistic regression analysis was conducted to identify risk factors for thyroid nodules in patients with T2DM.

Results

A total of 122 patients (mean age ± standard deviation: 52.57 ± 11.71 years; 74 males) were enrolled. 37.7% (n=46) of patients did not have TNs, while 62.3% (n=76) had TNs. The duration of diabetes, age, and HDL-C level were significantly higher in the T2DM group with TNs compared to the group without TNs (all P < 0.05). The area under the ROC curve (AUC) for the combination of IGF-1, IGFBP-3, and the serum IGF-1/IGFBP-3 molar ratio in predicting TNs in T2DM patients was 0.619 (P < 0.001). Additionally, multivariable logistic regression analysis revealed that the duration of diabetes, age, fasting plasma glucose (FPG), fasting insulin (FINS), thyroid-stimulating hormone (TSH), IGF-1, and IGFBP-3 levels were independent risk factors for thyroid nodules, while the serum IGF-1/IGFBP-3 molar ratio level was an independent protective factor for thyroid nodules in patients with T2DM (all P < 0.05).

Conclusion

The combination of IGF-1, IGFBP-3, and the serum IGF-1/IGFBP-3 molar ratio may have a better predictive value for TNs in T2DM patients than using any single marker alone. The duration of diabetes, age, FPG, FINS, TSH, IGF-1, IGFBP-3, and the serum IGF-1/IGFBP-3 molar ratio levels were independently associated with thyroid nodules in patients with T2DM.

Investigating the IGF axis as a pathway for intergenerational effects

Early nutritional and growth experiences can impact development, metabolic function, and reproductive outcomes in adulthood, influencing health trajectories in the next generation. The insulin-like growth factor (IGF) axis regulates growth, metabolism, and energetic investment, but whether it plays a role in the pathway linking maternal experience with offspring prenatal development is unclear. To test this, we investigated patterns of maternal developmental weight gain (a proxy of early nutrition), young adult energy stores, age, and parity as predictors of biomarkers of the pregnancy IGF axis (n = 36) using data from the Cebu Longitudinal Health and Nutrition Survey in Metro Cebu, Philippines. We analyzed maternal conditional weight measures at 2, 8, and 22 years of age and leptin at age 22 (a marker of body fat/energy stores) in relation to free IGF-1 and IGFBP-3 in mid/late pregnancy (mean age = 27). Maternal IGF axis measures were also assessed as predictors of offspring fetal growth. Maternal age, parity, and age 22 leptin were associated with pregnancy free IGF-1, offspring birth weight, and offspring skinfold thickness. We find that free IGF-1 levels in pregnancy are more closely related to nutritional status in early adulthood than to preadult developmental nutrition and demonstrate significant effects of young adult leptin on offspring fetal fat mass deposition. We suggest that the previously documented finding that maternal developmental nutrition predicts offspring birth size likely operates through pathways other than the maternal IGF axis, which reflects more recent energy status.

Differences in Bone Metabolism between Children with Prader-Willi Syndrome during Growth Hormone Treatment and Healthy Subjects: A Pilot Study

Despite therapy with growth hormone (GH) in children with Prader-Willi syndrome (PWS), low bone mineral density and various orthopedic deformities have been observed often. Therefore, this study aimed to analyze bone markers, with an emphasis on vitamin K-dependent proteins (VKDPs), in normal-weight children with PWS undergoing GH therapy and a low-energy dietary intervention. Twenty-four children with PWS and 30 healthy children of the same age were included. Serum concentrations of bone alkaline phosphatase (BALP), osteocalcin (OC), carboxylated-OC (Gla-OC), undercarboxylated-OC (Glu-OC), periostin, osteopontin, osteoprotegerin (OPG), sclerostin, C-terminal telopeptide of type I collagen (CTX-I), and insulin-like growth factor-I (IGF-I) were determined using immunoenzymatic methods. OC levels and the OC/CTX-I ratios were lower in children with PWS than in healthy children (p = 0.011, p = 0.006, respectively). Glu-OC concentrations were lower (p = 0.002), but Gla-OC and periostin concentrations were higher in patients with PWS compared with the controls (p = 0.005, p < 0.001, respectively). The relationships between IGF-I and OC (p = 0.013), Gla-OC (p = 0.042), and the OC/CTX-I ratio (p = 0.017) were significant after adjusting for age in children with PWS. Bone turnover disorders in children with PWS may result from impaired bone formation due to the lower concentrations of OC and the OC/CTX-I ratio. The altered profile of OC forms with elevated periostin concentrations may indicate more intensive carboxylation processes of VKDPs in these patients. The detailed relationships between the GH/IGF-I axis and bone metabolism markers, particularly VKDPs, in children with PWS requires further research.

Changes of GH-IGFs and its relationship with growth retardation in children with bronchial asthma

OBJECTIVE

To explore the relationship between Growth Hormone Insulin-like Growth Factors (GH-IGFs) and growth retardation in children with bronchial asthma.

METHODS

112 children with bronchial asthma and 50 healthy children were studied. Serum GH, IGF-1, and Insulin-like Growth Factor Binding Protein 3 (IGFBP3) were assessed by ELISA. GH-IGFs-related parameters were compared, and the correlation between the parameters and bronchial asthma severity was analyzed. The bronchial asthma group was divided into the growth retardation group and non-growth retardation group to analyze the diagnostic value of GH-IGFs in growth retardation and the relationship between GH-IGFs and growth retardation.

RESULTS

GH, IGF-1, and IGFBP3 in the bronchial asthma group were lower. GH, IGF-1, and IGFBP3 levels were decreased with the severity of bronchial asthma. GH, IGF-1, and IGFBP3 in the growth retardation group were lower than those in the non-growth retardation group. The AUC of GH-IGFs combined detection was higher than that of GH and IGFBP3 alone detection. GH < 9.27 μg/L and IGF-1 < 179.53 mmoL/L were risk factors for growth retardation in patients with bronchial asthma.

CONCLUSION

GH-IGFs-related parameters have diagnostic value for growth retardation in children, and decreased levels of GH and IGF-1 are risk factors for growth retardation in children.

Early psychomotor development and growth hormone therapy in children with Prader-Willi syndrome: a review

Prader-Willi syndrome (PWS) is a rare genetic disorder caused by the loss of imprinted gene expression on the paternal chromosome 15q11-q13. PWS is characterized by varying degrees of early psychomotor developmental deficits, primarily in cognition, language, and motor development. This review summarizes the early mental cognitive development, language development, and motor development in patients with PWS, compares the correlation of genotype with phenotype, and provides an update regarding the effects and concerns related to potential main side effects of treatment with recombinant human growth hormone on early psycho-cognitive and motor function development along with the linear growth and body composition of children with PWS.Conclusion: Early psychomotor development is strongly correlated with the prognosis of patients with PWS; moreover, current studies support that the initiation of interventions at an early age can exert significant beneficial effects on enhancing the cognitive and linguistic development of patients with PWS and allow them to "catch up" with motor development.  What is Known: • Prader-Willi syndrome is a rare genetic disorder characterized by multisystem damage, and children with Prader-Willi syndrome are typically characterized by early developmental delays, specifically in the areas of cognitive and motor development. • Recombinant human growth hormone therapy is the only medical treatment approved for Prader-Willi syndrome. What is New: • Extensive presentation of psycho-cognitive and motor development features and genotype-phenotype correlation in children with Prader-Willi syndrome.  • The effects of growth hormone on early psychomotor development in children with Prader-Willi syndrome were thoroughly reviewed, including their short- and long-term outcomes and any associated adverse effects.

Importance of Growth Factors and Bone Maturation Ratio in the Response to Growth Hormone Therapy

OBJECTIVE

The aim was to identify the influence of insulin-like growth factor I (IGF-1), IGF-binding protein-3 (IGFBP-3), and bone age (BA)/chronological age (CA) ratio on the response to GH therapy after 1 and 2 years of treatment and upon reaching final height.

METHODS

Longitudinal, retrospective, observational study of 139 patients treated for idiopathic growth hormone deficiency. Variables examined during follow-up: (1) genetic background; (2) perinatal history; (3) anthropometry; (4) height velocity, BA, BA/CA and height prognosis; (5) analytical results (IGF-1, IGFBP-3). Final response variables: adult height (AH), AH with respect to target height, AH with respect to initial height prognosis, AH with respect to height at the start of treatment, and AH with respect to height at onset of puberty.

RESULTS

Lower pretreatment IGF-1 levels and a greater increase in IGF-1 at the end of treatment imply a better response (r = -0.405, P = .007 and r = 0.274, P = .014, respectively), as does a greater increase in IGFBP-3 after 2 years of treatment and at the end of treatment (r = 0.207, P = .035 and r = 0.259, P = .020, respectively). A lower BA/CA ratio pretreatment and at the onset of puberty results in a better response (r = -0.502, P = .000 and r = -0.548, P = .000, respectively), as does a lower increase in BA and BA/CA ratio after the 1 and 2 years of treatment (r = -0.337, P = .000 and r = -0.332, P = .000, respectively).

CONCLUSION

Low pretreatment IGF-1, a greater BA delay with respect to CA pretreatment and at the onset of puberty, a greater increase in IGFBP-3 after 2 years of treatment, and a lower increase in BA and BA/CA ratio after 1 and 2 years of treatment imply a better long-term response.

Approach to the Patient: Case Studies in Pediatric Growth Hormone Deficiency and Their Management

CONTEXT

Pathologies attributed to perturbations of the GH/IGF-I axis are among the most common referrals received by pediatric endocrinologists.

AIM

In this article, distinctive cased-based presentations are used to provide a practical and pragmatic approach to the management of pediatric growth hormone deficiency (GHD).

CASES

We present 4 case vignettes based on actual patients that illustrate (1) congenital GHD, (2) childhood GHD presenting as failure to thrive, (3) childhood GHD presenting in adolescence as growth deceleration, and (4) childhood-onset GHD manifesting as metabolic complications in adolescence. We review patient presentation and a management approach that aims to highlight diagnostic considerations for treatment based on current clinical guidelines, with mention of new therapeutic and diagnostic modalities being used in the field.

CONCLUSION

Pediatric GHD is diverse in etiology and clinical presentation. Timely management has the potential not only to improve growth but can also ameliorate or even mitigate adverse metabolic outcomes, which can be directly attributed to a GH deficient state.

Long-Term Efficacy and Safety of Recombinant Human Growth Hormone in Children Born Small for Gestational Age

There is a lack of long-term data on the benefit of growth hormone (GH) treatment in Chinese children born small for gestational age (SGA). This study was conducted to assess the long-term efficacy and safety of GH treatment in children born SGA. One hundred and twenty prepubertal SGA children who did not achieve catch-up growth with height remained less than -2 standard deviations (SD) below gender-specific height were enrolled in this two-year, randomized, dose-comparative study followed by an extension study of up to 10 years. Daily subcutaneous injections of 0.23 mg/kg/week [low-dose (LD) group] or 0.46 mg/kg/week [high-dose (HD) group] somatropin were given for 104 weeks. Dosing in the extension study was≤0.46 mg/kg/week. The main outcome measures were change in height SD score (ΔHT-SDS), height velocity, insulin-like growth factor (IGF)-1, and IGF-1/IGF binding protein-3 (IGFBP-3) molar ratio. ΔHT-SDS at week 104 was 0.91±0.53 and 1.52±0.64 in the LD and HD groups (intergroup p<0.0001), respectively, and continued in an upward trend throughout the extension study, remaining above+2 for those who received treatment for a total of 7 years or more. At week 104, significant improvements were observed in height velocity, IGF-1 SDS, and IGF-1/IGFBP-3 molar ratio. Adult HT-SDS was -0.81±1.68 for boys and -0.82±1.05 for girls (p=0.9837). Glucose metabolism and thyroid function were within the normal reference range throughout treatment. Long-term recombinant human GH treatment was tolerable and effective at improving height in children born SGA.

Early recombinant human growth hormone treatment improves mental development and alleviates deterioration of motor function in infants and young children with Prader-Willi syndrome

BACKGROUND

Recombinant human growth hormone (rhGH) therapy has shown to improve height and body composition in children with Prader-Willi syndrome (PWS), the evidence of early rhGH treatment on motor and mental development is still accumulating. This study explored the time effect on psychomotor development, anthropometric indexes, and safety for infants and young children with PWS.

METHODS

A phase 3, single-arm, multicenter, self-controlled study was conducted in six sites. Patients received rhGH at 0.5 mg/m2/day for first four weeks, and 1 mg/m2/day thereafter for up to 52 weeks. Motor development was measured using Peabody Developmental Motor Scales-second edition, mental development using Griffiths Development Scales-Chinese (GDS-C). Height standard deviation score (SDS), body weight SDS, and body mass index (BMI) SDS were also assessed.

RESULTS

Thirty-five patients were enrolled totally. Significant improvements were observed in height, body weight, and BMI SDS at week 52; GDS-C score showed significant improvement in general quotient (GQ) and sub-quotients. In a linear regression analysis, total motor quotient (TMQ), gross motor quotient (GMQ), and fine motor quotient were negatively correlated with age; however, treatment may attenuate deterioration of TMQ and GMQ. Changes in GQ and locomotor sub-quotient in < 9-month group were significantly higher than ≥ 9-month group. Mild to moderate severity adverse drug reactions were reported in six patients.

CONCLUSION

Fifty-two-week treatment with rhGH improved growth, BMI, mental development, and lessened the deterioration of motor function in infants and young children with PWS. Improved mental development was more pronounced when instituted in patients < 9 months old.

Normal range for acid-labile subunit in paediatric patients in Spain and its association with age, sex, pubertal stage and other growth factors

INTRODUCTION

The acid-labile subunit (ALS) plays an important role in the endocrine effects of insulin-like growth factors (IGFs) on target tissues. Historically, it has attracted limited attention. The aim of our study was to describe the normal range of ALS in healthy children and its association with other growth factors.

PATIENTS AND METHODS

We designed a cross-sectional descriptive study. We collected data on age, height, body mass index, gestational age, anthropometry at birth and serum levels of ALS, IGF1 and IGFBP3 in healthy children aged 2-15 years with a normal height. The levels of ALS, IGF1 and IGFBP3 were measured by ELISA. We fitted GAMLSS normalization models to standardize the variables.

RESULTS

Samples were collected from 446 children. In prepubertal children, the levels of ALS, IGF1 and IGFBP3 were positively correlated in both sexes and with age (P < .01). We found significant differences in the levels of ALS, IGF1 and IGFBP3 and the IGF1/IGFBP3 molar ratio between the sexes and higher levels in pubertal boys (P < .01). We generated normal probability plots for each sex for each of the components of the ternary complex and for the IGF1/IGFBP3 and IGFBP3/ALS molar ratios. In addition, we extracted equations from the models for the calculation of z-scores for age and sex.

CONCLUSIONS

This study may contribute age- and sex-specific reference values for IGF1, IGFBP3 and ALS levels and IGF1/IGFBP3 and IGFBP3/ALS ratios in Spanish children and suggests an association between age, sex, and pubertal stage.

Serum IGF-1 to IGFBP-3 Molar Ratio: A Promising Diagnostic Tool for Growth Hormone Deficiency in Children

BACKGROUND

The serum insulin-like growth factor-1 (IGF-1)/insulin-like growth factor binding protein-3 (IGFBP-3) ratio has various potential applications in growth hormone-related disorders. This study aimed to investigate the performance of the IGF-1/IGFBP-3 ratio, independently and in combination with serum IGF-1 and IGFBP-3, in the diagnosis of growth hormone deficiency (GHD) in children with short stature (SS).

METHODS

A 7-year cross-sectional observational study was conducted on 235 children with SS. Participants with known disorders that may affect IGF-1 other than GHD were excluded. Participants were classified into GHD (n = 64) and non-GHD (n = 171) groups. GHD was defined as a slow growth rate (<25th percentile over 1 year) and suboptimal growth hormone (GH) response to 2 GH stimulation tests (peak GH < 6.25 ng/mL using the DiaSorin Liaison assay). The sensitivity and specificity of serum IGF-1, IGFBP-3, and IGF-1/IGFBP-3 molar ratio, independently and in various combinations, were determined.

RESULTS

GHD was diagnosed in 27.2% of participants. Among all studied variables, a low serum IGF-1/IGFBP-3 ratio demonstrated the greatest sensitivity for GHD (87.5%), with a comparable specificity (83.0%). The combination of low serum IGF-1, IGFBP-3, and IGF-1/IGFBP-3 ratio demonstrated the greatest specificity for GHD (97.7%), whereas the combination of normal serum IGF-1, IGFBP-3, and IGF-1/IGFBP-3 ratio demonstrated the greatest specificity for a non-GHD cause of SS (100.0%).

CONCLUSION

Our data suggest that the serum IGF-1/IGFBP-3 ratio is a useful marker for the diagnosis of GHD in children who do not have other disorders that may affect serum IGF-1 levels. Further large studies are needed to confirm the diagnostic utility of the serum IGF-1/IGFBP-3 ratio.

Long-acting PEGylated growth hormone in children with idiopathic short stature

OBJECTIVE

To evaluate the safety and efficacy of weekly PEGylated-recombinant human growth hormone (PEG-rhGH) in children with idiopathic short stature (ISS) in China.

DESIGN AND METHODS

This was a multicenter, phase II study in which all subjects were randomized 1:1:1 to weekly s.c. injections of PEG-rhGH 0.1 (low-dose (LD) group) or 0.2 mg/kg/week (high-dose (HD) group) or control for 52 weeks. The primary end point was change (Δ) in height s.d. score (HT-SDS) from baseline to week 52. Secondary end points were height velocity (HV), bone maturity, insulin-like growth factor-1 (IGF-1) SDS, and IGF-1/insulin-like growth factor-binding protein-3 (IGFBP-3) molar ratio.

RESULTS

A total of 360 children with ISS were recruited in the study (n = 120 in each group). At week 52, ΔHT-SDS was 0.56 ± 0.26, 0.98 ± 0.35, and 0.20 ± 0.26 in the LD, HD, and control groups, respectively (within-group P < 0.0001; intergroup P < 0.0001). Statistically significant values of ΔHV, IGF-1, IGF-1/IGFBP-3 ratio, and IGF-1 SDS at week 52 from baseline were observed in both treatment groups (P < 0.0001). There were clear dose-dependent responses for all auxological variables. PEG-rhGH was well tolerated throughout the treatment period with treatment-emergent adverse events (TEAEs) reported in 86.5%, 84.6%, and 91.3% of children in the HD, LD, and control groups, respectively. The incidence of TEAEs was similar in all treatment groups despite the difference in doses. A total of 27 (8.7%) children experienced drug-related TEAEs.

CONCLUSION

Fifty-two-week treatment with PEG-rhGH 0.1 or 0.2 mg/kg/week achieved significant improvement in HT-SDS and other growth-related variables, including HV, IGF-1 SDS, and IGF-1/IGFBP-3 ratio, in a dose-dependent manner. Both doses were well tolerated with similar safety profiles.

Declining Levels and Bioavailability of IGF-I in Cardiovascular Aging Associate With QT Prolongation-Results From the 1946 British Birth Cohort

Background

As people age, circulating levels of insulin-like growth factors (IGFs) and IGF binding protein 3 (IGFBP-3) decline. In rat cardiomyocytes, IGF-I has been shown to regulate sarcolemmal potassium channel activity and late sodium current thus impacting cardiac repolarization and the heart rate-corrected QT (QTc). However, the relationship between IGFs and IGFBP-3 with the QTc interval in humans, is unknown.

Objectives

To examine the association of IGFs and IGFBP-3 with QTc interval in an older age population-based cohort.

Methods

Participants were from the 1946 Medical Research Council (MRC) National Survey of Health and Development (NSHD) British birth cohort. Biomarkers from blood samples at age 53 and 60-64 years (y, exposures) included IGF-I/II, IGFBP-3, IGF-I/IGFBP-3 ratio and the change (Δ) in marker levels between the 60-64 and 53y sampled timepoints. QTc (outcome) was recorded from electrocardiograms at the 60-64y timepoint. Generalized linear multivariable models with adjustments for relevant demographic and clinical factors, were used for complete-cases and repeated after multiple imputation.

Results

One thousand four hundred forty-eight participants were included (48.3% men; QTc mean 414 ms interquartile range 26 ms). Univariate analysis revealed an association between low IGF-I and IGF-I/IGFBP-3 ratio at 60-64y with QTc prolongation [respectively: β -0.30 ms/nmol/L, (95% confidence intervals -0.44, -0.17), p < 0.001; β-28.9 ms/unit (-41.93, -15.50), p < 0.001], but not with IGF-II or IGFBP-3. No association with QTc was found for IGF biomarkers sampled at 53y, however both ΔIGF-I and ΔIGF-I/IGFBP-3 ratio were negatively associated with QTc [β -0.04 ms/nmol/L (-0.08, -0.008), p = 0.019; β -2.44 ms/unit (-4.17, -0.67), p = 0.007] while ΔIGF-II and ΔIGFBP-3 showed no association. In fully adjusted complete case and imputed models (reporting latter) low IGF-I and IGF-I/IGFBP-3 ratio at 60-64y [β -0.21 ms/nmol/L (-0.39, -0.04), p = 0.017; β -20.14 ms/unit (-36.28, -3.99), p = 0.015], steeper decline in ΔIGF-I [β -0.05 ms/nmol/L/10 years (-0.10, -0.002), p = 0.042] and shallower rise in ΔIGF-I/IGFBP-3 ratio over a decade [β -2.16 ms/unit/10 years (-4.23, -0.09), p = 0.041], were all independently associated with QTc prolongation. Independent associations with QTc were also confirmed for other previously known covariates: female sex [β 9.65 ms (6.65, 12.65), p < 0.001], increased left ventricular mass [β 0.04 ms/g (0.02, 0.06), p < 0.001] and blood potassium levels [β -5.70 ms/mmol/L (-10.23, -1.18) p = 0.014].

Conclusion

Over a decade, in an older age population-based cohort, declining levels and bioavailability of IGF-I associate with prolongation of the QTc interval. As QTc prolongation associates with increased risk for sudden death even in apparently healthy people, further research into the antiarrhythmic effects of IGF-I on cardiomyocytes is warranted.

Growth hormone treatment does not to lead to insulin resistance nor excessive rise in IGF-1 levels, while improving height in patients small for gestational age A long-term observational study

OBJECTIVE

In children born small for gestational age (SGA), the relationship between growth hormone (GH) treatment and insulin resistance (IR) has only been investigated for a short period, necessitating a longer observation period. This study aimed to evaluate the long-term (10 years) effect of GH to SGA-children on IR and safety during treatment.

DESIGN

This was a multicenter observational study.

PATIENTS

SGA-children who received GH treatment in Spain (stratified by Tanner-stage and age at GH onset [two groups: ≤6 years old or >6 years old]).

MEASUREMENTS

The analysed variables (yearly measures) included auxologic, metabolic (insulin-like growth factor-1 (IGF-1), height velocity [HV], weight and homeostatic model assessment-IR [HOMA-IR]) and safety data. Data were collected prospectively (since the study approval: 2007) and retrospectively (since the initiation of GH treatment: 2005-2007).

RESULTS

A total of 389 SGA children (369 Tanner-I) were recruited from 27 centres. The mean age (standard deviation) of the children at GH treatment onset was 7.2 (2.8) years old. IGF-1 (standard deviation score [SDS]) and HOMA-IR values tended to increase until the sixth year of GH-treatment, with significant differences being observed only during the first year, while these remained stable in the later years (within normal ranges). Height (SDS) increased significantly (basal: -3.0; tenth year: -1.13), and the maximum HV (SDS) occurred during the first year (2.75 ± 2.39).

CONCLUSIONS

HOMA-IR values increased significantly in SGA-children during the first year of GH-treatment, remained stable and were within normal ranges in all cases. Our 10-year data suggests that long-term GH treatment does not promote IR and is well-tolerated, safe and effective.

First year metabolic and hormonal behaviour define two different populations of SGA newborn for weight or height

Context

Small for gestational age (SGA) children have a particular metabolic and hormonal pattern at birth that change rapidly.

Objective

To evaluate the linear and weight growth in the first year of life in SGA children.

Design

Prospective, monocentric cohort study.

Setting

Real-world data collected from April 2012 to January 2016.

Patients

SGA newborns uniformly defined by either growth or length lower than -2 standard deviation for gestational age.

Interventions

All children were evaluated for one year after birth, at three days of life, then three, six and 12 months after birth.

Main outcome measures

Anthropometric parameters and biochemical variables, such as blood glucose, insulin, leptin, insulin-like growth factor (IGF)-1, IGF binding protein (IGFBP)3, and HOMA index.

Results

One hundred and thirty-three SGA children were enrolled. Length significantly improved one month after birth, whereas weight significantly increased only three months after birth. Biochemical variables increased during the first year of life, showing a prediction by IGFBP-3 and HOMA-index. Then, the casuistry was divided considering either weight, length or both, showing a different incidence. The biochemical variables changes recorded in the first step were maintained considering SGA children for weight or length, whereas they disappeared when weight and length were considered together.

Conclusions

Our study shows a specific catch-up growth for weight and length in SGA children. Moreover, we highlight that weight and length should be considered as independent parameters in SGA children, defining two different metabolic-hormonal populations with different conceivable predictive role in early catch-up growth and in later growth and metabolic status.

Inclusion and Withdrawal Criteria for Growth Hormone (GH) Therapy in Children with Idiopathic GH Deficiency—Towards Following the Evidence but Still with Unresolved Problems

According to current guidelines, growth hormone (GH) therapy is strongly recommended in children and adolescents with GH deficiency (GHD) in order to accelerate growth rate and attain normal adult height. The diagnosis of GHD requires demonstration of decreased GH secretion in stimulation tests, below the established threshold value. Currently, GHD in children is classified as secondary insulin-like growth factor-1 (IGF-1) deficiency. Most children diagnosed with isolated GHD present with normal GH secretion at the attainment of near-final height or even in mid-puberty. The most important clinical problems, related to the diagnosis of isolated GHD in children and to optimal duration of rhGH therapy include: arbitrary definition of subnormal GH peak in stimulation tests, disregarding factors influencing GH secretion, insufficient diagnostic accuracy and poor reproducibility of GH stimulation tests, discrepancies between spontaneous and stimulated GH secretion, clinical entity of neurosecretory dysfunction, discrepancies between IGF-1 concentrations and results of GH stimulation tests, significance of IGF-1 deficiency for the diagnosis of GHD, and a need for validation IGF-1 reference ranges. Many of these issues have remained unresolved for 25 years or even longer. It seems that finding solutions to them should optimize diagnostics and therapy of children with short stature.

Factors influencing height gain in children born small for gestational age treated with recombinant growth hormone: what extent is puberty involved?

OBJECTIVE

The objective was to analyze the efficacy of recombinant human growth hormone (rhGH) treatment in children born small for gestational age (SGA) without catch-up growth treated before the onset of puberty, with follow-up until adult height. The influence of demographic and auxological factors on the final response evaluated as adult height and height gain was assessed.

PATIENTS AND METHODS

A prospective longitudinal observational study performed in a tertiary hospital, involving SGA patients, who started treatment with rhGH between October 2003 and April 2015. Potential response predictors were evaluated by multiple regression analysis and receiver operating characteristic curves.

RESULTS

Of the initial 96 patients included, 61 patients (28 boys and 33 girls) reached adult height. Adult height gain in standard deviation (SDS) was 0.99 (0.8) and 1.49 (0.94), respectively (p < 0.05). An adult height greater than -2 SDS was reached in 75% of the girls but only in 53% of the boys. The pubertal height gain was 22.6 (5.8) cm in boys and 18.8 (4.5) cm in girls. The multiple regression model obtained for total height gain explained 42% of the variability in this variable including sex, height gain during the first year, and the difference from target height at the start of treatment. A first-year height gain of 0.69 SDS was the optimal point for assessing a final height gain greater than 1.5 SDS with a specificity of 70% and a sensitivity of 71%.

CONCLUSION

Most SGA patients achieve normalization of height above -2 SD, the percentage being higher in girls. According to our predictive model, height gain in the first year is the most important variable for predicting good response to treatment. During puberty, there is a loss of height SDS, probably due to a lower total pubertal gain with respect to the reference population, which is more marked in boys.

Relationship of Serum Total Insulin-Like Growth Factor Binding Protein-3 with Insulin-Like Growth Factor-I and Glucose Tolerance in Korean Children and Adolescents

Insulin is important in glucose metabolism. However, insulin-like growth factor binding protein (IGFBP) also plays an important role in glucose homeostasis, although the IGF-independent role of IGFBP-3 in the glucose intolerance state is poorly understood. We investigated the relationship of serum IGF-I with total IGFBP-3 levels and glucose tolerance in Korean children and adolescents who underwent the oral glucose tolerance test (OGTT). A total of 187 children without known diabetes underwent OGTT, and data related to their clinical and laboratory parameters were collected. Serum IGF-I and total IGFBP-3 levels, fasting plasma glucose levels, lipid profiles, insulin levels, C-peptide levels, homeostasis model assessment of insulin resistance (HOMA-IR) index, and glycated hemoglobin (HbA1c) levels were measured. Serum IGF-I and total IGFBP-3 levels were significantly higher in individuals with impaired glucose tolerance and type 2 diabetes (DM) than in those with normal glucose tolerance (NGT) (P < 0.05). Serum IGF-I and IGFBP-3 levels were correlated with age, HbA1c, C-peptide, insulin, and HOMA-IR in the NGT group. However, these relationships were altered in patients with glucose intolerance, especially in those with DM. In the DM group, serum IGF-I and total IGFBP-3 levels were positively correlated with fasting plasma glucose and HbA1c levels. In addition, total IGFBP-3 levels were positively correlated with total cholesterol and low-density lipoprotein cholesterol and IGF-I levels but not with age or body mass index. The IGF-I-IGFBP-3 axis, especially IGFBP-3, may be involved in the pathogenesis and metabolic control of glucose intolerance, specifically in diabetes patients. Moreover, IGFBP-3 might be a therapeutic marker.