Serum insulin-like growth factor 1 in congenital heart disease

Preoperative nutritional status and serum insulin-like growth factor of children with cyanotic and acyanotic congenital heart disease

BACKGROUND

Malnutrition is common among children with congenital heart disease (CHD). We compared the anthropometric indices, serum insulin-like growth factor (IGF), and IGF acid-labile subunit (IGFALS) of children with cyanotic and acyanotic CHD before corrective surgery.

METHODS

This 82-patient case-control study included 1- to 24-month-old CHD patients referred for corrective surgery. (41 with tetralogy of Fallot [TOF] and 41 with ventricular septal defect [VSD] or atrial septal defect [ASD]). Anthropometric indices represented as Z-scores were used to determine nutritional status. Serum IGF-1 and IGFALS levels were measured.

RESULTS

The median [quartile] age of the acyanotic group was 8 [7,11] months which was lower than the cyanotic group (11 [8,14.5] months). The prevalence of underweight (weight for age Z [WAZ] < -2), wasting (weight for length Z [WLZ] < -2), and thinness (body mass index Z [BMIZ] < -2) was significantly higher in children with acyanotic than cyanotic children with. WAZ, WLZ, and BMIZ were significantly lower in acyanotic children than cyanotic children with CHD (-2.5 ± 1.2 vs -1.0 ± 1.2, p < 0.001 for WAZ, -2.5 ± 1.5 vs -0.8 ± 1.4, p < 0.001 for WLZ, and -2.5 ± 1.5 vs -0.8 ± 1.4, p < 0.001 for BMIZ), but length for age Z was not different between the two groups (-1.2 ± 1.0 vs -0.8 ± 1.1, p = 0.31). A comparison of preoperative serum albumin, IGF-1, and IGFALS showed no differences.

CONCLUSIONS

In CHD children without corrective surgery, moderate to severe underweight and wasting were more common in acyanotic CHD (VSD and ASD) than in cyanotic CHD (TOF), but the higher prevalence of malnutrition was not associated with lower IGF-1 and IGFALS levels.

Role of leptin and Insulin like growth Factor-1 In regulation of growth in children with congenital cyanotic heart disease

BACKGROUND

Congenital cyanotic heart disease (CHD) in children is associated with several complications, amongst these complications is growth retardation which is believed to be multifactorial.

OBJECTIVES

The objective of this study is to find out the role of leptin and Insulin-Like Growth Factor-1 (IGF-1) in the growth of paediatric patients with cyanotic CHD of different anatomical defects.

DESIGN/METHODS

This is a cross-sectional study involving thirty-nine children known to suffer from congenital cyanotic heart disease followed by the cardiology outpatient department, and forty-seven matched controls. Serum leptin and IGF-1 were evaluated in all the enrolled subjects besides anthropometric measurement and assessment of average oxygen saturation.

RESULTS

The patients' group showed statistically significant lower height, weight, Body mass index (BMI), leptin levels, and IGF-1. In addition, the patient group had a significant positive correlation between serum leptin and BMI, as well as a positive correlation of IGF-1 with average oxygen saturation.

CONCLUSION

Children suffering from congenital cyanotic heart disease have a higher probability of developing poor growth. Serum leptin and IGF-1 are lower in affected children with congenital cyanotic cardiac defects suggesting that they may play a role in their poor growth.

Changes in blood biomarkers correlate with changes in cardiac size and function in patients with tetralogy of Fallot

Introduction

Patients after surgical correction of Tetralogy of Fallot (ToF) often show adverse cardiac remodeling. To better understand the underlying biological processes, we studied the relation between changes in blood biomarkers and changes in biventricular size and function as assessed by cardiac magnetic resonance imaging (CMR).

Methods

This study included 50 ToF patients, who underwent blood biomarker and CMR analysis at least twice between 2002 and 2018.34 (68 %) of these patients were male. Patients had an average age of 16.1 at first visit. Biomarkers were chosen based on earlier research by our group and included: NT-proBNP, ST2, GDF-15, DLK-1, IGFBP-1/7, and FABP-4. Pearson correlations coefficients (rpearson) were determined to quantify the relationship between changes in biomarkers and CMR measurements.

Results

For changes in parameters of right ventricular (RV) size significant correlations were observed with changes in NT-proBNP, ST-2, GDF-15, IGFBP7 and FABP-4 (rpearson between 0.28 and 0.51). Correlations with NT-proBNP were driven by changes in RV size induced by pulmonary valve replacement (n = 9). For LV serial size changes, significant correlations were noted with changes in NT-pro-BNP, ST-2, GDF-15 and FABP-4 (rpearson between 0.32 and 0.52).

Conclusion

In clinically stable ToF patients changes in right and left ventricular size and function correlated with alterations in blood biomarkers of inflammation and immune response to stress.

Associations between blood biomarkers, cardiac function and adverse outcome in a young tetralogy of Fallot cohort

BACKGROUND

To determine the potential prognostic value and clinical correlations of blood biomarkers in a cohort of patients with Tetralogy of Fallot (TOF).

METHODS

In the setting of multicenter prospective research studies TOF patients underwent blood sampling, cardiopulmonary exercise testing and low-dose dobutamine stress cardiac magnetic resonance (CMR) imaging. In the blood sample NT-proBNP, GDF-15, Galectin-3, ST-2, DLK-1, FABP4, IGFBP-1, IGFBP-7, MMP-2, and vWF were assessed. During subsequent follow-up, patients were evaluated for reaching the study endpoint (cardiac death, arrhythmia-related hospitalization or cardioversion/ablation, VO₂ max ≤65% of predicted). Regression analysis was used to explore the correlation between blood biomarkers (corrected for age and gender) and other clinical parameters. The potential predictive value of blood biomarkers and events were assessed with Kaplan-Meier analysis and Cox proportional hazard analysis.

RESULTS

We included 137 Fallot patients, median age 19.2 (interquartile range: 14.6-25.7) years, median age at TOF-repair 0.9 (0.5-1.9) years. After a median follow-up of 8.7 (6.3-10.7) years, 20 (14.6%) patients reached the composite endpoint. In a multivariable cox-regression analysis corrected for age at study baseline, elevated IGFBP-7 and MMP-2 levels were associated with the composite endpoint. We also noted a correlation between DLK-1 and relative change in right ventricular end systolic volume during dobutamine stress CMR (β = -0.27, p = 0.010), a correlation between FABP4 and Max VO₂ (β = -0.41, p ≤0.001 and between MMP-2 and tricuspid valve E/A ratio (β = -0.15, p = 0.037).

CONCLUSIONS

IGFBP-7, MMP-2 and DLK-1 levels are related to cardiac function and long-term outcome in TOF patients.

The Role of GDF15 as a Myomitokine

Growth differentiation factor 15 (GDF15) is a cytokine best known for affecting systemic energy metabolism through its anorectic action. GDF15 expression and secretion from various organs and tissues is induced in different physiological and pathophysiological states, often linked to mitochondrial stress, leading to highly variable circulating GDF15 levels. In skeletal muscle and the heart, the basal expression of GDF15 is very low compared to other organs, but GDF15 expression and secretion can be induced in various stress conditions, such as intense exercise and acute myocardial infarction, respectively. GDF15 is thus considered as a myokine and cardiokine. GFRAL, the exclusive receptor for GDF15, is expressed in hindbrain neurons and activation of the GDF15–GFRAL pathway is linked to an increased sympathetic outflow and possibly an activation of the hypothalamic-pituitary-adrenal (HPA) stress axis. There is also evidence for peripheral, direct effects of GDF15 on adipose tissue lipolysis and possible autocrine cardiac effects. Metabolic and behavioral outcomes of GDF15 signaling can be beneficial or detrimental, likely depending on the magnitude and duration of the GDF15 signal. This is especially apparent for GDF15 production in muscle, which can be induced both by exercise and by muscle disease states such as sarcopenia and mitochondrial myopathy.

MiR-23b targets GATA6 to down-regulate IGF-1 and promote the development of congenital heart disease

BACKGROUND

Congenital heart disease (CHD) is the most universal congenital defect disease. This study explores the interrelationship between miR-23b and GTAT6 in the development of CHD.

METHODS

We collected clinical samples and constructed in vitro cell models to evaluate the expression of miR-23b, GATA6, and IGF-1. CHD cell models were constructed by hypoxia in H9C2 cells. The expression levels of GATA6 and IGF-1 in H9C2 cells were determined by western blot and qPCR. MiR-23b was knocked down by transfection miR-23b inhibitor. GATA6 knockdown or overexpression vectors were established by the lentiviral approach and cell transfection, respectively. According to the CCK-8 assay and flow cytometry analysis, the proliferation and apoptosis of H9C2 cells were detected. The binding relationship between GATA6 and miR-23b was detected by luciferase reporter assay.

RESULTS

The expression level of miR-23b was escalated abnormally, while the expression levels of GATA6 and IGF-1 were decreased in the serum of CHD clinical patients and cell models. miR-23b knockdown in H9C2 cells could up-regulate the expression of GATA6, thus improved the proliferation and decreased apoptosis of H9C2 cells. Overexpression of GATA6 could up-regulate IGF-1 to promote proliferation and inhibit apoptosis in H9C2 cells. MiR-23b could target GATA6 and regulated IGF-1, thus affecting cell proliferation and apoptosis.

CONCLUSION

The expression level of miR-23b was remarkably up-regulated in serum of CHD patients and H9C2 cells in vitro, while the expression of GATA6 and IGF-1 was significantly decreased. MiR-23b could influence the proliferation and apoptosis of cardiomyocytes by targeting the down-regulation of the GATA6/IGF-1 axis.

Associations Between Blood Biomarkers, Cardiac Function, and Adverse Outcome in a Young Fontan Cohort

Background Patients who have undergone the Fontan procedure are at high risk of circulatory failure. In an exploratory analysis we aimed to determine the prognostic value of blood biomarkers in a young cohort who have undergone the Fontan procedure. Methods and Results In multicenter prospective studies patients who have undergone the Fontan procedure underwent blood sampling, cardiopulmonary exercise testing, and stress cardiac magnetic resonance imaging. Several biomarkers including NT-proBNP (N-terminal pro-B-type natriuretic peptide), GDF-15 (growth differentiation factor 15), Gal-3 (galectin-3), ST2 (suppression of tumorigenicity 2), DLK-1 (protein delta homolog 1), FABP-4 (fatty acid-binding protein 4), IGFBP-1 (insulin-like growth factor-binding protein 1), IGFBP-7, MMP-2 (matrix metalloproteinase 2), and vWF (von Willebrand factor) were assessed in blood at 9.6 (7.1-12.1) years after Fontan completion. After this baseline study measurement, follow-up information was collected on the incidence of adverse cardiac events, including cardiac death, out of hospital cardiac arrest, heart transplantation (listing), cardiac reintervention (severe events), hospitalization, and cardioversion/ablation for arrhythmias was collected and the relation with blood biomarkers was assessed by Cox proportional hazard analyses. The correlation between biomarkers and other clinical parameters was evaluated. We included 133 patients who have undergone the Fontan procedure, median age 13.2 (25th, 75th percentile 10.4-15.9) years, median age at Fontan 3.2 (2.5-3.9) years. After a median follow-up of 6.2 (4.9-6.9) years, 36 (27.1%) patients experienced an event of whom 13 (9.8%) had a severe event. NT-proBNP was associated with (all) events during follow-up and remained predictive after correction for age, sex, and dominant ventricle (hazard ratio, 1.89; CI, 1.32-2.68). The severe event-free survival was better in patients with low levels of GDF-15 (P=0.005) and vWF (P=0.008) and high levels of DLK-1 (P=0.041). There was a positive correlation (β=0.33, P=0.003) between DLK-1 and stress cardiac magnetic resonance imaging functional reserve. Conclusions NT-proBNP, GDF-15, vWF, DLK-1, ST-2 FABP-4, and IGFBP-7 levels relate to long-term outcome in young patients who have undergone the Fontan procedure.

Selection of cuffed endotracheal tube for children with congenital heart disease based on an ultrasound-based linear regression formula

It remains to be discovered whether a formula predicting the subglottic transverse diameter measured by ultrasound (SGD_formula) for the selection of an appropriate endotracheal tube (ETT) for children without congenital heart disease (CHD) is useful for children with CHD. A formula for predicting SGD was established after assessing 60 children ≤ 8 years without CHD and validated on 60 children with CHD. We selected the cuffed ETT size based on the SGD by ultrasound (SGD_ultra). Subsequently, the fit of the ETT cuff in 60 children with CHD was examined via air-leak test. The maximum allowed difference between the SGD_formula and the ETT size that fit was 0.2 mm. The agreement among and accuracy of SGD_ultra, SGD_formula, and the ETT used in children was analyzed. For children without CHD, we adopted a linear formula, given by SGD_formula (mm) = 0.4 × age + 5.3. For children with CHD, allometric formula was adopted, given by SGD_formula (mm) = 5.4 × age^0.18. A stronger agreement exists between SGD_ultra and ETT size compared to that between SGD_formula and ETT size. And the mean bias (SGD_formula-ETT size and SGD_ultra-ETT size) was 0.21 mm (95% confidence interval, - 0.59 to 1.01 mm) and 0.00 mm (- 0.79 to 0.84 mm). For the CHD group, the ultrasound-based method yielded a 78% success rate of ETT size choice, while the formula-based method permitted an appropriate ETT size in only 32% of subjects (P < 0.001). Our analysis showed that measuring the SGD_ultra was more accurate in predicting the correct OD of the ETT in children with CHD undergoing cardiovascular surgery, based on the correlation and agreement with ETT OD.

GDF15 is a heart-derived hormone that regulates body growth

The endocrine system is crucial for maintaining whole-body homeostasis. Little is known regarding endocrine hormones secreted by the heart other than atrial/brain natriuretic peptides discovered over 30 years ago. Here, we identify growth differentiation factor 15 (GDF15) as a heart-derived hormone that regulates body growth. We show that pediatric heart disease induces GDF15 synthesis and secretion by cardiomyocytes. Circulating GDF15 in turn acts on the liver to inhibit growth hormone (GH) signaling and body growth. We demonstrate that blocking cardiomyocyte production of GDF15 normalizes circulating GDF15 level and restores liver GH signaling, establishing GDF15 as a bona fide heart-derived hormone that regulates pediatric body growth. Importantly, plasma GDF15 is further increased in children with concomitant heart disease and failure to thrive (FTT). Together these studies reveal a new endocrine mechanism by which the heart coordinates cardiac function and body growth. Our results also provide a potential mechanism for the well-established clinical observation that children with heart diseases often develop FTT.

Measuring growth hormone and insulin-like growth factor-I in infants: what is normal?

The role of growth hormone (GH) and insulinlike growth factor-I (IGF-I) change through early childhood. Whereas poor growth is a later presenting feature, infants with isolated GH deficiency have a normal birth weight and length, and often present with hypoglycemia. IGF-I plays an important role antenatally and post-natally in somatic and brain growth. In order to evaluate the GH/IGF-I axis in infancy, an understanding of the normal physiology is required. Measurements of GH and IGF-I in this population should be interpreted in the context of the assays used, as well as their limitations. In this review, we summarize our current understanding of normal GH and IGF-I secretion in children under 18 months of age, and describe variations in the reported assay-specific measurements.

Do pediatric patients undergoing cardiac surgeries require larger-size cuffed endotracheal tubes? A prospective study

BACKGROUND

There is a controversy over using either smaller- or larger-size endotracheal tubes (ETT) in children undergoing cardiac surgery, and some anesthesiologists prefer to use ETT sizes different from the formula-based sizes. The aim of the present study was to compare proper-size cuffed ETT in children undergoing cardiac vs noncardiac surgeries.

METHODS

In an observational prospective study, 80 children planned to undergo noncardiac elective surgeries (NCS group) and 80 children scheduled for cardiac surgeries (CS group) were recruited. For intubation, initial cuffed ETT size was calculated based on the following formula: Tube size (mm ID) = age (year)/4 + 3.5. The estimated ETT size for each age group and the size of final utilized tubes for each age range were recorded.

RESULTS

Patients of tube sizes 4.5, 5, and 5.5 in the CS group were of lower age, weight, height, and body surface area compared with the patients of the same tube sizes in the NCS group (P < 0.05). The compatibility of the predicted vs actual required tube sizes was more in the NCS group compared to the CS group (72.5% vs. 56.2%; P = 0.02). Additionally, the cases with underestimated tube sizes were significantly more in the CS group compared with the NCS group (38.8% vs. 18.8%, P = 0.01).

CONCLUSION

Children undergoing cardiac surgeries in relation to their age and body size do require larger-size ETTs compared with the children scheduled for noncardiac surgeries.

IGF-II and MMP9 as surgical repair indicators of ventricular septal defects

OBJECTIVE

The insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein-3 (IGFBP-3) and human growth hormone (h-GH) have been recognized as therapeutic targets for the heart disease therapy. The bioavailability and actions of insulin-like growth factors-II (IGF-II) and matrix metalloproteinase-9 (MMP9) are important for embryonic development and cardiomyocyte differentiation as well. However, the clinical manifestations following the change in the serum IGF-II and MMP9 in infants with isolated ventricular septal defect (VSD) undergoing surgical repair have not been clearly defined.

STUDY DESIGN

Serum samples were collected from 72 infants: Twenty normal infants (group I) and 51 consecutive infants with echocardiography established isolated VSD (aged from 3 months to 1 year) were investigated. Among the 51 infants with VSD, 28 with shunt fraction, Qp/Qs < or = 1.5 were free of congestive heart failure symptoms (group II); 23 with shunt fraction, Qp/Qs > or = 2.0 were in congestive heart failure (group IIIa); and 23 of these 23 infants had undergone VSD repair 6 months before their second study (group IIIb). All insulin-like growth factors-II (IGF-II) and human growth hormone (h-GH), insulin like growth factor binding protein-3 (IGFBP-3) and its specific serum protease-MMP9 concentration were analyzed using ELISA and zymography, respectively.

RESULTS

Serum IGF-II and MMP9 exhibited significant decreasing trends among the three groups and significantly lower concentrations of IGF-II, IGF-II/IGFBP-3 ratio and MMP9, were found only in the severe group whereas h-GH/IGF-II ratio became significantly higher in this group. Moreover, there were no significant differences in these parameters between the infants after surgical correction and the normal ones.

CONCLUSIONS

The improvement in IGF-II and MMP9 serum concentration was identified in infants with VSD after surgical repair. These findings also indicate a significant relationship between IGF-II, MMP9 and VSD which might be used as diagnosis and prognosis indicators for this defect. Slight reductions in IGF-II/IGFBP3 ratio and slight increase in the h-GH/IGF-II ratio indicate mild VSD. The reductions in the MMP9, IGF-II, and IGF-II/IGFBP3 ratio plus high increase in the h-GH/IGF-II ratio indicate severe VSD.

The effect of corrective surgery on serum IGF-1, IGFBP-3 levels and growth in children with congenital heart disease

The aim of this study is to evaluate growth and insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) levels in infants with congenital heart disease (CHD) pre- and postoperatively over a period of a year. Anthropometric values and serum levels of IGF-1 and IGFBP-3 of 40 infants with CHD (20 cyanotic and 20 acyanotic) were compared with 32 healthy controls. Acyanotic infants and infants with pulmonary hypertension (PH) presented significantly more growth failure. Preoperatively, serum IGF-1 and IGFBP-3 levels were lower in the acyanotic group than the cyanotic and the control groups (p = 0.22; p < 0.01). The upward trend in IGF-1 and IGFBP-3 levels in this year-long study demonstrated that the values in the third month and the first year were higher than the preoperative values (p < 0.05). The parallel increase of weight gain and IGF-1, IGFBP-3 levels were the best evidence that these parameters are good nutritional indicators. Timing the corrective surgery before chronic malnutrition or PH develops is an important issue to maintain a normal growth for children with CHD.

Efficiency of transcatheter closure of atrial septal defects in small and symptomatic children

OBJECTIVES

We report the multicentric French experience with transcatheter closure in children weighing 15 kilograms or less, with the aim of assessing the efficacy of the procedure in this age group.

PATIENTS

We included all children weighing 15 kilograms or less, and seen between January, 1997, and June, 2004, who had successful transcatheter closure of an interatrial communication within the oval fossa.

RESULTS

Transcatheter closure was performed in 35 patients weighing 15 kilograms or less, of whom 14 were male and 21 female. The procedures were undertaken in 8 different centres, the patients having a median age of 3 years, with a range from zero to 6.2 years, and a mean weight of 13 kilograms, with a range from 3.6 to 15 kilograms. All the patients were symptomatic, with associated cardiac malformations present in 4 cases, and extracardiac anomalies in 4 patients, including Down's syndrome in 3, and Adams Oliver syndrome in the other case. In 1 patient, emergency cardiac surgery was needed 24 h after the procedure to correct a previously undiagnosed divided right atrium. No other complication occurred. After a median follow-up of 2 years, with a range from 0.5 to 5.2 years, all the patients are asymptomatic, except for one long-standing patient with bronchodysplasia. In 1 other patient, a small residual bidirectional shunt was detected by echocardiography. No patient presented significant arrhythmia. In the patients followed-up for more than 12 months, we found a significant gain in weight gain.

CONCLUSION

Transcatheter closure of an interatrial communication within the oval fossa is efficient in children weighing 15 kilograms or less, and can be proposed as a first line of treatment in symptomatic patients. Children with retarded growth tend to have complete recovery within one year of closure.

Maternal nutrient restriction during early to mid gestation up-regulates cardiac insulin-like growth factor (IGF) receptors associated with enlarged ventricular size in fetal sheep

Intrauterine undernutrition is associated with a high incidence of cardiovascular diseases in adulthood. We previously showed that maternal nutrient restriction during early to mid gestation produces ventricular enlargement, although the mechanism is unknown. We examined myocardial expression of insulin-like growth factor I (IGF-1), IGF-2, IGF binding protein 3 (IGFBP-3), IGF-receptor 1 (IGF-1R) and IGF-2R in fetal sheep with maternal undernutrition. Multiparous ewes were fed with 50% (nutrient-restricted, NR) or 100% (control-fed, C) of NRC requirements from day 28 to 78 of gestation. Some of NR and C ewes were euthanized on day 78, and the rest were fed 100% NRC requirements from day 79 to 135 of gestation. At necropsy on day 78 or day 135 of gestation, gravid uteri were recovered. mRNA expression of IGF-1 and IGF-2 in ventricles were measured with RT-PCR, and protein expression of IGF-1R, IGF-2R, IGFBP-3 was quantitated with Western blot. Crown-rump length was reduced and left ventricle was enlarged in NR fetuses on day 78. At day 135 after re-alimentation, ventricular weights were similar between the two groups although ventricular wall thicknesses were greater in NR than C fetuses. No difference was found in IGF-1, IGF-2 or IGFBP-3 levels between the NR and C groups at either gestational age. Protein expression of IGF-1R and IGF-2R in the left ventricle and IGF-1R in the right ventricle was significantly elevated in the NR group on day 78 of gestation. Only IGF-1R expression remained elevated after late gestational re-alimentation in association with increases in ventricular wall thickness. Our study suggest that maternal undernutrition from early to mid gestation may change the expression of IGF-1R and IGF-2R in fetal myocardium, and play a role in cardiac ventricular enlargement in fetal sheep.

Change of serum growth factors in infants with isolated ventricular defect undergoing surgical repair

BACKGROUND

Despite increasing clinical use and recent evidence that insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), and human growth hormone (hGH) target the heart, the clinical manifestations following the change in the serum growth factors in infants with isolated ventricular septal defect (VSD) undergoing surgical repair have not been clearly defined.

METHODS

Twenty normal infants (group I) and 44 consecutive infants with echocardiography established isolated VSD (aged from 3 months to 1 year; body weight from 6.0 +/- 1.8 kg to 8.2 +/- 1.6 kg) were investigated. Among 44 infants with VSD, 20 with shunt fraction, Qp/Qs < or = 1.5 were free of symptoms of congestive heart failure (group II); 24 with shunt fraction, Qp/Qs > or = 2.0 were in congestive heart failure (group IIIa); and 20 of these 24 infants had undergone VSD repair 6 months before their second study (group IIIb). Serum IGF-1, IGFBP-3, and hGH factors were determined by enzyme-linked immunosorbent assay using a monoclonal antibody.

RESULTS

The serum levels of IGF-1, IGFBP-3, and hGH factors were 111.9 +/- 2.3 ng/mL, 22.0 +/- 2.3 ng/mL, and 3.6 +/- 0.7 microIU/mL for group I; 63.8 +/- 8.2 ng/mL, 17.1 +/- 1.6 ng/mL, and 4.1 +/- 1.2 microIU/mL for group II; 24.0 +/- 2.6 ng/mL, 9.4 +/- 0.7 ng/mL, and 14.7 +/- 3.5 microIU/mL for group IIIa; 79.4 +/- 12 ng/mL, 20.3 +/- 1.3 ng/mL, and 4.3 +/- 0.7 microIU/mL for group IIIb. In comparison to group I, the decrease in serum levels of IGF-1 and IGFBP-3 in groups II and IIIa were statistically significant (in group II 43% and 32%, p < 0.05; in group IIIa 79% and 37%, p < 0.01). Also the increase in serum level of hGH concentration in group IIIa was significant (increased threefold, p < 0.01). Interestingly, the change in serum levels of IGF-1, IGFBP-3 (decrease), and hGH (increase), returned to the normal range of serum levels after VSD repair in group IIIb. All congestive heart failure symptoms subsided in group IIIb during follow-up.

CONCLUSIONS

Improvement in serum levels of IGF-1, IGFBP-3, and hGH were identified in infants with VSD after surgical repair.

Improvement in growth, and levels of insulin-like growth factor-I in the serum, after cavopulmonary connections

INTRODUCTION

The total cavopulmonary connection, and the bidirectional Glenn anastomosis, are widely used for palliation of patients with complex functionally univentricular hearts. Little attention has been paid to the potential for postoperative growth in children after these operations, which are now performed at increasingly younger age.

MATERIAL AND RESULTS

Physical growth, and levels of insulin-like growth factor I in the serum, were measured in 20 patients, aged 11.5 +/- 5.6 years, 2 (0.5-6) years after a total cavopulmonary connection in 12, or a Glenn anastomosis in 8. All patients were in functional class I or II of the categorisation of the New York Heart Association, with excellent haemodynamic and angiographic findings. None of the patients had clinical signs of protein losing enteropathy. Controls included 33 healthy children, aged 11.5 +/- 2.7 years. Preoperatively, the mean Z-scores for weight and height were negative, -1.1 +/- 0.8 and -0.5 +/- 1.5. At follow-up, both parameters had improved significantly by 1.1 +/- 0.9 and 0.8 +/- 1.2 percentiles, and Z-scores were comparable between the two groups (p=0.81 for weight and p=0.88 for height). No correlations were found between haemodynamics and the improvement in growth noted during follow-up. Increases equal to, or greater than 2 standard deviations for weight and height were seen only in children undergoing surgery before the age of 5 years. A significant correlation between age at operation and improvement in growth, however, could not be found. Levels of growth factor measured in the serum were not statistically different from levels in healthy children for either group of patients (p=0.07 for girls and p=0.37 for boys).

CONCLUSION

Physical growth improved significantly following the surgical procedures. The concentrations of the growth factor measured in the serum were not different from levels in healthy children, suggesting normal nutritional status in both palliative situations.

Chronic hypoxemia leads to reduced serum IGF-I levels in cyanotic congenital heart disease

Cyanotic congenital heart disease in children commonly causes more pronounced growth retardation in comparison with acyanotic congenital heart disease. Chronic hypoxemia has been suggested as the cause of poor growth in these patients, but the relationship between serum IGF-I levels and chronic hypoxemia is unclear. Serum IGF-I concentrations, oxygen saturation and nutritional status were evaluated in 29 patients with cyanotic congenital heart disease, and serum IGF-I levels were compared with a group of 20 well-nourished, age-matched control children to assess the relationship between IGF-I levels and chronic hypoxemia. The nutritional status of each patient was determined by using anthropometric parameters and calorie and protein intake ratios. The patients were divided into malnourished and well-nourished groups (21 and 8 patients, respectively) according to their nutritional status. Serum IGF-I concentrations were measured in the two patient groups and the controls. The malnourished group had the lowest IGF-I levels (48.14 +/- 21.8 ng/ml, p<0.05). However, the well-nourished group's IGF-I levels were significantly lower than the control subjects' despite improved nutritional status (85.5 +/- 30.2 and 107 +/- 19.7 ng/ml, respectively, p<0.05). In addition, we found a positive correlation between serum IGF-I levels and oxygen saturation of the patients (r=0.402, p<0.05). These findings indicate that chronic hypoxemia has a direct or indirect effect to reduce serum IGF-I concentrations and this may be a cause of the increased growth failure in patients with cyanotic congenital heart disease.

IGF-I in experimental daunorubicin-induced cardiomyopathy in rabbits

1. The occurrence of IGF-I was investigated in rabbits with experimentally daunorubicin-induced cardiomyopathy. IGF-I was measured in the heart, serum, liver and skeletal muscle. 2. A significant increase in the IGF-I was found in the left heart ventricle in daunorubicin cardiomyopathy (152.9 +/- 10.0 ng/g vs 95.1 +/- 4.2 ng/g in the control group). This site of increased IGF-I activity corresponded well with the maximum of morphological changes (dispersed cytolysis of cardiomyocytes mostly without developed subsequent interstitial myofibrosis). 3. The highest levels of IGF-I were present in right and left cardiac atrium (but without significant differences between the groups). Furthermore, in skeletal muscle, the levels of IGF-I in the daunorubicin group (839.0 +/- 142.1 ng/g) were significantly higher in comparison with the control group (482.5 +/- 83.1 ng/g). 4. The level of IGF-I in the left ventricle in the daunorubicin group (but not in the control group) was significantly higher than that in the liver. There were no correlations observed between the levels of IGF-I in the heart and in the serum. 5. The increase in IGF-I concentrations in the left heart ventricle after the administration of daunorubicin may thus reflect possible autocrine/paracrine role of IGF-I in cardiomyopathy.