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

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.

Prevalence and predictive factors of malnutrition in Thai children with congenital heart disease and short-term postoperative growth outcomes

Background: Growth restriction is still a common problem in children with congenital heart disease (CHD). Evidence demonstrates that performing cardiac surgery in appropriate timing may result in better growth outcome. Aim: To investigate prevalence and associated factors of malnutrition in pediatric patients with CHD who underwent cardiac surgery. In addition, post-operative growth outcomes at two weeks following cardiac surgery were also assessed. Methods: A retrospective cohort study was conducted in pediatric patients who underwent cardiac surgery at Chiang Mai University Hospital between January and September 2014. Results: One hundred patients with a median age of 28.5 months (range 14-62 months) were enrolled. Two-third of these patients had at least one form of malnutrition before receiving surgical treatment while wasting, stunting and combined wasting-stunting accounted for 23%, 28%, and 15% of patients, respectively. Multiple logistic regression analysis demonstrated that congestive heart failure-related symptoms were significantly associated with increasing risk of malnutrition (adjusted OR 4.4; 95% CI 1.78-11.26, p = 0.001). Two weeks after hospital discharge, wasting patients with regardless of stunting had significantly improved weight for height (WHZ) and weight for length Z-scores (WLZ) compared to growth parameters at the time of cardiac surgery, p = 0.012 and p < 0.001, respectively. Conclusion: The prevalence of acute and chronic malnutrition in pediatric patients with CHD who underwent cardiac surgery was very high in this study. Children with congestive heart failure had a four-time at risk of undernutrition. In short-term, cardiac surgery may mitigate acute malnutrition of these patients.

Nutritional Management of Patients with Fontan Circulation: A Potential for Improved Outcomes from Birth to Adulthood

Fontan circulation (FC) is a surgically achieved palliation state offered to patients affected by a wide variety of congenital heart defects (CHDs) that are grouped under the name of univentricular heart. The procedure includes three different surgical stages. Malnutrition is a matter of concern in any phase of life for these children, often leading to longer hospital stays, higher mortality rates, and a higher risk of adverse neurodevelopmental and growth outcomes. Notwithstanding the relevance of proper nutrition for this subset of patients, specific guidelines on the matter are lacking. In this review, we aim to analyze the role of an adequate form of nutritional support in patients with FC throughout the different stages of their lives, in order to provide a practical approach to appropriate nutritional management. Firstly, the burden of faltering growth in patients with univentricular heart is analyzed, focusing on the pathogenesis of malnutrition, its detection and evaluation. Secondly, we summarize the nutritional issues of each life phase of a Fontan patient from birth to adulthood. Finally, we highlight the challenges of nutritional management in patients with failing Fontan.

miRNA-486-5p: signaling targets and role in non-malignant disease

MicroRNAs (miRNAs) are short non-coding RNAs, highly conserved between species, that are powerful regulators of gene expression. Aberrant expression of miRNAs alters biological processes and pathways linked to human disease. miR-486-5p is a muscle-enriched miRNA localized to the cytoplasm and nucleus, and is highly abundant in human plasma and enriched in small extracellular vesicles. Studies of malignant and non-malignant diseases, including kidney diseases, have found correlations with circulating miR-486-5p levels, supporting its role as a potential biomarker. Pre-clinical studies of non-malignant diseases have identified miR-486-5p targets that regulate major signaling pathways involved in cellular proliferation, migration, angiogenesis, and apoptosis. Validated miR-486-5p targets include phosphatase and tensin homolog (PTEN) and FoXO1, whose suppression activates phosphatidyl inositol-3-kinase (PI3K)/Akt signaling. Targeting of Smad1/2/4 and IGF-1 by miR-486-5p inhibits transforming growth factor (TGF)-β and insulin-like growth factor-1 (IGF-1) signaling, respectively. Other miR-486-5p targets include matrix metalloproteinase-19 (MMP-19), Sp5, histone acetyltransferase 1 (HAT1), and nuclear factor of activated T cells-5 (NFAT5). In this review, we examine the biogenesis, regulation, validated gene targets and biological effects of miR-486-5p in non-malignant diseases.

Pubertal status of children with congenital heart disease

BACKGROUND

CHD influences many aspects of life in affected individuals. Puberty, a major aspect of development, is a concern for patients and families.

OBJECTIVES

We investigated pubertal status in children and adolescents with CHD.

METHODS

Patients with CHD aged 6-18 were enrolled. Cardiac diagnoses were confirmed using history, examination, and paraclinical tools including echocardiography. An endocrinologist determined pubertal stages, and the second Tanner stages for pubarche (P2), thelarche (B2), and gonadarche (G2) were considered as the pubertal onset. A study with a large sample size on pubertal onset in a normal population was used for comparison.

RESULTS

Totally, 451 patients (228 girls and 223 boys) at a median (10th-90th percentile) age of 10.79 (8.02-14.28) years for the girls and 10.72 (8.05-14.03) years for the boys were enrolled. The median (10th-90th percentile) ages at B2 and P2 in the girls with CHD were 10.77 (9.55-12.68) and 10.53 (9.39-12.28) years, respectively, which were higher than the median ages of 9.74 (8.23-11.94) and 10.49 (8.86-12.17) years in the normal girls.The median (10th-90th percentile) ages at G2 and P2 in the boys with CHD were 11.04 (8.85-13.23) and 11.88 (9.78-13.46) years, correspondingly, which were higher than the median ages of 9.01 (6.00-11.84) and 10.34 (6.84-13.10) years in the normal boys.

CONCLUSIONS

Pubertal onset could be delayed in children with CHD when compared with the normal population.

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.

Metabolic zonation of the liver: The oxygen gradient revisited

The liver has a multitude of functions which are necessary to maintain whole body homeostasis. This requires that various metabolic pathways can run in parallel in the most efficient manner and that futile cycles are kept to a minimum. To a large extent this is achieved due to a functional specialization of the liver parenchyma known as metabolic zonation which is often lost in liver diseases. Although this phenomenon is known for about 40 years, the underlying regulatory pathways are not yet fully elucidated. The physiologically occurring oxygen gradient was considered to be crucial for the appearance of zonation; however, a number of reports during the last decade indicating that β-catenin signaling, and the hedgehog (Hh) pathway contribute to metabolic zonation may have shifted this view. In the current review we connect these new observations with the concept that the oxygen gradient within the liver acinus is a regulator of zonation. This is underlined by a number of facts showing that the β-catenin and the Hh pathway can be modulated by the hypoxia signaling system and the hypoxia-inducible transcription factors (HIFs). Altogether, we provide a view by which the dynamic interplay between all these pathways can drive liver zonation and thus contribute to its physiological function.

Impact of hypoxia on IGF-I, IGF-II, IGFBP-3, ALS and IGFBP-1 regulation and on IGF1R gene expression in children

Hypoxia is one of many factors involved in the regulation of the IGF system. However, no information is available regarding the regulation of the IGF system by acute hypoxia in humans.

OBJECTIVE

The aim of this study was to evaluate the effect of acute hypoxia on the IGF system of children.

DESIGN

Twenty-seven previously health children (14 boys and 13 girls) aged 15 days to 9.5 years were studied in two different situations: during a hypoxemic state (HS) due to acute respiratory distress and after full recovery to a normoxemic state (NS). In these two situations oxygen saturation was assessed with a pulse-oximeter and blood samples were collected for serum IGF-I, IGF-II, IGFBP-1, IGFBP-3, ALS and insulin determination by ELISA; fluoroimmunometric assay determination for GH and also for IGF1R gene expression analysis in peripheral lymphocytes by quantitative real-time PCR. Data were paired and analyzed by the Wilcoxon non-parametric test.

RESULTS

Oxygen saturation was significantly lower during HS than in NS (P<0.0001). IGF-I and IGF-II levels were lower during HS than in NS (P<0.0001 and P=0.0004, respectively). IGFBP-3 levels were also lower in HS than in NS (P=0.0002) while ALS and basal GH levels were higher during HS (P=0.0015 and P=0.014, respectively). Moreover, IGFBP-1 levels were higher during HS than in NS (P=0.004). No difference was found regarding insulin levels. The expression of IGF1R mRNA as 2(-ΔΔCT) was higher during HS than in NS (P=0.03).

CONCLUSION

The above results confirm a role of hypoxia in the regulation of the IGF system also in humans. This effect could be direct on the liver and/or mediated by GH and it is not restricted to the hepatocytes but involves other cell lines. During acute hypoxia a combination of alterations usually associated with reduced IGF action was observed. The higher expression of IGF1R mRNA may reflect an up-regulation of the transcriptional process.

Catch-up growth in children after repair of Tetralogy of Fallot

PURPOSE

To evaluate the growth of children after repair of Tetralogy of Fallot, as well as the influence of residual lesions and socio-economic status.

METHODS

A total of 17 children, including 10 boys with a median age of 16 months at surgery, were enrolled in a retrospective cohort, in a tertiary care university hospital. Anthropometric (as z-scores), clinical, nutritional, and social data were collected.

RESULTS

Weight-for-age and weight-for-height z-scores decreased pre-operatively and recovered post-operatively in almost all patients, most markedly weight for age. Weight-for-height z-scores improved, but were still lower than birth values in the long term. Long-term height-for-age z-scores were higher than those at birth, surgery, and 3 months post-operatively. Most patients showed catch-up growth for height for age (70%), weight for age (82%), and weight for height (70%). Post-operative residual lesions (76%) influenced weight-for-age z-scores. Despite the fact that most patients (70%) were from low-income families, energy intake was above the estimated requirement for age and gender in all but one patient. There was no influence of socio-economic status on pre- and post-operative growth. Bone age was delayed and long-term-predicted height was within mid-parental height limits in 16 children (93%).

CONCLUSION

Children submitted to Tetralogy of Fallot repair had pre-operative acute growth restriction and showed post-operative catch-up growth for weight and height. Acute growth restriction could still be present in the long term.

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.

Ghrelin levels in children with congenital heart disease

BACKGROUND

Ghrelin is a novel growth hormone-releasing peptide that causes a positive energy balance by stimulating food intake and inducing adiposity and has effects on growth. Many children with congenital heart disease (CHD) present with growth retardation and malnutrition owing to multifactorial reasons.

AIM

To evaluate the circulating level of ghrelin in Egyptian children with congenital cyanotic and acyanotic heart disease and its relation to anthropometric measurements.

MATERIALS AND METHODS

The study included 40 patients with cyanotic and acyanotic CHD (18 cyanotic and 22 acyanotic) and 18 age- and sex-matched healthy control children. All children were subjected to measurement of height, weight, body mass index (BMI) and serum ghrelin was measured using ELISA technique.

RESULTS

Weight, height and BMI were significantly lower in cyanotic and acyanotic patients compared to the control group (p = 0.0001). Serum ghrelin levels were significantly higher in children with cyanotic and acyanotic CHD in comparison to the controls (p = 0.0001). There was a significant negative correlation between ghrelin and BMI in the three groups (r = -0.534, p = 0.023; r = -0.558, p = 0.007; r = -0.608, p = 0.007 respectively for cyanotic, acyanotic and the control groups).

CONCLUSION

Circulating ghrelin level was elevated in children with congenital cyanotic and acyanotic heart disease, and was associated with a decrease in BMI. This elevation in ghrelin level may represent malnutrition and growth retardation in those patients as obvious by anthropometric measures too. This may suggest that ghrelin may have an important role as a compensatory mechanism in the regulation of the metabolic balance in them.

Effect of supplemental oxygen on sleep architecture and cardiorespiratory events in preterm infants

OBJECTIVE

To investigate the effect of low-flow supplemental oxygen (SupOx) on sleep architecture and cardiorespiratory events in asymptomatic preterm infants.

METHODS

An overnight polysomnographic evaluation was conducted prospectively in 23 premature infants who were born at 30.0 +/- 3.2 (standard deviation) weeks' gestational age and studied at 38.1 +/- 4.4 weeks' postconceptional age. Infants were free of any adverse events, including cardiorespiratory monitor alarms in the nursery for at least 1 week before the study. Infants received room air (RA) or SupOx via nasal cannula at 0.25 L/min.

RESULTS

Quiet sleep density was increased during SupOx (33.3 +/- 10.8% vs 26.6 +/- 10.0% total sleep time [TST] in RA), and a reciprocal decrease in active sleep density was observed (61.5 +/- 11.1% vs 68.4 +/- 9.9% TST in RA). No differences in sleep efficiency emerged (69.7 +/- 10.6% SupOx vs 69.7 +/- 8.8% RA). SupOx elicited significant decreases in apnea index (3.8 +/- 2.4 events/h vs 11.1 +/- 6.4 events/h in RA) and in the percentage of time spent in periodic breathing (1.8 +/- 2.9% vs 6.7 +/- 8.9% in RA). In addition, SupOx decreased the frequency of bradycardic events (0.3 +/- 0.8 events vs 2.5 +/- 0.03 events in RA) and improved overall oxygen saturation (98.7 +/- 1.1% vs 96.4 +/- 2.2%). No changes in alveolar ventilation, as derived from end-tidal CO2 measurements, was detected (38.6 +/- 5.8 mm Hg in SupOx vs 38.4 +/- 5.4 mm Hg in RA).

CONCLUSIONS

Asymptomatic preterm infants exhibit frequent and potentially clinically adverse cardiorespiratory events when assessed in the sleep laboratory. Administration of SupOx to these infants is associated with an increase in the overall duration and percentage TST spent in quiet sleep with reciprocal changes in active sleep. In addition, improvement in respiratory stability is observed with the use of low-flow SupOx, as evidenced by a decrease in apnea, periodic breathing, and bradycardia, without adverse effects on alveolar ventilation.

Effects of insulin-like growth factor on weight gain in chronic hypoxic rats

Chronic hypoxemia has been suggested as the cause of weight loss in malnourished patients with chronic obstructive pulmonary disease. Insulin-like growth factor I (IGF-I) is believed to improve nitrogen balance and have anabolic effects, and it has been proposed as one of the mediators of vascular smooth muscle proliferation. The aim of this study was to assess the effects of IGF-I administration on the nutritional status and pulmonary vasculature in normoxic and chronic hypoxic rats. Twenty rats were randomly assigned to the normoxic (n = 10) and chronic hypoxic groups (n = 10). They received daily subcutaneous injections of either 3.2 mg/kg of recombinant human IGF-I (rhIGF-I) or isotonic saline (control group) for 3 weeks. Body weight was greater in IGF-I-treated rats compared with vehicle-treated rats, especially during the early and late stages of chronic hypoxic exposure, whereas similar weight gain was observed between IGF-I- and vehicle-treated normoxic rats. In addition, IGF-I treatment increased serum total protein and albumin at the end of hypoxic exposure. However, IGF-I had no additive effects on the degree of pulmonary hypertension. These results indicated that IGF-I promoted anabolism under chronic exposure to hypoxia, whereas no adverse effect was observed in the development of pulmonary hypertension.