Glucose homeostasis in the newborn

Macropod Pediatrics

Macropods belong to the marsupial family Macropodidae, which includes animals such as kangaroos and wallabies. Macropod offspring are highly altricial at birth and require specialized care and environmental conditions for healthy development. The care and management of pediatric macropods poses a challenge due to the unique physiology and reproductive strategy of macropods. In order to successfully work with pediatric macropods, clinical veterinarians should have knowledge of species-specific husbandry, normal postnatal development, and common medical conditions/treatments. With limited information available on macropod pediatric medicine, further research is warranted to improve the care and management of these animals in human care.

Proteomics identifies the developmental regulation of HKDC1 in liver of pigs and mice

During the perinatal period, unique metabolic adaptations support energetic requirements for rapid growth. To gain insight into perinatal adaptations, quantitative proteomics was performed comparing the livers of Yorkshire pigs at postnatal day 7 and adult. These data revealed differences in the metabolic control of liver function including significant changes in lipid and carbohydrate metabolic pathways. Newborn livers showed an enrichment of proteins in lipid catabolism and gluconeogenesis concomitant with elevated liver carnitine and acylcarnitines levels. Sugar kinases were some of the most dramatically differentially enriched proteins compared with neonatal and adult pigs including galactokinase 1 (Galk1), ketohexokinase (KHK), hexokinase 1 (HK1), and hexokinase 4 (GCK). Interestingly, hexokinase domain containing 1 (HKDC1), a newly identified fifth hexokinase associated with glucose disturbances in pregnant women, was highly enriched in the liver during the prenatal and perinatal periods and continuously declined throughout postnatal development in pigs and mice. These changes were confirmed via Western blot and mRNA expression. These data provide new insights into the developmental and metabolic adaptations in the liver during the transition from the perinatal period to adulthood in multiple mammalian species.

Different glucose analyzers report different glucose concentration values in term newborns

BACKGROUND

The American Academy of Pediatrics and Pediatric Endocrine Society neonatal hypoglycemia guidelines based their glucose concentration treatment thresholds on studies that predominantly used Beckman and Yellow Springs Glucose Oxidase Analyzers. Currently, a majority (76%) of U.S. hospital laboratories utilizing glucose oxidase methodology use Vitros^® Glucose Analyzers. However, a bias of ~+5% between glucose concentrations from Beckman vs. Vitros Glucose Analyzers has been reported; this could have a clinically significant effect when using published guideline treatment thresholds.

METHODS

To determine if there is similar instrument bias between Beckman and Vitros Analyzers in reported glucose concentrations from term newborns, we compared plasma glucose concentrations measured within the first 3 h after birth by Beckman vs. Vitros Analyzers in a total of 1,987 newborns (Beckman n = 904, Vitros n = 1,083). Data were fit using nonlinear cubic spline models between collection time and glucose concentration.

RESULTS

The non-linear patterns of initial glucose concentrations (during the first 3 h after birth) as measured by Beckman and Vitros Analyzers paralleled each other with no overlap of the fit spline curve 95% confidence intervals, with an approximate +5 mg/dL constant bias. Additionally, in method comparison studies performed in the Chemistry Laboratory on adult samples, there was a +4.2-7.4 mg/dL measured glucose bias for the Beckman vs. Vitros Analyzer.

CONCLUSION

Glucose concentrations from term, appropriate size for gestational age newborns were about 5 mg/dL higher when measured by Beckman vs. Vitros Analyzers. Perhaps, concentrations of 45 mg/dL reported from Beckman Analyzers may be equivalent to 40 mg/dL from Vitros Analyzers. When managing neonatal hypoglycemia, it is important to know which analyzer was used and whether adjusting for potential instrument bias is necessary when following published guidelines.

Embryonic Steroids Control Developmental Programming of Energy Balance

Glucose is a major energy source for growth. At birth, neonates must change their energy source from maternal supply to its own glucose production. The mechanism of this transition has not been clearly elucidated. To evaluate the possible roles of steroids in this transition, here we examine the defects associated with energy production of a mouse line that cannot synthesize steroids de novo due to the disruption of its Cyp11a1 (cytochrome P450 family 11 subfamily A member 1) gene. The Cyp11a1 null embryos had insufficient blood insulin and failed to store glycogen in the liver since embryonic day 16.5. Their blood glucose dropped soon after maternal deprivation, and the expression of hepatic gluconeogenic and glycogenic genes were reduced. Insulin was synthesized in the mutant fetal pancreas but failed to be secreted. Maternal glucocorticoid supply rescued the amounts of blood glucose, insulin, and liver glycogen in the fetus but did not restore expression of genes for glycogen synthesis, indicating the requirement of de novo glucocorticoid synthesis for glycogen storage. Thus, our investigation of Cyp11a1 null embryos reveals that the energy homeostasis is established before birth, and fetal steroids are required for the regulation of glycogen synthesis, hepatic gluconeogenesis, and insulin secretion at the fetal stage.

The adipokine FABP4 is a key regulator of neonatal glucose homeostasis

During pregnancy, fetal glucose production is suppressed, with rapid activation immediately postpartum. Fatty acid–binding protein 4 (FABP4) was recently demonstrated as a regulator of hepatic glucose production and systemic metabolism in animal models. Here, we studied the role of FABP4 in regulating neonatal glucose hemostasis. Serum samples were collected from pregnant women with normoglycemia or gestational diabetes at term, from the umbilical circulation, and from the newborns within 6 hours of life. The level of FABP4 was higher in the fetal versus maternal circulation, with a further rise in neonates after birth of approximately 3-fold. Neonatal FABP4 inversely correlated with blood glucose, with an approximately 10-fold increase of FABP4 in hypoglycemic neonates. When studied in mice, blood glucose of 12-hour-old WT, Fabp4^–/+, and Fabp4^–/– littermate mice was 59 ± 13 mg/dL, 50 ± 11 mg/dL, and 43 ± 11 mg/dL, respectively. Similar to our observations in humans, FABP4 levels in WT mouse neonates were approximately 8-fold higher compared with those in adult mice. RNA sequencing of the neonatal liver suggested altered expression of multiple glucagon-regulated pathways in Fabp4^–/– mice. Indeed, Fabp4^–/– liver glycogen was inappropriately intact, despite a marked hypoglycemia, with rapid restoration of normoglycemia upon injection of recombinant FABP4. Our data suggest an important biological role for the adipokine FABP4 in the orchestrated regulation of postnatal glucose metabolism.

METABOLIC AND NUTRITIONAL REPERCUSSIONS OF LIVER DISEASE ON CHILDREN: HOW TO MINIMIZE THEM?

Objective:

To describe the metabolic and nutritional repercussions of chronic liver disease (CLD), proposing strategies that optimize nutritional therapy in the pre- and post-liver transplantation (LT) period, in order to promote favorable clinical outcomes and adequate growth and development, respectively.

Data sources:

Bibliographic search in the PubMed, Lilacs and SciELO databases of the last 12 years, in English and Portuguese; target population: children from early childhood to adolescence; keywords in Portuguese and their correlates in English: “Liver Transplant,” “Biliary Atresia,” “Nutrition Therapy,” “Nutritional Status,” and “Child”; in addition to Boolean logics “and” and “or,” and the manual search of articles.

Data synthesis:

Malnutrition in children with CLD is a very common condition and an important risk factor for morbidity and mortality. There is an increase in energy and protein demand, as well as difficulties in the absorption of carbohydrates, lipids and micronutrients such as fat-soluble vitamins and some minerals. An increase in the supply of energy, carbohydrates and proteins and micronutrients, especially fat-soluble vitamins, iron, zinc and calcium, is suggested, except in cases of hepatic encephalopathy (this restriction is indicated for a short period).

Conclusions:

Based on metabolic changes and anthropometric and body composition monitoring, a treatment plan should be developed, following the nutritional recommendations available, in order to minimize the negative impact of malnutrition on clinical outcomes during and after LT.

Neonatal Hypoglycemia and Brain Vulnerability

Neonatal hypoglycemia is a common condition. A transient reduction in blood glucose values is part of a transitional metabolic adaptation following birth, which resolves within the first 48 to 72 h of life. In addition, several factors may interfere with glucose homeostasis, especially in case of limited metabolic stores or increased energy expenditure. Although the effect of mild transient asymptomatic hypoglycemia on brain development remains unclear, a correlation between severe and prolonged hypoglycemia and cerebral damage has been proven. A selective vulnerability of some brain regions to hypoglycemia including the second and the third superficial layers of the cerebral cortex, the dentate gyrus, the subiculum, the CA1 regions in the hippocampus, and the caudate-putamen nuclei has been observed. Several mechanisms contribute to neuronal damage during hypoglycemia. Neuronal depolarization induced by hypoglycemia leads to an elevated release of glutamate and aspartate, thus promoting excitotoxicity, and to an increased release of zinc to the extracellular space, causing the extensive activation of poly ADP-ribose polymerase-1 which promotes neuronal death. In this review we discuss the cerebral glucose homeostasis, the mechanisms of brain injury following neonatal hypoglycemia and the possible treatment strategies to reduce its occurrence.

An Overview of Hypoglycemia in Children Including a Comprehensive Practical Diagnostic Flowchart for Clinical Use

Hypoglycemia is the result of defects/impairment in glucose homeostasis. The main etiological causes are metabolic and/or endocrine and/or other congenital disorders. Despite hypoglycemia is one of the most common emergencies in neonatal age and childhood, no consensus on the definition and diagnostic work-up exists yet. Aims of this review are to present the current age-related definitions of hypoglycemia in neonatal-pediatric age, to offer a concise and practical overview of its main causes and management and to discuss the current diagnostic-therapeutic approaches. Since a systematic and prompt approach to diagnosis and therapy is essential to prevent hypoglycemic brain injury and long-term neurological complications in children, a comprehensive diagnostic flowchart is also proposed.

Nutrition in Chronic Liver Disease: Consensus Statement of the Indian National Association for Study of the Liver

Malnutrition and sarcopenia are common in patients with chronic liver disease and are associated with increased risk of decompensation, infections, wait-list mortality and poorer outcomes after liver transplantation. Assessment of nutritional status and management of malnutrition are therefore essential to improve outcomes in patients with chronic liver disease. This consensus statement of the Indian National Association for Study of the Liver provides a comprehensive review of nutrition in chronic liver disease and gives recommendations for nutritional screening and treatment in specific clinical scenarios of malnutrition in cirrhosis in adults as well as children with chronic liver disease and metabolic disorders.

The autophagy reaction in the human umbilical cord: a potential marker for estimating fetal nutrition and neonatal growth

Objective: To assess the induction of autophagy in the human umbilical cord for physiological adaptation against starvation.Methods: The expression of autophagy-related proteins (LC3-II, p62) in umbilical cord tissues from 40 neonates was assessed by Western blotting. The correlation between the expression of autophagy-related proteins and maternal findings (height, weight, body mass index [BMI]), placental weight, neonatal findings (gestational age, height, weight, Apgar score at 1 min and 5 min), and the pH of the umbilical arterial blood were analyzed using Spearman's rank correlation coefficient test (p values of <.05 were considered significant). Venous blood findings (pH, pCO₂, glucose, total protein, albumin, and lactic acid) were also evaluated in 16 neonates admitted to the NICU.Results: The expression of LC3-II was positively correlated with serum total protein (ρ = 0.564, p = .023). The p62 level was also correlated with maternal BMI (ρ = 0.376, p = .017), the neonatal Apgar score at 1 min (ρ = 0.331 p = .037), total protein (ρ = 0.588, p = .017), and albumin (ρ = 0.552, p = .027) positively. A multiple linear regression analysis that included clinical parameters related to fetal nutrition and neonatal growth revealed that serum total protein was significantly associated with both LC3-II (p = .024) and p62 (p = .034) in the umbilical cord.Conclusion: The LC3-II or p62 expression in the umbilical cord may suggest the autophagy reaction for the homeostasis of protein or amino acid metabolism in the perinatal period.

Swedish national guideline for prevention and treatment of neonatal hypoglycaemia in newborn infants with gestational age ≥35 weeks

AIM

Postnatal hypoglycaemia in newborn infants remains an important clinical problem where prolonged periods of hypoglycaemia are associated with poor neurodevelopmental outcome. The aim was to develop an evidence-based national guideline with the purpose to optimise prevention, diagnosis and treatment of hypoglycaemia in newborn infants with a gestational age ≥35 + 0 weeks.

METHODS

A PubMed search-based literature review was used to find actual and applicable evidence for all incorporated recommendations. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach was used for grading the evidence of the recommendations.

RESULTS

Recommendations for the prevention of neonatal hypoglycaemia were extended and updated, focusing on promotion of breastfeeding as one prevention strategy. Oral dextrose gel as a novel supplemental therapy was incorporated in the treatment protocol. A new threshold-based screening and treatment protocol presented as a flow chart was developed.

CONCLUSION

An updated and evidence-based national guideline for screening and treatment of neonatal hypoglycaemia will support standardised regimes, which may prevent hypoglycaemia and the risk for hypoglycaemia-related long-term sequelae.

Antidiabetic and antioxidative properties of the hydro-methanolic extract (60:40) of rhizomes of Curcuma amada roxb. (Zingiberaceae) in streptozotocin-induced diabetic male albino rat: a dose-dependent study through biochemical and genomic approaches

Background Curcuma amada is the most popular traditional medicine in India for the treatment of diabetes. The present study aimed to focus the antidiabetic and antioxidative activity of C. amada through the analysis of biochemical and genomic levels in a dose-dependent manner in streptozotocin-induced male adult rat. Method Streptozotocin-induced diabetic rats were administered orally with hydro-methanolic extract of C. amada at the dose of 10, 20, 40 and 80 mg/100 g body weight of rats for 28 days. The antidiabetic and antioxidative efficacy of the extract on glycemic, enzymatic, genomic and histological sensors along with toxicity study was investigated. Results The result showed a significant antidiabetic and antioxidative effect of the extract at dose-dependent manner. The significant recovery of fasting blood glucose level, serum insulin, activity of carbohydrate metabolic enzymes and antioxidative enzymes in extract-treated diabetic group as compared to untreated diabetic group were noted. After the extract treatment, the size of pancreatic islet and cell population densities were significantly increased. Activities of glutamate oxaloacetate transaminase and glutamate pyruvate transaminase in liver were significantly recovered along with the correction of Bax and Bcl-2 gene expression in hepatic tissue after the extract treatment in diabetic rats in respect to untreated diabetic group. Out of all the doses, the significant effects were noted at the dose of 20 mg/100 g body weight which has been considered as threshold dose in the concern. Conclusion It may be concluded that the significant and corrective effect in most of the sensors was noted at the minimum dose of 20 mg/100 g body weight of hydro-methanolic extract of C. amada without producing any toxicity.

Pragmatic and evidence-based approach to paediatric cerebrospinal fluid reference limits for white cell count and concentrations of total protein and glucose

Background

It is often impractical for each laboratory to establish its own paediatric reference intervals. This is particularly true for specimen types collected using invasive procedures, for example, cerebrospinal fluid (CSF).

Methods

Published CSF reference intervals for white cell count, and concentrations of total protein and glucose were reviewed by stakeholders in a paediatric hospital. Consensus reference intervals for the three CSF parameters were then subjected to verification using guidelines from the Clinical Laboratory Standards Institute and residual CSF specimens.

Results

Consensus paediatric reference intervals adapted from published studies with minor modifications were locally verified as follows. White cell count (x106 cells/L): 0–20 (<1 month); 0–10 (1–2 months); 0–5 (>2 months). Total protein (g/L): 0.3–1.2 (<1 month); 0.2–0.6 (1–3 months); 0.1–0.4 (>3 months). Glucose (mmol/L): 2.0–5.6 (<6 months); 2.4–4.3 (6 months or older).

Hypoglycemia in the preterm neonate: etiopathogenesis, diagnosis, management and long-term outcomes

Glucose, like oxygen, is of fundamental importance for any living being and it is the major energy source for the fetus and the neonate during gestation. The placenta ensures a steady supply of glucose to the fetus, while birth marks a sudden change in substrate delivery and a major change in metabolism. Hypoglycemia is one of the most common pathologies encountered in the neonatal intensive care unit and affects a wide range of neonates. Preterm, small for gestational age (GA) and intra-uterine growth restricted neonates are especially vulnerable due to their lack of metabolic reserves and associated co-morbidities. Nearly 30-60% of these high-risk infants are hypoglycemic and require immediate intervention. Preterm neonates are uniquely predisposed to developing hypoglycemia and its associated complications due to their limited glycogen and fat stores, inability to generate new glucose using gluconeogenesis pathways, have higher metabolic demands due to a relatively larger brain size, and are unable to mount a counter-regulatory response to hypoglycemia. In this review we will discuss the epidemiology; pathophysiology; clinical presentation; management and neurodevelopmental outcomes in affected infants and summarize evidence to develop a rational and scientific approach to this common problem.

Insulin resistance, glucagon-like peptide-1 and factors influencing glucose homeostasis in neonates

OBJECTIVES

To explore the relationships between postmenstrual age (PMA), insulin, C-peptide, glucagon and blood glucose concentrations (BGCs) in preterm and term neonates. To compare glucagon-like peptide-1 (GLP-1) concentrations in fed versus never-fed neonates.

DESIGN

Observational.

SETTING

Dunedin Hospital Neonatal Intensive Care Unit, New Zealand.

PATIENTS

Term or preterm euglycaemic neonates (102) receiving routine blood tests (343 samples).

INTERVENTIONS

None: plasma was obtained from surplus samples from routine clinical care.

MAIN OUTCOME MEASURES

Insulin, C-peptide, GLP-1 and glucagon concentrations were measured in temporal association with BGC.

RESULTS

Insulin and C-peptide concentrations were elevated in very preterm infants (PMA≤32 weeks) and decreased to term; this relationship persisted when BGCs were accounted for. Generalised linear mixed models showed that insulin:C-peptide ratio and insulin:BGC ratio decreased significantly with increasing PMA (p<0.001). GLP-1 increased following initial oral feeds regardless of PMA (p<0.001).

CONCLUSION

Preterm neonates exhibit insulin resistance in the absence of hyperglycaemia. Enteral feeds result in an increase in GLP-1. These factors are likely to contribute to the increased risk of hyperglycaemia in premature neonates (PMA<32 weeks).

Effect of gestational age and blood glucose on C-peptide excretion rate and clearance in neonates

AIMS

The aim of this study was to measure urinary C-peptide concentrations, and then calculate C-peptide clearance (Cl), and excretion rate (UER) in neonates. In addition, the effect of gestational age (GA) and blood glucose levels (BGL) on C-peptide UER were investigated.

METHODS

Insulin concentrations in plasma and C-peptide concentrations were measured in plasma and urine, in 20 neonates. Chemiluminescent immunoassays were used for insulin and C-peptide measurements, with urine diluted to 40% with bovine serum albumin 1% in phosphate buffered saline. Urine volume and time of collection were recorded and used to calculate UER and Cl.

RESULTS

The mean Cl of C-peptide was 0.309 ± 0.329 mL/min/kg, and UER was 0.0329 ± 0.0342 pmol/min/kg. Correlations between Cl or UER and GA were not significant (P > 0.05). No significant correlation was shown between Cl or UER and BGL (P > 0.05).

CONCLUSIONS

Both Cl and UER were highly variable in neonates, but were not correlated with GA. Additionally, BGL did not appear to affect C-peptide UER and Cl. As GA and BGL did not appear to affect Cl and UER, urinary C-peptide may provide a non-invasive method of measuring insulin production in neonates.

Endogenous glucose production from infancy to adulthood: a non-linear regression model

OBJECTIVE

To construct a regression model for endogenous glucose production (EGP) as a function of age, and compare this with glucose supplementation using commonly used dextrose-based saline solutions at fluid maintenance rate in children.

DESIGN

A model was constructed based on EGP data, as quantified by [6,6-(2)H2] glucose dilution after fasting overnight during normoglycaemia, in 40 healthy subjects aged 2.5-54.3 years old. The data were analysed using non-linear regression modelling with a 1-phase exponential decay curve fit. This model was compared to the amount of glucose provided with 2.5% or 5% dextrose-based saline solutions infused at fluid maintenance rate.

RESULTS

Non-linear regression analysis of the EGP data yielded the following regression model: EGP (mg/kg/min) = 6.50 × 2.72(-0.145 × age (y))+1.93. Glucose supplementation at fluid maintenance rate with a 5% dextrose-based saline solution ranged from 46% at age 1 year to 55% at age 18 years of the glucose required to preclude the need for EGP. With a 2.5% dextrose-based solution, these percentages are 23% at age 1 year to 27% at age 18 years.

CONCLUSIONS

we present an accurate non-linear regression model for EGP as a function of age. With standard dextrose-based saline solutions infused at fluid maintenance rate, only approximately 50% or less of EGP is provided. With prolonged infusion of these solutions, the deficit between exogenous glucose supplementation and EGP may induce a catabolic state and may ultimately lead to hypoglycaemia, especially in younger children.

'Two-step' head-to-body delivery activates foetal gluconeogenesis

AIM

The 'two-step' head-to-body delivery method, which involves waiting for the next contraction to deliver the shoulders, causes a decrease in umbilical artery pH. The aim of this study was to assess whether foetal acidemia activates gluconeogenesis.

METHODS

We tested umbilical artery cord blood glucose concentration and pH after 341 spontaneous and 25 vacuum extractor 'two-step' vaginal deliveries (VD) and after 85 elective and 49 emergency caesarean sections (CS).

RESULTS

Cord blood glucose concentration was significantly higher (95.5 ± 21.4 mg/dL vs 75.6 ± 16.4, p < 0.001), and pH values significantly lower (7.31 ± 0.09 vs 7.33 ± 0.06, p = 0.003) in 'two-step' VD neonates than in CS delivered neonates. In addition, cord blood glucose concentration was significantly higher (101.4 ± 30.6 mg/dL, p = 0.004), and pH values were significantly lower (7.26 ± 0.10, p < 0.001) in VD by vacuum extractor than in all other groups. The cord blood glucose concentration is significantly and negatively correlated with pH in the study population (r = -0.094, p = 0.036) and strongly significantly and negatively correlated in VD by vacuum extractor (r = -0.594, p = 0.007).

CONCLUSION

Cord blood glucose concentrations are significantly higher and pH values significantly lower in 'two-step' VD neonates, indicating activated foetal gluconeogenesis.

Nutrition assessment and support in children with end-stage liver disease

Malnutrition is a treatable complication in children with end-stage liver disease (ESLD). Biliary atresia and other cholestatic disorders are the most frequent cause of ESLD in children. No single variable provides adequate information about nutrition status, yet effective nutrition support is the one intervention known to improve pre- and posttransplant outcomes. A proactive approach consisting of screening anthropometry interpreted using appropriate growth references, recognition of clinical manifestations associated with micronutrient deficiency, and timely aggressive nutrition support is of a paramount importance to maximize anabolism and optimize outcomes. This article presents the principles of nutrition assessment, intervention, and monitoring in children with ESLD.

Influence of administration of 1 % glucose solution on neonatal blood glucose concentration in cesarean section

Perioperative administration of adequate glucose prevents hypercatabolism. However, excessive glucose administration until delivery of a fetus might cause newborn hypoglycemia in cesarean section. In this retrospective study, we investigated whether the administration of 1 % glucose solution during cesarean section influenced neonatal blood glucose concentration. We found 46 consecutive patients between 37 and 41 weeks of gestation who underwent cesarean section under combined epidural and spinal anesthesia. We divided the patients into two groups: those receiving 1 % glucose solution (group A, N = 23) and those receiving a solution without glucose (group B, N = 23) until delivery. We recorded umbilical cord blood glucose on delivery, neonatal blood glucose level 3 h after delivery, and 1- and 5-min Apgar scores. The dose of glucose administered until delivery of fetus in group A was 3.6 ± 1.7 mg/kg/min [mean ± standard deviation (SD)] and that in group B 0 mg/kg/min. Umbilical cord blood glucose concentration on delivery of fetus in group A was significantly higher than that in group B (101 ± 19 vs. 66 ± 10 mg/dl; P < 0.0001). Neonatal blood glucose level 3 h after delivery was not significantly different between groups (90 ± 15 vs. 90 ± 21 mg/dl; P = 0.96). The 1- and 5-min Apgar scores were similar between groups. In conclusion, administration of 1 % glucose solution in cesarean section might contribute to prevention of neonatal hypoglycemia.

Cerebrospinal fluid glucose and lactate: age-specific reference values and implications for clinical practice

Cerebrospinal fluid (CSF) analysis is an important tool in the diagnostic work-up of many neurological disorders, but reference ranges for CSF glucose, CSF/plasma glucose ratio and CSF lactate based on studies with large numbers of CSF samples are not available. Our aim was to define age-specific reference values. In 1993 The Nijmegen Observational CSF Study was started. Results of all CSF samples that were analyzed between 1993 and 2008 at our laboratory were systematically collected and stored in our computerized database. After exclusion of CSF samples with an unknown or elevated erythrocyte count, an elevated leucocyte count, elevated concentrations of bilirubin, free hemoglobin, or total protein 9,036 CSF samples were further studied for CSF glucose (n = 8,871), CSF/plasma glucose ratio (n = 4,516) and CSF lactate values (n = 7,614). CSF glucose, CSF/plasma glucose ratio and CSF lactate were age-, but not sex dependent. Age-specific reference ranges were defined as 5–95^th percentile ranges. CSF glucose 5^th percentile values ranged from 1.8 to 2.9 mmol/L and 95^th percentile values from 3.8 to 5.6 mmol/L. CSF/plasma glucose ratio 5^th percentile values ranged from 0.41 to 0.53 and 95^th percentile values from 0.82 to 1.19. CSF lactate 5^th percentile values ranged from 0.88 to 1.41 mmol/L and 95^th percentile values from 2.00 to 2.71 mmol/L. Reference ranges for all three parameters were widest in neonates and narrowest in toddlers, with lower and upper limits increasing with age. These reference values allow a reliable interpretation of CSF results in everyday clinical practice. Furthermore, hypoglycemia was associated with an increased CSF/plasma glucose ratio, whereas hyperglycemia did not affect the CSF/plasma glucose ratio.

The effect of a computerized prescribing and calculating system on hypo- and hyperglycemias and on prescribing time efficiency in neonatal intensive care patients

BACKGROUND

Prescribing glucose requires complex calculations because glucose is present in parenteral and enteral nutrition and drug vehicles, making it error prone and contributing to the burden of prescribing errors.

OBJECTIVE

Evaluation of the impact of a computerized physician order entry (CPOE) system with clinical decision support (CDS) for glucose control in neonatal intensive care patients (NICU) focusing on hypo- and hyperglycemic episodes and prescribing time efficiency.

METHODS

An interrupted time-series design to examine the effect of CPOE on hypo- and hyperglycemias and a crossover simulation study to examine the influence of CPOE on prescribing time efficiency. NICU patients at risk for glucose imbalance hospitalized at the University Medical Center Utrecht during 2001-2007 were selected. The risks of hypo- and hyperglycemias were expressed as incidences per 100 patient days in consecutive 3-month intervals during 3 years before and after CPOE implementation. To assess prescribing time efficiency, time needed to calculate glucose intake with and without CPOE was measured.

RESULTS

No significant difference was found between pre- and post-CPOE mean incidences of hypo- and hyperglycemias per 100 hospital days of neonates at risk in every 3-month period (hypoglycemias, 4.0 [95% confidence interval, 3.2-4.8] pre-CPOE and 3.1 [2.7-3.5] post-CPOE, P = .88; hyperglycemias, 6.0 [4.3-7.7] pre-CPOE and 5.0 [3.7-6.3] post-CPOE, P = .75). CPOE led to a significant time reduction of 16% (1.3 [0.3-2.3] minutes) for simple and 60% (8.6 [5.1-12.1] minutes) for complex calculations.

CONCLUSIONS

CPOE including a special CDS tool preserved accuracy for calculation and control of glucose intake and increased prescribing time efficiency.

Perinatal endocrinology: common endocrine disorders in the sick and premature newborn

Endocrine disorders are common in infants in the neonatal ICU. They often are associated with prematurity, low birth weight or very low birth weight, and small size for gestational age. They also frequently occur in infants who are critically ill or stressed. This article describes the most common conditions and current knowledge regarding management.

Modeling the glucose regulatory system in extreme preterm infants

BACKGROUND

Premature infants represent a significant proportion of the neonatal intensive care population. Blood glucose homeostasis in this group is often disturbed by immaturity of endogenous regulatory systems and the stress of their condition. Hypo- and hyperglycemia are frequently reported in very low birth weight infants, and more mature infants often experience low levels of glycemia. A model capturing the unique fundamental dynamics of the neonatal glucose regulatory system could be used to develop better blood glucose control methods.

METHODS

A metabolic system model is adapted from adult critical care to the unique physiological case of the neonate. Integral-based fitting methods were used to identify time-varying insulin sensitivity and non-insulin mediated glucose uptake profiles. The clinically important predictive ability of the model was assessed by assuming insulin sensitivity was constant over prediction intervals of 1, 2 and 4h forward and comparing model-simulated versus actual clinical glucose values for all recorded interventions. The clinical data included 1091 glucose measurements over 3567 total patient hours, along with all associated insulin and nutritional infusion data, for N=25 total cases. Ethics approval was obtained from the Upper South A Regional Ethics Committee for this study.

RESULTS

The identified model had a median absolute percentage error of 2.4% [IQR: 0.9-4.8%] between model-fitted and clinical glucose values. Median absolute prediction errors at 1-, 2- and 4-h intervals were 5.2% [IQR: 2.5-10.3%], 9.4% [IQR: 4.5-18.4%] and 13.6% [IQR: 6.3-27.6%] respectively.

CONCLUSIONS

The model accurately captures and predicts the fundamental dynamic behaviors of the neonatal metabolism well enough for effective clinical decision support in glycemic control. The adaptation from adult to a neonatal case is based on the data from the literature. Low prediction errors and very low fitting errors indicate that the fundamental dynamics of glucose metabolism in both premature neonates and critical care adults can be described by similar mathematical models.

Development of blood glucose control for extremely premature infants

Extremely premature neonates often experience hyperglycaemia, which has been linked to increased mortality and worsened outcomes. Insulin therapy can assist in controlling blood glucose levels and promoting needed growth. This study presents the development of a model-based stochastic targeted controller designed to adapt insulin infusion rates to match the unique and changing metabolic state and control parameters of the neonate. Long-term usage of targeted BG control requires successfully forecasting variations in neonatal metabolic state, accounting for differences in clinical practices between units, and demonstrating robustness to errors that can occur in everyday clinical usage. Simulation studies were used to evaluate controller ability to target several common BG ranges and evaluate controller sensitivity to missed BG measurements and delays in control interventions on a virtual patient cohort of 25 infants developed from retrospective data. Initial clinical pilot trials indicated model performance matched expected performance from simulations. Stochastic targeted glucose control developed using validated patient-specific virtual trials can yield effective protocols for this cohort. Long-term trials show fundamental success, however clinical interface design appears as a critical factor to ensuring good compliance and thus good control.

Hyperglycemia after pediatric cardiac surgery: impact of age and residual lesions

OBJECTIVE

We evaluated the effect of patient age and significant residual cardiac lesions on the association between hyperglycemia and adverse outcomes in children after cardiac surgery. The incidence, severity, and duration of hyperglycemia in this patient population and perioperative factors predisposing to hyperglycemia were also delineated.

DESIGN

Retrospective, observational cohort study.

SETTING

Eighteen-bed pediatric cardiac critical care unit.

PATIENTS

Seven hundred seventy-two children undergoing cardiac surgery with cardiopulmonary bypass during 2006 and 2007.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Postoperative glucose levels were reviewed in all children who underwent cardiac surgery with cardiopulmonary bypass at our institution during 2006 and 2007 who met all inclusion criteria and none of the exclusion criteria (n = 772). The composite morbidity-mortality outcome included hospital death, cardiac arrest, renal/hepatic failure, lactic acidosis, extracorporeal membrane oxygenation use, or infection. Hyperglycemia occurred in 90% of patients and resolved within 72 hrs in most without exogenous insulin. Preoperative factors, including prostaglandins, mechanical ventilation, and cyanosis, were significantly associated with increased odds of significant hyperglycemia (>180 mg/dL for >12 hrs or any level >270 mg/dL) as were increased surgical complexity and perioperative steroid administration. Thirty-one percent of the entire cohort reached the composite outcome and the odds were significantly increased after 54 hrs of mild (elevated, but <180 mg/dL), 12 hrs of moderate (180-270 mg/dL), or any period of severe hyperglycemia (>270 mg/dL). Neonates (<1 month of age) tolerated longer periods of hyperglycemia before showing increased odds of reaching the composite morbidity-mortality end point. In the setting of important residual cardiac lesions, mild or moderate hyperglycemia was not as strongly associated with adverse outcomes.

CONCLUSIONS

Age and residual cardiac lesions are important modifiers of the association between hyperglycemia and suboptimal outcomes after pediatric cardiac surgery. Use of insulin therapy for glucose control in this patient population may need to be carefully targeted toward high-risk subsets of patients.

Apical Na+-D-glucose cotransporter 1 (SGLT1) activity and protein abundance are expressed along the jejunal crypt-villus axis in the neonatal pig

Gut apical Na(+)-glucose cotransporter 1 (SGLT1) activity is high at the birth and during suckling, thus contributing substantially to neonatal glucose homeostasis. We hypothesize that neonates possess high SGLT1 maximal activity by expressing apical SGLT1 protein along the intestinal crypt-villus axis via unique control mechanisms. Kinetics of SGLT1 activity in apical membrane vesicles, prepared from epithelial cells sequentially isolated along the jejunal crypt-villus axis from neonatal piglets by the distended intestinal sac method, were measured. High levels of maximal SGLT1 uptake activity were shown to exist along the jejunal crypt-villus axis in the piglets. Real-time RT-PCR analyses showed that SGLT1 mRNA abundance was lower (P < 0.05) by 30-35% in crypt cells than in villus cells. There were no significant differences in SGLT1 protein abundances on the jejunal apical membrane among upper villus, middle villus, and crypt cells, consistent with the immunohistochemical staining pattern. Higher abundances (P < 0.05) of total eukaryotic initiation factor 4E (eIF4E) protein and eIE4E-binding protein 1 γ-isoform in contrast to a lower (P < 0.05) abundance of phosphorylated (Pi) eukaryotic elongation factor 2 (eEF2) protein and the eEF2-Pi to total eEF2 abundance ratio suggest higher global protein translational efficiency in the crypt cells than in the upper villus cells. In conclusion, neonates have high intestinal apical SGLT1 uptake activity by abundantly expressing SGLT1 protein in the epithelia and on the apical membrane along the entire crypt-villus axis in association with enhanced protein translational control mechanisms in the crypt cells.

FoxOs function synergistically to promote glucose production

Hepatic glucose production (HGP) plays a vital role in maintaining the supply of glucose to the body, and transcription factor FoxO1 is known to confer hormone responsiveness onto HGP. Mice with a liver-specific FoxO1 deletion (L-FoxO1) show reduced HGP and reduced expression of glucose production genes. To determine the contribution of additional transcription factors to HGP, we created double and triple liver-specific knock-outs lacking FoxO1, FoxO3, and FoxO4 or the related protein FoxA2. We show that, when compared with single knock-out of FoxO1, triple ablation of FoxO genes causes more pronounced fasting hypoglycemia, increased glucose tolerance, and enhanced insulin sensitivity, with decreased plasma insulin levels. In contrast, combined ablation of FoxO1 and FoxA2 phenocopied the single knock-out of FoxO1. These data indicate that FoxOs work in concert to regulate multiple aspects of hepatic glucose metabolism.

Perinatal endocrinology: common endocrine disorders in the sick and premature newborn

Endocrine disorders are common in infants in the neonatal ICU. They often are associated with prematurity, low birth weight or very low birth weight, and small size for gestational age. They also frequently occur in infants who are critically ill or stressed. This article describes the most common conditions and current knowledge regarding management.

Blood glucose controller for neonatal intensive care: virtual trials development and first clinical trials

BACKGROUND

Premature neonates often experience hyperglycemia, which has been linked to worsened outcomes. Insulin therapy can assist in controlling blood glucose (BG) levels. However, a reliable, robust control protocol is required to avoid hypoglycemia and to ensure that clinically important nutrition goals are met.

METHODS

This study presents an adaptive, model-based predictive controller designed to incorporate the unique metabolic state of the neonate. Controller performance was tested and refined in virtual trials on a 25-patient retrospective cohort. The effects of measurement frequency and BG sensor error were evaluated. A stochastic model of insulin sensitivity was used in control to provide a guaranteed maximum 4% risk of BG < 72 mg/dl to protect against hypoglycemia as well as account for patient variability over 1-3 h intervals when determining the intervention. The resulting controller is demonstrated in two 24 h clinical neonatal pilot trials at Christchurch Women's Hospital.

RESULTS

Time in the 72-126 mg/dl BG band was increased by 103-161% compared to retrospective clinical control for virtual trials of the controller, with fewer hypoglycemic measurements. Controllers were robust to BG sensor errors. The model-based controller maintained glycemia to a tight target control range and accounted for interpatient variability in patient glycemic response despite using more insulin than the retrospective case, illustrating a further measure of controller robustness. Pilot clinical trials demonstrated initial safety and efficacy of the control method.

CONCLUSIONS

A controller was developed that made optimum use of the very limited available BG measurements in the neonatal intensive care unit and provided robustness against BG sensor error and longer BG measurement intervals. It used more insulin than typical sliding scale approaches or retrospective hospital control. The potential advantages of a model-based approach demonstrated in simulation were applied to initial clinical trials.

Improving outcomes of transported newborns in Panama: impact of a nationwide neonatal provider education program

OBJECTIVE

To determine whether national distribution of a neonatal provider education program (the S.T.A.B.L.E. Program) positively impacts the health of ill newborns that require transport in Panama.

STUDY DESIGN

The investigation used a prospective, pre- and postintervention study design with a double pretest. The 10 birthing centers in Panama that routinely transport the greatest number of newborns received the education program intervention. Primary outcomes were body temperature and serum glucose level on arrival at the referral facility. Length of stay and mortality were evaluated as secondary outcomes. Variation in outcome indicators was compared for 7 months before and after the intervention. Data from all live newborns transported from outlying birthing center study sites during the study dates were included in the investigation.

RESULT

A total of 136 and 146 newborns were transported during the observation and postintervention periods, respectively. Significantly more patients in the postintervention group had temperatures within the normal range (56% in postintervention group vs 34% in observation group; P<0.01). No statistical difference was observed in serum glucose levels, length of stay or mortality.

CONCLUSION

Distribution of a neonatal provider educational program was associated with improved thermal management of transported newborns in Panama. Further study will help to confirm this association and determine the extent to which these findings are generalizable to other resource-constrained settings.

Global and gene-specific translational regulation in rat lung development

During the peripartum period, the lung must respond to dramatic changes in circulating hormones, nutritional factors, and physiologic signals during its transition to becoming the organ of gas exchange. Protein synthesis consumes a significant proportion of metabolic resources and is inhibited by many environmental stresses. We hypothesized that translational control mechanisms play a role in the perinatal lung. Immunoblots of late-gestation (Fetal Day [FD] 17-22) rat lung extracts revealed gradual decreases in phosphorylated forms of the mammalian target of rapamycin effectors, eukaryotic initiation factor (eIF) 4E-binding protein, p70 S6 kinase, and ribosomal protein S6, followed by sharp increases on Postnatal Day 1 (P1). Immunohistochemistry showed phospho-S6 staining was most prominent in epithelial cells of the large and small airways. m(7)GTP-sepharose pulldown experiments showed a decrease in association of translation initiation factor, eIF4E, with its inhibitor, eIF4E-binding protein, and a concomitant increase in eIF4E association with eIF4G immediately after birth, and polysome profiles confirmed a decrease in abundance of large polysomes between FD19 and FD22, which was reversed on P1. Microarray analysis of polysomal versus total RNA from FD19, FD22, and P1 lungs was used to identify specific genes, the association of which with large polysomes changed either pre- or postnatally. RT-PCR and Northern blotting were used to confirm translational changes in selected candidate genes, including a prenatal increase in IL-18 and a postnatal decrease in regulatory subunit 2 of protein phosphatase 1. Translational regulation of IL-18 and protein phosphatase 1 regulatory (inhibitor) subunit 2 is gene-specific, as these changes contrast with the corresponding global changes in polysome abundance.

Ontogenesis of mRNA levels and binding sites of hepatic alpha-adrenoceptors in young cattle

Catecholamines affect hepatic glucose production through (alpha- and beta2-) adrenoceptors (AR). We studied mRNA abundance and binding of hepatic alpha-AR in pre-term (P0) calves and in full-term calves at day 0 (F0), day 5 (F5) and day 159 (F159) to test the hypothesis that gene expression and numbers of hepatic alpha-AR in calves are influenced by age and associated with beta2-AR and selected traits of glucose metabolism. mRNA levels of alpha1- and alpha2-AR were measured by real time RT-PCR. alpha1- and alpha2-AR numbers (maximal binding, Bmax) were determined by saturation binding of (3H)-prazosin and (3H)-RX821002, respectively. alpha1- and alpha2-AR subtypes were evaluated by competitive binding. alpha1A-AR mRNA levels were lower in P0 than in F0, F5 and F159 and alpha(2AD)-AR mRNA levels were lower in F159 than in P0, F0 and F5, while alpha2C-AR mRNA levels increased from P0 and F0 to F5 and F159. Bmax of alpha1-AR increased from P0 to F5, then decreased in F159. Bmax of alpha2-AR decreased from F0 to F159. Bmax of alpha1-AR was positively associated with mRNA levels of alpha1A-AR (r = 0.7), Bmax of beta2-AR (r = 0.5) and negatively with hepatic glycogen content (r = -0.6). Bmax of alpha2-AR was negatively associated with Bmax of beta2-AR (r = -0.4). In conclusion, mRNA levels and binding sites of alpha1- and alpha2-AR in calves exhibited developmental changes and were negatively associated with hepatic glycogen content.