Hyperglycaemia in preterm neonates: what to know, what to do

Postnatal growth and metabolic blood biomarkers in preterm infants developing reversible retinopathy of prematurity

PURPOSE

To investigate predictive potential of growth and metabolic blood biomarkers in the development of milder, reversible retinopathy of prematurity (ROP) stages.

METHODS

Biomarkers were obtained from blood samples collected every second postnatal week in a prospective, longitudinal cohort study including 108 infants born with a gestational age (GA) <32 weeks in four hospitals in the Capital Region of Denmark, 2018-2019. ROP diagnoses were obtained from the electronic medical record system together with demographic, clinical and laboratory data. Measurement of glucose was summarised as mean and SD for every postnatal week and growth was summarised as increment in weight, head circumference (biparietal diameter) and length every postnatal week. The predictive potential of each biomarker and each marker of growth in turn were evaluated in univariate receiver operating characteristics curve analyses and in multivariate analyses including GA and small for gestational age (SGA) as known predictors.

RESULTS

The strongest isolated postnatal predictor of ROP was weight gain at the second postnatal week with an area under the curve (AUC) of 0.80 (95% CI: 0.70 to 0.89). However, it only added insignificantly to the AUC (0.85; 95% CI: 0.76 to 0.93, adj. p=0.89) compared with GA and SGA alone (AUC=0.80, 95% CI: 0.70 to 0.90). Mean glucose in PNA weeks 1-4, glycaemic variability as measured by glucose SD weeks 1-3 PNA, and concentrations of adiponectin/glucose (mean) ratio were also associated with ROP diagnosis (AUCs ranging from 0.679 to 0.77) but did also not contribute significantly to the AUC compared with GA and SGA alone.

CONCLUSIONS

Postnatal growth and metabolic blood biomarkers were significantly associated with milder, reversible ROP, but none of these gave prediction over and above GA and SGA. Due to the small sample sizes, potential predictors could only be investigated in univariate analyses. Larger studies are needed to fully explore the predictive potential of all the biomarkers.

Potential pathogenetic role of a novel ABCC8 missense variant on both transient neonatal diabetes mellitus and fetal growth restriction: a case report

BACKGROUND

The diagnosis of neonatal diabetes can be problematic in preterm infants with fetal growth restriction (FGR). Growth restricted fetuses may have impaired insulin production and secretion; low birthweight infants may have a reduced response to insulin. We report a novel missense ABCC8 variant associated with a clinical phenotype compatible with transient neonatal diabetes mellitus (TNDM) in a fetal growth restricted preterm infant.

METHODS AND RESULTS

A preterm growth restricted infant experienced hyperglycemia from the first day of life, requiring insulin therapy on the 13th and 15th day of life and leading to the diagnosis of TNDM. Glycemic values normalized from the 35th day of life onwards. Genetic screening was performed by next generation sequencing, using a Clinical Exon panel of 4800 genes, filtered for those associated with the clinical presentation and by means of methylation-specific multiplex ligation-dependent probe amplification analysis to identify chromosomal aberrations at 6q24. Genetic tests excluded defects at 6q24 and were negative for KCNJ11, SLC2A2 (GLUT-2) and HNF1B, but revealed the presence of the heterozygous missense variant c.2959T > C (p.Ser987Pro) in ABCC8 gene. The presence of the variant was excluded in parents' DNA and the proband variant was then considered de novo.

CONCLUSIONS

In our infant, the persistence of hyperglycemia beyond 3 weeks of life led us to the diagnosis of TNDM and to hypothesize a possible genetic cause. The genetic variant we found could be, most likely, the main cause of both FGR and TNDM.

Blood-Biomarkers for Glucose Metabolism in Preterm Infants

This was an exploratory, prospective, longitudinal, cohort study that aimed to establish "healthy" reference levels related to growth parameters and glucose metabolites in preterm infants. This was conducted to further investigate growth and metabolic disturbances potentially related to neonatal illness. The study sample consisted of 108 preterm infants born before 32 weeks in 2018-2019 in the Capital Region of Denmark. Repetitive blood samples were acquired at the neonatal wards, while clinical data were obtained from the regional hospital medical record system. Thirty-four "healthy" preterm infants (31%) were identified. The "ill" infants were divided into four subgroups dependent on gestational age and small for gestational age. Reference levels for the growth parameters and metabolic biomarkers glucose, albumin, and adiponectin, and two glucose control indicators, glycated albumin and fructosamine, were determined for the "healthy" and "ill" subgroups. The "ill" extremely preterm infants had increased glucose levels (mean difference 0.71 mmol/L, 95% CI 0.23; 1.18 mmol/L) and glycated albumin (corrected; %) (mean difference 0.92 mmol/L, 95% CI 0.38 mmol/L;1.47 mmol/L) compared to the "healthy" infants. In "ill" extremely preterm infants and "ill" very preterm infants born small for gestational age, levels of biomarkers containing proteins were decreased. In the "Ill" extremely preterm infants and infants born small for gestational age, postnatal growth was continuously decreased throughout the postconceptional period. The short-term glucose-control indicator, glycated albumin (corrected; %), reflected well the high glucose levels due to its correction for the depleted plasma-protein pool.

Macronutrients and Micronutrients in Parenteral Nutrition for Preterm Newborns: A Narrative Review

Preterm neonates display a high risk of postnatal malnutrition, especially at very low gestational ages, because nutritional stores are less in younger preterm infants. For this reason nutrition and growth in early life play a pivotal role in the establishment of the long-term health of premature infants. Nutritional care for preterm neonates remains a challenge in clinical practice. According to the recent and latest recommendations from ESPGHAN, at birth, water intake of 70-80 mL/kg/day is suggested, progressively increasing to 150 mL/kg/day by the end of the first week of life, along with a calorie intake of 120 kcal/kg/day and a minimum protein intake of 2.5-3 g/kg/day. Regarding glucose intake, an infusion rate of 3-5 mg/kg/min is recommended, but VLBW and ELBW preterm neonates may require up to 12 mg/kg/min. In preterm infants, lipid emulsions can be started immediately after birth at a dosage of 0.5-1 g/kg/day. However, some authors have recently shown that it is not always possible to achieve optimal and recommended nutrition, due to the complexity of the daily management of premature infants, especially if extremely preterm. It would be desirable if multicenter randomized controlled trials were designed to explore the effect of early nutrition and growth on long-term health.

Experience with enteral sulfonylurea monotherapy for extremely low birth weight infants with hyperglycemia

Limited data are available on the effects of enteral sulfonylurea (SU) monotherapy in extremely low birth weight infants (ELBWIs) with hyperglycemia. Therefore, we report our experience with enteral SU monotherapy for hyperglycemic ELBWIs. We retrospectively evaluated 11 hyperglycemic ELBWIs (seven male infants, median gestational age = 24.9 wk) who received SU between January 2016 and December 2019. Blood glucose (BG) levels were monitored before and after SU initiation and evaluated for the occurrence of adverse effects. We administered SU at a median of 15 d (interquartile range [IQR]: 12–20 d) after birth, with the median maximum dose of 0.2 mg/kg/d (IQR: 0.125–0.3 mg/kg/d). Hyperglycemia improved in all patients, and the target BG levels were achieved without severe side effects at a median of 6 d (IQR: 4–8.5 d) after initiation of treatment. The incidence of hypoglycemia during SU treatment was observed in 18 events per 1000 patient hours; however, the patients were asymptomatic. Based on these results, enteral SU monotherapy may be considered as an option for hyperglycemic ELBWIs.

The glucose infusion rate of parenteral nutrition in the first week of life in preterm infants: an observational study

Background

Most preterm infants require a continuous glucose infusion in the early postnatal period due to the interruption of the transplacental glucose supply after birth to promote better neurodevelopmental outcomes.

Aims

To investigate the glucose infusion rate (GIR) on parenteral nutrition (PN) in the first week of life administered in preterm infants and its effect on neonatal morbidity and mortality.

Methods

This study included 97 infants aged < 37 gestational weeks and weighed < 2500 g at birth. Infants recruited in this study were classified into 3 groups based on the GIR usage in parenteral nutrition as follows: GIR usage of 5- < 7 g/kg/day (Group I), GIR usage of 7–13 g/kg/day (Group II), and GIR usage of > 13–15 g/kg/day (Group III). Univariate and multivariate logistic regression analyzes were carried out to investigate whether the GIR usage in the three groups was associated with selected neonatal morbidities and mortality. Neonatal morbidities analyzed included respiratory distress syndrome (RDS), necrotizing enterocolitis, sepsis, retinopathy of prematurity, pulmonary hypertension, hypoglycemia, and hyperglycemia.

Result

Of 97 preterm infants included, 51.5% infants had a gestational age of 34- < 37 weeks, and 54.6% infants had a birth weight of 1500- < 2500 g. The multivariate logistic regression analysis showed that the GIR usage of 5- < 7 g/kg/day was an independent variable that significantly increased the risk of hypoglycemia (Adjusted Odds Ratio [AOR] = 4.000, 95% Confidence Interval [CI] = 1.384–11.565, P = 0.010) and reduced the risk of sepsis (AOR = 0.096, 95% CI = 0.012–0.757, P = 0.026). The GIR usage in all three groups did not increase the risk of mortality. For neonatal morbidity analyzed in this study, RDS (AOR = 5.404, 95%CI = 1.421–20.548, P = 0.013) was an independent risk factor of mortality.

Conclusion

The GIR usage of < 7 g/kg/day in PN in the first week of life administered to preterm infants was an independent variable in increasing hypoglycemia, but in contrast, reducing the risk of sepsis.

Influence of innate immune activation on endocrine and metabolic pathways in infancy

Prematurity is the leading cause of neonatal morbidity and mortality worldwide. Premature infants often require extended hospital stays, with increased risk of developing infection compared with term infants. A picture is emerging of wide-ranging deleterious consequences resulting from innate immune system activation in the newborn infant. Those who survive infection have been exposed to a stimulus that can impose long-lasting alterations into later life. In this review, we discuss sepsis-driven alterations in integrated neuroendocrine and metabolic pathways and highlight current knowledge gaps in respect of neonatal sepsis. We review established biomarkers for sepsis and extend the discussion to examine emerging findings from human and animal models of neonatal sepsis that propose novel biomarkers for early identification of sepsis. Future research in this area is required to establish a greater understanding of the distinct neonatal signature of early and late-stage infection, to improve diagnosis, curtail inappropriate antibiotic use, and promote precision medicine through a biomarker-guided empirical and adjunctive treatment approach for neonatal sepsis. There is an unmet clinical need to decrease sepsis-induced morbidity in neonates, to limit and prevent adverse consequences in later life and decrease mortality.

The Impact of 2 Weight-Based Standard Parenteral Nutrition Formulations Compared With One Standard Formulation on the Incidence of Hyperglycemia and Hypernatremia in Low Birth-Weight Preterm Infants

BACKGROUND

Standardized parenteral nutrition (PN) formulations are used in at-risk neonates to provide nutrition immediately following birth. However, evidence for the optimal formulation(s) to maximize growth while reducing the risks of glucose and electrolyte abnormalities is limited.

PURPOSE

The purpose of this study was to compare the rates of hypernatremia and hyperglycemia with 2 weight-based standardized PN formulations versus one standard PN in low birth-weight preterm neonates.

METHODS

This was a single-center observational study of infants less than 1800 g birth weight and less than 37 weeks' gestation who received standardized PN in the first 48 hours of life. Patients in the weight-based PN group were compared with a historical group of patients receiving single standard PN. Rates of hypernatremia and hyperglycemia were compared by χ2 analysis.

RESULTS

There was a nonsignificant (P = .147) reduction in hypernatremia in the weight-based PN group (9 of 87; 10.3%) compared with the single PN group (16 of 89; 18.0%). However, hyperglycemia was significantly more frequent in the weight-based group than in the single PN group (24.1% vs 12.4%, P = .035).

IMPLICATIONS FOR PRACTICE

The 2 weight-based PN standardized formulations studied did not significantly decrease the incidence of hypernatremia or hyperglycemia.

IMPLICATIONS FOR RESEARCH

Future studies to determine optimal standardized PN to provide early nutrition in high-risk neonates are warranted.

Monitoring the incidence, duration and distribution of hyperglycaemia in very-low-birth-weight newborns and identifying associated factors

Objectives Hyperglycaemia is a common metabolic disorder in very-low-birth-weight (VLBW) infants and is associated with increased morbidity and mortality. The objective is to describe the incidence, duration, episodes and distribution of hyperglycaemia during the first 7 days of life of VLBW infants. Methods This is a prospective cohort study of 60 newborns weighing <1,500 g. Blood glucose levels were monitored with a continuous glucose monitoring system (CGMS) during the first 7 days of life. Hyperglycaemia was defined as glucose ≥180 mg/dL (≥10 mmol/L). Results Incidence of hyperglycaemia recorded with the CGMS was 36.6% (95%CI: 24.6-50.1). In almost 74.6±5.48% of these cases the duration of the episode exceeded 30 min and in 45.25% (95%CI: 2.26-57.82) it exceeded 2 h. The condition occurred most frequently during the first 72 h of life. One-fifth of cases were not detected with scheduled capillary tests and 84.6% of these had hyperglycaemic episode durations of 30 min or more. Agreement between the two techniques was very good (r=0.90, p<0.001) and the CGMS proved to be reliable, accurate and safe. Hyperglycaemia detected by a CGMS is associated with lower gestational age (OR: 0.66, p=0.002), lower birth weight (OR: 0.99, p=0.003), the use of ionotropic drugs (OR: 11.07, p=0.005) and death (OR: 10.59, p=0.03), and is more frequent in preterm infants with sepsis (OR: 2.73, p=0.1). No other association was observed. Conclusions A CGMS could be useful during the first week of life in VLBW infants due to the high incidence and significant duration of hyperglycaemia and the high proportion of cases that remain undetected. The advantage of the CGMS is that it is able to detect hyperglycaemic episodes that the capillary test does not.

Neonatal Hyperglycemia, which threshold value, diagnostic approach and treatment?: Turkish Neonatal and Pediatric Endocrinology and Diabetes Societies consensus report

Hyperglycemia has become an important risk factor for mortality and morbidity in the neonatal period, especially with increased survival rates of very low birth weight neonates. Hyperglycemia in the neonatal period develops as a result of various mechanisms including iatrogenic causes, inability to supress hepatic glucose production, insulin resistance or glucose intolerance, specifically in preterm neonates. Initiation of parenteral or enteral feeding in the early period in preterm babies increases insulin production and sensitivity. The plasma glucose is targeted to be kept between 70 and 150 mg/dL in the newborn baby. While a blood glucose value above 150 mg/dL is defined as hyperglycemia, blood glucose values measured with an interval of 4 hours of >180-200 mg/dL and +2 glucosuria require treatment. Although glucose infusion rate is reduced in treatment, use of insulin is recommended, if two blood glucose values measured with an interval of 4 hours are >250 mg/dL and glucosuria is present in two separate urine samples.

Comparing the intestinal transcriptome of Meishan and Large White piglets during late fetal development reveals genes involved in glucose and lipid metabolism and immunity as valuable clues of intestinal maturity

Background

Maturity of intestinal functions is critical for neonatal health and survival, but comprehensive description of mechanisms underlying intestinal maturation that occur during late gestation still remain poorly characterized. The aim of this study was to investigate biological processes specifically involved in intestinal maturation by comparing fetal jejunal transcriptomes of two representative porcine breeds (Large White, LW; Meishan, MS) with contrasting neonatal vitality and maturity, at two key time points during late gestation (gestational days 90 and 110). MS and LW sows inseminated with mixed semen (from breed LW and MS) gave birth to both purebred and crossbred fetuses. We hypothesized that part of the differences in neonatal maturity between the two breeds results from distinct developmental profiles of the fetal intestine during late gestation. Reciprocal crossed fetuses were used to analyze the effect of parental genome. Transcriptomic data and 23 phenotypic variables known to be associated with maturity trait were integrated using multivariate analysis with expectation of identifying relevant genes-phenotypic variable relationships involved in intestinal maturation.

Results

A moderate maternal genotype effect, but no paternal genotype effect, was observed on offspring intestinal maturation. Four hundred and four differentially expressed probes, corresponding to 274 differentially expressed genes (DEGs), more specifically involved in the maturation process were further studied. In day 110-MS fetuses, Ingenuity® functional enrichment analysis revealed that 46% of DEGs were involved in glucose and lipid metabolism, cell proliferation, vasculogenesis and hormone synthesis compared to day 90-MS fetuses. Expression of genes involved in immune pathways including phagocytosis, inflammation and defense processes was changed in day 110-LW compared to day 90-LW fetuses (corresponding to 13% of DEGs). The transcriptional regulator PPARGC1A was predicted to be an important regulator of differentially expressed genes in MS. Fetal blood fructose level, intestinal lactase activity and villous height were the best predicted phenotypic variables with probes mostly involved in lipid metabolism, carbohydrate metabolism and cellular movement biological pathways.

Conclusions

Collectively, our findings indicate that the neonatal maturity of pig intestine may rely on functional development of glucose and lipid metabolisms, immune phagocyte differentiation and inflammatory pathways. This process may partially be governed by PPARGC1A.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-4001-2) contains supplementary material, which is available to authorized users.

Early postnatal hyperglycaemia is a risk factor for treatment-demanding retinopathy of prematurity

BACKGROUND

To investigate whether neonatal hyperglycaemia in the first postnatal week is associated with treatment-demanding retinopathy of prematurity (ROP).

METHODS

This is a Danish national, retrospective, case-control study of premature infants (birth period 2003-2006). Three national registers were searched, and data were linked through a unique civil registration number. The study sample consisted of 106 cases each matched with two comparison infants. Matching criteria were gestational age (GA) at birth, ROP not registered and born at the same neonatal intensive care unit. Potential 'new' risk factors were analysed in a multivariate logistic regression model, while adjusted for previously recognised risk factors (ie, GA at birth, small for gestational age, multiple birth and male sex).

RESULTS

Hospital records of 310 preterm infants (106 treated; 204 comparison infants) were available. Nutrition in terms of energy (kcal/kg/week) and protein (g/kg/week) given to the preterm infants during the first postnatal week were statistically insignificant between the study groups (Mann-Whitney U test; p=0.165/p=0.163). Early postnatal weight gain between the two study groups was borderline significant (t-test; p=0.047). Hyperglycaemic events (indexed value) were statistically significantly different between the two study groups (Mann-Whitney U test; p<0.001). Hyperglycaemia was a statistically independent risk factor (OR: 1.022; 95% CI 1.002 to 1.042; p=0.031).

CONCLUSION

An independent association was found between the occurrence of hyperglycaemic events during the first postnatal week and later development of treatment-demanding ROP, when adjusted for known risk factors.

Nutrition for the Extremely Preterm Infant

With advancements in the care of preterm infants, the goals in nutritional care have expanded from survival and mimicking fetal growth to optimizing neurodevelopmental outcomes. Inadequate nutritional support may be a risk factor for major complications of prematurity; conversely, higher disease burden is a risk for growth restriction. Early complete parenteral nutrition support, including intravenous lipid emulsion, should be adopted, and the next challenge that should be addressed is parenteral nutrition customized to fit the specific needs and metabolism of the extremely preterm infant. Standardized feeding protocols should be adopted.

Inhibition of corticotropin-releasing hormone receptor 1 and activation of receptor 2 protect against colonic injury and promote epithelium repair

Maternal separation (MS) in neonates can lead to intestinal injury. MS in neonatal mice disrupts mucosal morphology, induces colonic inflammation and increases trans-cellular permeability. Several studies indicate that intestinal epithelial stem cells are capable of initiating gut repair in a variety of injury models but have not been reported in MS. The pathophysiology of MS-induced gut injury and subsequent repair remains unclear, but communication between the brain and gut contribute to MS-induced colonic injury. Corticotropin-releasing hormone (CRH) is one of the mediators involved in the brain–gut axis response to MS-induced damage. We investigated the roles of the CRH receptors, CRHR1 and CRHR2, in MS-induced intestinal injury and subsequent repair. To distinguish their specific roles in mucosal injury, we selectively blocked CRHR1 and CRHR2 with pharmacological antagonists. Our results show that in response to MS, CRHR1 mediates gut injury by promoting intestinal inflammation, increasing gut permeability, altering intestinal morphology, and modulating the intestinal microbiota. In contrast, CRHR2 activates intestinal stem cells and is important for gut repair. Thus, selectively blocking CRHR1 and promoting CRHR2 activity could prevent the development of intestinal injuries and enhance repair in the neonatal period when there is increased risk of intestinal injury such as necrotizing enterocolitis.

Continuous glucose monitoring in preterm infants: evaluation by a modified Clarke error grid

Background

Continuous glucose monitoring using subcutaneous sensors has been validated in adults and children with diabetes, and was found to be useful in the management of glucose control. We aimed to assess feasibility and reliability of a new continuous glucose monitoring system (CGMS) in a population of preterm neonates using a Clarke error grid (CEG) specifically modified for preterm infants.

Methods

Preterm infants were recruited within 24 h from delivery. A subcutaneous sensor connected to a CGMS was inserted and maintained for 6 days. Data collected from CGMS were compared with data obtained using a glucometer. Management of the infants followed standard protocols and was not influenced by CGMS readings.

Results

Twenty patients (9 males) were included. Median (range) gestational age was 32 weeks (27–36) and median (range) birth weight was 1350 g (860–3360). Average CGMS recording time was 137 h, for a total of 449 paired glucose levels. CEG and modified CEG criteria for clinical significance were met.

Conclusion

CGMS is a safe and clinically adequate method to estimate glucose levels in preterm infants. As the glucose level can be evaluated in real time, this CGMS could be useful to reduce the number of heel sticks, to observe glycaemic trends and to promptly detect episodes of both hypo- and hyper-glycaemia.

Perioperative glycaemic control for preterm infant with transient neonatal hyperglycaemia and gastroschisis

Background

Neonatal hyperglycaemia is a rare metabolic disorder. There are no reports of an association between neonatal hyperglycaemia and gastroschisis.

Case presentation

This report presents preoperative and intraoperative management of blood sugar in a low birth weight Thai preterm neonate with gastroschisis and a diagnosis of neonatal hyperglycaemia. The patient underwent an emergency, multi-staged, surgical repair under general anaesthesia.

Conclusion

Anaesthesiologists should be aware of possible perioperative dysglycaemic conditions in these patients. Proper timing of surgery and appropriate preanaesthetic preparation are necessary to reduce the morbidity and mortality related to hyperglycaemia and gastroschisis.

Consent

The patient’s guardian has given consent for the case report to be published.

Glucosuria as an early marker of late-onset sepsis in preterms: a prospective cohort study

Background

Early and accurate diagnosis of late-onset sepsis (LONS) in preterm infants is difficult since presenting signs are subtle and non-specific. Because neonatal sepsis may be accompanied by glucose intolerance and glucosuria, we hypothesized that glucosuria may be associated with LONS in preterms, in an early stage. We aim to evaluate the association of glucosuria and late-onset neonatal sepsis (LONS) in preterm infants, in an attempt to improve early and accurate diagnosis of LONS.

Methods

We performed a prospective observational cohort study in 316 preterms (<34 weeks). We daily measured glucosuria and followed patients for occurrence of LONS, defined as clinical and blood culture-proven sepsis occurring after 72 h. Attending physicians were blinded to glucosuria results. We assessed the diagnostic value of glucosuria for clinical and blood culture-proven LONS using logistic regression analysis.

Results

Glucosuria was found in 65.8 % of 316 preterm patients, and sepsis was suspected 157 times in 123 patients. LONS was found in 47.1 % of 157 suspected episodes. The presence of glucosuria was associated with LONS (OR 2.59, 95 % CI 1.24–5.43, p = 0.012) with sensitivity 69.0 % and specificity 53.8 % (Likelihoodratio 1.49). After adjustment for gestational age, birth weight, and postnatal age, this association weakened and was no longer significant (adjusted OR 2.16; 95 % CI 0.99–1.85, p = 0.055). An increase in glucosuria 48–24 h before onset of symptoms was not associated with LONS.

Conclusion

In preterms glucosuria is associated with LONS within 24 h, however this association is too weak to be of diagnostic value.

Effect of premedication regimen on infant pain and stress response to endotracheal intubation

OBJECTIVE

(1) Evaluate the effect of different medications on pain and stress in neonates during nonemergent endotracheal intubation; (2) determine whether gestational age affects medication use; (3) determine whether better sedation results in a decrease in the number of attempts and/or total time for the procedure.

STUDY DESIGN

Prospective observational study. Infant responses were measured using a clinical pain scale and blood glucose, a biochemical marker of acute stress.

RESULT

A total of 166 infants were included, with adjusted gestational ages 24 to 44 weeks at the time of procedure. Premedication regimens included no medication ('none,' 27%), morphine (19%), morphine+midazolam (11%), fentanyl (14%), fentanyl+midazolam (19%) and midazolam alone (10%). Fentanyl+midazolam resulted in lower pain scores and less increase in blood glucose (both P<0.0001). No other regimen was different from 'none'. The most immature infants were less likely to receive premedication (P=0.023), although their pain scores and blood glucose responses were similar to more mature infants. None of the medication regimens reduced the total procedure time (P=0.55) or the number of attempts (P=0.145).

CONCLUSION

Only fentanyl+midazolam significantly attenuated both the clinical pain score and the increase in blood glucose. Less mature infants had responses similar to those of more mature infants, but were less likely to receive premedication. None of the regimens decreased the time or number of attempts required for successful intubation.

Dose-dependent effects of morphine exposure on mRNA and microRNA (miR) expression in hippocampus of stressed neonatal mice

Morphine is used to sedate critically ill infants to treat painful or stressful conditions associated with intensive care. Whether neonatal morphine exposure affects microRNA (miR) expression and thereby alters mRNA regulation is unknown. We tested the hypothesis that repeated morphine treatment in stress-exposed neonatal mice alters hippocampal mRNA and miR expression. C57BL/6 male mice were treated from postnatal day (P) 5 to P9 with morphine sulfate at 2 or 5 mg/kg ip twice daily and then exposed to stress consisting of hypoxia (100% N₂ 1 min and 100% O₂ 5 min) followed by 2h maternal separation. Control mice were untreated and dam-reared. mRNA and miR expression profiling was performed on hippocampal tissues at P9. Overall, 2 and 5 mg/kg morphine treatment altered expression of a total of 150 transcripts (>1.5 fold change, P<0.05) from which 100 unique mRNAs were recognized (21 genes were up- and 79 genes were down-regulated), and 5 mg/kg morphine affected 63 mRNAs exclusively. The most upregulated mRNAs were fidgetin, arginine vasopressin, and resistin-like alpha, and the most down-regulated were defensin beta 11, aquaporin 1, calmodulin-like 4, chloride intracellular channel 6, and claudin 2. Gene Set Enrichment Analysis revealed that morphine treatment affected pathways related to cell cycle, membrane function, signaling, metabolism, cell death, transcriptional regulation, and immune response. Morphine decreased expression of miR-204-5p, miR-455-3p, miR-448-5p, and miR-574-3p. Nine morphine-responsive mRNAs that are involved in neurodevelopment, neurotransmission, and inflammation are predicted targets of the aforementioned differentially expressed miRs. These data establish that morphine produces dose-dependent changes in both hippocampal mRNA and miR expression in stressed neonatal mice. If permanent, morphine–mediated neuroepigenetic effects may affect long-term hippocampal function, and this provides a mechanism for the neonatal morphine-related impairment of adult learning.

The metabolomics of necrotising enterocolitis in preterm babies: an exploratory study

OBJECTIVE

No single diagnostic investigation is currently available for necrotising enterocolitis (NEC). We implemented a novel, untargeted, exploratory study to determine whether metabolomics can reveal early biomarker(s) of NEC. The effect of gestational age on the metabolome was also investigated.

METHODS

Two serum samples were obtained from 12 preterm babies (born <30 weeks gestation) and eight term controls: sample "A" at ≤1 week of age and sample "B" once fully fed. Samples were subjected to gas chromatography-mass spectrometry. Metabolomic data was analysed by principal component analysis (PCA), univariate and network analysis.

RESULTS

Sixteen metabolite features significantly differed when B samples were compared between preterm babies who subsequently developed NEC and preterm/term controls (p value <0.05). Of these seven metabolites were linked to up-regulation of IL-1β. Significant differences in 54 metabolite features (p value <0.05) were observed between preterm and term metabolomes. Of these, 12 metabolite features were linked to one network involved in carbohydrate/lipid metabolism (p = 1 × 10(-30)).

CONCLUSIONS

Metabolomic differences were observed in preterm babies at risk of NEC. However, sample sizes were insufficient to confidently identify a biomarker. Network modelling of preterm and term metabolomes suggest possible nutritional deficiency and altered pro-insulin action in preterm babies.

Reliability of reagent strips for semi-quantitative measurement of glucosuria in a neonatal intensive care setting

BACKGROUND

Glucosuria in preterm infants is often measured using a visually readable reagent strip, e.g., when monitoring total parenteral nutrition or during sepsis or when treating with corticosteroids. However, the specific circumstances in a neonatal intensive care unit (NICU), such as the use of diapers and the high temperature in incubators, could affect its reliability.

OBJECTIVES

To evaluate the reliability of the semi-quantitative measurement of glucosuria under the specific circumstances of a NICU setting.

METHODS

Nine hundred assessments of artificially supplemented (contrived) urine samples, intended to simulate pathological specimens, were performed under the following varying conditions: environmental temperature (21°C and 34°C); different times of contact of the urine with the diaper; and using two different methods of collecting urine from the diaper. Each reagent strip was read independently by three observers. The test strips scores were categorized as 0, 1+, 2+, 3+, or 4+ in ascending degree of glucosuria.

RESULTS

Agreement was excellent under all the different conditions (temperature, weighted kappa (κ(w)) = 0.92; method of urine collection, κ(w) = 0.88; time, p = 0.266). Inter-observer reliability was very good (multi-rater κ = 0.81). The deviation between the different conditions was seldom larger than one category (2.9%). The reagent strip readings were concordant with the true urinary glucose concentrations in 79.0% of assessments. The discordance was never larger than one category.

CONCLUSION

The reliability of the semi-quantitative measurement of glucosuria in newborn infants using reagent strips is good, even under the conditions of a NICU. Changes in the rating of reagent strips of more than one category are most likely to be beyond measurement error.

Instability of glucose values in very preterm babies at term postmenstrual age

OBJECTIVE

To determine if very preterm (VPT) babies are capable of maintaining glucose levels within normal ranges at or near term postmenstrual age.

STUDY DESIGN

Glucose levels were intermittently or continuously monitored during 48 hours in a cohort of 60 VPT infants near hospital discharge. Hypoglycemic (≤45 mg/dL, 2.5 mmol/L) and hyperglycemic (≥140 mg/dL or 7.8 mmol/L, severe if ≥180 mg/dL or 10 mmol/L) episodes were considered relevant if they lasted longer than 30 minutes. Feeding regimes followed current practice.

RESULTS

With intermittent capillary, 2 hypoglycemic values and another 3 that were abnormally high were detected. With continuous monitoring, 6 babies (10.0%) had isolated hypoglycemia ≤45 mg/dL (2.5 mmol/L) (3 of them reaching 40 mg/dL, 2.2 mmol/L), 14 (23.3%) had isolated hyperglycemia, and 8 (13.3%) had episodes of both. The mean duration of hypoglycemia per patient was 2.8 ± 2.9 hours and 4.68 ± 4.35 hours in the case of hyperglycemia, with 12 infants becoming severely hyperglycemic. Of the 12 severely hyperglycemic patients, 5 also developed severe hypoglycemia. No specific characteristics identified the hypoglycemic babies. A history of intrauterine growth restriction (P = .037) and female sex (P = .063) seemed to increase the risk of severe hyperglycemia.

CONCLUSIONS

VPT infants continue to have abnormal glucose values, especially hyperglycemia, by the time of hospital discharge. No specific factors identify babies at higher risk for hypoglycemia, and intrauterine growth restriction and female sex seemed to predispose to hyperglycemia.

A prospective study on hyperglycemia and retinopathy of prematurity

OBJECTIVE

Retinopathy of prematurity (ROP) constitutes a significant morbidity in premature infants that can lead to blindness. Multiple retrospective studies have identified neonatal hyperglycemia as a risk for developing ROP. However, in the absence of any reported prospective study, it is not clear whether hyperglycemia is associated with ROP independent of the commonly associated comorbidities. The objective of this study was to investigate whether hyperglycemia in premature infants is independently associated with ROP.

STUDY DESIGN

Premature infants (<1500 g or⩽32 weeks gestational age) were enrolled in a prospective longitudinal cohort study. All demographic, clinical and laboratory data were collected. Bedside whole-blood glucose concentration was measured every 8 h daily for 7 days. For any glucose reading<50 or>150 mg dl(-1), serum sample was sent to the laboratory for confirmation. Hyperglycemia was defined as any blood glucose level⩾150 mg dl(-1). ROP patients were compared with non-ROP patients in a bivariate analysis. Variables significantly associated with ROP were studied in a logistic regression model.

RESULT

A total of 65 patients were enrolled with gestational age 31.1±1.2 weeks and birth weight 1385±226 g. Thirty-one patients (48%) were identified with hyperglycemia. On eye examination, 19 cases (29.2%) had ROP (13 with stage 1, 4 with stage 2 and 2 with stage 3). There were more cases of ROP in the hyperglycemia group compared with the euglycemia group (45% vs 15%, P=0.007). Patients who developed ROP had significantly higher maximum and average glucose concentrations when compared with non-ROP patients. Multiple factors have been associated with ROP on bivariate analysis, including gestational age, exposure to oxygen, respiratory support and poor weight gain. However, in a logistic regression model including all significant variables, average blood glucose in the first week of life was the factor independently associated with ROP with an odds ratio of: 1.77 (95% confidence interval: 1.08 to 2.86), P=0.024.

CONCLUSION

In a cohort of premature infants, elevated average blood glucose concentrations in the first week of life is independently associated with the development of ROP.

The effect of blood glucose and pCO2 on spectral EEG of premature infants during the first three days of life

BACKGROUND

Spectral EEG analysis using automated quantification of total absolute band power (tABP) expresses brain function. We hypothesized that pCO2 or blood glucose affects tABP during the critical first days of life in premature infants.

OBJECTIVE

To use automated tABP quantification to determine whether EEG background activity in premature infants during the first 3 days of life is influenced by pCO2 or blood glucose levels.

METHODS

Preterm infants, group 1 [gestational age (GA) = 24-27 weeks] and group 2 (GA = 28-30 weeks), underwent continuous EEG monitoring for 3 days after birth. Biochemical data were extracted from the observational datasheet used during monitoring. Blood samples were taken at the request of the attending physician. Statistical analyses were performed as repeated measurements using linear mixed models with a random intercept. The effect of time was treated as a fixed covariate and the GA groups as a fixed factor in all models. Continuous data were described using the mean ± SD or median and range, and categorical data were described using the number of patients and percentages unless otherwise indicated.

RESULTS

There was an association between increased pCO2 and tABP and between increased blood glucose and tABP. Further, there were no differences in the responses between groups 1 and 2.

CONCLUSION

Both hyperglycemia and hypercapnia showed a negative effect on brain activity decreasing tABP during the first 3 days of life in premature infants.

Insulin dysregulation

Abnormalities of insulin metabolism include hyperinsulinaemia and insulin resistance, and these problems are collectively referred to as insulin dysregulation in this review. Insulin dysregulation is a key component of equine metabolic syndrome: a collection of endocrine and metabolic abnormalities associated with the development of laminitis in horses, ponies and donkeys. Insulin dysregulation can also accompany prematurity and systemic illness in foals. Causes of insulin resistance are discussed, including pathological conditions of obesity, systemic inflammation and pituitary pars intermedia dysfunction, as well as the physiological responses to stress and pregnancy. Most of the discussion of insulin dysregulation to date has focused on insulin resistance, but there is increasing interest in hyperinsulinaemia itself and insulin responses to feeding. An oral sugar test or in-feed oral glucose tolerance test can be performed to assess insulin responses to dietary carbohydrates, and these tests are now recommended for use in clinical practice. Incretin hormones are likely to play an important role in postprandial hyperinsulinaemia and are the subject of current research. Insulin resistance exacerbates hyperinsulinaemia, and insulin sensitivity can be measured by performing a combined glucose-insulin test or i.v. insulin tolerance test. In both of these tests, exogenous insulin is administered and the rate of glucose uptake into tissues measured. Diagnosis and management of hyperinsulinaemia is recommended to reduce the risk of laminitis. The term insulin dysregulation is introduced here to refer collectively to excessive insulin responses to sugars, fasting hyperinsulinaemia and insulin resistance, which are all components of equine metabolic syndrome.

Permissive hyperglycemia in extremely low birth weight infants

The aim of this study is to evaluate the outcomes of permissive hyperglycemia up to < 300 mg/dL in extremely-low-birth-weight infants (ELBWIs). We retrospectively reviewed the medical records of 260 live-born ELBWIs at Samsung Medical Center between 2004 and 2008, grouped according to peak blood glucose level and management during the first 14 days of life. The groups were normoglycemia (N), blood glucose ≤ 200 mg/dL; permissive hyperglycemia (P), blood glucose 201-299 mg/dL without insulin treatment; treated hyperglycemia (T), blood glucose ≥ 300 mg/dL with insulin. Only 15% of patients were grouped as N, with 39% as P and 46% as T. Although P had lower birth weight, P had a similar daily calorie and glucose intake as well as urine output compared to N. There was no significant correlation between blood glucose level and urine output on day 7. Compared to N, P showed faster weight gain and similar mortality, morbidities, and long-term neurological outcomes. Permissive hyperglycemia up to < 300 mg/dL without insulin treatment during the first 14 days of life is not associated with osmotic diuresis or increased mortality or morbidities, suggesting that it is not detrimental in ELBWIs.