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

Management of Neonatal Hyperglycaemia in Sweden-A Survey Study

AIM

Neonatal hyperglycaemia is associated with a multitude of adverse outcomes, including mortality and impaired neurological development. The aim of this study was to characterise the current management of neonatal hyperglycaemia in Swedish neonatal units.

METHODS

A digital survey was sent to 27 Swedish neonatal units providing care to preterm infants born before 32 completed gestational weeks.

RESULTS

Sixty-eight responses were collected from 21 different units. Thirty-two percent (22/68) of clinicians reported having a local treatment guideline for neonatal hyperglycaemia. Hyperglycaemia was defined as a glucose concentration above a value in the range of 8.0-10.0 mmol/L by 62.5% of clinicians, while 16.7% and 21.8% used a definition between 10.1 and 12.0 mmol/L and > 12 mmol/L, respectively. Intravenous glucose reduction was initiated at higher glucose concentrations by clinicians working at university hospital units (p = 0.006). Glucose concentration threshold for initiation of insulin treatment varied between 8 and 30 mmol/L. Three clinicians (3/35 (8.5%)) reported having experienced problems with frequent hypoglycaemia during ongoing insulin treatment.

CONCLUSIONS

This study demonstrates extensive differences in clinical practice regarding neonatal hyperglycaemia both within and between neonatal units in Sweden. Randomised controlled trials are needed to provide evidence for clinical guidelines and to improve and standardise the care of these infants.

Glucose disturbances in very low-birthweight infants-Results from the prospective LIGHT study

AIM

To describe glucose homeostasis disturbances (dysglycaemia) in very low-birthweight infants (<1500 g) during the admission period and explore associated risk factors.

METHODS

The LIGHT (very low-birthweight infants - glucose and hormonal profile over time) study was a prospective observational cohort study that included 49 very low-birthweight infants admitted to the tertiary neonatal intensive care unit in Umeå, Sweden, during 2016-2019. All glucose concentrations (n = 3515) sampled during the admission period were registered.

RESULTS

Hyperglycaemia >10 mmol/L and hypoglycaemia <2.6 mmol/L were registered in 63% and 55% of the infants, respectively. Onset of dysglycaemia occurred almost exclusively in the first postnatal week. Hyperglycaemia followed 15% of corticosteroid doses given; all were preceded by pre-existing hyperglycaemia. Pre-existing hyperglycaemia was found in 66.7% of hyperglycaemic infants who received inotrope treatment. Upon commencement, 72.5% of antimicrobial treatments given were neither preceded nor followed by hyperglycaemia.

CONCLUSION

Dysglycaemia was common in very low-birthweight infants. Daily means of glucose concentrations seemed to follow a postmenstrual age-dependent pattern, decreasing towards term age suggesting a postmenstrual age-dependent developmental mechanism. The primary mechanism causing hyperglycaemia was independent of sepsis, and corticosteroid and inotrope treatments. No hypoglycaemia was registered during ongoing insulin treatment.

Insulin for Treatment of Neonatal Hyperglycemia in Premature Infants: Prevalence over Time and Association with Outcomes

OBJECTIVE

Our objective was to determine the prevalence of insulin treatment in premature infants with hyperglycemia and evaluate the association of length of treatment with outcomes.

STUDY DESIGN

The study included cohort of 29,974 infants 22 to 32 weeks gestational age (GA) admitted to over 300 neonatal intensive care unit (NICU) from 1997 to 2018 and diagnosed with hyperglycemia.

RESULTS

Use of insulin significantly decreased during the study period (p = 0.002) among studied NICUs. The percentage of hyperglycemic infants exposed to insulin ranged from 0 to 81%. Infants who received insulin were more likely to have lower GA, birth weight, 5-minute Apgar score, longer duration of stay, and require mechanical ventilation. After adjustment for GA, infants requiring insulin for >14 days were more likely to have treated retinopathy of prematurity (ROP) and develop chronic lung disease (CLD). Insulin treatment of 1 to 7 days had increased odds of death, death/ROP, and death/CLD compared with no exposure.

CONCLUSION

Insulin use decreased over time, and differing durations of use were associated with adverse outcomes.

KEY POINTS

· Insulin use decreased over time.. · There is a temporal relation between the duration of treatment and adverse outcomes.. · Further studies are needed to determine the efficacy and safety of insulin use..

Insulin resistance prior to term age in very low birthweight infants: a prospective study

OBJECTIVE

To explore the glucose-related hormone profile of very low birthweight (VLBW) infants and assess the association between neonatal hyperglycaemia and insulin resistance during the admission period.

DESIGN

A prospective observational study-the Very Low Birth Weight Infants, Glucose and Hormonal Profiles over Time study.

SETTING

A tertiary neonatal intensive care unit and four neonatal units in county hospitals in Sweden.

PATIENTS

48 infants born <1500 g (VLBW) during 2016-2019.

OUTCOME MEASURES

Plasma concentrations of glucose-related hormones and proteins (C-peptide, insulin, ghrelin, glucagon-like peptide 1 (GLP-1), glucagon, leptin, resistin and proinsulin), insulin:C-peptide and proinsulin:insulin ratios, Homoeostatic Model Assessment 2 (HOMA2) and Quantitative Insulin Sensitivity Check (QUICKI) indices, measured on day of life (DOL) 7 and at postmenstrual age 36 weeks.

RESULTS

Lower gestational age was significantly associated with higher glucose, C-peptide, insulin, proinsulin, leptin, ghrelin, resistin and GLP-1 concentrations, increased HOMA2 index, and decreased QUICKI index and proinsulin:insulin ratio. Hyperglycaemic infants had significantly higher glucose, C-peptide, insulin, leptin and proinsulin concentrations, and lower QUICKI index, than normoglycaemic infants. Higher glucose and proinsulin concentrations and insulin:C-peptide ratio, and lower QUICKI index on DOL 7 were significantly associated with longer duration of hyperglycaemia during the admission period.

CONCLUSIONS

VLBW infants seem to have a hormone profile consistent with insulin resistance. Lower gestational age and hyperglycaemia are associated with higher concentrations of insulin resistance markers.

Hyperglycemia and prematurity: a narrative review

Hyperglycemia is commonly encountered in extremely preterm newborns and physiologically can be attributed to immaturity in several biochemical pathways related to glucose metabolism. Although hyperglycemia is associated with a variety of adverse outcomes frequently described in this population, evidence for causality is lacking. Variations in definitions and treatment approaches have further complicated the understanding and implications of hyperglycemia on the immediate and long-term effects in preterm newborns. In this review, we describe the relationship between hyperglycemia and organ development, outcomes, treatment options, and potential gaps in knowledge that need further research. IMPACT: Hyperglycemia is common and less well described than hypoglycemia in extremely preterm newborns. Hyperglycemia can be attributed to immaturity in several cellular pathways involved in glucose metabolism in this age group. Hyperglycemia has been shown to be associated with a variety of adverse outcomes frequently described in this population; however, evidence for causality is lacking. Variations in definitions and treatment approaches have complicated the understanding and the implications of hyperglycemia on the immediate and long-term effects outcomes. This review describes the relationship between hyperglycemia and organ development, outcomes, treatment options, and potential gaps in knowledge that need further research.

Should continuous glucose monitoring be used to manage neonates at risk of hypoglycaemia?

The National Institute for Clinical Excellence (NICE) now recommends that continuous glucose monitoring (CGM) be offered to adults and children with diabetes who are at risk from hypoglycaemia. Hypoglycaemia is common in the neonatal period, and is a preventable cause of poor neurodevelopmental outcome, but is CGM helpful in the management of neonates at risk of hypoglycaemia? Neonatal studies have shown that CGM can detect clinically silent hypoglycaemia, which has been associated with reduced executive and visual function in early childhood. Intervention trials have further shown CGM can support the targeting of glucose levels in high-risk extremely preterm neonates. In spite of significant advances in technology, including smaller sensors, better accuracy and factory calibration, further progress and adoption into clinical practice has been limited as current devices are not designed nor have regulatory approval for the specific needs of the newborn. The use of CGM has the potential to support clinical management, and prevention of hypoglycaemia but must be set within its current limitations. The data CGM provides however also provides an important opportunity to improve our understanding of potential risks of hypoglycaemia and the impact of clinical interventions to prevent it.

Neonatal Hyperglycemia Related to Parenteral Nutrition Affects Long-Term Neurodevelopment in Preterm Newborn: A Prospective Cohort Study

(1) Background: Recent evidence reported a reduced tolerance of macronutrient parenteral intakes in subjects in critically ill conditions. We designed a prospective cohort study to evaluate the effects of hyperglycemia (HG) related to parenteral nutrition (PN) on neurodevelopment (NDV) in survived preterm newborns. (2) Methods: Enrolled newborns with gestational age < 32 weeks or birth weight < 1500 g, were divided in two cohorts: (A) exposed to moderate or severe HG (glucose blood level > 180 mg/dL) in the first week of life; (B) not exposed to HG. We considered as the primary outcome the rate of preterm newborns survived without NDV delay at 24 months of life, evaluated with Bayley Scales of Infants Development III edition. (3) Results: We analyzed 108 (A 32 vs. B 76) at 24 months of life. Newborns in cohort A showed a higher rate of cognitive and motor delay (A 44% vs. B 22 %, p = 0.024; A 38% vs. B 8%, p < 0.001). When adjusting for background characteristics, HG remained a risk factor for motor delay. (4) Conclusions: High nutritional intakes through PN soon after birth increase the risk of HG. The consequences of this severe metabolic complication affect long-term NDV and survival in preterm newborns.

Monitoring the Frequency and Duration of Hypoglycemia in Preterm Infants and Identifying Associated Factors

Hypoglycemia is common in very low birth weight neonates and may have adverse effects. Material and Method: Sixty preterm infants were monitored using continuous glucose monitoring (CGMS) and capillary techniques during the first week of life. Hypoglycemia was defined as glucose ≤47 mg/dL (≤2.6 mmol/L). Results: Hypoglycemic episodes were detected in 41.66% (95% CI: 29.07-55.12). In 69.64% the duration was greater than thirty minutes, in 26.78% (95% CI: 15.83-40.3) hypoglycemia exceeded two hours. Hypoglycemia was observed most frequently during the first 48 hours. In 35.7%, hypoglycemia was not detected with capillary tests. The agreement between the two techniques was good (r = 0.77, p < 0.001), Hypoglycemia was associated with a lower birth weight (OR: 0.99, p = 0.06). Conclusions: Hypoglycemia is frequent with significant duration in very low birth weight neonates. CGMS could be considered for use in these neonates to improve their glycemic control and prevent the associated morbidity.

Hyperglycemia in Extremely Preterm Infants

Hyperglycemia after birth is common in extremely preterm infants (<28 weeks of gestation). Lower gestational age, lower birthweight, presence of severe illness, and higher parenteral glucose intake increase the risk for hyperglycemia, while provision of higher amounts of amino acids and lipids in parenteral nutrition and early initiation and faster achievement of full enteral feeding decrease the risk. Hyperglycemia is associated with increased mortality and morbidity in the neonatal period. Limited data show an association with long-term adverse effects on growth, neurodevelopment, and cardiovascular and metabolic health. Lowering the glucose infusion rate and administration of insulin are the 2 treatment options. Lowering the glucose infusion could lead to calorie deficits and long-term adverse effects on growth and neurodevelopment. Conversely, insulin use increases the risk for hypoglycemia and requires close blood glucose monitoring and frequent adjustments to glucose infusion and insulin dosage. Randomized trials of varying strategies of nutrient provision and/or insulin therapy and long-term follow-up are needed to improve clinical care and overall health of extremely preterm infants with hyperglycemia.

Hyperglycaemia in the Newborn Infant. Physiology Verses Pathology

Hyperglycemia is common in newborns requiring intensive care, particularly in preterm infants, in sepsis and following perinatal hypoxia. The clinical significance, and optimal intervention strategy varies with context, but hyperglycaemia is associated with increased mortality and morbidity. The limited evidence for optimal clinical targets mean controversy remains regarding thresholds for intervention, and management strategies. The first consideration in the management of hyperglycaemia must be to ascertain potentially treatable causes. Calculation of the glucose infusion rate (GIR) to insure this is not excessive, is critical but the use of insulin is often helpful in the extremely preterm infant, but is associated with an increased risk of hypoglycaemia. The use of continuous glucose monitoring (CGM) has recently been demonstrated to be helpful in targeting glucose control, and reducing the risk from hypoglycaemia in the preterm infant. Its use in other at risk infants remains to be explored, and further studies are needed to provide a better understanding of the optimal glucose targets for different clinical conditions. In the future the combination of CGM and advances in computer algorithms, to provide intelligent closed loop systems, could allow a safer and more personalized approached to management.

Neonatal Hypoglycaemia: A Never-Ending Story?

Neonatal hypoglycaemia is a common metabolic disorder presenting in the first days of life and one potentially preventable cause of brain injury. However, a universal approach to diagnosis and management is still lacking. The rapid decrease in blood glucose (BG) after birth triggers homeostatic mechanisms. Most episodes of hypoglycaemia are asymptomatic, and symptoms, when they occur, are nonspecific. Therefore, neonatologists are presented with the challenge of identifying infants at risk who might benefit from a rapid and effective therapy while sparing others unnecessary sampling and overtreatment. There is much controversy regarding the definition of hypoglycaemia, and one level does not fit all infants since postnatal age and clinical situations trigger different accepted thresholds for therapy. The concentration and duration of BG which cause neurological damage are unclear. Recognizing which newborn infants are at risk of hypoglycaemia and establishing protocols for treatment are essential to avoid possible deleterious effects on neurodevelopment. Early breastfeeding may reduce the risk of hypoglycaemia, but in some cases, the amount of breast milk available immediately after birth is insufficient or non-existent. In these situations, other therapeutic alternatives such as oral dextrose gel may lower the risk for NICU admissions. Current guidelines continue to be based on expert opinion and weak evidence. However, malpractice litigation related to neurodevelopmental disorders is frequent in children who suffered hypoglycaemia in the neonatal period even if they had other important factors contributing to the poor outcome. This review is aimed to help the practicing paediatricians and neonatologists to comprehend neonatal hypoglycaemia from physiology to therapy, hoping it will result in a rational decision-making process in an area not sufficiently supported by evidence.

Accuracy of continuous glucose monitoring in preterm infants: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Continuous glucose monitoring (CGM) could be a valuable instrument for measurement of glucose concentration in preterm neonate. We undertook a systematic review and meta-analysis to compare the diagnostic accuracy of CGM devices to intermittent blood glucose evaluation methods for the detection of hypoglycaemic or hypoglycaemic events in preterm infants.

DATA SOURCES

A structured electronic database search was performed for studies that assessed the accuracy of CGM against any intermittent blood glucose testing methods in detecting episodes of altered glycaemia in preterm infants. No restrictions were used. Three review authors screened records and included studies.

DATA EXTRACTION

Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. From individual patient data (IPD), sensitivity and specificity were determined using predefined thresholds. The mean absolute relative difference (MARD) of the studied CGM devices was assessed and if those satisfied the accuracy requirements (EN ISO 15197). IPD datasets were meta-analysed using a logistic mixed-effects model. A bivariate model was used to estimate the summary receiver operating characteristic curve (ROC) curve and extract the area under the curve (AUC). The overall level of certainty of the evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

Among 4481 records, 11 were included. IPD datasets were obtained for five studies. Only two of the studies showed an MARD lower than 10%, with none of the five CGM devices studied satisfying the European Union (EU) ISO 15197 requirements. Pooled sensitivity and specificity of CGM devices for hypoglycaemia were 0.39 and 0.99, whereas for hyperglycaemia were 0.87 and 0.99, respectively. The AUC was 0.70 and 0.86, respectively. The certainty of the evidence was considered as low to moderate. Limitations primarily related to the lack of representative population, reference standard and CGM device.

CONCLUSIONS

CGM devices demonstrated low sensitivity for detecting hypoglycaemia in preterm infants, however, provided high accuracy for detection of hyperglycaemia.

PROSPERO REGISTRATION NUMBER

CRD42020152248.

Prematurity at less than 24 weeks of gestation is a risk for prolonged hyperglycemia in extremely low-birth weight infants

Hyperglycemia in extremely low-birth weight infants (ELBWIs) is frequently observed during the acute perinatal phase, (i.e., first 1-2 weeks postnatal period); however it can occasionally persists for >2 weeks, extending to the post-acute phase. Since such prolonged hyperglycemia (PH) is not typical for ELBWIs, the aim of the present study was to further understand the clinical details of PH. Twenty-five hyperglycemic ELBWIs born before 28 weeks of gestation from 2015 to 2018 were included in the study. Based on the duration of hyperglycemia, we separated the subjects into two groups: non-prolonged hyperglycemia (NPH) who achieved remission within ≤2 weeks [n = 18, median 3.0 (range, 2.0-4.0) days], and PH, whose hyperglycemia persisted for >2 weeks [n = 7, median 50.0 (range, 33.5-66.0) days]. Compared to the NPH group, glucose metabolism of the PH group was more deteriorate. The peak blood glucose level was significantly higher in the PH group [PH: median 472 mg/dL, NPH: median 275 mg/dL, p < 0.001], and a higher proportion of subjects in the PH group required insulin therapy [PH: 100% (7/7) vs. NPH: 22% (4/22)]. Multivariate analysis revealed that among perinatal factors, prematurity was the only independent risk factor for PH (glucocorticoid therapy: p = 0.884, gestational age: p = 0.006), with a cutoff of 23W4D determined by receiver operating characteristic analysis. Our data revealed distinctive clinical features of PH, suggesting a type different from the previously reported hyperglycemia in ELBWIs. Specifically, extreme prematurity, less than 24 weeks of gestation, is a risk for PH, and aggressive interventions, such as insulin would be required.

Relationships between Early Nutrition, Illness, and Later Outcomes among Infants Born Preterm with Hyperglycemia

OBJECTIVE

To evaluate the effects of hyperglycemia on body composition and neurodevelopment, and how early nutrition and illness modify these relationships in infants born preterm.

STUDY DESIGN

Prospective data were collected from infants born <32 weeks of gestational age (N = 97), including inpatient days of hyperglycemia (blood glucose >150 mg/dL) and nutrient intake. Body composition was measured at discharge and 4 months' postmenstrual age (PMA). Bayley Scales of Infant Development III (BSID-III) were administered at 12 months' PMA. Linear regression analysis was performed, adjusting for birth gestational age. Associations between hyperglycemia, body composition, and BSID-III were analyzed in models accounting for first-week nutrition and early illness severity via Score for Neonatal Acute Physiology-II.

RESULTS

Mean birth gestational age was 27.8 (SD 2.4) weeks. Hyperglycemia occurred in 48.5% of infants. Hyperglycemia for ≥5 days was negatively associated with fat mass and fat free mass z scores at discharge, and fat free mass z score at 4 months' PMA (P < .05 all). Hyperglycemia for ≥5 days was negatively associated with cognition, language, and motor scores on the BSDI at 12 months (P ≤ .01 all). Associations with body composition and BSID-III were diminished when models included first week nutrition yet remained unchanged when illness severity was included.

CONCLUSIONS

In infants <32 weeks, ≥5 days of hyperglycemia is associated with decreased lean mass at 4 months' PMA and poorer neurodevelopmental outcome at 12 months' PMA. These associations may be mediated by decreased first week nutrition, potentially related to reduced glucose infusion rate for management of hyperglycemia.

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.

Real time continuous glucose monitoring in neonatal intensive care

Hypoglycaemia and hyperglycaemia are common in infants requiring intensive care and are associated with worse clinical outcomes. However, glucose levels are taken infrequently, and there remains controversy regarding optimal management. In adults and children continuous glucose monitoring (CGM) is now established as an important adjunct to caring for patients at risk from dysglycaemia. This technology is also increasingly providing insights into glucose regulation in the newborn, demonstrating significant periods of clinically silent hypoglycaemia and hyperglycaemia. This baseline data will be important to allow the significance of glucose dysregulation on long-term outcomes to be assessed. Small studies have also shown the potential for CGM to safely support targeting of glucose control in preterm infants, and a large multicentre trial is ongoing. Current technology is not specifically designed for use in NICU, but with rapid technological developments, CGM holds promise for the future care of babies in NICU.

Factors influencing glycaemic stability after neonatal hypoglycaemia and relationship to neurodevelopmental outcome

Higher and unstable glucose concentrations in the first 48 hours in neonates at risk of hypoglycaemia have been associated with neurosensory impairment. It is unclear what defines and contributes to instability. This was a prospective study of term and late preterm babies (N = 139) born at risk of neonatal hypoglycaemia who had interstitial glucose (IG) monitoring and ≥1 hypoglycaemic episode <48 hours after birth (blood glucose concentration <2.6 mmol/l [<47 mg/dl]). For 6-hour epochs after each hypoglycaemic episode, masked IG parameters (time to reach maximum IG concentration [hours]; range, average, maximum and minimum IG concentrations; proportion of IG measurements outside the central band of 3–4 mmol/l [54–72 md/dl]; and total duration [hours] of IG concentrations <2.6 mmol/l) were analysed in tertiles and related to: (i) glycaemic instability in the first 48 hours (defined as the proportion of blood glucose concentrations outside the central band in the first 48 hours); (ii) risk factors and treatment for each episode; and (iii) risk of neurosensory impairment at 4.5 years, or at 2 years if a child was not seen at 4.5 years. Glycaemic instability in the first 48 hours was related to IG instability after hypoglycaemia. Risk factors for hypoglycaemia were not related to IG parameters. Treatment with intravenous dextrose was associated with higher IG maximum and range, and lower minimum compared to treatment with dextrose gel plus breast milk, breast milk alone or formula alone. The risk of neurosensory impairment was increased with both shorter and longer time to reach maximum epoch IG (P = 0.04; lower tertile [0.4–2.2 hours] vs middle [2.3–4.2 hours] OR 3.10 [95% CI 1.03; 9.38]; higher tertile [4.3–6.0 hours] vs middle OR 3.07; [95% CI 1.01; 9.24]). Glycaemic response to hypoglycaemia contributes to overall glycaemic instability in newborns and is influenced by treatment. Slow or rapid recovery of hypoglycaemia appears to be associated with neurosensory impairment.

Hyperglycemia in Extremely Preterm Infants-Insulin Treatment, Mortality and Nutrient Intakes

OBJECTIVE

To explore the prevalence of hyperglycemia and the associations between nutritional intakes, hyperglycemia, insulin treatment, and mortality in extremely preterm infants.

STUDY DESIGN

Prospectively collected data from the Extremely Preterm Infants in Sweden Study (EXPRESS) was used in this study and included 580 infants born <27 gestational weeks during 2004-2007. Available glucose measurements (n = 9850) as well as insulin treatment and nutritional data were obtained retrospectively from hospital records for the first 28 postnatal days as well as 28- and 70-day mortality data.

RESULTS

Daily prevalence of hyperglycemia >180 mg/dL (10 mmol/L) of up to 30% was observed during the first 2 postnatal weeks, followed by a slow decrease in its occurrence thereafter. Generalized additive model analysis showed that increasing parenteral carbohydrate supply with 1 g/kg/day was associated with a 1.6% increase in glucose concentration (P < .001). Hyperglycemia was associated with more than double the 28-day mortality risk (P < .01). In a logistic regression model, insulin treatment was associated with lower 28- and 70-day mortality when given to infants with hyperglycemia irrespective of the duration of the hyperglycemic episode (P < .05).

CONCLUSIONS

Hyperglycemia is common in extremely preterm infants throughout the first postnatal month. Glucose infusions seem to have only a minimal impact on glucose concentrations. In the EXPRESS cohort, insulin treatment was associated with lower mortality in infants with hyperglycemia. Current practices of hyperglycemia treatment in extremely preterm infants should be reevaluated and assessed in randomized controlled clinical trials.

Perioperative continuous glucose monitoring in a preterm infant

Surgery in the neonatal period presents challenges, especially in preterm infants weighing <1 kg. Their small size, minimal reserves and physiological immaturity means attention to detail and careful monitoring is critical to avoid cardiovascular instability; maintaining fluid balance and metabolic stability is also problematic due to often limited vascular access and small blood volumes. Developments in technology have meant that cardiovascular parameters such as heart rate, blood pressure and oxygen saturations are all routinely and continuously monitored before and during surgery.We have been exploring the role of continuous glucose monitoring (CGM) for metabolic monitoring and management of glucose control in very preterm infants (24-32 weeks gestation). In this paper, we report on a preterm infant who uniquely underwent surgery while wearing a continuous glucose monitor, blinded to the clinical team. This case highlights the metabolic vulnerability of these babies and a possible role for real-time CGM during surgical procedures.

Neonatal hypoglycemia: continuous glucose monitoring

PURPOSE OF REVIEW

Continuous glucose monitoring (CGM) is increasingly used in the management of diabetes in children and adults, but there are few data regarding its use in neonates. The purpose of this article is to discuss the potential benefits and limitations of CGM in neonates.

RECENT FINDINGS

Smaller electrodes in new sensors and real-time monitoring have made CGM devices more approachable for neonatal care. CGM is well tolerated in infants including very low birth weight babies, and few if any local complications have been reported. Use of CGM in newborns may reduce the frequency of blood sampling and improve glycemic stability, with more time spent in the euglycemic range. However, CGM may also lead to more intervention, with potential adverse effects on outcomes. More information is also needed about reliability, calibration and interpretation of CGM in the neonate.

SUMMARY

Although the use of CGM in neonates appears to be well tolerated, feasible and has been associated with better glycemic status, there is not yet any evidence of improved clinical outcomes. Clinical utility of CGM should be demonstrated in randomized trials prior to its introduction into regular neonatal care.

Continuous glucose monitoring in neonates: a review

Continuous glucose monitoring (CGM) is well established in the management of diabetes mellitus, but its role in neonatal glycaemic control is less clear. CGM has provided important insights about neonatal glucose metabolism, and there is increasing interest in its clinical use, particularly in preterm neonates and in those in whom glucose control is difficult. Neonatal glucose instability, including hypoglycaemia and hyperglycaemia, has been associated with poorer neurodevelopment, and CGM offers the possibility of adjusting treatment in real time to account for individual metabolic requirements while reducing the number of blood tests required, potentially improving long-term outcomes. However, current devices are optimised for use at relatively high glucose concentrations, and several technical issues need to be resolved before real-time CGM can be recommended for routine neonatal care. These include: 1) limited point accuracy, especially at low or rapidly changing glucose concentrations; 2) calibration methods that are designed for higher glucose concentrations of children and adults, and not for neonates; 3) sensor drift, which is under-recognised; and 4) the need for dynamic and integrated metrics that can be related to long-term neurodevelopmental outcomes. CGM remains an important tool for retrospective investigation of neonatal glycaemia and the effect of different treatments on glucose metabolism. However, at present CGM should be limited to research studies, and should only be introduced into routine clinical care once benefit is demonstrated in randomised trials.

Hepatic Insulin Resistance and Altered Gluconeogenic Pathway in Premature Baboons

Premature infants have altered glucose regulation early in life and increased risk for diabetes in adulthood. Although prematurity leads to an increased risk of diabetes and metabolic syndrome in adult life, the role of hepatic glucose regulation and adaptation to an early extrauterine environment in preterm infants remain unknown. The purpose of this study was to investigate developmental differences in glucose metabolism, hepatic protein content, and gene expression of key insulin-signaling/gluconeogenic molecules. Fetal baboons were delivered at 67%, 75%, and term gestational age and euthanized at birth. Neonatal baboons were delivered prematurely (67% gestation), survived for two weeks, and compared with similar postnatal term animals and underwent serial hyperinsulinemic-euglycemic clamp studies. Premature baboons had decreased endogenous glucose production (EGP) compared with term animals. Consistent with these results, the gluconeogenic molecule, phosphoenolpyruvate carboxykinase messenger RNA, was decreased in preterm baboons compared with terms. Hepatic insulin signaling was altered by preterm birth as evidenced by decreased insulin receptor-β, p85 subunit of phosphoinositide 3-kinase, phosphorylated insulin receptor substrate 1, and Akt-1 under insulin-stimulated conditions. Furthermore, preterm baboons failed to have the normal increase in glycogen synthase kinase-α from fetal to postnatal life. The blunted responses in hepatic insulin signaling may contribute to the hyperglycemia of prematurity, while impaired EGP leads to hypoglycemia of prematurity.

Serial investigation of continuous glucose monitoring in a very low birth weight infant with transient late-onset hyperglycemia

Transient late-onset hyperglycemia was detected in a very low birth weight (VLBW) infant (gestational age 28 weeks, birth weight 1,082 g) by routine point-of-care glucose monitoring.　The infant had no clinical symptom.　Serial continuous glucose monitoring (CGM) was conducted for 3 days at 31, 35, and 39 weeks' post conceptual age.　The difference values between the maximum and minimum blood glucose levels during the interval from one enteral feeding to the next enteral feeding were 32.3±14.3 mg/dL, 47.5±22.9 mg/dL, and 27.5±12.9 mg/dL for the 1^st, 2^nd, and 3^rd CGM, respectively.　The serial change in the values was statistically significant (p<0.01).CGM is widely used as a routine clinical practice, which is true even in VLBW infants.　Hyperglycemic events detected by only once of CGM in otherwise healthy preterm infants have already been reported on larger numbers of patients.　To our knowledge, this is the first report that the change of glucose intolerance in a VLBW infant with transient late-onset hyperglycemia was investigated by serial CGM.

Intraday glucose fluctuation is common in preterm infants receiving intermittent tube feeding

BACKGROUND

We previously reported on three preterm infants with blood glucose abnormalities after reaching full enteral feeding. Recently, it has been shown that clinically stable preterm infants may have large fluctuations in blood glucose after the establishment of enteral nutrition. We hypothesized that intraday glucose fluctuation is a common finding in preterm infants, but improves at term post-conceptual age. This report describes a case series.

METHODS

From June 2010 to July 2012, 13 preterm infants (29.5 ± 2.1 post-conceptual weeks, 1144 ± 319 g) were enrolled in this study. Continuous glucose monitoring (CGM) was conducted on average at 33.5 ± 1.4 post-conceptual weeks, when they received gastric tube feeding every 3 h in the absence of i.v. glucose supply.

RESULTS

Eight infants (62%) had large intraday glucose fluctuation with repeated hyperglycemic (>150 mg/dL) and hypoglycemic (<50 mg/dL) events. In five infants, follow-up CGM at 36-38 weeks post-conceptual age showed more stable glycemic changes without any abnormal glucose levels.

CONCLUSIONS

On CGM, in some preterm infants intermittent tube feeding resulted in large intraday glucose fluctuation at 31-35 post-conceptual weeks, but the pattern disappeared before discharge (36-38 post-conceptual weeks).