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

Neonatal dysglycemia: a review of dysglycemia in relation to brain health and neurodevelopmental outcomes

Neonatal dysglycemia has been a longstanding interest of research in neonatology. Adverse outcomes from hypoglycemia were recognized early but are still being characterized. Premature infants additionally introduced and led the reflection on the importance of neonatal hyperglycemia. Cohorts of infants following neonatal encephalopathy provided further information about the impacts of hypoglycemia and, more recently, highlighted hyperglycemia as a central concern for this population. Innovative studies exposed the challenges of management of neonatal glycemic levels with a "u-shape" relationship between dysglycemia and adverse neurological outcomes. Lately, glycemic lability has been recognized as a key factor in adverse neurodevelopmental outcomes. Research and new technologies, such as MRI and continuous glucose monitoring, offered novel insight into neonatal dysglycemia. Combining clinical, physiological, and epidemiological data allowed the foundation of safe operational definitions, including initiation of treatment, to delineate neonatal hypoglycemia as ≤47 mg/dL, and >150-180 mg/dL for neonatal hyperglycemia. However, questions remain about the appropriate management of neonatal dysglycemia to optimize neurodevelopmental outcomes. Research collaborations and clinical trials with long-term follow-up and advanced use of evolving technologies will be necessary to continue to progress the fascinating world of neonatal dysglycemia and neurodevelopment outcomes. IMPACT STATEMENT: Safe operational definitions guide the initiation of treatment of neonatal hypoglycemia and hyperglycemia. Innovative studies exposed the challenges of neonatal glycemia management with a "u-shaped" relationship between dysglycemia and adverse neurological outcomes. The importance of glycemic lability is also being recognized. However, questions remain about the optimal management of neonatal dysglycemia to optimize neurodevelopmental outcomes. Research collaborations and clinical trials with long-term follow-up and advanced use of evolving technologies will be necessary to progress the fascinating world of neonatal dysglycemia and neurodevelopment outcomes.

Diazoxide for Severe or Recurrent Neonatal Hypoglycemia: A Randomized Clinical Trial

Importance

Neonatal hypoglycemia is an important preventable cause of neurodevelopmental impairment, but there is a paucity of evidence to guide treatment.

Objective

To evaluate whether early, low-dose oral diazoxide for severe or recurrent neonatal hypoglycemia reduces time to resolution of hypoglycemia.

Design, Setting, and Participants

This 2-arm, placebo-controlled randomized clinical trial was conducted from May 2020 to February 2023 in tertiary neonatal units at 2 New Zealand hospitals. Participants were neonates born at 35 or more weeks' gestation and less than 1 week of age with severe hypoglycemia (blood glucose concentration <22 mg/dL or <36 mg/dL despite 2 doses of dextrose gel) or recurrent hypoglycemia (≥3 episodes of a blood glucose concentration <47 mg/dL within 48 hours).

Interventions

Newborns were randomized 1:1 to receive diazoxide suspension (loading dose, 5 mg/kg; maintenance, 1.5 mg/kg every 12 hours) or placebo, titrated per protocol.

Main Outcome and Measures

The primary outcome was time to resolution of hypoglycemia, defined as enteral bolus feeding without intravenous fluids and normoglycemia (blood glucose concentration of 47-98 mg/dL) for at least 24 hours, compared between groups using adjusted Cox proportional hazards regression. Hazard ratios adjusted for stratification variables and gestation length are reported. Prespecified secondary outcomes, including number of blood glucose tests and episodes of hypoglycemia, duration of hypoglycemia, and time to enteral bolus feeding and weaning from intravenous fluids, were compared by generalized linear models. Newborns were followed up for at least 2 weeks.

Results

Of 154 newborns screened, 75 were randomized and 74 with evaluable data were included in the analysis (mean [SD] gestational age for the full cohort, 37.6 [1.6] weeks), 36 in the diazoxide group and 38 in the placebo group. Baseline characteristics were similar: in the diazoxide group, mean (SD) gestational age was 37.9 (1.6) weeks and 26 (72%) were male; in the placebo group, mean (SD) gestational age was 37.4 (1.5) weeks and 27 (71%) were male. There was no significant difference in time to resolution of hypoglycemia (adjusted hazard ratio [AHR], 1.39; 95% CI, 0.84-2.23), possibly due to increased episodes of elevated blood glucose concentration and longer time to normoglycemia in the diazoxide group. Resolution of hypoglycemia, when redefined post hoc as enteral bolus feeding without intravenous fluids for at least 24 hours with no further hypoglycemia, was reached by more newborns in the diazoxide group (AHR, 2.60; 95% CI, 1.53-4.46). Newborns in the diazoxide group had fewer blood glucose tests (adjusted count ratio [ACR], 0.63; 95% CI, 0.56-0.71) and episodes of hypoglycemia (ACR, 0.32; 95% CI, 0.17-0.63), reduced duration of hypoglycemia (adjusted ratio of geometric means [ARGM], 0.18; 95% CI, 0.06-0.53), and reduced time to enteral bolus feeding (ARGM, 0.74; 95% CI, 0.58-0.95) and weaning from intravenous fluids (ARGM, 0.72; 95% CI, 0.60-0.87). Only 2 newborns (6%) treated with diazoxide had hypoglycemia after the loading dose compared with 20 (53%) with placebo.

Conclusions and Relevance

In this randomized clinical trial, early treatment of severe or recurrent neonatal hypoglycemia with low-dose oral diazoxide did not reduce time to resolution of hypoglycemia but reduced time to enteral bolus feeding and weaning from intravenous fluids, duration of hypoglycemia, and frequency of blood glucose testing compared with placebo.

Trial Registration

ANZCTR.org.au Identifier: ACTRN12620000129987.

Neonatal Hypoglycemia

Neonatal hypoglycemia (NH) is broadly defined as a low plasma glucose concentration that elicits hypoglycemia-induced impaired brain function. To date, no universally accepted threshold (reference range) for plasma glucose levels in newborns has been published, as data consistently indicate that neurologic responses to hypoglycemia differ at various plasma glucose concentrations. Infants at risk for NH include infants of diabetic mothers, small or large for gestational age, and premature infants. Common manifestations include jitteriness, poor feeding, irritability, and encephalopathy. Neurodevelopmental morbidities associated with NH include cognitive and motor delays, cerebral palsy, vision and hearing impairment, and poor school performance. This article offers a timely discussion of the state of the science of NH and recommendations for neonatal providers focused on early identification and disease prevention.

Neonatal hypoglycaemia

Low blood concentrations of glucose (hypoglycaemia) soon after birth are common because of the delayed metabolic transition from maternal to endogenous neonatal sources of glucose. Because glucose is the main energy source for the brain, severe hypoglycaemia can cause neuroglycopenia (inadequate supply of glucose to the brain) and, if severe, permanent brain injury. Routine screening of infants at risk and treatment when hypoglycaemia is detected are therefore widely recommended. Robust evidence to support most aspects of management is lacking, however, including the appropriate threshold for diagnosis and optimal monitoring. Treatment is usually initially more feeding, with buccal dextrose gel, followed by intravenous dextrose. In infants at risk, developmental outcomes after mild hypoglycaemia seem to be worse than in those who do not develop hypoglycaemia, but the reasons for these observations are uncertain. Here, the current understanding of the pathophysiology of neonatal hypoglycaemia and recent evidence regarding its diagnosis, management, and outcomes are reviewed. Recommendations are made for further research priorities.

Infants Eligible for Neonatal Hypoglycemia Screening: A Systematic Review

Importance

Neonatal hypoglycemia is common, occurring in up to 50% of infants at risk for hypoglycemia (infant of diabetic mother [IDM], small for gestational age [SGA], large for gestational age [LGA], and preterm) and is associated with long-term neurodevelopmental impairment. Guidelines recommend screening infants at risk of hypoglycemia. The proportion of infants who require screening for neonatal hypoglycemia is unknown.

Objective

To determine the proportion of infants eligible for neonatal hypoglycemia screening using criteria from the highest-scoring critically appraised clinical guideline.

Design, Setting, and Participants

This systematic review of the literature was conducted to identify clinical practice guidelines for neonatal hypoglycemia and took place at a tertiary maternity hospital in Auckland, New Zealand. Eligible guidelines were critically appraised using the Appraisal of Guidelines for Research and Evaluation II tool. Using screening criteria extracted from the highest-scoring guideline, the proportion of infants eligible for neonatal hypoglycemia screening was determined in a retrospective observational cohort study of infants born January 1, 2004, to December 31, 2018. Data were analyzed by logistic regression. Infant participants were included if gestational age was 35 weeks or more, birth weight was 2000 g or more, and they were not admitted to a neonatal intensive care unit less than 1 hour after birth. The data were analyzed from November 2022 through February 2023. A total of 101 372 infants met the inclusion criteria.

Exposure

Risk factors for neonatal hypoglycemia.

Main Outcome

Proportion of infants eligible for neonatal hypoglycemia screening.

Results

The study team screened 2366 abstracts and 18 guidelines met inclusion criteria for appraisal. There was variability in the assessed quality of guidelines and a lack of consensus between screening criteria. The highest-scoring guideline defined screening criteria as: IDM, preterm (less than 37 weeks' gestation), SGA (less than 10th percentile), birth weight of less than 2500 g or more than 4500 g, LGA (more than 90th percentile), or gestational age more than 42 weeks. A total of 101 372 infants met criteria for inclusion in the cohort study; median (IQR) gestational age was 39 (38-40) weeks and 51% were male. The overall proportion of infants eligible for screening was 26.3%. There was an increase in the proportion of eligible infants from 25.6% to 28.5% over 15 years, which was not statistically significant after adjustment for maternal age, body mass index, ethnicity, and multiple pregnancy (odds ratio, 0.99; 95% CI, 0.93-1.03; change in proportion per year).

Conclusion

A systematic review found that practice guidelines providing recommendations for clinical care of neonatal hypoglycemia were of variable quality with is a lack of consensus regarding definitions for infants at risk for hypoglycemia. In the cohort study, one-quarter of infants were eligible for hypoglycemia screening. Further research is required to identify which infants may benefit from neonatal hypoglycemia screening.

Mid-Childhood Outcomes after Dextrose Gel Treatment of Neonatal Hypoglycaemia: Follow-Up of the Sugar Babies Randomized Trial

INTRODUCTION

Dextrose gel is widely used as first-line treatment for neonatal hypoglycaemia given its cost-effectiveness and ease of use. The Sugar Babies randomized trial first showed that 40% dextrose gel was more effective in reversing hypoglycaemia than feeding alone. Follow-up of the Sugar Babies Trial cohort at 2 and 4.5 years of age reported that dextrose gel appeared safe, with similar rates of neurosensory impairment in babies randomized to dextrose or placebo gel. However, some effects of neonatal hypoglycaemia may not become apparent until school age.

METHODS

Follow-up of the Sugar Babies Trial cohort at 9-10 years of age was reported. The primary outcome was low educational achievement in reading or mathematics. Secondary outcomes included other aspects of educational achievement, executive function, visual-motor function, and psychosocial adaptation.

RESULTS

Of 227 eligible children, 184 (81%) were assessed at a mean (SD) age of 9.3 (0.2) years. Low educational achievement was similar in dextrose and placebo groups (36/86 [42%] vs. 42/94 [45%]; RR 1.04, 95% CI 0.76, 1.44; p = 0.79). Children allocated to dextrose gel had lower visual perception standard scores (95.2 vs. 100.6; MD -5.68, 95% CI -9.79, -1.57; p = 0.006) and a greater proportion had low (<85) visual perception scores (20/88 [23%] vs. 10/95 [11%]; RR 2.23, 95% CI 1.13, 4.37; p = 0.02). Other secondary outcomes, including other aspects of visual-motor function, were similar in both groups.

CONCLUSION

Treatment dextrose gel does not appear to result in any clinically significant differences in educational achievement or other neurodevelopmental outcomes at mid-childhood.

Application of the screening test principles to screening for neonatal hypoglycemia

Severe and prolonged neonatal hypoglycemia can cause brain injury, while the long-term consequences of mild or transitional hypoglycemia are uncertain. As neonatal hypoglycemia is often asymptomatic it is routine practice to screen infants considered at risk, including infants of mothers with diabetes and those born preterm, small or large, with serial blood tests over the first 12-24 h after birth. However, to prevent brain injury, the gold standard would be to determine if an infant has neuroglycopenia, for which currently there is not a diagnostic test. Therefore, screening of infants at risk for neonatal hypoglycemia with blood glucose monitoring does not meet several screening test principles. Specifically, the long-term neurodevelopmental outcomes of transient neonatal hypoglycemia are not well understood and there is no direct evidence from randomized controlled trials that treatment of hypoglycemia improves long-term neurodevelopmental outcomes. There have been no studies that have compared the long-term neurodevelopmental outcomes of at-risk infants screened for neonatal hypoglycemia and those not screened. However, screening infants at risk of hypoglycemia and treating those with hypoglycaemic episodes to maintain the blood glucose concentrations ≥2.6 mmol/L appears to preserve cognitive function compared to those without episodes. This narrative review explores the evidence for screening for neonatal hypoglycemia, the effectiveness of blood glucose screening as a screening test and recommend future research areas to improve screening for neonatal hypoglycemia. Screening babies at-risk of neonatal hypoglycemia continues to be necessary, but as over a quarter of all infants may be screened for neonatal hypoglycemia, further research is urgently needed to determine the optimal method of screening and which infants would benefit from screening and treatment.

Neonatal Hyperglycemia and Neurodevelopmental Outcomes in Preterm Infants: A Review

Glucose impairment is common in preterm infants but the impact of early neonatal hyperglycemia on long term neurodevelopment is still highly controversial. This review reports current evidence of the effect of hyperglycemia on neurodevelopmental outcome. It was conducted according to the PRISMA guidelines. We searched MEDLINE via PubMed; EMBASE via Ovid; the Cochrane Central Register of Controlled Trials; the Cochrane Library; ClinicalTrials.gov; and the World Health Organization's International Trials Registry and Platform. We included studies that investigated the association between hyperglycemia, defined as at least one episode of glycemia ≥8 mmol/L, and neurodevelopment outcome evaluated either through the Griffiths Mental Developmental Scales (GMDS) or the Bayley Scales of Infant Development (BSID) for the first 5 years of life, and the Wechsler Intelligence Scale for Children (WISC) and the Movement Assessment Battery for Children (MABC) for the following age category. We selected six studies, comprising 2226 infants in total and which included 1059 (48%) infants for whom neurodevelopment assessment was available. We found an association between hyperglycemia and neurological delay in the first two years of life, especially for motor functions; this result was confirmed in later childhood. The quality of evidence was poor; therefore, the negative influence of neonatal hyperglycemia on the neurological development of preterm infants must be investigated in further studies.

Neurocognitive Outcomes at Age 2 Years After Neonatal Hypoglycemia in a Cohort of Participants From the hPOD Randomized Trial

IMPORTANCE

Neonatal hypoglycemia is common, but its association with later neurodevelopment is uncertain.

OBJECTIVE

To examine associations between neonatal hypoglycemia and neurocognitive outcomes at corrected age 2 years.

DESIGN, SETTING, AND PARTICIPANTS

Exploratory cohort analysis of the Hypoglycaemia Prevention With Oral Dextrose (hPOD) randomized clinical trial was conducted. The trial recruited participants from January 9, 2015, to May 5, 2019, with follow-up between January 26, 2017, and July 31, 2021. Infants were recruited from 9 maternity hospitals in New Zealand and assessed at home or in a research clinic. Children born late preterm and at term at risk of neonatal hypoglycemia but without evidence of acute or imminent illness in the first hour after birth were screened and treated to maintain blood glucose concentrations greater than or equal to 47 mg/dL.

EXPOSURES

Hypoglycemia was defined as any blood glucose concentration less than 47 mg/dL, recurrent as 3 or more episodes, and severe as less than 36 mg/dL.

MAIN OUTCOMES AND MEASURES

Neurologic examination and tests of development (Bayley III) and executive function. The primary outcome was neurosensory impairment (any of the following: blindness, deafness, cerebral palsy, developmental delay, or executive function total score worse than 1.5 SD below the mean).

RESULTS

A total of 1197 of 1321 (91%) eligible children were assessed at a mean of corrected age 24 months; 616 (52%) were male. Compared with the normoglycemia group, children who experienced hypoglycemia were more likely to have neurosensory impairment (111 [23%] vs 125 [18%]; adjusted risk ratio [aRR], 1.28; 95% CI, 1.01-1.60), particularly if they experienced severe episodes (30 [28%] vs 125 [18%]; aRR, 1.68; 95% CI, 1.20-2.36), but not recurrent episodes (12 [19%] vs 125 [18%]; aRR, 1.06; 95% CI, 0.63-1.80). The risk of cognitive, language, or motor delay was similar between groups, but children who experienced hypoglycemia had lower Bayley-III composite cognitive (adjusted mean difference [aMD], -1.48; 95% CI, -2.79 to -0.18) and motor scores (aMD, -2.05; 95% CI, -3.30 to -0.79).

CONCLUSIONS AND RELEVANCE

In children born at risk of hypoglycemia but otherwise well, those who experienced neonatal hypoglycemia were more likely to have neurosensory impairment at corrected age 2 years, with higher risks after severe episodes. Further research is required to determine causality.

Cerebral Effects of Neonatal Dysglycemia

This article summarizes the available evidence reporting the relationship between perinatal dysglycemia and long-term neurodevelopment. We review the physiology of perinatal glucose metabolism and discuss the controversies surrounding definitions of perinatal dysglycemia. We briefly review the epidemiology of hypoglycemia and hyperglycemia in fetal, preterm, and term infants. We discuss potential pathophysiologic mechanisms contributing to dysglycemia and its effect on neurodevelopment. We highlight current strategies to prevent and treat dysglycemia in the context of neurodevelopmental outcomes. Finally, we discuss areas of future research and the potential role of continuous glucose monitoring.

Dextrose Gel for Neonates at Risk With Asymptomatic Hypoglycemia: A Randomized Clinical Trial

BACKGROUND AND OBJECTIVES

Hypoglycemia occurs in 5% to 15% of neonates in the first few days. A significant proportion requires admission for intravenous fluids. Dextrose gel may reduce admissions and mother-infant separation. We aimed to study the utility of dextrose gel in reducing the need for intravenous fluids.

METHODS

This stratified randomized control trial included at-risk infants with asymptomatic hypoglycemia. Study populations were stratified into 3 categories: small for gestational age (SGA) and intrauterine growth-restriction (IUGR), infants of diabetic mothers (IDM) and large for gestational age (LGA), and late preterm (LPT) neonates. Intervention group received dextrose gel followed by breastfeeding, and the control group (CG) received only breastfeeding.

RESULTS

Among 629 at-risk infants, 291 (46%) developed asymptomatic hypoglycemia; 147 (50.4%) in the dextrose gel group (DGG) and 144 (49.6%) in CG. There were 97, 98, and 96 infants in SGA/IUGR, IDM/LGA, and LPT categories, respectively. Treatment failure in the DGG was 17 (11.5%) compared to 58 (40.2%) in CG, with a risk ratio of 0.28 (95% confidence interval [CI]: 0.17-0.46; P < .001). Treatment failure was significantly less in DGG in all 3 categories: SGA/IUGR, IDM/LGA, and LPT with a risk ratio of 0.29 (95% CI:0.13-0.67), 0.31 (95% CI:0.14-0.66) and 0.24 (95% CI:0.09-0.66), respectively.

CONCLUSIONS

Dextrose gel reduces the need for intravenous fluids in at-risk neonates with asymptomatic hypoglycemia in the first 48 hours of life.

Association of Neonatal Hypoglycemia With Academic Performance in Mid-Childhood

IMPORTANCE

Neonatal hypoglycemia is associated with increased risk of poor executive and visual-motor function, but implications for later learning are uncertain.

OBJECTIVE

To test the hypothesis that neonatal hypoglycemia is associated with educational performance at age 9 to 10 years.

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort study of moderate to late preterm and term infants born at risk of hypoglycemia. Blood and masked interstitial sensor glucose concentrations were measured for up to 7 days. Infants with hypoglycemic episodes (blood glucose concentration <47 mg/dL [2.6 mmol/L]) were treated to maintain a blood glucose concentration of at least 47 mg/dL. Six hundred fourteen infants were recruited at Waikato Hospital, Hamilton, New Zealand, in 2006-2010; 480 were assessed at age 9 to 10 years in 2016-2020.

EXPOSURES

Hypoglycemia was defined as at least 1 hypoglycemic event, representing the sum of nonconcurrent hypoglycemic and interstitial episodes (sensor glucose concentration <47 mg/dL for ≥10 minutes) more than 20 minutes apart.

MAIN OUTCOMES AND MEASURES

The primary outcome was low educational achievement, defined as performing below or well below the normative curriculum level in standardized tests of reading comprehension or mathematics. There were 47 secondary outcomes related to executive function, visual-motor function, psychosocial adaptation, and general health.

RESULTS

Of 587 eligible children (230 [48%] female), 480 (82%) were assessed at a mean age of 9.4 (SD, 0.3) years. Children who were and were not exposed to neonatal hypoglycemia did not significantly differ on rates of low educational achievement (138/304 [47%] vs 82/176 [48%], respectively; adjusted risk difference, -2% [95% CI, -11% to 8%]; adjusted relative risk, 0.95 [95% CI, 0.78-1.15]). Children who were exposed to neonatal hypoglycemia, compared with those not exposed, were significantly less likely to be rated by teachers as being below or well below the curriculum level for reading (68/281 [24%] vs 49/157 [31%], respectively; adjusted risk difference, -9% [95% CI, -17% to -1%]; adjusted relative risk, 0.72 [95% CI, 0.53-0.99; P = .04]). Groups were not significantly different for other secondary end points.

CONCLUSIONS AND RELEVANCE

Among participants at risk of neonatal hypoglycemia who were screened and treated if needed, exposure to neonatal hypoglycemia compared with no such exposure was not significantly associated with lower educational achievement in mid-childhood.

Prophylactic Oral Dextrose Gel and Neurosensory Impairment at 2-Year Follow-up of Participants in the hPOD Randomized Trial

Importance

Prophylactic oral dextrose gel reduces neonatal hypoglycemia, but later benefits or harms remain unclear.

Objective

To assess the effects on later development of prophylactic dextrose gel for infants born at risk of neonatal hypoglycemia.

Design, Setting, and Participants

Prospective follow-up of a multicenter randomized clinical trial conducted in 18 Australian and New Zealand hospitals from January 2015 to May 2019. Participants were late preterm or term at-risk infants; those randomized in 9 New Zealand centers (n = 1359) were included and followed up between January 2017 and July 2021.

Interventions

Infants were randomized to prophylactic 40% dextrose (n = 681) or placebo (n = 678) gel, 0.5 mL/kg, massaged into the buccal mucosa 1 hour after birth.

Main Outcomes and Measures

The primary outcome of this follow-up study was neurosensory impairment at 2 years' corrected age. There were 44 secondary outcomes, including cognitive, language, and motor composite Bayley-III scores (mean [SD], 100 [15]; higher scores indicate better performance).

Results

Of eligible infants, 1197 (91%) were assessed (581 females [49%]). Neurosensory impairment was not significantly different between the dextrose and placebo gel groups (20.8% vs 18.7%; unadjusted risk difference [RD], 2.09% [95% CI, -2.43% to 6.60%]; adjusted risk ratio [aRR], 1.13 [95% CI, 0.90 to 1.41]). The risk of cognitive and language delay was not significantly different between the dextrose and placebo groups (cognitive: 7.6% vs 5.3%; RD, 2.32% [95% CI, -0.46% to 5.11%]; aRR, 1.40 [95% CI, 0.91 to 2.17]; language: 17.0% vs 14.7%; RD, 2.35% [95% CI, -1.80% to 6.50%]; aRR, 1.19 [95% CI, 0.92 to 1.54]). However, the dextrose gel group had a significantly higher risk of motor delay (2.5% vs 0.7%; RD, 1.81% [95% CI, 0.40% to 3.23%]; aRR, 3.79 [95% CI, 1.27 to 11.32]) and significantly lower composite scores for cognitive (adjusted mean difference [aMD], -1.30 [95% CI, -2.55 to -0.05]), language (aMD, -2.16 [95% CI, -3.86 to -0.46]), and motor (aMD, -1.40 [95% CI, -2.60 to -0.20]) performance. There were no significant differences between groups in the other 27 secondary outcomes.

Conclusions and Relevance

Among late preterm and term infants born at risk of neonatal hypoglycemia, prophylactic oral 40% dextrose gel at 1 hour of age, compared with placebo, resulted in no significant difference in the risk of neurosensory impairment at 2 years' corrected age. However, the study may have been underpowered to detect a small but potentially clinically important increase in risk, and further research including longer-term follow-up is required.

Trial Registration

anzctr.org.au Identifier: ACTRN12614001263684.

Glucagon for Neonatal Hypoglycaemia: Systematic Review and Meta-Analysis

INTRODUCTION

Glucagon is often used in neonatal hypoglycaemia, but its effects have not been systematically assessed. We undertook a systematic review to determine the efficacy and safety of glucagon treatment for neonatal hypoglycaemia.

METHODS

We searched MEDLINE, CINAHL, EMBASE, and CENTRAL from inception until May 2021. We included studies that reported one or more prespecified outcomes and compared glucagon with placebo or no glucagon. Studies were excluded if the majority (>70%) of participants were >1 month of age. Two authors independently extracted data. We used ROB-2/modified ROBINS-I to assess risk of bias, GRADE for certainty of evidence, and RevMan for meta-analysis.

RESULTS

100 studies were screened, 37 reviewed in full, and seven single-arm non-randomised intervention studies, involving 348 infants, were included (no trials). Data were insufficient to undertake meta-analysis of the critical outcomes (time to blood glucose normalization, recurrent hypoglycaemia, neurocognitive impairment). In 3 studies, ≥80% of neonates achieved normoglycaemia within 4 h of glucagon administration. However, recurrent hypoglycaemia was common (up to 55%). Glucagon increased blood glucose concentration at 1-2 h by 2.3 mmol/L (95% CI 2.1, 2.5) (low certainty evidence, 6 studies, N = 323). There were few data for other important clinical outcomes.

CONCLUSION

There is a paucity of evidence about the efficacy and safety of glucagon for treatment of neonatal hypoglycaemia. Low certainty evidence suggests that glucagon may increase blood glucose by ∼2.3 mmol/L but recurrent hypoglycaemia appears common. High-quality, randomized controlled trials are required to determine the role of glucagon in managing neonatal hypoglycaemia.

How Much Glucose Is in the Gel Used to Treat Neonatal Hypoglycemia?

OBJECTIVE

To compare glucose concentrations in three sections of individual tubes and among tubes of commercial oral glucose gels commonly used to treat neonatal hypoglycemia in the United States (Glutose 15 [Perrigo, Minneapolis, MN] and Insta-Glucose [Valeant Pharmaceuticals North America LLC, Bridgewater, NJ]).

DESIGN

A quantitative laboratory study.

METHODS

We measured glucose concentrations in aliquots taken from the top, middle, and bottom sections of three different lots and in whole tubes from different lots of Glutose 15 and Insta-Glucose. We measured the glucose content in the gel using hexokinase and glucose-6-phosphate dehydrogenase enzymes on the Siemens ADVIA 1800 analyzer (Siemens Healthcare Diagnostics, Inc., Tarrytown, NY).

RESULTS

The percent difference observed among the three sections of the Glutose 15 tubes was 12.3% to 53.8%. The difference among the three sections of the Insta-Glucose tubes was 40.7% to 79.6%. The concentration of glucose gel is labeled as 40%, but the actual concentration in aliquots of Glutose 15 ranged from 39.64% to 70.96%. The actual concentration in aliquots of Insta-Glucose ranged from 16.45% to 27.47%. The difference in the concentration of glucose among three lots of whole tubes of Glutose 15 was 1.6%, and the difference in concentration among three lots of whole tubes of Insta-Glucose was 8.8%. In Glutose 15, the concentration ranged from 48.3% to 49.1%, and Insta-Glucose, the concentration ranged from 17.2% to 18.8%.

CONCLUSION

Glucose was not uniformly distributed within tubes of Glutose 15 and Insta-Glucose, and this may account for variable results on the efficacy of oral glucose gel as a treatment for neonatal hypoglycemia.

Nutrition and management of glycemia in neonates with neonatal encephalopathy treated with hypothermia

Adequate nutrition and glycemic homeostasis are increasingly recognized as potentially neuroprotective for the developing brain. In the context of hypoxia-ischemia, evidence is scarce regarding optimal nutritional support and administration route, as well as the short- and long-term consequences of such interventions. In this review, we summarize current knowledge on disturbances of brain metabolism of glucose and substrates by hypoxia-ischemia, and compound effects of these mechanisms on brain injury characterized by specific patterns on EEG and MRI. Risks and benefits of nutrition delivery via parenteral or enteral routes are examined. Nutrition could mitigate adverse neurodevelopmental outcomes, and the impact of nutritional strategies and specific nutritional interventions are reviewed. Limited literature highlights the need for further studies to understand the changes in energy metabolism during and after hypoxic-ischemic injury, to optimize nutritional regimens and glucose management, and to inform the neuroprotective role of nutrition.

Effect of Prophylactic Dextrose Gel on Continuous Measures of Neonatal Glycemia: Secondary Analysis of the Pre-hPOD Trial

OBJECTIVE

To determine the effects of different doses of prophylactic dextrose gel on glycemic stability assessed using continuous glucose monitoring in the first 48 hours when given to babies at risk of neonatal hypoglycemia.

STUDY DESIGN

Continuous glucose monitoring was undertaken for the first 48 hours in 133 infants at risk of hypoglycemia who participated in the pre-hPOD randomized dosage trial of dextrose gel prophylaxis.

RESULTS

Low glucose concentrations were detected in 41% of infants by blood glucose monitoring and 68% by continuous interstitial glucose monitoring. The mean ± SD duration of low interstitial glucose concentrations was 295 ± 351 minutes in the first 48 hours. Infants who received any dose of dextrose gel seemed to be less likely than those who received placebo gel to experience low glucose concentrations (<47 mg/dL [2.6 mmol/L]; P = .08), particularly if they received a single dose of 200 mg/kg (relative risk, 0.70; 95% CI, 0.50-0.10; P = .049). They also spent a greater proportion of time in the central glucose concentration range of 54-72 mg/dL (3-4 mmol/L) (any dose, mean ± SD, 58.2 ± 20.3%; placebo, 50.0 ± 21.9%; mean difference, 8.20%; 95% CI, 0.43-15.9%; P = .038). Dextrose gel did not increase recurrent or severe episodes of low glucose concentrations and did not increase the peak glucose concentration. These effects were similar for all trial dosages.

CONCLUSIONS

Low glucose concentrations were common in infants at risk of hypoglycemia despite blood glucose monitoring and treatment. Prophylactic dextrose gel reduced the risk of hypoglycemia without adverse effects on glucose stability.

Strategies to improve neurodevelopmental outcomes in babies at risk of neonatal hypoglycaemia

Neonatal hypoglycaemia is associated with adverse development, particularly visual-motor and executive function impairment, in childhood. As neonatal hypoglycaemia is common and frequently asymptomatic in at-risk babies-ie, those born preterm, small or large for gestational age, or to mothers with diabetes, it is recommended that these babies are screened for hypoglycaemia in the first 1-2 days after birth with frequent blood glucose measurements. Neonatal hypoglycaemia can be prevented and treated with buccal dextrose gel, and it is also common to treat babies with hypoglycaemia with infant formula and intravenous dextrose. However, it is uncertain if screening, prophylaxis, or treatment improves long-term outcomes of babies at risk of neonatal hypoglycaemia. This narrative review assesses the latest evidence for screening, prophylaxis, and treatment of neonates at risk of hypoglycaemia to improve long-term neurodevelopmental outcomes.

Effect on mortality of increasing the cutoff blood glucose concentration for initiating hypoglycaemia treatment in severely sick children aged 1 month to 5 years in Malawi (SugarFACT): a pragmatic, randomised controlled trial

BACKGROUND

Low blood glucose concentrations are common in sick children who present to hospital in low-resource settings and are associated with increased mortality. The cutoff blood glucose concentration for the diagnosis and treatment of hypoglycaemia currently recommended by WHO (2·5 mmol/L) is not evidence-based. We aimed to assess whether increasing the cutoff blood glucose concentration for hypoglycaemia treatment in severely ill children at presentation to hospital improves mortality outcomes.

METHODS

We did a pragmatic, randomised controlled trial at two referral hospitals in Malawi. Severely ill children aged 1 month to 5 years presenting to the emergency department with a capillary blood glucose concentration of between 2·5 mmol/L (3·0 mmol/L in severely malnourished children) and 5·0 mmol/L were randomly assigned (1:1) by a computer-generated randomisation sequence, stratified by study site and severe malnutrition, to receive either an immediate intravenous bolus of 10% dextrose at 5 mL/kg followed by a 24-h maintenance infusion of 10% dextrose at 100 mL/kg for the first 10 kg of bodyweight, 50 mL/kg for the next 10 kg, and 20 mL/kg for each subsequent kg of bodyweight (intervention group) or observation for a minimum of 60 min and standard care (control group). Participants and study personnel were not masked to treatment allocation. The primary outcome was all-cause in-hospital mortality, assessed on an intention-to-treat basis. Safety was also assessed in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT02989675.

FINDINGS

Between Dec 5, 2016, and Jan 22, 2019, 10 947 children were screened, of whom 332 were randomly assigned, and 322 were included in the final analysis (n=162 in the control group and n=160 in the intervention group). The study was terminated after an interim analysis at 24% enrolment indicated futility. The median age of participants was 2·3 years (IQR 1·4-3·2), 65 (45%) were female, and the baseline characteristics of participants were similar between the two groups. The number of in-hospital deaths from any cause was 26 (16%) in the control group and 24 (15%) in the intervention group, with an absolute mortality difference of 1·0% (95% CI -6·9 to 9·0). Serious adverse events, including hypoglycaemia, hyperglycaemia, convulsions, reduced consciousness, and death, were reported in 47 (29%) children in the control group and 39 (24%) children in the intervention group.

INTERPRETATION

Increasing the cutoff blood glucose concentration for hypoglycaemia treatment in severely sick children in Malawi from 2·5 mmol/L to 5·0 mmol/L did not reduce all-cause in-hospital mortality. Our findings do not support changing the cutoff for dextrose administration, and further research on the optimal management of severely ill children who present to the emergency department with low blood glucose concentrations is warranted.

FUNDING

Swedish Research Council and Stockholm Country Council.