Neonatal hypoglycemia in the rhesus monkey: Effect on development and behavior

Association of early dysglycemia with intraventricular hemorrhage and mortality in very low birth weight infants

To investigate the combined effect of hyperglycemia and hypoglycemia on intraventricular hemorrhage (IVH) and mortality recognizing that previous research has predominantly focused on examining these conditions independently. This study included very preterm infants who were born at King Saud Medical City, a tertiary referral center, and admitted to a level 3 neonatal intensive care unit between January 2020 and January 2024. Modified log-Poisson regression with generalized linear models and a robust variance estimator (Huber-White) were used to adjust for potential confounding factors. A total of 554 infants met the inclusion criteria. Hyperglycemia and/or hypoglycemia developed in 75.5% (418) patients within the first postnatal week. During the study period, IVH occurred in 28.5% (N = 158), and severe IVH occurred in 13% (72) infants. In addition, 13.7% (76) of infants died during the study period. The multivariate regression revealed an association between the isolated hyperglycemia, combined exposure of hypo- and hyperglycemia, and development of IVH (relative risk [RR], 2.10; 95% confidence interval [CI], 1.36, 3.25; RR, 2.33; 95% CI, 1.34, 4.06, respectively). Severe IVH was significantly associated with isolated hyperglycemia (adjusted relative risk [aRR], 2.46; 95% CI, 1.16, 5.23). Death was associated with combined hypo- and hyperglycemia (adjusted hazardous ratio [aHR], 3.19; 95% CI, 1.23, 8.26).Conclusion: Combined hyper- and hypoglycemia in the first week of life of premature babies increases the risk and severity of IVH and neonatal mortality.

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.

Continuous glucose monitoring in newborn babies at risk of hypoglycemia

OBJECTIVE

To determine the usefulness of continuous glucose monitoring in babies at risk of neonatal hypoglycemia.

STUDY DESIGN

Babies >/=32 weeks old who were at risk of hypoglycemia and admitted to newborn intensive care received routine treatment, including intermittent blood glucose measurement using the glucose oxidase method, and blinded continuous interstitial glucose monitoring.

RESULTS

Continuous glucose monitoring was well tolerated in 102 infants. There was good agreement between blood and interstitial glucose concentrations (mean difference, 0.0 mmol/L; 95% CI, -1.1-1.1). Low glucose concentrations (<2.6 mmol/L) were detected in 32 babies (32%) with blood sampling and in 45 babies (44%) with continuous monitoring. There were 265 episodes of low interstitial glucose concentrations, 215 (81%) of which were not detected with blood glucose measurement. One hundred seven episodes in 34 babies lasted >30 minutes, 78 (73%) of which were not detected with blood glucose measurement.

CONCLUSION

Continuous interstitial glucose monitoring detects many more episodes of low glucose concentrations than blood glucose measurement. The physiological significance of these previously undetected episodes is unknown.

Growth and developmental outcomes of three high-risk infant rhesus macaques (Macaca mulatta)

Infants classified as "high risk" are born with a greater chance of developing medical complications at birth, and may have cognitive and other developmental complications later in life. Very few reports exist regarding the survival and outcome of such infants in primate colonies. Here we present early growth and developmental data on three high-risk infant rhesus macaques (one female and two males) that were born either with intrauterine growth restriction (IUGR; born below the 1st birth weight percentile for gestational age) or extremely prematurely (at gestational days 128 and 140; mean full-term gestation=164 days). We compared the outcome of these infants with that of healthy controls born at term and found no gross developmental delays in these infants with respect to growth, neonatal reflex and motor skill development, early cognitive development, or social behavior. Neurological and cognitive assessments were compared in terms of both postnatal and gestational age. The survival of these infants was dependent on a 24-hr staffed nursery and a fluid protocol that catered to each high-risk infant's individual needs. When such measures are implemented, infants such as these have a good chance of survival and can serve as excellent models for high-risk human babies and their subsequent development.

The Accutrend sensor glucose analyzer may not be adequate in bedside testing for neonatal hypoglycemia

The aim of this prospective observational study was to compare a bedside test with the reference laboratory method in routine postnatal glucose monitoring. Term newborns with increased risk or clinical signs of hypoglycemia were screened with a bedside test. In case of a glucose value below 2.25 mmol/L, a second blood sample was taken and a duplicate glucose measurement done in the laboratory using a bedside test (Accutrend sensor) and the reference laboratory method (hexokinase method) at the same time and from the same sample. From 110 term newborns, 122 blood samples were obtained for duplicate measurements (median 1.69 mmol/L, SD 0.45 mmol/L). Of these 122, Accutrend correctly identified 97% as being <2.25 mmol/L by the laboratory method. A Bland-Altman plot revealed a mean underestimation of the Accutrend of only -0.09 mmol/L. However, due to high scattering, the maximal over- and underestimation was 0.89 and 1.39 mmol/L, respectively. Only 75% of the results from the Accutrend were within +/-20% of the result of the laboratory method. If the cut-off for low glucose concentrations was set 0.6 mmol/L higher for the bedside test as compared to the laboratory method, all patients except one would have been correctly identified as hypoglycemic.

CONCLUSION

When using the Accutrend sensor, single infants with even marked hypoglycemia might be missed. Some delay in receiving accurate measurements might be more helpful for clinical decisions and long-term outcome than immediate but potentially misleading results.

Effects of diabetic pregnancy on the fetus and newborn

Diabetes in pregnancy is unique because of the diversity of problems that can affect the embryo/fetus beginning with conception. Considerable effort has been devoted to understanding the basic developmental biology from observing young embryos in vitro or in vivo. Maternal glucose control has been identified as an important event. The preponderance of evidence indicates that rigid glucose control will minimize the incidence of anomalies incurred before 9 weeks of pregnancy. Later events are related to fetal hyperinsulinemia. These include fetal macrosomia, respiratory distress syndrome, neonatal hypoglycemia, neonatal hypocalcemia, and neonatal hypomagnesemia. Control of maternal metabolism can have a significant impact on each of the above. Finally, the long-term effects of maternal diabetes are as diverse as the pathogenetic events during pregnancy. Surprisingly, there is a significant transmission rate of 2% of type I diabetes if the mother has insulin-dependent diabetic mother, whereas the rate is 6% for the father. The Diabetes in Early Pregnancy Study showed that good maternal control was associated with normal neurodevelopmental outcome.

Hypoglycemia in the neonate

After a brief history of the development of neonatal hypoglycemia, this review emphasizes the current approach to the anticipation, diagnosis, and management of the neonate with a low plasma glucose concentration. Current techniques for studying the neurophysiological and endocrine-metabolic effects of significant hypoglycemia provide new approaches for establishing relevant definitions of significant hypoglycemia, its prognosis, and pathogenesis. The inadequacy of glucose oxidase strips for screening, the definition of high-risk infants, new definitions for low plasma glucose concentrations, and their treatment are presented as well as the ability of the neonate to respond to significantly low glucose values. New data concerning the hereditary aspects of hyperinsulinemia (Glaser, this issue), hereditary defects in branched-chain amino acid, 3-methylglutaconic aciduria and mitochondrial betaoxidation, and degradation of fatty acids (Ozand, this issue), the role of glucose transporters (Vannucci and Vannucci, this issue), and the newer computed tomography and magnetic resonance imaging techniques (Kinnala, this issue) to study neonatal hypoglycemia are reviewed elsewhere in this issue.

Nutritional requirements of extremely low birthweight infants

Extremely low birthweight (ELBW) infants are unique in many developmental characteristics that determine nutritional requirements, including: low energy reserves (both carbohydrate and fat); higher metabolic rate (intrinsically, due to a higher body content of more metabolically active organs, e.g. brain, heart, liver); higher protein turnover rate (especially when growing); higher glucose needs for energy and brain metabolism; higher lipid needs to match the in utero rate of fat deposition, and for essential fatty acids for brain, neural and vascular development; excessive evaporative rates, and occasionally very high urinary water and solute losses; low rates of gastrointestinal peristalsis; limited production of gut digestive enzymes and growth factors; high incidence of stressful events (e.g. hypoxemia, respiratory distress, sepsis); and abnormal neurological outcome if not fed adequately. Postnatally, ELBW infants do not grow well, or at all, often for weeks. This leads to a virtual "growth deficit", which has unknown consequences (which for the most part are not good) and requires excessive feeding later on to catch up to normal growth rates and body composition. The major future challenge for the nutrition of these infants is to define more accurately their nutritional requirements, particularly in the early postnatal period, in order to feed them more appropriately, to reduce to a minimum the nutritional and growth deficits that they so commonly develop and to prevent neurodevelopmental handicaps that are the result of nutritional deficiencies.