Failure of glucagon release in infants of diabetic mothers

Maternal obesity and degree of glucose intolerance on neonatal hypoglycaemia and birth weight: a retrospective observational cohort study in women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is an increasing problem worldwide. Postnatal hypoglycaemia and excess foetal growth are known important metabolic complications of neonates born to women with diabetes. This retrospective cohort study aims to determine the influence of obesity and glucose intolerance on neonatal hypoglycaemia and birth weight over the 90th percentile (LGA). Data were abstracted from 303 patient medical records from singleton pregnancies diagnosed with GDM. Data were recorded during routine hospital visits. Demographic data were acquired by facilitated questionnaires and anthropometrics measured at the first antenatal appointment. Blood biochemical indices were recorded. Plasma glucose area under the curve (PG-AUC) was calculated from OGTT results as an index of glucose intolerance. OGTT results of 303 pregnant women aged between 33.6 years (29.8-37.7) diagnosed with GDM were described. Neonates of mothers with a BMI of over 30 kg/m² were more likely to experience neonatal hypoglycaemia (24 (9.2%) vs. 23 (8.8%), p = 0.016) with odds ratio for neonatal hypoglycaemia significantly higher at 2.105, 95% CI (1.108, 4.00), p = 0.023. ROC analysis showed poor strength of association (0.587 (95% CI, .487 to .687). Neonatal LGA was neither associated with or predicted by PG-AUC nor obesity; however, multiparous women were 2.8 (95% CI (1.14, 6.78), p = 0.024) times more likely to have a baby born LGA.Conclusion: Maternal obesity but not degree of glucose intolerance increased occurrence of neonatal hypoglycaemia. Multiparous women had greater risk of neonates born LGA.What is Known:•Excess foetal growth in utero has long-term metabolic implications which track into adulthood.•Neonatal hypoglycaemia is detrimental to newborns in the acute phase with potential long-term implications on the central nervous system.What is New:•Maternal obesity but not degree of glucose intolerance in a GDM cohort increased occurrence of neonatal hypoglycaemia.•Multiparous women diagnosed had greater risk of neonates born LGA.

Candidate SNP markers of reproductive potential are predicted by a significant change in the affinity of TATA-binding protein for human gene promoters

BACKGROUND

The progress of medicine, science, technology, education, and culture improves, year by year, quality of life and life expectancy of the populace. The modern human has a chance to further improve the quality and duration of his/her life and the lives of his/her loved ones by bringing their lifestyle in line with their sequenced individual genomes. With this in mind, one of genome-based developments at the junction of personalized medicine and bioinformatics will be considered in this work, where we used two Web services: (i) SNP_TATA_Comparator to search for alleles with a single nucleotide polymorphism (SNP) that alters the affinity of TATA-binding protein (TBP) for the TATA boxes of human gene promoters and (ii) PubMed to look for retrospective clinical reviews on changes in physiological indicators of reproductive potential in carriers of these alleles.

RESULTS

A total of 126 SNP markers of female reproductive potential, capable of altering the affinity of TBP for gene promoters, were found using the two above-mentioned Web services. For example, 10 candidate SNP markers of thrombosis (e.g., rs563763767) can cause overproduction of coagulation inducers. In pregnant women, Hughes syndrome provokes thrombosis with a fatal outcome although this syndrome can be diagnosed and eliminated even at the earliest stages of its development. Thus, in women carrying any of the above SNPs, preventive treatment of this syndrome before a planned pregnancy can reduce the risk of death. Similarly, seven SNP markers predicted here (e.g., rs774688955) can elevate the risk of myocardial infarction. In line with Bowles' lifespan theory, women carrying any of these SNPs may modify their lifestyle to improve their longevity if they can take under advisement that risks of myocardial infarction increase with age of the mother, total number of pregnancies, in multiple pregnancies, pregnancies under the age of 20, hypertension, preeclampsia, menstrual cycle irregularity, and in women smokers.

CONCLUSIONS

According to Bowles' lifespan theory-which links reproductive potential, quality of life, and life expectancy-the above information was compiled for those who would like to reduce risks of diseases corresponding to alleles in own sequenced genomes. Candidate SNP markers can focus the clinical analysis of unannotated SNPs, after which they may become useful for people who would like to bring their lifestyle in line with their sequenced individual genomes.

Insulin and glucagon levels of umbilical cord blood in appropriate for gestational age - preterm infants with or without postnatal hypoglycemia

PURPOSE

To determine whether serum insulin and glucagon levels of umbilical cord blood correlate with subsequent postnatal hypoglycemia in appropriate for gestational age (AGA) - preterm infants at different gestational ages (GAs).

METHODS

The serum insulin and glucagon levels of umbilical cord blood were measured using magnetic bead based multiplex immunoassay in 69 AGA - premature infants, stratified according to GA: GA 23-30 weeks, early preterm (EP, n=31); GA 31-34 weeks, late preterm (LP, n=38). Postnatal hypoglycemia was defined as a capillary glucose level <40 mg/dL within the first 60 minutes of life, regardless of GA.

RESULTS

The capillary glucose concentration in EP infants (65.5±21.2 mg/dL) was significantly higher than that of LP infants (55.9±17.3 mg/dL) (P=0.043). The serum glucagon level in EP infants (44.3±28.7 pg/mL) was significantly higher than that in LP infants (28.1±13.6 pg/mL) (P=0.006). There was not a significant difference in serum insulin level between EP and LP infants (372.7±254.2 pg/mL vs. 372.4±209.1 pg/mL, P=0.996). There was a significant difference in the serum glucagon level between infants with and without hypoglycemia (27.7±8.9 mg/dL vs. 36.8±24.6 mg/dL, P=0.036), but not in the serum insulin level (451.9±256.9 pg/mL vs. 357.4±222.2 pg/mL, P=0.211). Postnatal glucose concentration within the first 60 minutes of life had a significant positive correlation with serum glucagon levels (r=0.256, P=0.034), but not with serum insulin levels (r=-0.020, P=0.867).

CONCLUSION

Lower glucagon levels of cord blood were seen in premature infants with higher GA, which might contribute to the occurrence of postnatal hypoglycemia.

Glucose control during labor and delivery

Neonatal hypoglycemia is an important consequence for the infant of the mother with diabetes. We have reviewed 24 published papers of various protocols for control of glucose in pregnant diabetic women during labor and delivery including our own published work. A relationship of maternal glucose during labor and neonatal hypoglycemia was sought in 19 of these studies. A significant inverse relationship was found in 10 reports with 3 others showing a similar trend. In all but 1 of these 13 studies the participants had pregestational diabetes. Three of the 6 studies not reporting an inverse relationship involved women with GDM. From this review it appears that the maternal glucose should be maintained between 4.0 and 6.0-7.0 mmol/L during labor. Most women with gestational diabetes, especially if they require <1.0 units/kg/d of insulin, can simply be monitored without intravenous insulin. Our own results demonstrate that a target glucose of 4.0-6.0 mmol/L can be used safely and results in a low rate of neonatal hypoglycemia using an iterative glucose insulin infusion protocol for women with pregestational diabetes and when needed for women with gestational diabetes.

Neonatal liver physiology

In the neonate, the liver is relatively immature and undergoes several changes in its functional capacity during the early postnatal period. The essential liver functions can be classified into three categories: metabolism, detoxification, and bile synthesis. In general, the immature liver function has limited consequences on the healthy term neonate. However, preterm neonates are particularly susceptible to the effects of the immature liver function placing them at risk of hypoglycemia, hyperbilirubinemia, cholestasis, bleeding, and impaired drug metabolism. An appreciation of the dynamic changes in liver function during the neonatal period is essential for successful management of neonates who require medical and surgical interventions. This review will focus on the neonatal liver function as well as the changes that the liver undergoes as it matures.

Low glucose sensitivity and polymodal chemosensing in neonatal rat adrenomedullary chromaffin cells

Glucose is the primary metabolic fuel in mammalian fetuses, yet mammals are incapable of endogenous glucose production until several hours after birth. Thus, when the maternal supply of glucose ceases at birth there is a transient hypoglycemia that elicits a counterregulatory surge in circulating catecholamines. Because the innervation of adrenomedullary chromaffin cells (AMCs) is immature at birth, we hypothesized that neonatal AMCs act as direct glucosensors, a property that could complement their previously established roles as hypoxia and acid hypercapnia sensors. During perforated-patch, whole cell recordings, low glucose depolarized and/or excited a subpopulation of neonatal AMCs; in addition, aglycemia (0 mM glucose) caused inhibition of outward K+ current, blunted by the simultaneous activation of glibenclamide-sensitive KATP channels. Some cells were excited by each of the three metabolic stimuli, i.e., aglycemia, hypoxia (Po2 ∼30 mmHg), and isohydric hypercapnia (10% CO2; pH = 7.4). Using carbon fiber amperometry, aglycemia and hypoglycemia (3 mM glucose) induced robust catecholamine secretion that was sensitive to nickel (50 μM and 2 mM) and the L-type Ca2+ channel blocker nifedipine (10 μM), suggesting involvement of both T-type and L-type voltage-gated Ca2+ channels. Fura-2 measurements of intracellular Ca2+ ([Ca2+] i) revealed that ∼42% of neonatal AMCs responded to aglycemia with a significant rise in [Ca2+] i. Approximately 40% of these cells responded to hypoxia, whereas ∼25% cells responded to both aglycemia and hypoxia. These data suggest that together with hypoxia and acid hypercapnia, low glucose is another important metabolic stimulus that contributes to the vital asphyxia-induced catecholamine surge from AMCs at birth.

Continuous Subcutaneous Glucose Monitoring System in diabetic mothers during labour and postnatal glucose adaptation of their infants

AIMS

To assess a new technique for continuous monitoring of glucose concentration during labour in diabetic mothers. A second objective was to study maternal glucose levels in relation to postnatal glucose adaptation and the need for intravenous (IV) glucose treatment in the newborn infant.

METHODS

Fifteen pregnant women with insulin-treated diabetes mellitus participated in this prospective pilot study. To measure their glucose control during labour we used the Continuous Subcutaneous Glucose Monitoring System (CGMS; Medtronic, Minneapolis, MN, USA) to calculate the mean glucose concentration and the area under the curve (AUC) in the last 120 min before delivery. All infants of these women were transferred to the neonatal care unit for early oral feeding and blood glucose measurements up to 14 h after delivery. Infants received IV glucose if blood glucose values were repeatedly < 2.2 mmol/l.

RESULTS

All women coped well with the CGMS monitoring. AUC 0-120 min before delivery, mean glucose concentration 0-120 min before delivery and cord plasma insulin level were all significantly associated with the need for IV glucose in the newborn children.

CONCLUSIONS

In this study we found an association between maternal glucose concentrations during labour and postnatal glucose adaptation and need for IV glucose treatment in the infants. Online monitoring of glucose levels during delivery might help us to achieve maternal normoglycaemia and further reduce the risk of postnatal hypoglycaemia in the offspring.

Metabolic adaptation at birth

After birth, the neonate must make a transition from the assured continuous transplacental supply of glucose to a variable fat-based fuel economy. The normal infant born at term accomplishes this transition through a series of well-coordinated metabolic and hormonal adaptive changes. The patterns of adaptation in the preterm infant and the baby born after intrauterine growth restriction are, however, different to that of a full-term neonate, with the risk for former groups that there will be impaired counter-regulatory ketogenesis. There is much less precise linkage of neonatal insulin secretion to prevailing blood glucose concentrations. These patterns of metabolic adaptation are further influenced by feeding practices.

The offspring of gestational diabetes

Gestational diabetes mellitus (GDM) usually develops in the second half of pregnancy and, in order to address the impact of GDM on the conceptus, several issues must be raised: what are the immediate implications for the fetus and the neonate and why do they happen? What are the consequences for the offspring? What can be done? In a theoretical model the whole pathogenesis and spectrum of fetal and neonatal mortality and morbidity could primarily be attributed to the excessive transferal of glucose from mother of fetus, inducing fetal hyperglycemia, leading to fetal pancreatic islet hypertrophy and beta-cell hyperplasia with a consequent rise in insulin secretion. However, besides, and in addition to glucose, it is quite possible that other metabolic fuels, from amino acids to lipids, may also cross the placenta further contributing to the adverse intrauterine environment. Depending upon the time of gestation during critical developmental stages, the same metabolic fuels would have different effects upon the fetus, the neonate and quite possibly, upon the long-term outcome from neurological and psychosocial impairment to the adult development of metabolic and cardiovascular disorders. Based on clinical and experimental evidence that poor maternal homeostasis is at the core of the problem, it is of paramount importance to identify women at risk of GDM and to keep a tight metabolic control in order to avoid immediate and long-term consequences for their offspring.

Effects of glucagon on in vitro liquid production by lungs from fetal guinea pigs

BACKGROUND

Lung liquid reabsorption in newborns with respiratory distress syndrome can be deficient. Respiratory distress syndrome is often seen in infants of diabetic mothers, in whom the neonatal surge of glucagon is suppressed.

AIM

To investigate the possible effects of glucagon on lung liquid reabsorption.

METHODS

Lungs from near term fetal guinea pigs (62 (2) days gestation; term = 67 days) were supported in vitro for three hours; lung liquid production and reabsorption were monitored by a dye dilution method.

RESULTS

Untreated control preparations produced fluid at 1.75 (0.33) ml/h per kg body weight, and did not change significantly in three hours; those immersed in 10(-12) M glucagon during the middle hour showed no significant change, but those given higher concentrations all showed significant reductions in fluid production or even reabsorption (65.6 (10.3)% fall at 10(-11) M, 70.0 (6.3)% fall at 10(-10) M, and 90.6 (11.1)% fall at 10(-9) M; based on 54 preparations). At 10(-9) M glucagon, 12 out of 30 preparations reabsorbed fluid. The linear log dose-response curve (r(2) = 0.94) gave a theoretical threshold at 4 x 10(-15) M glucagon. Responses appeared to involve the amiloride sensitive Na(+) based reabsorptive system: responses to 10(-9) M glucagon appeared to be reduced by 10(-6) M amiloride, and were abolished by 10(-5) M amiloride (based on 72 preparations).

CONCLUSIONS

The results suggest that the surge of glucagon at birth may help to drain the lungs of fluid. As glucagon liberates cAMP, which also stimulates surfactant, glucagon is worth consideration for possible use in neonatal respiratory distress.

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.

Early postnatal hypoglycaemia in newborn infants of diabetic mothers

This study found that early postnatal hypoglycaemia was mainly induced by foetal hyperinsulinaemia, in close relation to maternal hyperglycaemia, even in well-controlled pregnancies of 59 mothers with insulin-treated diabetes mellitus, 29 with insulin-dependent diabetes mellitus and 30 with gestational diabetes mellitus. Ten of the newborn children (17%) had a blood glucose concentration below 1.0 mmol l(-1) at 2 h postnatally. Cord insulin-like growth factor-I or glucagon concentrations were not related to the early decline of blood glucose.

Assessing the effect of disease on nutrition of the preterm infant

OBJECTIVE

To review existing data on nutritional requirements of extremely low birth weight (ELBW) and very low birth weight (VLBW) preterm infants (those who weigh < 1000 g and 1000-1500 g at birth, respectively), and the effects of diseases on these nutritional requirements.

DATA SOURCES

A literature search was conducted on applicable articles related to nutritional requirements of preterm ELBW and VLBW infants and the effects of diseases in these infants on their nutritional and metabolic requirements.

DATA SYNTHESIS

The literature was analyzed to determine nutritional requirements of preterm ELBW and VLBW infants, to select the most common diseases that have significant and important effects on nutrition and metabolism in these infants, and to make recommendations about diagnostic and therapeutic approaches to nutritional problems as affected by diseases in ELBW and VLBW infants.

CONCLUSIONS

Many diseases unique to preterm infants, either directly or by enhancing the effects of stress on the metabolism of such infants, provide important changes in the nutrient requirements. The overriding observation from all studies, however, is that ELBW and VLBW preterm infants are underfed during the early postnatal period and that this condition, combined with additional stresses from various diseases, increases the risk of long-term neurological sequelae. The value of achieving a specific body composition and growth weight is less certain. There remains a critical need for determining the right quality as well as quantity of nutrients for these infants.

Diabetes and pregnancy

Prior to the introduction of insulin, a vast majority of pregnancies complicated by diabetes ended in perinatal death, with an associated risk of maternal death. Currently, virtually all diabetic women can undergo pregnancy with the expectation of good maternal and fetal outcome. However, many challenges still remain in preventing congenital anomalies and macrosomia.

Enzymes of lysosomal origin in the serum of infants of diabetic mothers behavior in the first days after birth

The serum levels of the two enzymes of lysosomal origin, beta-N-acetyl-D-glucosaminidase and beta-D-glucuronidase, and the isozyme pattern of the former, were determined in control infants and in infants of diabetic mothers (IDM) on the 1st and 5th day after birth. IDM were divided into three groups. Group 1: class A diabetic mothers treated dietetically; Groups 2 and 3: class A and classes B, C, D diabetic mothers, respectively, treated with insulin. All, but one, diabetic mothers were in excellent metabolic control. In the controls the serum levels of both enzymes were quite elevated on the 1st day after birth, reflecting the condition of the mothers at the end of pregnancy, and increased further on the 5th day, presumably as a result of the concurrent burst of antiinsulin hormones. In Group 1 IDM the serum levels of the two enzymes were higher than in controls, on the 1st day, probably reflecting the higher concentrations present in the mothers at the end of pregnancy than in controls, but equalling the condition of normal neonates on the 5th day. This indicates that IDM of this group had a normal post-natal response of the lysosomal apparatus to hormone stress. In Groups 2-3 IDM the enzyme levels on the 1st day could not be distinguished from those of controls, while on the 5th day a decrease was seen, suggesting reduced effect of the antiinsulin hormone burst on the lysosomal apparatus. The isozyme pattern of beta-N-acetyl-D-glucosaminidase in all IDM was similar to that of controls. The behavior of serum lysosomal enzymes of Groups 2-3 IDM is a further indication that the lysosomal apparatus is extremely sensitive to even small metabolic perturbations occurring in diabetic mothers during pregnancy.

Increased platelet thromboxane B2 production in newborn infants of diabetic mothers

Platelet thromboxane B2 (TxB2) production, plasma concentrations of C-peptide and pancreatic glucagon as well as blood glucose levels were measured in 12 infants of insulin-dependent diabetic mothers and eight healthy controls at the age of two hours. Platelet TxB2 production (p less than 0.05) and plasma C-peptide levels (p less than 0.02) were significantly higher and blood glucose concentrations lower (p less than 0.002) in the infants of the diabetic mothers than in the controls. The data suggest that platelets of infants of diabetic mothers produce increased amounts of proaggregatory thromboxane A2, which may contribute to the hyperaggregation in these infants.

Carbohydrate metabolism in the fetus and neonate and altered neonatal glucoregulation

Altered glucose homeostasis in the neonate often results from antecedent events during fetal life. This article describes the normal and altered development of glucoregulatory capabilities during perinatal life and relates it to problems of hypo- and hyperglycemia in the neonate.

Relation of enteroinsular hormones at birth to macrosomia and neonatal hypoglycemia in infants of diabetic mothers

To study the role of enteroinsular hormones in fetal macrosomia and neonatal hypoglycemia in infants of diabetic mothers, we measured plasma concentrations of free and total immunoreactive insulin, C-peptide, pancreatic glucagon, enteroglucagon, and gastric inhibitory polypeptide at birth in 35 IDMs and 35 infants of normal mothers. Twenty fasting adults of normal weight were also studied. Sixteen IDMs were macrosomic at birth; 17 developed neonatal hypoglycemia over the first postnatal hours. The IDMs had ten times higher concentrations of free IRI than the normal infants in cord blood. Free IRI concentrations were related to the severity of maternal diabetes, with the infants of white class D to F mothers having the highest levels. The IDMs with macrosomia had a twofold increase in the concentrations of free IRI when compared with IDMs of normal weight. There was a significant correlation between the birth weight ratio and the concentrations of free IRI. The IDMs who developed neonatal hypoglycemia had considerably higher concentrations of free IRI than did normoglycemic IDMs. The decrease of blood glucose over the first postnatal hours correlated strongly with the free IRI concentrations in the cord blood. The IDMs had a threefold increase of the C-peptide concentrations over those in normal infants. Six IDMs had a molar ratio of C-peptide to free IRI of less than 1. Both the IDMs and normal infants had substantially higher concentrations of enteroglucagon and lower concentrations of GIP than did the fasting adults. Our data provide direct evidence that IDMs are markedly hyperinsulinemic at birth and that ambient hyperinsulinemia plays a crucial role in the development of fetal macrosomia and neonatal hypoglycemia. Moreover, the observed discrepancy in the relative increase of free IRI and C-peptide, combined with the low molar ratio of C-peptide to IRI, suggests a decreased metabolic clearance of insulin or transplacental passage of insulin from the maternal circulation in infants of mothers with insulin-treated diabetes.

Glucose kinetics in infants of diabetic mothers

Glucose kinetic studies were performed to define the glucose turnover rate with 78% enriched D-[U-13C] glucose by the prime constant infusion technique at less than or equal to 6 hours of age in nine infants of diabetic mothers (four insulin-dependent and five chemical diabetic patients) at term. Five normal infants were studied as control subjects. All infants received 0.9% saline intravenously during the study with the tracer. Fasting plasma glucose, insulin, and glucose13/12C ratios were measured during the steady state, and the glucose turnover rate was derived. The average plasma glucose concentration was similar during the steady state in the infants of the diabetic mothers and in the control infants, and the glucose turnover rate was not significantly different among the groups: 2.3 +/- 0.6 mg . kg-1 min-1 in infants of insulin-dependent diabetic patients; 2.4 +/- 0.4 mg . kg-1 min-1 in infants of chemical diabetic patients; and 3.2 +/- 0.3 mg . kg-1 min-1 in the control subjects. Good control of maternal diabetes evidenced by the normal maternal hemoglobin A1c and plasma glucose concentration at delivery and cord plasma glucose concentration resulted in glucose kinetic values in the infants of diabetic mothers that were indistinguishable from those of control subjects. The data further support the importance of good control of the diabetic state in the pregnant woman to minimize or prevent neonatal hypoglycemia.

Metabolic and endocrine consequences of depriving preterm infants of enteral nutrition

Plasma enteroglucagon, pancreatic polypeptide, gastrin, motilin, neurotensin, gastric inhibitory polypeptide, secretin, vasoactive intestinal peptide and blood glucose, alanine, ketone bodies, lactate and pyruvate were measured on the sixth postnatal day in (a) a group of 10 preterm infants who on account of hyaline membrane disease had not received enteral feeding since birth and (b) before and at 55, 90, and 120 minutes after feeding in a group of healthy preterm infants fed three-hourly on human milk. Gut hormones were also measured in umbilical venous cord blood. The infants receiving regular boluses of milk from birth demonstrated postnatal surges in preprandial concentrations of gut hormones together with cyclical hormonal responses to feeding. None of these changes were seen in infants receiving intravenous fluids. The latter infants also had lower concentrations of blood alanine, glycerol and hydroxybutyrate and lacked the phasic changes in intermediary metabolites seen in the infants receiving enteral boluses of milk. Thus deprivation of enteral feeding results in a profound alteration of the metabolic and endocrine milieu which may have important effect on the process of adaptation to postnatal life.

Plasma noradrenaline and adrenaline in infants of diabetic mothers at birth and at two hours of age

Plasma noradrenaline and adrenaline in the umbilical artery were very high in many infants of both diabetic mothers (IDM) and non-diabetic mothers (controls) compared to values obtained in adults. Blood pH was slightly but significantly lower in IDM than in controls at delivery. There was a significant negative correlation between plasma noradrenaline and blood pH in IDM at birth, but no correlation between plasma noradrenaline and blood glucose, birth weight and Apgar scores. Plasma noradrenaline decreased significantly from birth to two hours of age both in IDM and controls. At two hours of age plasma noradrenaline and adrenaline were significantly greater in IDM compared to controls whereas blood glucose concentration was lower in the former group. There was a close inverse correlation between plasma noradrenaline and adrenaline, respectively, and blood glucose in IDM at two hours of age but not in controls. The elevated plasma noradrenaline at delivery in IDM may be explained by clinically undetectable acidosis whereas elevated plasma catecholamines at two hours are probably due to hypoglycaemia.

Metabolic events in infants of diabetic mothers during first 24 hours after birth. II. Changes in plasma lipids

Changes in plasma glycerol (FG), free fatty acids (FFA) and triglyceride (TG) were studied in 24 normo- and 8-hypoglycemic infants of diabetic mothers (IDM). In both groups a normal rise in plasma FG 2 hours after birth was found indicating unimpaired lipolysis. The rise in plasma FFA, however, was only about 50% of normal in normoglycemic IDM and about 25% of normal in hypoglycemic IDM. The rise in plasma TG was normal in normoglycemic and about 70% of normal in hypoglycemic IDM. The 2 hour rise in plasma FFA correlated with the 2 hour concentration of insulin and glucose, whereas the rise in plasma FG and TG did not. Maternal plasma FFA correlated with fetal FFA retention (umbilical vein minus artery (V-A) FFA concentrations). No correlations were found between maternal plasma FFA values and birth-weights nor between umbilical V-A FFA concentrations and birth-weights.

Metabolic events in infants of diabetic mothers during first 24 hours after birth. I. Changes in plasma glucose, insulin and glucagon

Changes in plasma glucose, nonantibody-bound insulin and glucagon concentrations were studied in 32 newborn infants of diabetic mothers (IDM) during the first 24 hours after birth. Ten infants were born to White class A mothers and 22 to class B-F mothers. The infants were kept fasting during the investigative period and blood was sampled from an umbilical artery catheter. At birth, plasma glucose and glucagon levels were similar in the class A and B-F infants, whereas nonantibody-bound insulin levels were approximately 15-fold higher in the class B-F infants than in the class A infants (p less than 0.001). After birth, plasma glucose fell in all infants, the nadir being reached at two hours (p less than 0.01). Plasma glucose fell by approximately 35% in the class A infants and 63% in the class B-F infants (p less than 0.01). Eight IDM had asymptomatic hypoglycemia (plasma glucose less than 1.9 mmol/l) and four of these infants had glucose levels below 1.7 mmol/l and were withdrawn from further study. In the remaining four hypoglycemic IDM, plasma glucose was about 1.6-fold higher (p less than 0.01) and insulin about 11-fold higher (p less than 0.001) at birth compared to the 24 normoglycemic IDM. The hypoglycemia was attended by unchanged insulin levels in the class A infants, whereas insulin fell in the class B-F infants (p less than 0.01). However, during the whole investigative period, plasma insulin of the class B-F infants was higher than that of the class A infants (p less than 0.01). After birth, plasma glucagon increased slowly in all IDM and peak values were reached after 12 hours in the class A infants (p less than 0.05) and 24 hours in the class B-F infants (p less than 0.01). Only those infants who became hypoglycemic after birth exhibited a significant increment in plasma glucagon from 0.2 hours (p less than 0.05). These results suggest that neonatal hypoglycemia of IDM results from high plasma levels of nonantibody-bound insulin together with a very retarded increment in plasma glucagon levels. The degree of neonatal hypoglycemia and hyperinsulinemia of an individual IDM seems to be positively correlated to the severity of the diabetes of the mother.

Blood glucose, plasma insulin and glucagon response to arginine in infants during the first month of life

Blood glucose, plasma insulin and plasma glucagon were determined during an arginine test at 0, 30 and 60 min in 1 to 7 and 30 day infants. The results were compared with those obtained in the 2-10-year-old children. Basal levels of blood glucose increased from the 1st to the 30th day; by the 30th day they were comparable with those observed in the 2-10-year-old children. Basal levels of plasma insulin were higher in 1 day infants, lower in 7 day infants and similar to those of the 2-10-year-old children in the 30 day infants. Basal values of plasma glucagon were higher in 1 day infants than in the 2-10-year-old children; the lowest levels were found in 7 day infants. After arginine, blood glucose increased in the 2-10-year-old children, the variations were negligible in the 1 to 7 and 30 day infants. Plasma insulin increased in 2-10-year-old children, there was a slight increase in 1 and 30 day infants and a negligible one in the 7 day infants. Plasma glucagon increased in the 2-10-year old children, and was similar in 1 day infants; the increase was reduced in 30 day infants and virtually absent in 7 day infants. These results suggest that there is a transitory alpha cell insensitivity to arginine during the first week of life.

Blunting of spontaneous and alanine-stimulated glucagon secretion in newborn infants of diabetic mothers

Spontaneous and alanine-stimulated glucagon secretion, and its relation to plasma glucose concentration was investigated in two groups of infants during the initial two hours of life. At birth, plasma glucagon and glucose concentrations were not significantly different in healthy term newborn infants (control subjects) and infants born to insulin-dependent diabetic mothers(IDM-l). In control infants during the first hour of life, glucose fell by 43 +/- 16 mg per deciliter (mean +/- S.E.M.) while plasma glucagon rose by 44 +/- 16 pg. per milliliter (p less than 0.05 for both). However, in IDM-I despite a fall in glucose greater than in control infants, plasma glucagon failed to significantly increase. Intravenous alanine, 150 mg. per kilogram, given at one hour of life, elicited significant increments in glucose and glucagon which were positively correlated in control infants. No significant change in glucose or glucagon occurred in the diabetic group. None of the control infants developed symptomatic or biochemical hypoglycemia (plasma glucose less than 20 mg. per deciliter) whereas five of ten IDM-I developed hypoglycemia. These results suggest that spontaneous and alanine-stimulated glucagon secretion is obtunded in IDM and that this may contribute to hypoglycemia in these infants.

Urinary cyclic AMP in infants admitted to a neonatal intensive care unit

The urinary excretion of cyclic AMP was studied during the first 3 days of life in 46 randomly selected infants admitted to a neonatal intensive care unit. The data were compared with those of normal newborn infants. Urinary cyclic AMP concentrations were significantly correlated with gestational age (all patients), and with birth weight (all patients except infants of diabetic mothers (IDMs)). The urinary cyclic AMP/creatine ratio increased from day 1 to day 3 in normal newborns and in IDMs, and tended to increase also in small-for-gestational age (SGA), low birth weight (LBW), and sick, term infants, although the changes in the latter groups were not statistically significant. Four infants studied with parallel determinations showed increased cyclic AMP/creatinine ratio from day 1 to day 3 both in plasma and urine. All urinary cyclic AMP/creatine ratios were lower than the corresponding ratios found in plasma. In LBW infants, there was an inverse relationship between urinary cyclic AMP and serum calcium. In IDMs a positive correlation was observed between urinary cyclic AMP and blood glucose concentration. In conclusion, the excretion of cyclic AMP in sick newborn infants is influenced by the following factors: gestational age, postnatal age, birth weight, and derangements of serum calcium and blood glucose concentrations.

Metabolism during normal and diabetic pregnancy and its effect on neonatal outcome

Diurnal profile studies have been used to define the fetal carbohydrate and lipid substrate environment in normal and diabetic women during late pregnancy. In women with normal glucose tolerance the diurnal plasma glucose concentration was maintained within close limits (mean +/- S.D., 4.70 +/- 0.38 mmol/l) but in chemical and insulin-dependent diabetics there was a marked increase in both the mean diurnal glucose value and in the variability of the plasma glucose levels observed through the day (mean +/- S.D., 5.61 +/- 5.61 +/- 1.03 and 6.02 +/- 1.26 mmol/l respectively, P less than 0.01). No difference was observed between the peripheral insulin activity of the normal and chemical diabetic women, and the impaired glucose tolerance of the latter group was due to a deficient insulin response to goucose. The diurnal glucose variability, expressed as the standard deviation of the mean, was found to be inversely correlated with the residual C-peptide response in insulin-requiring diabetics. The mean diurnal plasma free fatty acid (FFA) concentration was slightly raised in chemical diabetic subjects compared to normal women (mean +/- S.D., 0.77 +/- 0.34 and 0.68 +/- 0.20 mmol/l respectively) but this difference was not significant. Insulin treatment produced a marked reduction in circulating FFA concentration, with a mean value in the insulin-dependent diabetic group of 0.45 +/- 0.11 mmol/l (P less than 0.001). Neonatal glucose assimilation during the first two hours of life correlated strongly with several functions of maternal carbohydrate tolerance. This was associated with higher plasma insulin concentrations at birth, and a marked tendency to hypoglycaemia in the infants of untreated chemical diabetic women. Impaired mobilization of triglyceride stores was also observed during the two hours after birth in the infants of diabetic women. This, however, appears to be due not to impaired lipolysis but to rapid re-esterification of FFA. These findings all indicate a state of functional hyperinsulinism in the infant of the diabetic women secondary to maternal hyperglycaemia.

The outcome of diabetic pregnancies: a prospective study

In a large prospective study of pregnancy the perinatal mortality rate was 141/1000 births for diabetic gestations in which the onset of labour was spontaneous, 33/1000 for diabetic gestations in which labour was induced or the infant delivered by Caesarean section and 34/1000 for the non-diabetics. Forty per cent of the perinatal mortality excess in the diabetics was due to the consequences of maternal vascular lesions, i.e. large placental infarcts and marked retardation of placental growth. Seventeen per cent of the perinatal mortality excess was related to maternal acidosis or to insulin shock, 12% to severe congenital anomalies, 12% to the complications of Caesarean sections and the remainder to other disorders. Mothers with diabetes mellitus had more than twice the frequency of atheromata, fibrinoid change and thrombi in decidual arteries as non-diabetic mothers. Histological grading revealed that overweight newborns of diabetic mothers had immature lungs by comparison with the lungs of normally grown infants of diabetic mothers and infants of non-diabetic mothers. Low IQ values and an excess of neurological abnormalities in children of diabetic mothers who were ketotic during pregnancy were found to be due to amniotic fluid bacterial infections and their complications rather than to the maternal ketosis.

Endocrine and metabolic response in the human newborn to first feed of breast milk

The hormonal and metabolic response to the first feed of breast milk was studied in 12 infants at 4-6 hours of age. After the feed there was an increase in blood glucose concentration but no changes in the concentrations of lactate, pyruvate, alanine, or ketone bodies. The feed was followed by an increase in the concentrations of plasma insulin, growth hormone, gastrin, and enteroglucagon, but no change in levels of plasma glucagon or gastric inhibitory peptide. Several hormone systems are functionally active at birth and are stimulated by the first feed of milk.

Fetal carbohydrate metabolism: its clinical importance

A basic understanding of fetal nutrition and metabolism is essential in the clinical management of the obstetric patient. The fetus depends upon a constant infusion of glucose for energy production and growth. Maternal glucose is the prime source of this nutrient. Alterations in maternal carbohydrate homeostasis will lead to changes in fetal metabolism. In diabetes mellitus, hyperglycemia may produce hyperinsulinemia and macrosomia. The growth-retarded fetus may have a decreased supply of maternal glucose and reduced amounts of hepatic glycogen and adipose tissue. The fetus must depend upon these stores for survival during periods of intrauterine hypoxia. In the newborn period, hypothermia and hypoxia may rapidly deplete energy reserves. With this information, the clinician may more knowledgeably manage dietary demands in the antepartum patient, fetal distress during labor, and the immediate newborn period.

Development of glucagon sensitivity in neonatal rat liver

The ontogenesis of the hepatic glucagon-sensitive adenylate cyclase system has been studied in the rat. With a partially purified liver membrane preparation, fetal adenylate cyclase was less responsive to glucagon than the enzyme from neonatal or adult livers. Similar results were obtained in gently prepared liver homogenates, suggesting that destruction of essential components of the fetal liver membrane did not account for the relative unresponsiveness of the adenylate cyclase enzyme to glucagon. Investigation of other factors that might account for diminished fetal hepatic responsiveness to glucagon indicate (a) minimal glucagon degradation by fetal membranes relative to 8-day or adult tissue; and (b) available adenylate cyclase enzyme, as suggested by a 13-fold increase over basal cyclic AMP formation with NaF in fetal liver membranes. These results indicate that neither enhanced glucagon degradation nor adenylate cyclase enzyme deficiency accounts for the relative insensitivity of the fetal hepatic adenylate cyclase system to glucagon. In early neonatal life, hepatic adenylate cyclase responsiveness to glucagon rapidly developed and was maximal 6 days after birth. These changes were closely paralleled by a fivefold increase in glucagon binding and the kinetically determined Vmax for cyclic AMP formation. These observations suggest that (a) fetal hepatic unresponsiveness to glucagon may be explained by a limited number of glucagon receptor sites; (b) during the neonatal period, the development of glucagon binding is expressed primarily as an increase in adenylate cyclase Vmax; (c) the ontogenesis of hepatic responsiveness to glucagon may be important in the resolution of neonatal hypoglycemia.

Effects of exogenous hormones and glucose on plasma levels and hepatic metabolism of amino acids in the fetus and in the newborn rat

The present study examines the role of insulin, glucagon and cortisol in the regulation of gluconeogenesis from lactate and amino acids in fetal and newborn rats. Injection of glucagon in the full-term fetal rat caused a rise in glucose (and insulin) and a fall in blood levels of most individual amino acids, stimulated hepatic accumulation of 14C-amino isobutyric acid and 14C-cycloleucine and increased the conversion of 14C lactate, alanine and serine to glucose in vivo and in vitro (liver slices). Such changes were equivalent to the changes seen in 4 h old newborn rats. When glucagon was administered at birth, little difference was observed between control and treated animals in plasma amino acids and a smaller increment in conversion of 14C substrate to glucose occurred. By contrast, insulin injection at birth caused hypoglycemia, suppression of levels of certain amino acids and inhibition of conversion of 14C substrates into glucose. Glucose injection at birth caused elevated glycemia and plasma insulin and suppression of most amino acid levels and of conversion of 14C substrate into glucose. Cortisol injection at birth caused a marked, generalized by hyperaminoacidemia, a stimulation of glucagon secretion and of conversion of 14C substrates into glucose. These observations support the thesis that glucagon plays a major role in the induction of hepatic gluconeogenesis and that insulin acts as an antagonist hormone.

Neonatal small left colon syndrome: intramural not intraluminal obstruction

We have described a characteristic syndrome of intestinal dysfunction in infants of diabetic mothers. This finding appears to result from a transient intramural dysfunction. Many respond to rectal irrigations alone. However, a significant number will require close observation and possible diversion for persistent partial intestinal obstruction. Failure to recognize persistent obstruction may result in intestinal perforation.

Neontal hypoglycaemia in infants of insulin-dependent diabetic mothers

Neonatal hypoglycaemia (blood glucose smaller than 20 mg/100 ml) occurred in the first 6 hours of life in 25 of 34 infants born to diabetic mothers receiving insulin. Despite severe hypoglycaemia (blood glucose smaller than 10 mg/100 ml) in 17, clinical features of hypoglycaemia were absent in all but 2. Hypoglycaemia was not related either to the level of plasma insulin in cord blood, determined as nonextracted immunoreactive insulin, or to the degree of control of maternal blood glucose during pregnancy. The frequent occurrence of severe neonatal hypoglycaemia in the infants born to diabetic mothers receiving insulin appears to be due rather to failure to maintain basal glucose homoeostasis after birth than to hyperinsulinism.