Maternal Hyperglycemia Directly and Rapidly Induces Cardiac Septal Overgrowth in Fetal Rats

Guidelines for in vivo models of developmental programming of cardiovascular disease risk

Research using animals depends on the generation of offspring for use in experiments or for the maintenance of animal colonies. Although not considered by all, several different factors preceding and during pregnancy, as well as during lactation, can program various characteristics in the offspring. Here, we present the most common models of developmental programming of cardiovascular outcomes, important considerations for study design, and provide guidelines for producing and reporting rigorous and reproducible cardiovascular studies in offspring exposed to normal conditions or developmental insult. These guidelines provide considerations for the selection of the appropriate animal model and factors that should be reported to increase rigor and reproducibility while ensuring transparent reporting of methods and results.

Fetal echocardiography changes of the right ventricle of well-controlled gestational diabetes mellitus

BACKGROUND

There is few evidence of right ventricular (RV) function in fetuses with gestational diabetes mellitus (GDM). Therefore, the aim of this study was to assess the RV function of fetuses using routine and two-dimensional speckle-tracking echocardiography (2D STE) to determine the effects of well-controlled GDM in the third trimester.

METHODS

We used a Philips Epiq7C ultrasound instrument to obtain RV data sets from 63 subjects from July 2019 to February 2022. We compared the free wall thickness (FWT), fractional area change (FAC), Tei index (TEI), tricuspid annular plane systolic excursion (TAPSE) and free wall longitudinal strain(FWLS)of the RV in mothers with well-controlled GDM and normal gestational age-matched fetuses.

RESULTS

63 third trimester fetuses (32 GDM; 31 healthy controls) met the enrolment criteria. Significant differences in fetal RV were detected between the GDM and control groups for the FAC (36.35 ± 6.19 vs. 41.59 ± 9.11; P = 0.008) and the FWLS (-18.28 ± 4.23 vs. -20.98 ± 5.49; P = 0.021). There was a significant difference among the segmental strains of the base, middle and apex of the RV free wall in the healthy controls (P = 0.003), but in the GDM group, there was no statistical difference (p = 0.076). RV FWLS had a strong correlation with FAC (r = 0.467; P = 0.0002).

CONCLUSIONS

In well-controlled GDM, there was measurable fetal RV hypertrophy and significant systolic function decline, indicating the presence of ventricular remodeling and dysfunction. 2D-STE can evaluate the RV free wall contraction in a more comprehensive way.

Fetal echocardiographic parameters in pregnancies complicated by diabetes: a case control study

Background

At present, the prevalence of pregestational diabetes is 2.2% with an overall prevalence of hyperglycaemia in pregnancy of about 16.2%. Fetuses of diabetic mothers are at risk of functional cardiac abnormalities without structural cardiac anomalies especially in the third trimester. The main aim of this study was to assess the association of diabetes with different fetal echocardiographic parameters.

Methods

A case control study comprising a total of 120 pregnant women (60 cases and 60 controls). The cases group included fetuses of mothers known to have pre-gestational type 2 diabetes (DM group) while the control group included fetuses of euglycaemic healthy pregnant women. They were examined twice at 23–24 weeks' gestation (visit 1) and followed up at 27–28 weeks’ gestation (visit 2). The Modified Myocardial Performance Index (Mod MPI) was obtained in all fetuses. Also, M-mode echocardiography was used to measure the interventricular septum thickness at diastole in a transverse four chamber view.

Results

There was a significant increase in Iso-volumetric contraction time (ICT) (45.4 ms ± 8.9), Iso-volumetric relaxation time (IRT) (54.7 ms ± 11.22), Interventricular septal thickness (IVST) (4.08 mm ± 0.8), aortic acceleration time (AAT) (54.16 ms ± 12.77) and MPI (0.64 ± 0.09) in the diabetic group compared to the normal control group ICT (38.5 ms ± 9.59), IRT (46.13 ms ± 10.29), IVST (3.17 mm ± 0.6), AAT (49.73 ms ± 10.68) and MPI (0.5 ± 0.1) (all P values were < 0.001).

When comparing parameters assessed at both visits among diabetic patients, there was a significant increase in IVST in the second visit (4.74 ± 0.78 mm) compared to the first visit (4.08 ± 0.8 mm) (P value < 0.05).

The incidence of hypertrophic cardiomyopathy (HCM) was significantly higher in diabetic patients than in the control group. This is was observed in both first and second visit (33.4% and 56.7%) (P value < 0.001).

Conclusions

Fetuses of diabetic pregnant females show a significant increase in MPI, decrease in E\A ratio and HCM. These alterations in cardiac functions and structure were found to be continuous throughout the period of time between the two visits.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04969-5.

Preconception lifestyle intervention in women with obesity and echocardiographic indices of cardiovascular health in their children

BACKGROUND

Improving maternal lifestyle before conception may prevent the adverse effects of maternal obesity on their children's future cardiovascular disease (CVD) risk. In the current study, we examined whether a preconception lifestyle intervention in women with obesity could alter echocardiographic indices of cardiovascular health in their children.

METHODS

Six years after a randomized controlled trial comparing the effects of a 6-month preconception lifestyle intervention in women with obesity and infertility prior to fertility care to prompt fertility care, 315 of the 341 children conceived within 24 months after randomization were eligible for this study. The intervention was aimed at weight loss (≥5% or until BMI < 29 kg/m²). Children underwent echocardiographic assessment of cardiac structure and function, conducted by a single pediatric cardiologist, blinded to group allocation. Results were adjusted for multiple variables including body surface area, age, and sex in linear regression analyses.

RESULTS

Sixty children (32 girls, 53%) were included, mean age 6.5 years (SD 1.09). Twenty-four children (40%) were born to mothers in the intervention group. Children of mothers from the intervention group had a lower end-diastolic interventricular septum thickness (-0.88 Z-score, 95%CI -1.18 to -0.58), a lower left ventricle mass index (-8.56 g/m², 95%CI -13.09 to -4.03), and higher peak systolic and early diastolic annular velocity of the left ventricle (1.43 cm/s 95%CI 0.65 to 2.20 and 2.39 cm/s 95%CI 0.68 to 4.11, respectively) compared to children of mothers from the control group.

CONCLUSIONS

Children of women with obesity, who underwent a preconception lifestyle intervention, had improved cardiac structure and function; a thinner interventricular septum, lower left ventricle mass, and improved systolic and diastolic tissue Doppler velocities. Despite its high attrition rates, our study provides the first experimental human evidence suggesting that preconception lifestyle interventions may present a method of reducing CVD risk in the next generation.

CLINICAL TRIAL REGISTRATION

LIFEstyle study: Netherlands Trial Register: NTR1530 ( https://www.trialregister.nl/trial/1461 ). This follow-up study was approved by the medical ethics committee of the University Medical Centre Groningen (METC code: 2008/284).

Diabetic pregnancy as a novel risk factor for cardiac dysfunction in the offspring-the heart as a target for fetal programming in rats

AIMS/HYPOTHESIS

The impact of diabetic pregnancy has been investigated extensively regarding offspring metabolism; however, little is known about the influence on the heart. We aimed to characterise the effects of a diabetic pregnancy on male adult offspring cardiac health after feeding a high-fat diet in an established transgenic rat model.

METHODS

We applied our rat model for maternal type 2 diabetes characterised by maternal insulin resistance with hyperglycaemia and hyperinsulinaemia. Diabetes was induced preconceptionally via doxycycline-induced knock down of the insulin receptor in transgenic rats. Male wild-type offspring of diabetic and normoglycaemic pregnancies were raised by foster mothers, followed up into adulthood and subgroups were challenged by a high-fat diet. Cardiac phenotype was assessed by innovative speckle tracking echocardiography, circulating factors, immunohistochemistry and gene expression in the heart.

RESULTS

When feeding normal chow, we did not observe differences in cardiac function, gene expression and plasma brain natriuretic peptide between adult diabetic or normoglycaemic offspring. Interestingly, when being fed a high-fat diet, adult offspring of diabetic pregnancy demonstrated decreased global longitudinal (-14.82 ± 0.59 vs -16.60 ± 0.48%) and circumferential strain (-23.40 ± 0.57 vs -26.74 ± 0.34%), increased relative wall thickness (0.53 ± 0.06 vs 0.37 ± 0.02), altered cardiac gene expression, enlarged cardiomyocytes (106.60 ± 4.14 vs 87.94 ± 1.67 μm), an accumulation of immune cells in the heart (10.27 ± 0.30 vs 6.48 ± 0.48 per fov) and higher plasma brain natriuretic peptide levels (0.50 ± 0.12 vs 0.12 ± 0.03 ng/ml) compared with normoglycaemic offspring on a high-fat diet. Blood pressure, urinary albumin, blood glucose and body weight were unaltered between groups on a high-fat diet.

CONCLUSIONS/INTERPRETATION

Diabetic pregnancy in rats induces cardiac dysfunction, left ventricular hypertrophy and altered proinflammatory status in adult offspring only after a high-fat diet. A diabetic pregnancy itself was not sufficient to impair myocardial function and gene expression in male offspring later in life. This suggests that a postnatal high-fat diet is important for the development of cardiac dysfunction in rat offspring after diabetic pregnancy. Our data provide evidence that a diabetic pregnancy is a novel cardiac risk factor that becomes relevant when other challenges, such as a high-fat diet, are present.

Impact of maternal hyperglycemia on cardiac development: Insights from animal models

Congenital heart disease (CHD) is the leading cause of birth defect-related death in infants and is a global pediatric health concern. While the genetic causes of CHD have become increasingly recognized with advances in genome sequencing technologies, the etiology for the majority of cases of CHD is unknown. The maternal environment during embryogenesis has a profound impact on cardiac development, and numerous environmental factors are associated with an elevated risk of CHD. Maternal diabetes mellitus (matDM) is associated with up to a fivefold increased risk of having an infant with CHD. The rising prevalence of diabetes mellitus has led to a growing interest in the use of experimental diabetic models to elucidate mechanisms underlying this associated risk for CHD. The purpose of this review is to provide a comprehensive summary of rodent models that are being used to investigate alterations in cardiac developmental pathways when exposed to a maternal diabetic setting and to summarize the key findings from these models. The majority of studies in the field have utilized the chemically induced model of matDM, but recent advances have also been made using diet based and genetic models. Each model provides an opportunity to investigate unique aspects of matDM and is invaluable for a comprehensive understanding of the molecular and cellular mechanisms underlying matDM-associated CHD.

Third Trimester Myocardial Performance Index in Fetuses from Women with Hyperglycemia in Pregnancy: A Systematic Review and Meta-Analysis

INTRODUCTION

 The myocardial performance index (MPI) has been proposed to evaluate cardiac dysfunction in newborns from diabetic mothers. Although MPI is routinely assessed in newborns, its role in the evaluation of fetuses from women with hyperglycemia in pregnancy (HIP) is still under evaluation. We aimed to evaluate the differences in third trimester fetal MPI in pregnant women with hyperglycemia compared to healthy controls.

MATERIALS AND METHODS

 Seven electronic databases were searched for all studies assessing women with HIP who underwent evaluation of fetal left MPI during pregnancy compared to a control group. The summary measures were reported as mean differences (MD) in the mean fetal left MPI between women with HIP and healthy controls, with a 95 % confidence interval (CI). A post hoc subgroup analysis based on the type of HIP - pregestational diabetes, GDM, or gestational impaired glucose tolerance (GIGT) - was performed as an additional analysis.

RESULTS

 14 studies assessing 1326 fetuses (580 from women with HIP and 746 from controls) were included. Women with HIP had a significantly higher mean left fetal MPI compared to controls (MD 0.08; 95 %CI: 0.05 to 0.11; p < 0.00 001). Subgroup analysis according to the type of HIP concurred with the overall analysis for women with DM (MD 0.07; 95 %CI: 0.01 to 0.13; p = 0.02) and for women with GDM (MD 0.012; 95 %CI: 0.07 to 0.17; p < 0.00 001) but not for women with GIGT (MD -0.01, 95 % CI -0.28 to 0.27; p = 0.96).

CONCLUSION

 Fetal left MPI is increased in pregnancies with HIP appearing as a potential marker of cardiac dysfunction.

Organisational alteration of cardiac myofilament proteins by hyperglycaemia in mouse embryonic stem cell-derived cardiomyocytes

The exposure of the developing foetal heart to hyperglycaemia in mothers with diabetes mellitus is a major risk factor for foetal cardiac complications that lead to heart failure. We studied the effects of hyperglycaemia on the layout of cardiac myofilament proteins in stem cell-derived cardiomyocytes and their possible underlying mechanisms. Mouse embryonic stem cells (mESCs) were differentiated into cardiac-like cells and cultured in media containing baseline- or high glucose concentrations. Cellular biomarkers were detected using Western blot analysis, immunocytochemistry, 5-ethynyl-2'-deoxyuridine (EdU) cell proliferation assay, and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay. High glucose decreased the proportion of cardiac troponin T and α-actinin 2 positive mESCs as well as disrupted the α-actinin 2 striated pattern and the distribution of the cardiac myosin heavy chain α- and β isoforms. However, there was no alteration of the cellular EdU uptake nor the expression of the receptor of advanced glycation end-product (RAGE). High glucose also increased the presence of the oxidative stress marker nitrotyrosine as well as the number of TUNEL-stained nuclei in cardiac-like cells. Treatment with the antioxidant N-acetyl cysteine decreased the number of TUNEL-stained cells in high glucose and improved the α-actinin 2 striated pattern. Hyperglycaemia negatively impacted the expression and cellular organisation of cardiac myofilament proteins in mESC-derived cardiomyocytes through oxidative stress. The results add further insights into the pathophysiological mechanisms of cardiac contractile dysfunction in diabetic cardiac developmental disease.

Hypertrophic Cardiomyopathy in Infants from the Perspective of Cardiomyocyte Maturation

Hypertrophic cardiomyopathy (HCM) in infancy is rare and many fulminant cases are fatal. Infantile HCM shows a rapid progressive clinical course and different characteristics compared with late-onset HCM presenting during the prepubertal age. There are also spontaneously resolving phenotypes of HCM that are diagnosed in neonates being treated for bronchopulmonary dysplasia with corticosteroids or in those with other problems related to maternal endocrine diseases. The pathophysiology of infantile HCM has not been well described. Therefore, this review updates the pathophysiology of infantile HCM and includes molecular studies on maturation of cardiomyocytes from a clinician's point of view.

Hypertrophic cardiomyopathy (HCM) is characterized by ventricular wall hypertrophy with diastolic dysfunction. Pediatric HCM is distinguished from the adult in many aspects. Most children with HCM do not present clinically until the adolescent period, even when they are born with genetic mutations. Some infants with early-onset HCM present with massive progressive myocardial hypertrophy in the first few months of life, which is often fatal. The mortality of pediatric HCM peaks during the infantile and adolescent periods. These periods roughly correlate with children's growth spurt. Non-sarcomeric causes of HCM are more frequent in pediatric HCM, while sarcomeric causes are more common in adults. From the perspective of cardiac development, the fetal heart has immature cardiomyocytes, which are characterized by proliferation and exit their cell cycles with a decreased regenerative property after birth. In the perinatal period, there is a dynamic change in maturation of cardiomyocytes from immature to mature cells. Infants who are treated with steroids or born to mothers with diabetes or hyperthyroidism often show phenotypes of HCM, which gradually resolve. With remarkable advancement of molecular biology, understanding on maturation of cardiomyocytes has increased. Neonates undergo abrupt environmental changes during the transitional circulation, which is affected by oxygen, metabolic and hormonal fluctuations. Derangement in physiological transition to the normal postnatal environment may influence maturation of proliferative immature cardiomyocytes during early infancy. This article reviews updates of infantile HCM and recent molecular studies related to maturation of cardiomyocytes from the clinical point of view of identifying distinct characteristics of infantile HCM.

Mending a broken heart: In vitro, in vivo and in silico models of congenital heart disease

Birth defects contribute to ∼0.3% of global infant mortality in the first month of life, and congenital heart disease (CHD) is the most common birth defect among newborns worldwide. Despite the significant impact on human health, most treatments available for this heterogenous group of disorders are palliative at best. For this reason, the complex process of cardiogenesis, governed by multiple interlinked and dose-dependent pathways, is well investigated. Tissue, animal and, more recently, computerized models of the developing heart have facilitated important discoveries that are helping us to understand the genetic, epigenetic and mechanobiological contributors to CHD aetiology. In this Review, we discuss the strengths and limitations of different models of normal and abnormal cardiogenesis, ranging from single-cell systems and 3D cardiac organoids, to small and large animals and organ-level computational models. These investigative tools have revealed a diversity of pathogenic mechanisms that contribute to CHD, including genetic pathways, epigenetic regulators and shear wall stresses, paving the way for new strategies for screening and non-surgical treatment of CHD. As we discuss in this Review, one of the most-valuable advances in recent years has been the creation of highly personalized platforms with which to study individual diseases in clinically relevant settings.

Nutritional and developmental programming effects of insulin

The discovery of insulin in 1921 was a major breakthrough in medicine and for therapy in patients with diabetes. The dramatic rise in the prevalence of overweight and obesity has been tightly linked to an increased prevalence of gestational diabetes mellitus (GDM), which poses major health concerns. Babies born to GDM mothers are more likely to develop obesity, type 2 diabetes and cardiovascular disease later in life. Evidence accumulated during the past two decades has revealed that high levels insulin, such as those observed during GDM, can have a widespread effect on the development and function of a variety of organs. This review summarises our current knowledge on the role of insulin in the placenta, cardiovascular system and brain during critical periods of development, as well as how it can contribute to lifelong metabolic regulation. We also discuss possible intervention strategies to ameliorate and hopefully reverse the developmental defects associated with obesity and GDM.

Fetal cardiovascular hemodynamics in type 1 diabetic pregnancies at near-term gestation

INTRODUCTION

Poor glycemic control in maternal type 1 diabetes mellitus during pregnancy can affect fetal cardiac and placental function. However, studies concerning fetal central hemodynamics have revealed conflicting results. We hypothesized that in pregnancies complicated by maternal type 1 diabetes, fetal cardiovascular and placental hemodynamics are comparable to the control fetuses at near-term gestation. In addition, we investigated the relation between newborn serum biomarkers of cardiac function and fetal cardiovascular and placental hemodynamics. Furthermore, we studied whether maternal diabetes is associated with placental inflammation.

MATERIAL AND METHODS

In this prospective case-control study, fetal central and peripheral hemodynamics were assessed by ultrasonography in 33 women with type 1 diabetes and in 67 controls with singleton pregnancies between 34⁺² and 40⁺² gestational weeks. Newborn umbilical cord serum was collected to analyze cardiac natriuretic peptides (atrial and B-type natriuretic peptides) and troponin T concentrations. Placental tissue samples were obtained for cytokine analyses.

RESULTS

Fetal ventricular wall thicknesses were greater and weight-adjusted stroke volumes and cardiac outputs were lower in the type 1 diabetes group than in the control group. Pulsatility in the aortic isthmus and inferior vena cava blood flow velocity waveforms was greater in the type 1 diabetes group fetuses than in the controls. A positive correlation was found between branch pulmonary artery and aortic isthmus pulsatility index values. Umbilical artery pulsatility indices were comparable between the groups. Umbilical cord serum natriuretic peptide and troponin T concentrations were elevated in the type 1 diabetes fetuses. These cardiac biomarkers correlated significantly with cardiovascular hemodynamics. Placental cytokine levels were not different between the groups.

CONCLUSIONS

In maternal type 1 diabetes pregnancies, fetal cardiovascular hemodynamics is impaired. Maternal type 1 diabetes does not seem to alter placental vascular impedance or induce placental inflammation.

Associations of Maternal Glycemia in the First Half of Pregnancy With Alterations in Cardiac Structure and Function in Childhood

OBJECTIVE

Gestational diabetes mellitus has been associated with offspring cardiac congenital malformations, ventricular hypertrophy, and diastolic dysfunction in large observational cohort studies and experimental animal models. We assessed the associations of maternal random glucose concentrations across the full range with childhood cardiac ventricular structure and function.

RESEARCH DESIGN AND METHODS

In a population-based prospective cohort among 1,959 women and their offspring, maternal random glucose concentrations were measured at a median 13.1 weeks' gestation (95% range 10.5-16.8 weeks). We obtained offspring cardiac outcomes, relative to body size, through cardiac MRI at 10 years.

RESULTS

The mean maternal random glucose concentration was 4.4 mmol/L (SD 0.8). The highest quintile of maternal glucose concentrations, compared with the lowest quintile, was associated with a lower childhood left ventricular mass (-0.19 SD score [SDS]; 95% CI -0.31, -0.07) and left ventricular end-diastolic volume (-0.17 SDS; 95% -0.28, -0.05). Also, higher maternal glucose concentrations across the full range per 1 mmol/L increase were associated with a lower childhood left ventricular mass and left ventricular end-diastolic volume (P values ≤0.05). Adjustment for maternal prepregnancy BMI, gestational age, and weight at birth or childhood BMI and blood pressure did not influence the effect estimates. Maternal glucose concentrations were not significantly associated with childhood right ventricular end-diastolic volume or left and right ventricular ejection fraction.

CONCLUSIONS

Higher maternal random glucose concentrations in the first half of pregnancy are associated with a lower childhood left ventricular mass and left ventricular end-diastolic volume, with the strongest associations for childhood left ventricular mass. These associations were not explained by maternal, birth, or childhood characteristics. Further studies are needed to replicate these findings using repeated maternal glucose measurements throughout pregnancy and offspring cardiac outcomes throughout childhood and adulthood.

Metabolic Regulation of Human Pluripotent Stem Cell-Derived Cardiomyocyte Maturation

PURPOSE OF REVIEW

This review summarizes the important role that metabolism plays in driving maturation of human pluripotent stem cell-derived cardiomyocytes.

RECENT FINDINGS

Human pluripotent stem cell-derived cardiomyocytes provide a model system for human cardiac biology. However, these models have been unable to fully recapitulate the maturity observed in the adult heart. By simulating the glucose to fatty acid transition observed in neonatal mammals, human pluripotent stem cell-derived cardiomyocytes undergo structural and functional maturation also accompanied by transcriptional changes and cell cycle arrest. The role of metabolism in energy production, signaling, and epigenetic modifications illustrates that metabolism and cellular phenotype are intimately linked. Further understanding of key metabolic factors driving cardiac maturation will facilitate the generation of more mature human pluripotent stem cell-derived cardiomyocyte models. This will increase our understanding of cardiac biology and potentially lead to novel therapeutics to enhance heart function.

Stillbirth in women with diabetes: a retrospective analysis of fetal autopsy reports

Introduction: Diabetes in pregnancy is associated with an increased rate of stillbirth. There are a wide variety of factors that have been implicated including placental insufficiency, hypoxia, hyperinsulinemia and impaired cardiac function. Furthermore, there is evidence that diabetic pregnancies have an increased rate of fetal cardiomyopathy as compared to non-diabetic pregnancies. Prior studies have indicated that this association can also be an etiology for diabetic stillbirth. The purpose of this study was to determine if diabetic pregnancies have an increased risk of fetal cardiomyopathy identified on fetal autopsy as compared to non-diabetic women with a stillbirth in a cohort of pregnancies that had evaluation with a fetal autopsy.Materials and methods: Retrospective cohort study of women with a stillbirth who consented to fetal autopsy at an academic medical center from 2011 to 2017. Stillbirth was defined as an intrauterine fetal demise at ≥20 weeks' gestation. Women with diabetes defined as pre-gestational diabetes type 1, pre-gestational diabetes type 2, and gestational diabetes were compared to women without diabetes. Primary outcome was fetal cardiomyopathy. Other etiologies for stillbirth were also evaluated and classified according to the Stillbirth Collaborative Research Network (SCRN) initial causes of fetal death. Fisher exact test, χ2 test, and Mann Whitney U tests were performed as appropriate, with p < .05 considered significant. Generalized linear models were performed for fetal organ weights controlling for gestational age of delivery, maternal chronic hypertension, delivery body mass index, and birthweight.Results: A total of 78 women elected to have fetal autopsy examinations during the study period. Of these, 75 had complete information available for review. A total of 60 women did not have diabetes and 15 women had diabetes. Of pregnancies complicated by diabetes, 11 had insulin dependent diabetes and 4 had non-insulin dependent diabetes. Fetal cardiomyopathy was diagnosed on autopsy for 7 (46.7%) of pregnancies with diabetes and 2 (3.3% of pregnancies without diabetes (RR 14.00 [95% CI 3.23-60.65], p < .001). These associations were still significant even when analyzing only those pregnancies without fetal congenital heart disease (7 [46.7%] diabetic pregnancies with cardiomyopathy versus 1 [2.0%] nondiabetic pregnancy with cardiomyopathy, RR 23.80 [95% CI 3.17-178.46], p < .001). There was no difference between diabetic and non-diabetic pregnancies in regards to other causes for stillbirth. Stillbirths in pregnancies with diabetes also had larger fetal heart, liver, and adrenal weights on fetal autopsy.Conclusion: Women with diabetes have 14 times the risk of fetal cardiomyopathy identified at fetal autopsy as compared to women without diabetes. As the prediction and prevention of diabetic stillbirth is limited, information on potential causes of stillbirth may help future research identify those pregnancies at the greatest risk for adverse outcome.

Maternal hyperglycemia and fetal cardiac development: Clinical impact and underlying mechanisms

Congenital heart disease (CHD) is the most common type of birth defect and is both a significant pediatric and adult health problem, in light of a growing population of survivors. The etiology of CHD has been considered to be multifactorial with genetic and environmental factors playing important roles. The combination of advances in cardiac developmental biology, which have resulted in the elucidation of molecular pathways regulating normal cardiac morphogenesis, and genome sequencing technology have allowed the discovery of numerous genetic contributors of CHD ranging from chromosomal abnormalities to single gene variants. Conversely, mechanistic details of the contribution of environmental factors to CHD remain unknown. Maternal diabetes mellitus (matDM) is a well-established and increasingly prevalent environmental risk factor for CHD, but the underlying etiologic mechanisms by which pregestational matDM increases the vulnerability of embryos to cardiac malformations remains largely elusive. Here, we will briefly discuss the multifactorial etiology of CHD with a focus on the epidemiologic link between matDM and CHD. We will describe the animal models used to study the underlying mechanisms between matDM and CHD and review the numerous cellular and molecular pathways affected by maternal hyperglycemia in the developing heart. Last, we discuss how this increased understanding may open the door for the development of novel prevention strategies to reduce the incidence of CHD in this high-risk population.

Fetal hyperglycemia acutely induces persistent insulin resistance in skeletal muscle

Offspring exposed in utero to maternal diabetes exhibit long-lasting insulin resistance, though the initiating mechanisms have received minimal experimental attention. Herein, we show that rat fetuses develop insulin resistance after only 2-day continuous exposure to isolated hyperglycemia starting on gestational day 18. Hyperglycemia-induced reductions in insulin-induced AKT phosphorylation localized primarily to fetal skeletal muscle. The skeletal muscle of hyperglycemia-exposed fetuses also exhibited impaired in vivo glucose uptake. To address longer term impacts of this short hyperglycemic exposure, neonates were cross-fostered and examined at 21 days postnatal age. Offspring formerly exposed to 2 days late gestation hyperglycemia exhibited mild glucose intolerance with insulin signaling defects localized only to skeletal muscle. Fetal hyperglycemic exposure has downstream consequences which include hyperinsulinemia and relative uteroplacental insufficiency. To determine whether these accounted for induction of insulin resistance, we examined fetuses exposed to late gestational isolated hyperinsulinemia or uterine artery ligation. Importantly, 2 days of fetal hyperinsulinemia did not impair insulin signaling in murine fetal tissues and 21-day-old offspring exposed to fetal hyperinsulinemia had normal glucose tolerance. Similarly, fetal exposure to 2-day uteroplacental insufficiency did not perturb insulin-stimulated AKT phosphorylation in fetal rats. We conclude that fetal exposure to hyperglycemia acutely produces insulin resistance. As hyperinsulinemia and placental insufficiency have no such impact, this occurs likely via direct tissue effects of hyperglycemia. Furthermore, these findings show that skeletal muscle is uniquely susceptible to immediate and persistent insulin resistance induced by hyperglycemia.

Propolis improves pregnancy outcomes and placental oxidative stress status in streptozotocin-induced diabetic rats

BACKGROUND

This study assessed the effects of propolis alone or combined with insulin on maternal status, pregnancy outcomes and placental oxidative stress in streptozotocin-induced diabetic rats.

METHODS

Forty female rats were randomly assigned into five groups (n = 8/group) i.e. non-DM (non-diabetes), DM (diabetes), DM + Propolis (diabetes on propolis orally); DM + Insulin (diabetes on insulin subcutaneously) and DM + Combined (diabetes on propolis and insulin) groups. Propolis and insulin were given at 300 mg/kg/day orally and 5.0 IU/kg/day subcutaneously, respectively, for 4 weeks.

RESULTS

Fasting blood glucose, conception period, implantation losses, foetal blood glucose and placental oxidative stress markers such as malonaldehyde and protein carbonyl were significantly higher while maternal weight gain, foetal body weight and total antioxidant capacity were significantly lower in DM group compared with non-DM group. These changes were significantly improved in rats treated with propolis or insulin alone with greater significant effects in rats treated with both propolis and insulin.

CONCLUSION

This study may suggest the protective effects of propolis against DM-induced impaired pregnancy outcomes and placental oxidative stress with greater effects when combined with insulin.

Offspring of mothers with hyperglycaemia in pregnancy: The short term and long-term impact. What is new?

The continuing rise in the global prevalence of diabetes and overweight or obesity has become a major burden for global health, as the pandemic is affecting both high and low-middle income countries (LMIC). At the same time, a similar pattern has been observed for all forms of hyperglycemia in pregnancy (HIP), diabetes during pregnancy and gestational diabetes. The offspring of mothers with HIP and/or overweight-obesity is receiving increasing attention as advances in early detection and treatment of HIP did not completely prevent macrosomia and its associated short-term perinatal disorders, whilst long term consequences are observed in the mother and in offspring as it reaches adulthood. This review discusses the current developments in the consequences of HIP in the offspring, with a particular focus on its long-term health at adulthood, and on intergenerational and transgenerational effects. HIP is emerging as one of the factors that can contribute, during the window of sensitivity to environmental cues constituted by the preconception, pregnancy, and early childhood, and as an amplifying factor linked to reproduction, to the current global epidemic of diabetes and non-communicable diseases (NCDs).

Effect of well-controlled gestational diabetes on left ventricular diastolic dysfunction in neonates

BACKGROUND

There are some evidences supporting the relation between gestational diabetes mellitus (GDM) and diastolic dysfunction. The aim of our study was to investigate the effect of well-controlled GDM on morphological and functional myocardium.

MATERIALS AND METHODS

We designed a prospective cross-sectional study to evaluate left ventricular (LV) diastolic function of 60 neonates born from mothers with well-controlled GDM (case group) on days of 3-5 after birth. The infants of diabetic mothers (IDM) group were divided into two groups: diabetic mothers treated only with diet (class A) and group of mothers on medical therapy by insulin or metformin (class B). Traditional echocardiography and pulsed-wave Doppler (PWD), tissue Doppler imaging (TDI) were performed for all the neonates.

RESULTS

The study group consisted of 60 neonates as males (M) = 32, (0.53%) and females (F) = 28, (0.46%). Using M-mode echocardiography, interventricular septum thickness (IVS), and LV mass were significantly higher in IDM than control group (p = .0001). The PWD showed both a significantly more peak mitral flow at early diastolic wave (E) and an early filling deceleration time (E-DT) (p = .0001). Tissue Doppler echocardiography parameters A' (cm/s) (p = .0001), E' (cm/s) (p = .002), and E'/A' ratio (p = .0001), left ventricular myocardial performance index (LVMPI), and isovolumetric relaxation time (IVRT) were outstandingly different between the two groups (p = .0001, respectively). Evaluating the GDM group mothers of class A and class B, no significant difference was noted in PWD or TDI parameters compared with the healthy ones.

CONCLUSIONS

It seems that neonates of mothers with well-controlled GDM are still at increased risk of cardiac hypertrophy, subclinical diastolic dysfunction, and impaired left ventricular relaxation. This can be interpreted that focusing only on glycemic control is not enough to prevent cardiac dysfunction.

Maternal glycoregulation in pregnancies complicated by diabetes mellitus in the prediction of fetal echography findings and perinatal outcomes

AIM

We aimed to determine maternal hemoglobin A1c (HbA1c) levels and pregestational body mass index (BMI) as the predictors of glycemic control and its importance for fetal echography findings and perinatal outcomes in pregnancies complicated by diabetes mellitus (DM).

METHODS

Our intention was to evaluate how BMI and HbA1c levels might be used to predict fetal interventricular septum (IVS) thickness, atrioventricular inflow early diastole (E)/ atrial systole (A) velocity ratio, and perinatal outcomes. Patients in the 38th gestational week were divided into three groups according to their insulin therapy: (i) patients with gestational diabetes mellitus (GDM) treated only with dietary changes (GDM group, n = 32); (ii) patients with GDM treated with insulin therapy (DM2 group, n = 27); and (iii) patients with type 1 DM (DM1 group, n = 22).

RESULTS

In the DM1 group, we found statistically significant correlations between BMI and IVS thickness (P = 0.036), HbA1c and IVS thickness, as well as the mitral E/A velocity ratio (P = 0.013 vs P = 0.007). In this group, HbA1c showed a statistically significant correlation to neonatal birth weight (P = 0.037) and BMI influenced on appearance respiratory distress syndrome in neonates in DM1 group (P = 0.027). The values of HbA1c predict neonatal respiratory distress syndrome in DM2 and GDM groups (P = 0.036).

CONCLUSION

As good predictors of maternal glycoregulation, BMI and HbA1c levels determine fetal echography findings as well as neonatal outcomes in pregnancies complicated by DM.

Pregestational type 2 diabetes mellitus induces cardiac hypertrophy in the murine embryo through cardiac remodeling and fibrosis

BACKGROUND

Cardiac hypertrophy is highly prevalent in patients with type 2 diabetes mellitus. Experimental evidence has implied that pregnant women with type 2 diabetes mellitus and their children are at an increased risk of cardiovascular diseases. Our previous mouse model study revealed that maternal type 2 diabetes mellitus induces structural heart defects in their offspring.

OBJECTIVE

This study aims to determine whether maternal type 2 diabetes mellitus induces embryonic heart hypertrophy in a murine model of diabetic embryopathy.

STUDY DESIGN

The type 2 diabetes mellitus embryopathy model was established by feeding 4-week-old female C57BL/6J mice with a high-fat diet for 15 weeks. Cardiac hypertrophy in embryos at embryonic day 17.5 was characterized by measuring heart size and thickness of the right and left ventricle walls and the interventricular septum, as well as the expression of β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, desmin, and adrenomedullin. Cardiac remodeling was determined by collagen synthesis and fibronectin synthesis. Fibrosis was evaluated by Masson staining and determining the expression of connective tissue growth factor, osteopontin, and galectin-3 genes. Cell apoptosis also was measured in the developing heart.

RESULTS

The thicknesses of the left ventricle walls and the interventricular septum of embryonic hearts exposed to maternal diabetes were significantly thicker than those in the nondiabetic group. Maternal diabetes significantly increased β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, and desmin expression, but decreased expression of adrenomedullin. Moreover, collagen synthesis was significantly elevated, whereas fibronectin synthesis was suppressed, in embryonic hearts from diabetic dams, suggesting that cardiac remodeling is a contributing factor to cardiac hypertrophy. The cardiac fibrosis marker, galectin-3, was induced by maternal diabetes. Furthermore, maternal type 2 diabetes mellitus activated the proapoptotic c-Jun-N-terminal kinase 1/2 stress signaling and triggered cell apoptosis by increasing the number of terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling-positive cells (10.4 ± 2.2% of the type 2 diabetes mellitus group vs 3.8 ± 0.7% of the nondiabetic group, P < .05).

CONCLUSION

Maternal type 2 diabetes mellitus induces cardiac hypertrophy in embryonic hearts. Adverse cardiac remodeling, including elevated collagen synthesis, suppressed fibronectin synthesis, profibrosis, and apoptosis, is implicated as the etiology of cardiac hypertrophy.