A fetal rat model of ventricular noncompaction caused by intrauterine hyperglycemia

BACKGROUND

This study aims to develop a fetal rat model of ventricular noncompaction (NVM) using streptozotocin (STZ)-induced gestational hyperglycemia and compare it with a retinoic acid (RA) model.

METHODS

Female SD rats were categorized into STZ, RA, and normal control (NC) groups. The STZ group was given a high-fat diet pre-pregnancy and 35 mg/kg of 2% STZ postpregnancy. The RA group received a 90 mg/kg dose of RA on day 13 postpregnancy. Embryonic myocardial morphology was analyzed through HE staining, and embryonic cardiomyocyte ultrastructures were studied using electron microscopy. Diagnoses of NVM were based on a ratio of noncompact myocardium (N) to compact myocardium (C) >1.4, accompanied by thick myocardial trabeculae and a thin myocardial compaction layer. Kruskal-Wallis test determined N/C ratio differences among groups.

RESULTS

Both STZ and RA groups displayed significant NVM characteristics. The left ventricular (LV) N/C in the STZ, RA, and NC groups were 1.983 (1.423-3.527), 1.640 (1.197-2.895), and 0.927 (0.806-1.087), respectively, with a statistically significant difference (P<0.001). The right ventricular (RV) N/C in the STZ, RA, and NC groups were 2.097 (1.364-3.081), 1.897 (1.337-2.662), and 0.869 (0.732-1.022), respectively, with a significant difference (P<0.001). Electron microscopy highlighted marked endoplasmic reticulum swelling in embryonic cardiomyocytes from both STZ and RA groups.

CONCLUSION

Our model underscores the pivotal role of an adverse intrauterine developmental environment in the onset of NVM. This insight holds significant implications for future studies exploring the pathogenesis of NVM.

Sex differences in glycolipidic disorders after exposure to maternal hyperglycemia during early development

PURPOSE

The aim of this review was to summarize sex differences in glycolipid metabolic phenotypes of human and animal models after exposure to maternal hyperglycemia and overview the underlying mechanisms, providing a new perspective on the maternal hyperglycemia-triggered risk of glycolipidic disorders in offspring.

METHODS

A comprehensive literature search within PubMed was performed. Selected publications related to studies on offspring exposed to maternal hyperglycemia investigating the sex differences of glycolipid metabolism were reviewed.

RESULTS

Maternal hyperglycemia increases the risk of glycolipid metabolic disorders in offspring, such as obesity, glucose intolerance and diabetes. Whether with or without intervention, metabolic phenotypes have been shown to exhibit sex differences between male and female offspring in response to maternal hyperglycemia, which may be related to gonadal hormones, organic intrinsic differences, placenta, and epigenetic modifications.

CONCLUSION

Sex may play a role in the different incidences and pathogenesis of abnormal glycolipid metabolism. More studies investigating both sexes are needed to understand how and why environmental conditions in early life affect long-term health between male and female individuals.

Gestational diabetes: Implications for fetal growth, intervention timing, and treatment options

Maternal gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy, which can adversely affect the short- and long-term health of mothers and newborns. In recent years, several studies have revealed the early impact of maternal hyperglycemia on fetal growth trajectory and birth weight abnormalities in GDM-exposed pregnancies. However, an intense debate continues regarding the mode and optimal timing of diagnosis and treatment of this condition. The purpose of this review is to provide a brief overview of the understanding of GDM and its implications for fetal growth, addressing the modulatory role of medical nutrition therapy and available pharmacological antidiabetic agents (i.e. insulin, metformin, and glyburide), and to identify gaps in current knowledge toward which future research should be directed.

Associations of maternal early-pregnancy blood glucose and insulin concentrations with DNA methylation in newborns

BACKGROUND

Intrauterine exposure to a disturbed maternal glucose metabolism is associated with adverse offspring outcomes. DNA methylation is a potential mechanism underlying these associations. We examined whether maternal early-pregnancy glucose and insulin concentrations are associated with newborn DNA methylation. In a population-based prospective cohort study among 935 pregnant women, maternal plasma concentrations of non-fasting glucose and insulin were measured at a median of 13.1 weeks of gestation (95% range 9.4-17.4). DNA methylation was measured using the Infinium HumanMethylation450 BeadChip (Ilumina). We analyzed associations of maternal early-pregnancy glucose and insulin concentrations with single-CpG DNA methylation using robust linear regression models. Differentially methylated regions were analyzed using the dmrff package in R. We stratified the analyses on normal weight versus overweight or obese women. We also performed a look-up of CpGs and differently methylated regions from previous studies to be associated with maternal gestational diabetes, hyperglycemia or hyperinsulinemia, or with type 2 diabetes in adults.

RESULTS

Maternal early-pregnancy glucose and insulin concentrations were not associated with DNA methylation at single CpGs nor with differentially methylated regions in the total group. In analyses stratified on maternal BMI, maternal early-pregnancy glucose concentrations were associated with DNA methylation at one CpG (cg03617420, XKR6) among normal weight women and at another (cg12081946, IL17D) among overweight or obese women. No stratum-specific associations were found for maternal early-pregnancy insulin concentrations. The two CpGs were not associated with birth weight or childhood glycemic measures (p values > 0.1). Maternal early-pregnancy insulin concentrations were associated with one CpG known to be related to adult type 2 diabetes. Enrichment among nominally significant findings in our maternal early-pregnancy glucose concentrations was found for CpGs identified in a previous study on adult type 2 diabetes.

CONCLUSIONS

Maternal early-pregnancy glucose concentrations, but not insulin concentrations, were associated with DNA methylation at one CpG each in the subgroups of normal weight and of overweight or obese women. No associations were present in the full group. The role of these CpGs in mechanisms underlying offspring health outcomes needs further study. Future studies should replicate our results in larger samples with early-pregnancy information on maternal fasting glucose metabolism.

Relationship between threatened miscarriage and gestational diabetes mellitus

Background

Both threatened miscarriage and gestational diabetes mellitus (GDM) are common complications of pregnancy. However, only one pilot study has reported that these complications are not related. We aimed to investigate whether threatened miscarriage is one of the risk factors of GDM.

Methods

An unmatched case-control study of 1567 pregnant Korean women who underwent a two-step approach to diagnose GDM was retrospectively conducted. The eligible women were classified into normal (n = 840), borderline GDM (n = 480), and GDM (n = 247) groups. We analyzed the associations with threatened miscarriage in all groups with adjustment for confounding factors.

Results

The proportion of women who experienced threatened miscarriage was significantly lower in the GDM group than in the normal group (adjusted odds ratio (OR), 0.38; 95% confidence interval (CI), 0.18–0.78). It was significantly lower in the maternal hyperglycemia group (borderline GDM and GDM groups) than in the normal group (adjusted OR, 0.66; 95% CI, 0.47–0.91). The proportion of women who experienced threatened miscarriage was also significantly lower in the GDM group than in the normal (adjusted OR, 0.35; 95% CI, 0.17–0.70) and borderline GDM groups (adjusted OR, 0.46; 95% CI, 0.22–0.94). Moreover, the proportion of women who experienced threatened miscarriage significantly decreased according to the severity of glucose intolerance (adjusted OR, 0.94; 95% CI, 0.76–1.16).

Conclusion

This study demonstrates that threatened miscarriage is associated with decreased risk of GDM and the severity of glucose intolerance in Korean women. Additional studies are warranted to understand the pathophysiologic mechanisms that might exist between these frequent complications of pregnancy.

Unexpected regulation of miRNA abundance during adaptation of early-somite mouse embryos to diabetic pregnancy

Maternal diabetes is one of major causes of congenital malformations in offspring, but the underlying mechanism is still unclear. MiRNAs play an important role in transcriptional and post-transcriptional regulation of gene expression. However, no miRNA expression profiling of hyperglycemic offspring are thus far available. Female mice were made diabetic with streptozotocin, treated with slow-release insulin tablets, and mated. MiRNA expression profiling with Next Generation Sequencing on the SOLiD5 platform was performed on 8 control and 5 hyperglycemic embryonic day (ED)8.5 and 9 control and 6 hyperglycemic ED9.5 embryos. Differential expression was analyzed with the Wald test. On ED8.5, the abundance of expressed miRNAs was similar in control and hyperglycemic ED8.5 embryos. The spectrum of expressed miRNAs had not changed in ED9.5 embryos, but the abundance of most miRNAs increased ∼5-fold in control embryos. However, hyperglycemic D9.5 embryos were unable to mount this increase in prevalence. Only 3 miRNAs were differentially expressed in control and hyperglycemic ED9.5 embryos, but their putative target genes were underrepresented in the Jackson database of genes causing cardiovascular or neural malformations.

Maternal hyperglycemia during labor and related immediate post-partum maternal and perinatal outcomes at the Yaoundé Central Hospital, Cameroon

BACKGROUND

Data on the prevalence and complications of gestational diabetes are very scarce in Cameroon. The aim of this study was to evaluate the uptake of screening for gestational diabetes and assess the immediate post-partum outcome of hyperglycemic parturient mothers and perinatal outcome of their babies.

METHODS

A prospective cohort study was held at the Maternity of the Yaoundé Central Hospital from March to June 2013. One hundred volunteer women in labor without overt diabetes mellitus and having fasted for 8 to 12 h were recruited. No intervention was given. A clinical examination was done and capillary glucose recorded. Parturient women were categorized into two groups (hyperglycemic and non-hyperglycemic subjects) based on glycemia results interpreted according to the International Association of Diabetes and Pregnancy Study Groups. Mothers' clinical examination was repeated and neonates examined immediately after delivery. Perinatal outcomes associated with maternal hyperglycemia during labor were assessed using relative risks. A p value <0.05 was considered statistically significant.

RESULTS

One hundred women with a mean age of 27 (SD 6) years were recruited. Of them, 22 (22 %) had already been screened for gestational diabetes at baseline. Thirty-one (31 %) were diagnosed with hyperglycemia during labor, and this condition was highly associated with macrosomia in neonates (RR = 8.9, 95 % CI 2.70-29.32; p < 0.001). Other complications associated with maternal hyperglycemia during labor were perineal tears, cesarean section, and intrauterine fetal death, though the association was not statistically significant.

CONCLUSIONS

The main finding of this study is that maternal hyperglycemia during labor is highly associated with macrosomia in neonates. About a third of mothers were concerned with hyperglycemia during labor, and gestational diabetes was insufficiently screened in this series.