The possible role of visceral fat in early pregnancy as a predictor of gestational diabetes mellitus by regulating adipose-derived exosomes miRNA-148 family: protocol for a nested case-control study in a cohort study

The role of microRNAs in pregnancies complicated by maternal diabetes

With the global prevalence of diabetes increasing, more people of reproductive age are experiencing hyperglycaemic pregnancies. Maternal Type 1 (T1DM) or Type 2 (T2DM) diabetes mellitus, and gestational diabetes mellitus (GDM) are associated with maternal cardiovascular and metabolic complications. Pregnancies complicated by maternal diabetes also increase the risk of short- and long-term health complications for the offspring, including altered fetal growth and the onset of T2DM and cardiometabolic diseases throughout life. Despite advanced methods for improving maternal glucose control, the prevalence of adverse maternal and offspring outcomes associated with maternal diabetes remains high. The placenta is a key organ at the maternal-fetal interface that regulates fetal growth and development. In pregnancies complicated by maternal diabetes, altered placental development and function has been linked to adverse outcomes in both mother and fetus. Emerging evidence suggests that microRNAs (miRNAs) are key molecules involved in mediating these changes. In this review, we describe the role of miRNAs in normal pregnancy and discuss how miRNA dysregulation in the placenta and maternal circulation is associated with suboptimal placental development and pregnancy outcomes in individuals with maternal diabetes. We also discuss evidence demonstrating that miRNA dysregulation may affect the long-term health of mothers and their offspring. As such, miRNAs are potential candidates as biomarkers and therapeutic targets in diabetic pregnancies at risk of adverse outcomes.

Gestational diabetes mellitus in the era of COVID-19: Challenges and opportunities

BACKGROUND AND AIMS

The impact of the coronavirus disease 2019 (COVID-19) pandemic on pregnant women, especially those with gestational diabetes mellitus (GDM), has yet to be fully understood. This review aims to examine the interaction between GDM and COVID-19 and to elucidate the pathophysiological mechanisms underlying the comorbidity of these two conditions.

METHODS

We performed a systematic literature search using the databases of PubMed, Embase, and Web of Science with appropriate keywords and MeSH terms. Our analysis included studies published up to January 26, 2023.

RESULTS

Despite distinct clinical manifestations, GDM and COVID-19 share common pathophysiological characteristics, which involve complex interactions across multiple organs and systems. On the one hand, infection with severe acute respiratory syndrome coronavirus 2 may target the pancreas and placenta, resulting in β-cell dysfunction and insulin resistance in pregnant women. On the other hand, the hormonal and inflammatory changes that occur during pregnancy could also increase the risk of severe COVID-19 in mothers with GDM. Personalized management and close monitoring are crucial for treating pregnant women with both GDM and COVID-19.

CONCLUSIONS

A comprehensive understanding of the interactive mechanisms of GDM and COVID-19 would facilitate the initiation of more targeted preventive and therapeutic strategies. There is an urgent need to develop novel biomarkers and functional indicators for early identification and intervention of these conditions.

The effect of MicroRNAs variants on idiopathic recurrent pregnancy loss

BACKGROUND

Although the importance of miRNA variants in female reproductive disorders has been frequently reported, the association between miRNA polymorphisms and recurrent pregnancy loss (RPL) has been poorly studied. In this study, we aimed to assess the correlation of four different miRNA variants to unexplained RPL.

METHODS AND RESULTS

The prevalence of four SNPs including miR-21 rs1292037, miR-155-5p rs767649, miR-218-2 rs11134527, and miR-605 rs2043556 in 280 cases with iRPL and 280 controls was performed. The DNA was extracted from all subjects and the SNPs were genotyped using RFLP-PCR methods. The data revealed that rs1292037 and rs767649 were significantly associated with higher rates of iRPL in patients compared with controls while rs11134527 and rs2043556 showed no association with increased rates of iRPL among patients. The haplotypes T-A-G-G and T-A-G-A were the most frequent in both cases and controls. Three haplotypes including T-T-G-A, C-T-G-G, and T-A-A-A showed significantly different frequencies in patients in comparison to healthy females.

CONCLUSION

This study suggests that rs1292037 and rs767649 could be risk factors for increased rates of iRPL.

An early prediction model for gestational diabetes mellitus based on metabolomic biomarkers

BACKGROUND

Gestational diabetes mellitus (GDM) represents the main metabolic alteration during pregnancy. The available methods for diagnosing GDM identify women when the disease is established, and pancreatic beta-cell insufficiency has occurred.The present study aimed to generate an early prediction model (under 18 weeks of gestation) to identify those women who will later be diagnosed with GDM.

METHODS

A cohort of 75 pregnant women was followed during gestation, of which 62 underwent normal term pregnancy and 13 were diagnosed with GDM. Targeted metabolomics was used to select serum biomarkers with predictive power to identify women who will later be diagnosed with GDM.

RESULTS

Candidate metabolites were selected to generate an early identification model employing a criterion used when performing Random Forest decision tree analysis. A model composed of two short-chain acylcarnitines was generated: isovalerylcarnitine (C5) and tiglylcarnitine (C5:1). An analysis by ROC curves was performed to determine the classification performance of the acylcarnitines identified in the study, obtaining an area under the curve (AUC) of 0.934 (0.873-0.995, 95% CI). The model correctly classified all cases with GDM, while it misclassified ten controls as in the GDM group. An analysis was also carried out to establish the concentrations of the acylcarnitines for the identification of the GDM group, obtaining concentrations of C5 in a range of 0.015-0.25 μmol/L and of C5:1 with a range of 0.015-0.19 μmol/L.

CONCLUSION

Early pregnancy maternal metabolites can be used to screen and identify pregnant women who will later develop GDM. Regardless of their gestational body mass index, lipid metabolism is impaired even in the early stages of pregnancy in women who develop GDM.

Evaluating the Adipose Tissue Depth as a Predictor Factor for Gestational Diabetes in Later Pregnancy-A Systematic Review

The increasing prevalence of gestational diabetes mellitus (GDM) requires non-invasive and precise techniques for evaluating the predisposing risk factors such as visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). According to PRISMA, we developed a systematic review and searched after "visceral adipose tissue AND gestational diabetes" and identified 221 articles on the MEDLINE and Word of Science databases. After assessing them for inclusion criteria and two researchers screened them, 11 relevant articles were included. Although evidence is conflicting, more studies favor using US-determined VAT in GDM prediction. VAT may be more valuable than body mass index or SAT in predicting GDM. VAT can represent an additive factor to the prediction tool of the risk of developing GDM when used in conjunction with other anthropometric or biological parameters or maternal risk factors. US measurements are heterogeneous given different evaluation techniques, cut-off values and inter-operator variation. A significant limitation is the lack of a gold standard to identify GDM confidently. Pregnant women may benefit from early monitoring and preventive care if classified as high risk for GDM early in the gestational period. US-measured VAT during the first trimester of pregnancy seems a valuable and inexpensive screening approach to predict GDM development later in pregnancy, either by itself or if used in conjunction with other clinical and biological parameters.

Joint effect of maternal pre-pregnancy body mass index and folic acid supplements on gestational diabetes mellitus risk: a prospective cohort study

Background

The joint effect of folic acid (FA) supplements and maternal pre-pregnancy body mass index (BMI) on gestational diabetes mellitus (GDM) has not been fully addressed. This study aimed to examine the joint effect of FA supplements and pre-pregnancy BMI on GDM.

Methods

Pregnant women at 4 to 14 weeks of gestation (n = 3186) were recruited during their first prenatal visit in Qingdao from May 1, 2019, to June 27, 2021. The main outcome was GDM at 24–28 weeks’ gestation. Screening was based on 75 g 2-hour oral glucose tolerance (OGTT), a fasting glucose ≥ 5.1 mmol/L, or a 1-hour result ≥ 10.0 mmol/L, or a 2-hour result ≥ 8.5 mmol/L. The interactive effect of FA supplements and pre-pregnancy BMI on GDM was examined using logistic regression analysis and ratio of odds ratios (ROR) was used to compare subgroup differences.

Results

Overall, 2,095 pregnant women were included in the analysis, and GDM incidence was 17.76%. Compared with women with pre-pregnancy BMI lower than 25.0 kg/m² and FA-Sufficient supplements ≥ 400 µg/day (FA-S) population, the adjusted odds ratios (aORs) of FA-S and FA-Deficiency supplements < 400 µg/d (FA-D) were 3.57 (95% confidence interval [CI]: 2.02–6.34) and 10.82 (95% CI: 1.69–69.45) for the obese women (BMI ≥ 30.0 kg/m²), and the aORs of FA-S and FA-D were 2.17 (95% CI: 1.60–2.95) and 3.27 (95% CI: 1.55–6.92) for overweight women (25.0 kg/m² ≤ BMI < 30.0 kg/m²). However, the risk of GDM did not differ significantly between the FA-D and the FA-S group in pre-pregnancy obese women (ROR = 2.70, 95%CI: 0.47–2.30), or overweight women (ROR = 0.66, 95%CI: 0.30–1.49). After further stratification of FA supplementation time, F-D and FA-S in obese women showed an interaction when FA supplement intake time < 3 months. However, there was no significant difference between subgroups (ROR = 1.63, 95% CI: 0.37–7.04).

Conclusion

Maternal pre-pregnancy BMI was associated with the incidence of GDM, the dose of FA supplementation from pre-pregnancy to early pregnancy was not found to be related to the incidence of GDM. The dosage of FA supplement was not associated with GDM irrespective of maternal pre-pregnancy BMI.

Maternal circulating exosomal miR-185-5p levels as a predictive biomarker in patients with recurrent pregnancy loss

PURPOSE

The aim of this study was to explore the predictive role of microRNAs (miRNAs) from maternal serum exosomes in early recurrent pregnancy loss (RPL) and the related mechanism in early pregnancy.

METHODS

Maternal serum was collected from pregnant women with RPL history or women with ongoing pregnancy (OP); serum exosomes were extracted and identified. Differentially expressed (DE) miRNAs in exosomes were screened by RNA sequencing and further validated by qRT-PCR. Next, the predictive value of exosomal miRNA and the clinical indicators for subsequent miscarriage in RPL patients were evaluated. Additionally, we verified the regulatory relationship between miR-185-5p and vascular endothelial growth factor (VEGF) in decidual natural killer (dNK) cells by overloading or inhibiting the exosomal miR-185-5p level in trophoblast cells.

RESULTS

The miRNA sequencing revealed 43 DE miRNAs between OP and RPL patients. The five most significant DE miRNAs (miR-22-3p, miR-185-5p, miR-335-3p, miR-362-5p, and miR-378a-3p) were selected for identification, and miR-185-5p was increased in RPL patients. The area under curve (AUC) of the receiver operating characteristic was 0.925 when using miR-185-5p as a biomarker for subsequent miscarriage in RPL patients. In addition, miR-185-5p in exosomes secreted from HTR-8 cells reduces VEGF expression of dNK cells.

CONCLUSIONS

The current study, for the first time, successfully constructed the correlation between maternal circulating exosomal miR-185-5p expression pattern and RPL, which may be involved in the pathogenesis of RPL by downregulating the VEGFA of dNK cells and perturbing angiogenesis at the maternal-fetal interface.

Maternal gestational diabetes in singleton pregnancies conceived by ART may be modified by periconceptional B vitamins

Background

The risk of maternal gestational diabetes mellitus (GDM) may be influenced by pregnancies conceived through assisted reproductive technology (ART). However, the influence of the dosage of B vitamins (folate, vitamin B6 and vitamin B12) on GDM weren't considered. Thus, we hypothesized that periconceptional B vitamins could modify maternal GDM in singleton pregnancies conceived by ART.

Methods

This study is a prospective cohort study using data from 3,252 women with singleton pregnancies and received a 75 g oral glucose tolerance test (OGTT) at 24-28 weeks of gestation. We included an interaction term in the multivariable logistic and linear regression models, respectively, to test our hypothesis.

Results

Women who underwent ART were significantly associated with the incidence of GDM compared with spontaneous pregnancy women. The adjusted odds ratio (aOR) was 1.59, and the 95% confidence interval (CI) was 1.08-2.34. ART pregnancies also elevated OGTT (oral glucose tolerance test) 1-h blood glucose levels and OGTT 2-h blood glucose levels (P < 0.05). A positive association between dietary vitamin B6 (aOR = 1.60, 95% CI: 1.13-2.27), dietary vitamin B12 (aOR = 1.88, 95% CI: 1.34-2.64) and dietary folate (aOR = 1.66, 95% CI: 1.19-2.32) with GDM risk comparing the highest to the lowest quartile (all P _trend < 0.001). The aORs of GDM for inadequate (< 400 μg/day), adequate (400-800 μg/day), and excessive (> 800 μg/day) supplemental folate intake were 1.00, 0.93, and 1.30, respectively (P _trend = 0.033). Since only the supplemental folate illustrates a statistically significant interaction with ART (P for interaction < 0.05), the association between ART and GDM and OGTT blood glucose levels stratifying by supplemental folate were further evaluated. These increased risks of GDM (aOR = 1.62, 95% CI: 1.39-3.39) and the regression coefficients (β) of 1-h blood glucose (β = 0.76, 95% CI: 0.39-1.13) and 2-h blood glucose (β = 0.60, 95% CI: 0.29-0.92) in the multiple linear regression model were significant only in the ART group with excessive supplemental folate (> 800 μg/day).

Conclusion

The risk of GDM is significantly elevated, particularly among those women who conceived ART with the intake of excessive supplemental folate (> 800 μg/day).

Exosomes as Promising Nanostructures in Diabetes Mellitus: From Insulin Sensitivity to Ameliorating Diabetic Complications

Diabetes mellitus (DM) is among the chronic metabolic disorders that its incidence rate has shown an increase in developed and wealthy countries due to lifestyle and obesity. The treatment of DM has always been of interest, and significant effort has been made in this field. Exosomes belong to extracellular vesicles with nanosized features (30-150 nm) that are involved in cell-to-cell communication and preserving homeostasis. The function of exosomes is different based on their cargo, and they may contain lipids, proteins, and nucleic acids. The present review focuses on the application of exosomes in the treatment of DM; both glucose and lipid levels are significantly affected by exosomes, and these nanostructures enhance lipid metabolism and decrease its deposition. Furthermore, exosomes promote glucose metabolism and affect the level of glycolytic enzymes and glucose transporters in DM. Type I DM results from the destruction of β cells in the pancreas, and exosomes can be employed to ameliorate apoptosis and endoplasmic reticulum (ER) stress in these cells. The exosomes have dual functions in mediating insulin resistance/sensitivity, and M1 macrophage-derived exosomes inhibit insulin secretion. The exosomes may contain miRNAs, and by transferring among cells, they can regulate various molecular pathways such as AMPK, PI3K/Akt, and β-catenin to affect DM progression. Noteworthy, exosomes are present in different body fluids such as blood circulation, and they can be employed as biomarkers for the diagnosis of diabetic patients. Future studies should focus on engineering exosomes derived from sources such as mesenchymal stem cells to treat DM as a novel strategy.

MicroRNAs and Exosomal microRNAs May Be Possible Targets to Investigate in Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is defined as glucose intolerance that occurs during the second or third trimester of pregnancy. As the incidence of GDM rises, so does the risk of maternal and fetal complications with short- and long-term consequences. As a result, early diagnosis and treatment of this condition are important to avoiding adverse pregnancy outcomes. Exosomes are tiny vesicles secreted by living cells which contain a variety of bioactive substances. They are released by cells to facilitate cell-to-cell communication and regulate a variety of biological processes such as cellular immune response, inflammatory response, and apoptosis, among others. Many studies have recently confirmed that changes in the expression and secretion of exosomal miRNAs can be used as novel markers for the diagnosis, prognosis, and treatment of GDM. In this review, we summarized the various roles of exosomal miRNAs and circulating miRNAs in GDM. We found that the changes in the expression of certain miRNAs could be used to diagnosing GDM. Exosomal miRNAs target metabolic pathways, resulting in insulin resistance. We also highlighted the potential for miRNAs and exosomal miRNAs to be used as biomarkers for diagnosis or therapeutic agents.