Insulin-mediated immune dysfunction in the development of preeclampsia

Causal relationship between gestational diabetes and preeclampsia: A bidirectional mendelian randomization analysis

AIMS

The study aimed to explore the potential causal link between gestational diabetes mellitus (GDM) and preeclampsia (PE) using a bidirectional mendelian randomization (MR) analysis.

MATERIALS

We conducted a bidirectional MR analysis to investigate the causal relationship between GDM and PE. Data from public genome-wide association studies (GWAS) for GDM and PE were obtained from the FinnGen consortium. Various MR methods were employed, including inverse-variance weighted (IVW), MR-Egger, and sensitivity analyses. Additionally, a knowledge-based approach identified genes underlying this potential connection.

RESULTS

The IVW method revealed a lack of significant association between GDM and PE (OR: 1.04, 95 % CI: 0.96-1.14; p = 0.275). Conversely, IVW analysis indicated a causal connection from PE to GDM (OR: 1.14, 95 % CI: 1.06-1.23; p < 0.001). Molecular pathway analysis identified 20 key genes, including ASAP2, central to the PE-GDM relationship. Tissue enrichment analysis showed pertinent gene expression in significant tissues. Moreover, lower ASAP2 expression was detected in PE patients' placentas.

CONCLUSIONS

Our bidirectional MR analysis offers evidence supporting a causal link between PE and GDM, elucidating their interconnected pathogenesis. Genetic and knowledge-based insights facilitate a deeper comprehension of these complex pregnancy complications.

Circulating miRNAs and Preeclampsia: From Implantation to Epigenetics

In this review, we comprehensively present the literature on circulating microRNAs (miRNAs) associated with preeclampsia, a pregnancy-specific disease considered the primary reason for maternal and fetal mortality and morbidity. miRNAs are single-stranded non-coding RNAs, 20-24 nt long, which control mRNA expression. Changes in miRNA expression can induce a variation in the relative mRNA level and influence cellular homeostasis, and the strong presence of miRNAs in all body fluids has made them useful biomarkers of several diseases. Preeclampsia is a multifactorial disease, but the etiopathogenesis remains unclear. The functions of trophoblasts, including differentiation, proliferation, migration, invasion and apoptosis, are essential for a successful pregnancy. During the early stages of placental development, trophoblasts are strictly regulated by several molecular pathways; however, an imbalance in these molecular pathways can lead to severe placental lesions and pregnancy complications. We then discuss the role of miRNAs in trophoblast invasion and in the pathogenesis, diagnosis and prediction of preeclampsia. We also discuss the potential role of miRNAs from an epigenetic perspective with possible future therapeutic implications.

Role of leptin in the pathophysiology of preeclampsia

Preeclampsia (PE) is a severe pregnancy complication. The exact pathogenesis of PE remains unclear, but it is related to immune, inflammatory, circulatory, and oxidative stress factors. Leptin is a protein involved in these processes and is essential for maintaining a normal pregnancy and healthy fetal growth. Abnormal increases in leptin levels have been observed in the peripheral blood and placenta of patients with PE. Disturbances in leptin can affect the proliferation and hypertrophy of vascular smooth muscle cells, which are important for placentation. Leptin also regulates arterial tension and trophoblast function in pregnant women. In addition, consistently high levels of leptin are linked to hyperactive inflammation and oxidative stress reactions in both patients with PE and animal models. This review focuses on the role of leptin in the pathophysiology of PE and elucidates its potential mechanisms.

Regulation of the immune system by the insulin receptor in health and disease

The signaling pathways downstream of the insulin receptor (InsR) are some of the most evolutionarily conserved pathways that regulate organism longevity and metabolism. InsR signaling is well characterized in metabolic tissues, such as liver, muscle, and fat, actively orchestrating cellular processes, including growth, survival, and nutrient metabolism. However, cells of the immune system also express the InsR and downstream signaling machinery, and there is increasing appreciation for the involvement of InsR signaling in shaping the immune response. Here, we summarize current understanding of InsR signaling pathways in different immune cell subsets and their impact on cellular metabolism, differentiation, and effector versus regulatory function. We also discuss mechanistic links between altered InsR signaling and immune dysfunction in various disease settings and conditions, with a focus on age related conditions, such as type 2 diabetes, cancer and infection vulnerability.

A global view of hypertensive disorders and diabetes mellitus during pregnancy

Two important maternal cardiometabolic disorders (CMDs), hypertensive disorders in pregnancy (HDP) (including pre-eclampsia) and gestational diabetes mellitus (GDM), result in a large disease burden for pregnant individuals worldwide. A global consensus has not been reached about the diagnostic criteria for HDP and GDM, making it challenging to assess differences in their disease burden between countries and areas. However, both diseases show an unevenly distributed disease burden for regions with a low income or middle income, or low-income and middle-income countries (LMICs), or regions with lower sociodemographic and human development indexes. In addition to many common clinical, demographic and behavioural risk factors, the development and clinical consequences of maternal CMDs are substantially influenced by the social determinants of health, such as systemic marginalization. Although progress has been occurring in the early screening and management of HDP and GDM, the accuracy and long-term effects of such screening and management programmes are still under investigation. In addition to pharmacological therapies and lifestyle modifications at the individual level, a multilevel approach in conjunction with multisector partnership should be adopted to tackle the public health issues and health inequity resulting from maternal CMDs. The current COVID-19 pandemic has disrupted health service delivery, with women with maternal CMDs being particularly vulnerable to this public health crisis.

Overt diabetes imposes a comparable burden on outcomes as pregestational diabetes: a cohort study

BACKGROUND

Women with diabetes first diagnosed during pregnancy (overt diabetes) may be at the same risk level of adverse outcomes as those with known pregestational diabetes. We compared pregnancy outcomes between these groups.

METHODS

We evaluated pregnant women with type 2 diabetes, pregestational or overt diabetes, attending high risk antenatal care in two public hospitals in Southern Brazil, from May 20, 2005 to June 30, 2021. Outcomes were retrieved from electronic medical records. Risk of adverse outcomes, expressed as relative risk (RR) and 95% confidence interval (CI), were calculated using Poisson regression with robust estimates.

RESULTS

Of 618 women, 33% were labelled as having overt diabetes and 67%, pregestational diabetes. Baseline maternal characteristics were similar: there was a slight, non-clinically relevant, difference in maternal age (33 ± 5.7 years in women with pregestational diabetes vs. 32 ± 6.0 years in women with overt diabetes, p = 0.004); and women with overt diabetes reported smoking almost twice compared to those with pregestational diabetes (12.3% vs. 6.5%, p = 0.024). There were no relevant differences between the groups regarding pregnancy outcomes, although there was a trend of higher neonatal intensive care admission in the group of women with pregestational diabetes (45.2% vs. 36.1%, p = 0.051).

CONCLUSIONS

Overt diabetes was diagnosed in one third of this cohort of pregnant women with hyperglycemia. Their pregnancy outcomes were similar to those of women with pregestational diabetes and were mostly related to maternal demographic characteristics and metabolic control. A call to action should be made to identify women of childbearing age at risk for pre-pregnancy diabetes; to detect hyperglycemia before conception; and to implement timely preconception care to all women with diabetes.

First-Trimester Triglyceride-Glucose Index and Risk of Pregnancy-Related Complications: A Prospective Birth Cohort Study in Southeast China

PURPOSE

To evaluate the relationships of the triglyceride-glucose (TyG) index with pregnancy-related complications (PRCs) and to clarify the predictability of the TyG index for PRCs.

PATIENTS AND METHODS

Totally of 11,387 women with a singleton pregnancy were prospectively followed until after delivery. Maternal fasting lipids and glucose concentration were measured in the first trimester (11 weeks gestation on average). The TyG index was calculated as ln [triglyceride (mg/dL) × fasting plasma glucose (mg/dL)/2]. We used generalized linear models to calculate the relative risks and 95% confidence intervals. Receiver-operating characteristic curve analysis was employed to assess the ability of the TyG index to predict the risks of PRCs.

RESULTS

Smooth spline reveals that the probability of gestational diabetes mellitus (GDM) is intensified with the increasing TyG index. Multivariate logistic regression adjusted for risk factors demonstrates a 1-unit and a 1-SD increment in the TyG index raises the risk of GDM by 3.63 and 1.57 times, respectively. Identically, the risk of GDM maximizes in the TyG quintile 5 (OR: 3.14; 95% CI: 2.55~3.85) relative to the lowest TyG index group. However, no association between TyG index and the risk of other PRCs was observed after full adjustment. The area under receiver operating characteristic curves is 0.647 (95% CI: 0.632-0.66) for GDM, and the optimal predictive cut-off is 8.55, with a specificity of 0.679 and sensitivity of 0.535.

CONCLUSION

The first-trimester TyG index is significantly associated with the risk of incident GDM, while the relationships between the TyG index and other PRCs need further exploration.