Association of LEPTIN and other inflammatory markers with preeclampsia: A systematic review

The association between leptin and diabetes: A meta-analysis

PURPOSE

The study object was to determine the relationship between leptin and diabetes.

METHODS

We searched for the literature on the relationship between leptin and diabetes from PubMed, EMBASE, Cochrane Library, and CNKI databases. We carried out the meta-analysis by calculating the Std. Mean Difference (SMD) and 95% confidence intervals (CIs) to study the relationship between leptin and diabetes. We performed the Chi-square-based Q test and I2 statistics to evaluate the potential heterogeneity, and the sensitivity analysis was performed to evaluate the stability of our results. Moreover, Begg's test was performed to evaluate the publication bias.

RESULTS

There are 10 studies in this study for meta-analysis, which include 1879 patients (diabetic (n = 1024); and nondiabetic patients (n = 855)). The results indicated that the levels of serum leptin were significantly increased in patients with diabetes (SMD = 1.78, 95% CI [0.81, 2.76]), especially those with gestational diabetes mellitus compared with controls (SMD = 3.03, 95% CI [1.21, 4.86]). However, the results showed that there was no difference in serum leptin levels between type 2 diabetes and controls (SMD = 0.34, 95% CI [-1.06, 1.74]).

CONCLUSIONS

Our analysis indicated that the levels of serum leptin were significantly elevated in patients with diabetes especially those with gestational diabetes mellitus compared with controls.

The Role of Obesity in the Development of Preeclampsia

PURPOSE OF REVIEW

This comprehensive review provides an in-depth exploration of the complex relationship between obesity and preeclampsia (PE) and emphasizes the clinical implications of this association. It highlights the crucial role of screening tools in assessing individual risk and determining the need for additional antenatal care among women with obesity. The review investigates various markers for identifying the risk of developing PE, while emphasizing the significance of interventions such as exercise, weight management, and a balanced diet in reducing the incidence of preeclampsia and improving outcomes for both mother and fetus.

RECENT FINDINGS

Actually, there is a global pandemic of obesity, particularly among women of childbearing age and pregnant women. PE, which is characterized by maternal hypertension, proteinuria, and complications, affects 2-4% of pregnancies worldwide, posing significant risks to maternal and perinatal health. Women with obesity face an elevated risk of developing PE due to the systemic inflammation resulting from excess adiposity, which can adversely affect placental development. Adipose tissue, rich in proinflammatory cytokines and complement proteins, contributes to the pathogenesis of PE by promoting the expression of antiangiogenic factors in the mother. This review emphasizes the need for appropriate screening, interventions, and a holistic approach to reduce the incidence of preeclampsia and enhance maternal-fetal well-being, thus providing valuable insights into the multifaceted association between obesity and PE.

Raised levels of chemerin in women with preeclampsia: A meta-analysis

Chemerin is a multifunctional adipokine associated with systemic inflammation, angiogenesis, and oxidative stress. Emerging evidence suggests a potential link between chemerin and the pathogenesis of preeclampsia (PE). In this systematic review and meta-analysis, we aimed to evaluate the serum chemerin levels in women with PE. A systematic search was conducted across Medline, Web of Science, and Embase databases from inception until April 15, 2023, to identify studies comparing serum chemerin levels in pregnant women with and without PE. A random-effects model was employed to pool the results, accounting for heterogeneity. Thirteen datasets from 10 observational studies, encompassing 832 women with PE and 1298 healthy pregnant women, were analyzed. The pooled findings indicated a statistically significant elevation in serum chemerin levels in women with PE compared to controls (mean difference [MD] = 89.56 ng/mL, 95% confidence interval [CI] 62.14 - 116.98; P < 0.001; I2 = 87%). The subgroup analysis revealed consistent findings across studies that measured chemerin levels before or after the diagnosis of PE, studies that did or did not match the body mass index (BMI), and studies with varying quality scores (P values for subgroup differences were all > 0.05). Compared to controls, women with severe PE exhibited a significantly greater increase in serum chemerin levels than those with mild PE (P value for subgroup difference = 0.007). Additionally, meta-regression analysis results suggested that the mean BMI of the included pregnant women might positively modify the difference in circulating chemerin levels between women with and without PE (coefficient = 8.92; P = 0.045). In conclusion, this meta-analysis suggests a positive correlation between elevated serum chemerin levels and PE diagnosis in comparison to pregnant women without the condition.

Association between maternal epicardial adipose tissue, gestational diabetes mellitus, and pregnancy-related hypertensive disorders: a systematic review and meta-analysis

Several small studies have evaluated the association between epicardial adipose tissue (EAT) and pregnancy-related cardiovascular risk factors such as gestational diabetes mellitus (GDM) or hypertensive disorders. The objective of this study was to quantitatively compare EAT thickening between patients with GDM or pregnancy-related hypertensive disorders and healthy controls. This systematic review and meta-analysis were performed according to PRISMA guidelines. A literature search was performed to detect studies that have quantified EAT in women with GDM and pregnancy-related hypertensive disorders compared to a control group. The primary outcome was EAT thickening estimated by ultrasound expressed in millimeters. Random or fixed effects models were used. Nine observational studies including 3146 patients were identified and considered eligible for this systematic review. The quantitative analysis showed that patients with GDM have a higher EAT thickness (mean difference: 1.1 mm [95% confidence interval: 1.0-1.2]; I2 = 24%) compared to the control group. Moreover, patients with pregnancy-related hypertensive disorders showed higher EAT thickness (mean difference: 1.0 mm [95% confidence interval: 0.6-1.4]; I2 = 83%) compared to the control group. In conclusion, this study demonstrated that EAT thickening is increased in patients with GDM and pregnancy-related hypertensive disorders compared with healthy controls. Whether or not this association is causal should be evaluated in prospective studies.

Mechanisms of leptin-induced endothelial dysfunction

PURPOSE OF REVIEW

Endothelial dysfunction is a major risk factor for many cardiovascular diseases, notably hypertension. Obesity increases the risk of endothelial dysfunction in association with increasing production of the adipokine leptin. Preclinical studies have begun to unravel the mechanisms whereby leptin leads to the development of endothelial dysfunction, which are sex-specific. This review will summarize recent findings of mechanisms of leptin-induced endothelial impairment in both male and females and in pregnancy.

RECENT FINDINGS

Leptin receptors are found in high concentrations in the central nervous system (CNS), via which leptin promotes appetite suppression and upregulates sympathetic nervous system activation. However, leptin receptors are expressed in many other tissues, including the vascular endothelial cells and smooth muscle cells. Recent studies in mice with vascular endothelial or smooth muscle-specific knockdown demonstrate that endothelial leptin receptor activation plays a protective role against endothelial dysfunction in male animals, but not necessarily in females. Clinical studies indicate that women may be more sensitive to obesity-associated vascular endothelial dysfunction. Emerging preclinical data indicates that leptin and progesterone increase aldosterone production and endothelial mineralocorticoid receptor activation, respectively. Furthermore, decades of clinical studies indicate that leptin levels increase in the hypertensive pregnancy disorder preeclampsia, which is characterized by systemic endothelial dysfunction. Leptin infusion in mice induces the clinical characteristics of preeclampsia, including endothelial dysfunction.

SUMMARY

Novel preclinical data indicate that the mechanisms whereby leptin promotes endothelial dysfunction are sex-specific. Leptin-induced endothelial dysfunction may also play a role in hypertensive pregnancy as well.

The Role of Fetal Membranes during Gestation, at Term, and Preterm Labor

During pregnancy, the fetal membranes (i.e., amniochorionic membranes) surround the intrauterine cavity and provide mechanical, immune, and endocrine support to protect the fetus. Though they are a vital component of the intrauterine cavity, the fetal membranes are largely overlooked as an extension of the placenta, leading to a poor understanding of their role during gestation, parturition, or preterm birth. The fetal membranes are comprised of fetal cellular and stromal layers and line up with maternal decidua forming the feto-maternal interface during pregnancy. This interface plays a large role during pregnancy and the induction of term or preterm parturition (e.g., labor). Here we summarize the function of the fetal membranes focusing on their role during gestation at term, and during preterm births.