Serum levels of leptin, adiponectin and resistin in relation to clinical characteristics in normal pregnancy and preeclampsia

Both endothelial mineralocorticoid receptor expression and hyperleptinemia are required for clinical characteristics of placental ischemia in mice

One of the initiating events in preeclampsia (PE) is placental ischemia. Rodent models of placental ischemia do not present with vascular endothelial dysfunction, a hallmark of PE. We previously demonstrated a role for leptin in endothelial dysfunction in pregnancy in the absence of placental ischemia. We hypothesized that placental ischemia requires hyperleptinemia and endothelial mineralocorticoid receptor (ECMR) expression to induce PE-associated endothelial dysfunction in pregnant mice. We induced placental ischemia via the reduced uterine perfusion pressure (RUPP) procedure in pregnant ECMR-intact (ECMR+/+) and ECMR deletion (ECMR-/-) mice at gestational day (GD) 13. ECMR+/+ RUPP pregnant mice also received concurrent leptin infusion via miniosmotic pump (0.9 mg/kg/day). RUPP increased blood pressure via radiotelemetry and decreased fetal growth in ECMR+/+ pregnant mice. Both increases in blood pressure and reduced fetal growth were abolished in RUPP ECMR-/- mice. Placental ischemia did not decrease endothelial-dependent relaxation to acetylcholine (ACh) but increased phenylephrine (Phe) contraction in mesenteric arteries of pregnant mice, which was ablated by ECMR deletion. Addition of leptin to RUPP mice significantly reduced ACh relaxation in ECMR+/+ pregnant mice, accompanied by an increase in soluble FMS-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PLGF) ratio. In conclusion, our data indicate that high leptin levels drive endothelial dysfunction in PE and that ECMR is required for clinical characteristics of hypertension and fetal growth restriction in placental ischemia PE. Collectively, we show that both ECMR and leptin play a role to mediate PE.NEW & NOTEWORTHY Leptin is a key feature of preeclampsia that initiates vascular endothelial dysfunction in preeclampsia characterized by placental ischemia. Endothelial mineralocorticoid receptor (ECMR) deletion in placental ischemia protects pregnant mice from elevations in blood pressure and fetal growth restriction in pregnancy. Increases in leptin production mediate the key pathological feature of endothelial dysfunction in preeclampsia in rodents. ECMR activation contributes to the increase in blood pressure and fetal growth restriction in preeclampsia.

Serum levels of sirtuins, leptin and adiponectin in women with pregnancy-induced hypertension

INTRODUCTION

Pregnancy-induced hypertension (PIH) and preeclampsia (PE) are associated with disturbed maternal inflammatory response, oxidative stress and vascular endothelial cell dysfunction. Obesity is one of risk factors of PE. Leptin is elevated in obesity and its level correlates positively with the amount of adipose tissue. In contrast, adiponectin levels are decreased in obesity. Sirtuins are expressed in the placenta, however their role in pregnancy-related pathology in humans is not known.

AIM OF THE STUDY

The aim of our study was to measure serum concentrations of selected sirtuins, adiponectin and leptin in healthy pregnancy and in women with PIH.

MATERIALS AND METHODS

The study included 70 women: 38 healthy pregnant women and 32 women with PIH. Blood samples were obtained between the 20th and 40th week of gestation. Serum levels of sirtuins 1, 3, 6, leptin and adiponectin were measured with ELISA.

RESULTS

Leptin levels were significantly higher in PIH group as compared to the controls and correlated positively with BMI. Highest leptin levels were observed in women who needed a cesarean section. Levels of sirtuins 1, 3 and 6 were similar in both groups and did not correlate with BMI.

CONCLUSIONS

High leptin levels in PIH women during 3rd trimester might be helpful to predict the necessity for a caesarian section. Blood levels of sirtuins 1, 3 and 6 measured after the 20th week of gestation cannot be regarded as a single diagnostic test for PIH or preeclampsia. More studies to clarify significance of sirtuins in PIH and PE development and diagnosis are needed.

Interaction effect between low birthweight and resistin gene rs1862513 variant on insulin resistance and type 2 diabetes mellitus in adulthood: Toon Genome Study

AIMS/INTRODUCTION

Gene-environment interactions are considered to critically influence type 2 diabetes mellitus development; however, the underlying mechanisms and specific interactions remain unclear. Given the increasing prevalence of low birthweight (LBW) influenced by the intrauterine environment, we sought to investigate genetic factors related to type 2 diabetes development in individuals with LBW.

MATERIALS AND METHODS

The interaction between 20 reported type 2 diabetes susceptibility genes and the development of type 2 diabetes in LBW (<2,500 g) individuals in a population-based Japanese cohort (n = 1,021) was examined by logistic regression and stratified analyses.

RESULTS

Logistic regression analyses showed that only the G/G genotype at the rs1862513 locus of the resistin gene (RETN), an established initiator of insulin resistance, was closely related to the prevalence of type 2 diabetes in individuals with LBW. Age, sex and current body mass index-adjusted stratified analyses showed a significant interaction effect of LBW and the RETN G/G genotype on fasting insulin, homeostatic model assessment 2-insulin resistance, Matsuda index and the prevalence of type 2 diabetes (all P-values for interaction <0.05). The adjusted odds ratio for type 2 diabetes in the LBW + G/G genotype group was 7.33 (95% confidence interval 2.43-22.11; P = 0.002) compared with the non-LBW + non-G/G genotype group. Similar results were obtained after excluding the influence of malnutrition due to World War II.

CONCLUSIONS

Simultaneous assessment of LBW and the RETN G/G genotype can more accurately predict the risk of future type 2 diabetes than assessing each of these factors alone, and provide management strategies, including early lifestyle intervention in LBW population.

The effects of leptin on human cytotrophoblast invasion are gestational age and dose-dependent

Introduction

Leptin and its receptors are expressed by the human placenta throughout gestation, yet the role of leptin in early human placental development is not well characterized. Leptin is overexpressed in the placentas from preeclamptic (PE) pregnancies. PE can result from the impaired invasion of fetal placental cells, cytotrophoblasts (CTBs), into the maternal decidua. We hypothesized that elevated leptin levels would impair human CTB invasion.

Methods

The effects of leptin on the invasion of human CTBs were evaluated in three cell models, HTR-8/SVneo cells, primary CTBs, and placental villous explants using invasion assays. Further, leptin receptor expression was characterized in all three cell models using RT-PCR. Further phosphokinase assays were performed in HTR-8/SVneo cells to determine signaling pathways involved in CTB invasion in response to differential leptin doses.

Results

We found that, prior to 8 weeks gestation, leptin promoted CTB invasion in the explant model. After 11 weeks gestation in explants, primary CTBs and in HTR-8/SVneo cells, leptin promoted invasion at moderate but not at high concentrations. Further, leptin receptor characterization revealed that leptin receptor expression did not vary over gestation, however, STAT, PI3K and MAPK pathways showed different signaling in response to varied leptin doses.

Discussion

These data suggest that the excess placental leptin observed in PE may cause impaired CTB invasion as a second-trimester defect. Leptin's differential effect on trophoblast invasion may explain the role of hyperleptinemia in preeclampsia pathogenesis.

Adipokines in pregnancy

Reproductive success consists of a sequential events chronology, starting with the ovum fertilization, implantation of the embryo, placentation, and cellular processes like proliferation, apoptosis, angiogenesis, endocrinology, or metabolic changes, which taken together finally conduct the birth of healthy offspring. Currently, many factors are known that affect the regulation and proper maintenance of pregnancy in humans, domestic animals, or rodents. Among the determinants of reproductive success should be distinguished: the maternal microenvironment, genes, and proteins as well as numerous pregnancy hormones that regulate the most important processes and ensure organism homeostasis. It is well known that white adipose tissue, as the largest endocrine gland in our body, participates in the synthesis and secretion of numerous hormones belonging to the adipokine family, which also may regulate the course of pregnancy. Unfortunately, overweight and obesity lead to the expansion of adipose tissue in the body, and its excess in both women and animals contributes to changes in the synthesis and release of adipokines, which in turn translates into dramatic changes during pregnancy, including those taking place in the organ that is crucial for the proper progress of pregnancy, i.e. the placenta. In this chapter, we are summarizing the current knowledge about levels of adipokines and their role in the placenta, taking into account the physiological and pathological conditions of pregnancy, e.g. gestational diabetes mellitus, preeclampsia, or intrauterine growth restriction in humans, domestic animals, and rodents.

Metabolic hormones are integral regulators of female reproductive health and function

The female reproductive system is strongly influenced by nutrition and energy balance. It is well known that food restriction or energy depletion can induce suppression of reproductive processes, while overnutrition is associated with reproductive dysfunction. However, the intricate mechanisms through which nutritional inputs and metabolic health are integrated into the coordination of reproduction are still being defined. In this review, we describe evidence for essential contributions by hormones that are responsive to food intake or fuel stores. Key metabolic hormones-including insulin, the incretins (glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1), growth hormone, ghrelin, leptin, and adiponectin-signal throughout the hypothalamic-pituitary-gonadal axis to support or suppress reproduction. We synthesize current knowledge on how these multifaceted hormones interact with the brain, pituitary, and ovaries to regulate functioning of the female reproductive system, incorporating in vitro and in vivo data from animal models and humans. Metabolic hormones are involved in orchestrating reproductive processes in healthy states, but some also play a significant role in the pathophysiology or treatment strategies of female reproductive disorders. Further understanding of the complex interrelationships between metabolic health and female reproductive function has important implications for improving women's health overall.

Leptin-Mediated Induction of IL-6 Expression in Hofbauer Cells Contributes to Preeclampsia Pathogenesis

Leptin plays a crucial role in regulating energy homoeostasis, neuroendocrine function, metabolism, and immune and inflammatory responses. The adipose tissue is a main source of leptin, but during pregnancy, leptin is also secreted primarily by the placenta. Circulating leptin levels peak during the second trimester of human pregnancy and fall after labor. Several studies indicated a strong association between elevated placental leptin levels and preeclampsia (PE) pathogenesis and elevated serum interleukin-6 (IL-6) levels in PE patients. Therefore, we hypothesized that a local increase in placental leptin production induces IL-6 production in Hofbauer cells (HBCs) to contribute to PE-associated inflammation. We first investigated HBCs-specific IL-6 and leptin receptor (LEPR) expression and compared their immunoreactivity in PE vs. gestational age-matched control placentas. Subsequently, we examined the in vitro regulation of IL-6 as well as the phosphorylation levels of intracellular signaling proteins STAT3, STAT5, NF-κB, and ERK1/2 by increasing recombinant human leptin concentrations (10 to 1000 ng/mL) in primary cultured HBCs. Lastly, HBC cultures were incubated with leptin ± specific inhibitors of STAT3 or STAT5, or p65 NF-κB or ERK1/2 MAPK signaling cascades to determine relevant cascade(s) involved in leptin-mediated IL-6 regulation. Immunohistochemistry revealed ~three- and ~five-fold increases in IL-6 and LEPR expression, respectively, in HBCs from PE placentas. In vitro analysis indicated that leptin treatment in HBCs stimulate IL-6 in a concentration-dependent manner both at the transcriptional and secretory levels (p < 0.05). Moreover, leptin-treated HBC cultures displayed significantly increased phosphorylation levels of STAT5, p65 NF-κB, and ERK1/2 MAPK and pre-incubation of HBCs with a specific ERK1/2 MAPK inhibitor blocked leptin-induced IL-6 expression. Our in situ results show that HBCs contribute to the pathogenesis of PE by elevating IL-6 expression, and in vitro results indicate that induction of IL-6 expression in HBCs is primarily leptin-mediated. While HBCs display an anti-inflammatory phenotype in normal placentas, elevated levels of leptin may transform HBCs into a pro-inflammatory phenotype by activating ERK1/2 MAPK to augment IL-6 expression.

Association Between Circulating Resistin Level and Preeclampsia: A Meta-Analysis

Resistin, a diminutive secretory adipokine, has been linked to obesity and its related ailments. A growing body of evidence suggests that resistin may also be related to the pathogenesis preeclampsia. However, results of previous studies were not consistent. We performed a systematic review and meta-analysis to evaluate the level of circulating resistin in women with PE. A systematic search of Medline, Web of Science, and Embase databases from inception to April 28, 2023, was conducted to identify studies that compared blood resistin levels in pregnant women with and without PE. A random-effects model was utilized to pool the results, accounting for heterogeneity. The present study analyzed eighteen datasets from sixteen observational studies. The results of the meta-analysis demonstrated a statistically significant increase in blood resistin levels among women with PE compared to the control group. (standardized mean difference=0.35, 95% confidence interval: 0.16 to 0.54, p<0.001; I2=74%). The findings of the subgroup analysis indicate that various study characteristics, including study design, timing, and methods for measuring resistin, matching of body mass index between cases and controls, and study quality scores did not exert a significant impact on the outcomes. Nonetheless, it is noteworthy that the diagnostic criteria for PE employed in the studies included in the analysis may have influenced the results (p for subgroup difference=0.001). Women with preeclampsia exhibit a greater concentration of resistin in circulation when compared to healthy pregnant controls.

Serum leptin levels and relationship with maternal weight gain at term among obese and non-obese pregnant women in Enugu, Nigeria: a comparative cross-sectional study

OBJECTIVE

To determine and compare the mean maternal serum leptin levels, the prevalence of high serum leptin levels and mean gestational weight gain at term among obese and non-obese pregnant women in Enugu, Nigeria.

METHODS

This cross-sectional comparative study enrolled obese and non-obese pregnant women. The serum leptin levels of the women were determined using an enzyme-linked immunosorbent assay kit. Anthropometric and sociodemographic data were obtained and compared. Mean weight gain during pregnancy was determined.

RESULTS

A total of 170 pregnant women were included in the study. The mean ± SD serum leptin level (99.39 ± 50.2 ng/ml) and the prevalence of hyperleptinaemia (81 of 85 patients; 95.3%) among the obese pregnant women at term were significantly higher than those of the non-obese pregnant women (48.98 ± 30.35 ng/ml/65 of 85 patients; 76.5%). The mean percentage weight gain was significantly higher in the non-obese women compared with the obese women at term. The predictors of high maternal serum leptin level at term among the participants were the employment status and levels of education of the participants.

CONCLUSION

Maternal serum leptin level, maternal weight gain and prevalence of hyperleptinaemia at term were significantly higher in the obese compared with the non-obese pregnant women.

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.

Serum levels and gestational curve of adiponectin and leptin during adolescent pregnancy

OBJECTIVE

This study aimed to develop a curve of weekly serum levels of adiponectin and leptin among pregnant adolescents. In addition, pregestational body mass index and weight gain were assessed and correlated with the serum concentration of these molecules.

METHODS

This was a prospective cohort study, including only pregnant adolescents with eutrophic pre-gestational body mass index who were weekly followed during the evolution of gestation. The serum concentrations of adipokines were determined using commercial ELISA kits and were correlated to pre-gestational body mass index and pregnancy weight gain. A total of 157 pregnant women participated in this study.

RESULTS

Adiponectin levels showed a significant decrease among the trimesters (p=0.0004). However, we did not observe significant differences among its levels when compared weekly, neither of which was between adiponectin concentration and pre-gestational body mass index or weight gain (p=0.36 and p=0.10, respectively). In contrast, we detected a significant increase in weekly serum leptin levels (p<0.0001), positively correlated to both pre-gestational body mass index and weight gain (p=0.003 and p=0.0007, respectively).

CONCLUSION

These adipokines present a different profile throughout adolescent pregnancy.

Obesity and recurrent miscarriage: The interconnections between adipose tissue and the immune system

Currently, obesity is considered a global public health problem. It is the main risk factor for noncommunicable diseases and reproductive complications, such as recurrent miscarriage (RM). RM affects approximately 1% of couples of reproductive age, and recent studies suggest that its prevalence is increasing. Immunological abnormalities may be responsible for a significant number of cases of unexplained RM. Obesity is recognized as a chronic low-grade inflammatory condition. The accumulation of fat in obese adipose tissue promotes changes in the local and systemic immune response. Adipokines, exosomes, micro-RNAs, lipids, and other factors released or secreted by adipose tissue are responsible for the interconnection between obesity and the immune system. Obesity-induced dysregulation of the innate and acquired immune response is also involved in the immunopathology of pregnancy loss in patients with unexplained RM. Therefore, understanding the communication pathways between maternal adipose tissue and the immune response in women living with obesity and RM is an important objective. Thus, diagnostic tools and new immunomodulatory therapies may be proposed for the management of patients with concurrent obesity and RM.

Adipokines in Pregnancy: A Systematic Review of Clinical Data

Adipokines are signaling proteins involved in metabolic, endocrinological, vascular and immunogenic processes. Associations of various adipokines with not only insulin resistance but also with increased insulin sensitivity, increased systolic blood pressure, and atherosclerosis highlight the significance of adipokines in several components of metabolic syndrome and metabolic diseases in general. As pregnancy presents a unique metabolic state, the role of adipokines in pregnancy, and even in various pregnancy complications, appears to be key to elucidating these metabolic processes. Many studies in recent years have attempted to clarify the role of adipokines in pregnancy and gestational pathologies. In this review, we aim to investigate the changes in maternal adipokine levels in physiological gestation, as well as the association of adipokines with pregnancy pathologies, such as gestational diabetes mellitus (GDM) and preeclampsia (PE). Furthermore, we will analyze the association of adipokines in both maternal serum and cord blood with parameters of intrauterine growth and various pregnancy outcomes.

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.

Midgestation Leptin Infusion Induces Characteristics of Clinical Preeclampsia in Mice, Which Is Ablated by Endothelial Mineralocorticoid Receptor Deletion

BACKGROUND

Patients with preeclampsia demonstrate increases in placental leptin production in midgestation, and an associated increase in late gestation plasma leptin levels. The consequences of mid-late gestation increases in leptin production in pregnancy is unknown. Our previous work indicates that leptin infusion induces endothelial dysfunction in nonpregnant female mice via leptin-mediated aldosterone production and endothelial mineralocorticoid receptor (ECMR) activation, which is ablated by ECMR deletion. Therefore, we hypothesized that leptin infusion in mid-gestation of pregnancy induces endothelial dysfunction and hypertension, hallmarks of clinical preeclampsia, which are prevented by ECMR deletion.

METHODS

Leptin was infused via miniosmotic pump (0.9 mg/kg per day) into timed-pregnant ECMR-intact (WT) and littermate-mice with ECMR deletion (KO) on gestation day (GD)11-18.

RESULTS

Leptin infusion decreased fetal weight and placental efficiency in WT mice compared with WT+vehicle. Radiotelemetry recording demonstrated that blood pressure increased in leptin-infused WT mice during infusion. Leptin infusion reduced endothelial-dependent relaxation responses to acetylcholine (ACh) in both resistance (second-order mesenteric) and conduit (aorta) vessels in WT pregnant mice. Leptin infusion increased placental ET-1 (endothelin-1) production evidenced by increased PPET-1 (preproendothelin-1) and ECE-1 (endothelin-converting enzyme-1) expressions in WT mice. Adrenal aldosterone synthase (CYP11B2) and angiotensin II type 1 receptor b (AT1Rb) expression increased with leptin infusion in pregnant WT mice. KO pregnant mice demonstrated protection from leptin-induced reductions in pup weight, placental efficiency, increased BP, and endothelial dysfunction.

CONCLUSIONS

Collectively, these data indicate that leptin infusion in midgestation induces endothelial dysfunction, hypertension, and fetal growth restriction in pregnant mice, which is ablated by ECMR deletion.

Serum biomarkers for the prediction and diagnosis of preeclampsia: A meta-analysis

Objective

Preeclampsia is a major risk factor for maternal and foetal mortality and morbidity. There have been tremendous efforts to identify serum biomarkers which can reliably predict the occurrence of preeclampsia. The study aims to assess the biomarkers that have the greatest utility in the diagnosis of preeclampsia.

Methods

A systematic search was performed on the PubMed literature database, and chain references were retrieved. Original research articles composed of case controls, cohorts, randomised control trials, and cross-sectional studies were included. The recorded variables included each study's design, type, year, and location; the value (mean ± standard deviation) of the markers in the patients and the pregnant controls; and the p-value, unit of measurement, and the sample size of each study. The results were interpreted based on the standardised mean difference (SMD) values.

Results

A total of 398 studies were retrieved from the PubMed database. After further analysis, 89 studies were selected for this review. An additional 47 studies were included based on chain referencing. Later, 136 full-text articles were reviewed in detail and their data were entered. Finally, 25 studies, in which 13 serum biomarkers were assessed, were selected for this meta-analysis. The levels of the angiogenic markers fms-like tyrosine kinase (sFlt), sFlt/placental growth factor (PlGF), and endoglin were significantly higher in patients with preeclampsia than in the pregnant controls. The levels of PlGF and the lipid biomarkers high density lipoprotein (HDL) and adiponectin were significantly lower, while the levels of triglycerides, apolipoprotein B (APO-B), and leptin were elevated in the preeclamptic patients compared to the pregnant controls (p < 0.05).

Conclusion

In our study, the values of the serum biomarkers sFlt, PlGF, sFlt/PlGF, HDL, adiponectin, leptin, triglycerides, and APO-B differed significantly between preeclampsia patients and the pregnant controls. These findings demand advanced evaluation of biomarkers to enhance diagnostic screening for preeclampsia.

Obesity-associated cardiovascular risk in women: hypertension and heart failure

The pathogenesis of obesity-associated cardiovascular diseases begins long prior to the presentation of a cardiovascular event. In both men and women, cardiovascular events, and their associated hospitalizations and mortality, are often clinically predisposed by the presentation of a chronic cardiovascular risk factor. Obesity increases the risk of cardiovascular diseases in both sexes, however, the clinical prevalence of obesity, as well as its contribution to crucial cardiovascular risk factors is dependent on sex. The mechanisms via which obesity leads to cardiovascular risk is also discrepant in women between their premenopausal, pregnancy and postmenopausal phases of life. Emerging data indicate that at all reproductive statuses and ages, the presentation of a cardiovascular event in obese women is strongly associated with hypertension and its subsequent chronic risk factor, heart failure with preserved ejection fraction (HFpEF). In addition, emerging evidence indicates that obesity increases the risk of both hypertension and heart failure in pregnancy. This review will summarize clinical and experimental data on the female-specific prevalence and mechanisms of hypertension and heart failure in women across reproductive stages and highlight the particular risks in pregnancy as well as emerging data in a high-risk ethnicity in women of African ancestry (AA).

The role of resistin in early preeclampsia prediction

Resistin might be involved with general inflammation and endothelial dysfunction observed in preeclampsia. We aimed to investigate longitudinal changes in resistin concentrations during high-risk pregnancies and evaluate their significance in preeclampsia development. Ninety-one patients were recruited at 11-14 weeks of gestation. They were followed towards the end of each trimester and before their deliveries. Of the 91 pregnant women, 21 developed preeclampsia, while 70 women did not develop preeclampsia despite being at risk. Compared to the 1^st trimester, resistin concentration significantly increased during the 2^nd trimester (p<.001). When women were divided into groups of those who developed preeclampsia and those who did not develop preeclampsia, we noticed a significant difference only in women who did not develop preeclampsia (p<.001). Moreover, resistin concentration in the 1^st trimester was statistically higher in women who developed preeclampsia when compared to those who did not develop preeclampsia (p<.001). The analysis of the Receiver Operating Characteristics (ROC) curves indicated that inclusion of triglycerides (TG), high-sensitivity C-reactive protein (CRP), and resistin (AUC = 0.870) improved diagnostic accuracy of the basic model including demographic and clinical parameters (AUC = 0.777) for preeclampsia prediction (p<.05). If the concentration of resistin is high in the 1^st trimester, such pregnancy at risk is likely to develop preeclampsia as a complication, indicating that resistin concentration in the 1^st trimester might contribute to existing predictive and prognostic models for preeclampsia. A multi-marker model, possibly including also resistin and other clinical, metabolic, and inflammatory parameters, seems to be the best approach in late-onset preeclampsia prediction.

Resistin in pregnancy: Analysis of determinants in pairs of umbilical cord blood and maternal serum

Objective

Despite intensive research on the cytokine resistin only few studies investigated mother-newborn-pairs during healthy pregnancy and reported about interactions with clinical obstetric variables or other cytokines. Comparison of existing studies is difficult due to differences between assays, sample collection, gestational age, definition of healthy controls and patient characteristics. Furthermore, differences between rodent models and humans do not allow for a direct comparison.

Methods

In this cross-sectional, prospective study 109 healthy mother-newborn pairs were analyzed. Maternal venous blood samples were taken on admission to the labor ward; newborn venous blood samples were drawn from the placental part of the umbilical cord (UC), immediately after clamping. Resistin, leptin, adiponectin, TNF-α, IL-6 and brain derived neurotrophic factor (BDNF) serum concentrations were measured with commercially available immunoassays. Determinants of maternal and newborn resistin levels were analyzed using simple and multiple linear regression.

Results

UC resistin levels were higher than maternal concentrations (median 17.69 ng/mL, IQR 7.36 vs. median 8.04 ng/mL, IQR 4.30). Correlation between UC and maternal resistin levels was moderate (R = 0.503, p < 0.01). In multiple regression analysis levels of maternal resistin and newborn TNF-α remained significant determining factors for UC resistin levels. Gestational age and maternal BDNF-levels remained significant factors for maternal resistin levels.

Conclusion

In healthy, term newborns and their respective mothers a positive correlation between maternal and newborn levels and an association with gestational age around term can be found and point to a placental source of resistin. Further investigations are needed to clarify the possible contribution of transplacental transport of resistin into the fetal circulation. Except for gestational age most of the clinical obstetric variables tested do not seem to be determining factors for fetal or maternal resistin. Interactions of resistin with other cytokines like TNF-α and BDNF could be the missing link for the conflicting results in literature.

The Role of Leptin in Fetal Growth during Pre-Eclampsia

Leptin is secreted by the placenta and has a multi-facetted role in the regulation of functions related to pregnancy. Metabolic disorders and insufficient homeostatic compensatory mechanisms involving leptin during pregnancy play a decisive role in the development of pre-eclampsia (PE) and give rise to compromised intrauterine growth conditions and aberrant birth weight of offspring. This review was compiled to elucidate the metabolic background of PE and its relationship with adverse intrauterine growth conditions through the examination of leptin as well as to describe possible mechanisms linking leptin to fetal growth restriction. This review illustrates that leptin in PE is dysregulated in maternal, fetal, and placental compartments. There is no single set of unifying mechanisms within the spectrum of PE, and regulatory mechanisms involving leptin are specific to each situation. We conclude that dysregulated leptin is involved in fetal growth at many levels through complex interactions with parallel pregnancy systems and probably throughout the entirety of pregnancy.

Correlation of serum resistin level and other metabolic hormones and immune function in neonatal umbilical cord blood

The present study was conducted with an attempt to explore the correlation of serum resistin level and other metabolic hormones and immune function in neonatal umbilical cord blood.The levels of umbilical cord blood resistin, adiponectin, insulin, growth hormone, leptin, thyrotropin, thyroid hormone (T3, T4), lgM, lgA, lgG, CD4, and CD8 were measured in 180 full-term newborns delivered in hospital from October 2018 to November 2019. The delivery mode, weight, height, and gender at birth were recorded.The levels of resistin, insulin, and growth hormone in umbilical cord blood of newborns delivered vaginally were significantly higher than those born by cesarean section (P < .05), while the levels of adiponectin, leptin, TST, T3, T4, lgM, lgA, lgG, CD4, and CD8 were comparable between the 2 groups (P > .05). The levels of resistin, adiponectin, insulin, growth hormone, leptin, TST, T3, T4, lgM, lgA, lgG, CD4, and CD8 in cord blood of male and female newborns were comparable (P > .05). The newborns with birth weight ≥ 3501 g reported comparable results in the levels of resistin and growth hormone compared with those with birth weight of 3000 to 3500 g (P > .05), but were significantly higher than those with birth weight ≤ 2999 g (P < 0.05). In addition, the levels of adiponectin, insulin, leptin, TST, T3, T4, lgM, lgA, lgG, CD4, and CD8 were comparable among the 3 groups (P > .05). Based on Pearson correlation analysis, neonatal umbilical cord blood resistin was positively correlated with adiponectin, leptin, growth hormone, T3, and T4 (r = 0.281, 0.287, 0.321, 0.276, 0.269, P < .05). However, there was no significant correlation between neonatal umbilical cord blood resistin and insulin, TST, lgM, lgA, lgG, CD4, and CD8.The level of serum resistin in neonatal umbilical cord blood was associated with the delivery mode and birth weight, and positively correlated with adiponectin, leptin, growth hormone, T3, and T4. However, no correlation was observed between serum resistin in neonatal umbilical cord blood and insulin, TST, lgM, lgA, lgG, CD4, and CD8.

Integrated analysis of multiple microarray studies to identify potential pathogenic gene modules in preeclampsia

BACKGROUND

Preeclampsia is a life-threatening hypertensive disorder during pregnancy, while underlying pathogenesis and its diagnosis are incomplete.

METHODS

In this study, we utilized the Robust Rank Aggregation method to integrate 6 eligible preeclampsia microarray datasets from Gene Expression Omnibus database. We used linear regression to assess the associations between significant differentially expressed genes (DEGs) and blood pressure. Functional annotation, protein-protein interaction, Gene Set Enrichment Analysis (GSEA) and single sample GSEA were employed for investigating underlying pathogenesis in preeclampsia.

RESULTS

We filtered 52 DEGs and further screened for 5 hub genes (leptin, pappalysin 2, endoglin, fms related receptor tyrosine kinase 1, tripartite motif containing 24) that were positively correlated with both systolic blood pressure and diastolic blood pressure. Receiver operating characteristic indicated that hub genes were potential biomarkers for diagnosis and prognosis in preeclampsia. GSEA for single hub gene revealed that they were all closely related to angiogenesis and estrogen response in preeclampsia. Moreover, single sample GSEA showed that the expression levels of 5 hub genes were correlated with those of immune cells in immunologic microenvironment at maternal-fetal interface.

CONCLUSIONS

These findings provide new insights into underlying pathogenesis in preeclampsia; 5 hub genes were identified as biomarkers for diagnosis and prognosis in preeclampsia.

The Role of the Adipokines in the Most Common Gestational Complications

Adipocytokines are hormonally active molecules that are believed to play a key role in the regulation of crucial biological processes in the human body. Numerous experimental studies established significant alterations in the adipokine secretion patterns throughout pregnancy. The exact etiology of various gestational complications, such as gestational diabetes, preeclampsia, and fetal growth abnormalities, needs to be fully elucidated. The discovery of adipokines raised questions about their potential contribution to the molecular pathophysiology of those diseases. Multiple studies analyzed their local mRNA expression and circulating protein levels. However, most studies report conflicting results. Several adipokines such as leptin, resistin, irisin, apelin, chemerin, and omentin were proposed as potential novel early markers of heterogeneous gestational complications. The inclusion of the adipokines in the standard predictive multifactorial models could improve their prognostic values. Nonetheless, their independent diagnostic value is mostly insufficient to be implemented into standard clinical practice. Routine assessments of adipokine levels during pregnancy are not recommended in the management of both normal and complicated pregnancies. Based on the animal models (e.g., apelin and its receptors in the rodent preeclampsia models), future implementation of adipokines and their receptors as new therapeutic targets appears promising but requires further validation in humans.

Evaluating Relationships between Visceral Fat Measures and Adipokines Concentrations among Women with a History of Preeclampsia

OBJECTIVE

We sought to evaluate associations between postpartum plasma adipokine concentrations among women with a history of preeclampsia (PE) without severe features (MPE), PE with severe features (SPE), and no PE (NPE). We also investigated relationships between adipokines and computed tomography (CT)-quantified measures of visceral fat (VF) area (VFA) and subcutaneous fat area (SCFA).

STUDY DESIGN

We performed a secondary analysis of data collected as part of a previously performed cross-sectional study at our institution. Women with and without a history of PE were recruited in 10 years after delivery. VFA and SCFA measures were performed by CT scan. Anthropometric data and peripheral blood samples from subjects were collected concurrently.

RESULTS

Plasma adiponectin concentrations (µg/mL) were significantly lower among MPE (18.5 ± 7.1) compared with NPE (27.3 ± 13.8) and SPE (25.7 ± 9.6). Leptin (p = 0.32) and resistin (p = 0.93) concentrations were similar among the groups. Adiponectin concentrations more closely aligned with VFA (β = -0.001, p = 0.03), while resistin concentrations trended toward correlating with SCFA (β = 0.02, p = 0.05). Leptin was not preferential to VFA or SCFA.

CONCLUSION

VF distribution may contribute to the variation in PE phenotype. Adiponectin specifically may be a promising marker representing VFA.

Adipocytokines: Are they the Theory of Everything?

INTRODUCTION

Adipose tissue secretes various bioactive peptides/proteins, immune molecules and inflammatory mediators which are known as adipokines or adipocytokines. Adipokines play important roles in the maintenance of energy homeostasis, appetite, glucose and lipid metabolism, insulin sensitivity, angiogenesis, immunity and inflammation. Enormous number of studies from all over the world proved that adipocytokines are involved in the pathogenesis of diseases affecting nearly all body systems, which raises the question whether we can always blame adipocytokines as the triggering factor of every disease that may hit the body.

OBJECTIVE

Our review targeted the role played by adipocytokines in the pathogenesis of different diseases affecting different body systems including diabetes mellitus, kidney diseases, gynecological diseases, rheumatologic disorders, cancers, Alzheimer's, depression, muscle disorders, liver diseases, cardiovascular and lung diseases.

METHODOLOGY

We cited more than 33 recent literature reviews that discussed the role played by adipocytokines in the pathogenesis of different diseases affecting different body systems.

CONCLUSION

More evidence is being discovered to date about the role played by adipocytokines in more diseases and extra research is needed to explore hidden roles played by adipokine imbalance on disease pathogenesis.

Protein-9 (CTRP9) levels associated with C1q tumor necrosis factor in obese preeclamptic, non-obese preeclamptic, obese and normal pregnant women

AIM

The incidence of obesity and preeclampsia is increasing more and more all over the world. Inflammation and endovascular dysfunction play an important role in the etiopathogenesis of preeclampsia. Obesity has been reported to contribute to the development of preeclampsia by developing a low-grade inflammatory environment and adversely affecting maternal endothelial function. Studies on the relationship between obesity and preeclampsia and how this relationship contributes to endothelial dysfunction continue. The complement C1q tumor necrosis factor-associated protein (CTRP) family (CTRP1-15) secreted from the adipose tissue is a new generation adipokine family with important functions in the immunomodulatory, anti-inflammatory, apoptosis, autoimmunity, vascular system, glucose and lipid metabolism in the body. In recent years, CTRP9, a member of this family, has been shown to have a strong vasorelaxation effect with the Adiponectin Receptor-1/AMPK/eNOS/Nitric Oxide Signaling Pathway. The study aims to find out the role of CTRP9, an adipocytokine, in the pathogenesis of obesity and preeclampsia.

MATERIAL AND METHOD

The CTRP9 levels were measured by the enzyme-linked immunosorbent assay (ELISA) in 40 obese preeclamptic, 40 non-obese preeclamptic, 40 obese pregnant women and 40 normal BMI (Body mass index) pregnant women.

RESULTS

The CTRP9 level of the obese preeclampsia group was found to be lower compared to the non-obese preeclampsia, obese pregnant and normal BMI pregnant control groups (p < .001). The obese preeclampsia group had higher systolic and diastolic blood pressure values compared to the non-obese preeclampsia group (p < .001). There was no difference between the CTRP9 levels of the normal BMI and non-obese preeclampsia groups (p > .05). The serum CTRP9 levels were inversely correlated with age, BMI, blood pressure, and aspartate aminotransferase (AST) (p < .001).

CONCLUSION

Obesity causes a decrease in CTRP9 levels and contributes to the pathogenesis of preeclampsia with adverse effects on the vascular and placental system. Serum CTRP9 levels in pregnant women help identify pregnancies at risk in terms of obesity and preeclampsia.

The role of serum adipokine levels in preeclampsia: A systematic review

BACKGROUND

Preeclampsia represents a major pregnancy complication, associated with high rates of perinatal morbidity. The aim of this systematic review is to accumulate current literature evidence in order to examine the pattern of serum adipokine levels among preeclamptic women and asses their potential efficacy in the prediction of the disease.

METHODS

Medline, Scopus, CENTRAL, Clinicaltrials.gov and Google Scholar databases were systematically searched from inception. All observational studies reporting serum adipokine values among preeclamptic and healthy pregnant women were held eligible.

RESULTS

A total of 163 studies were included, comprising 23,482 women. Leptin was evaluated in 91 studies and its values were found to be significantly elevated in preeclamptic women during all pregnancy trimester, independently of disease onset and severity. Preeclampsia was also associated with increased serum fatty acid binding protein-4 and chemerin levels, when measured both during the 1st and 3rd trimester. Data concerning the rest adipokines were either conflicting or limited to reach firm conclusions. Quality of evidence was evaluated to be high for leptin, moderate for serum fatty acid binding protein-4 and chemerin and low for the other adipokines.

CONCLUSIONS

The existing evidence suggests that preeclampsia is linked to increased levels of leptin, chemerin and fatty acid binding protein-4 in all pregnancy trimesters and forms of the disease. Inconsistent data currently exists concerning the role of the other adipokines. Large-scale prospective studies should longitudinally evaluate the serum concentration of novel adipokines and define the optimal threshold and timing of measurement to be widely applied in clinical practice.

A Review of Candidate Genes and Pathways in Preeclampsia-An Integrated Bioinformatical Analysis

: Preeclampsia is a pregnancy-specific disorder characterized by the presence of hypertension with the onset of either proteinuria, maternal organ or uteroplacental dysfunction. Preeclampsia is one of the leading causes of maternal and fetal mortality and morbidity worldwide. However, the etiopathologies of preeclampsia are not fully understood. Many studies have indicated that genes are differentially expressed between normal and in the disease state. Hence, this study systematically searched the literature on human gene expression that was differentially expressed in preeclampsia. An electronic search was performed through 2019 through PubMed, Scopus, Ovid-Medline, and Gene Expression Omnibus where the following MeSH (Medical Subject Heading) terms were used and they had been specified as the primary focus of the articles: Gene, placenta, preeclampsia, and pregnancy in the title or abstract. We also found additional MeSH terms through Cochrane Library: Transcript, sequencing, and profiling. From 687 studies retrieved from the search, only original publications that had performed high throughput sequencing of human placental tissues that reported on differentially expressed genes in pregnancies with preeclampsia were included. Two reviewers independently scrutinized the titles and abstracts before examining the eligibility of studies that met the inclusion criteria. For each study, study design, sample size, sampling type, and method for gene analysis and gene were identified. The genes listed were further analyzed with the DAVID, STRING and Cytoscape MCODE. Three original research articles involving preeclampsia comprising the datasets in gene expression were included. By combining three studies together, 250 differentially expressed genes were produced at a significance setting of p < 0.05. We identified candidate genes: LEP, NRIP1, SASH1, and ZADHHC8P1. Through GO analysis, we found extracellular matrix organization as the highly significant enriched ontology in a group of upregulated genes and immune process in downregulated genes. Studies on a genetic level have the potential to provide new insights into the regulation and to widen the basis for identification of changes in the mechanism of preeclampsia. Integrated bioinformatics could identify differentially expressed genes which could be candidate genes and potential pathways in preeclampsia that may improve our understanding of the cause and underlying molecular mechanisms that could be used as potential biomarkers for risk stratification and treatment.

Adipokines and Endothelium Dysfunction Markers in Pregnant Women with Gestational Hypertension

Objective

The aim of the study was to evaluate the levels of adipokines such as adiponectin and leptin as well as soluble intercellular adhesion molecule-1 (sICAM-1) and endogenous NOS inhibitor-asymmetric dimethylarginine (ADMA), as the endothelium dysfunction markers in pregnant women with gestational hypertension (GH).

Patients and Methods

Adiponectin, leptin, sICAM-1, and ADMA concentrations were measured in a group of 34 patients with GH and in 32 healthy pregnant women between the 24^th and 34^th week of gestation with ELISA tests.

Results

The patients with GH compared with healthy ones were characterized by significantly higher BMI (28.09 ± 7.90 vs. 22.34 ± 4.21 kg/m², p=0.016) and higher concentrations of leptin (45.89 ± 35.91 vs. 24.09 ± 24.40 ng/mL, p=0.006). sICAM-1 levels were also higher in the GH group but without the statistical significance (264.51 ± 50.99 vs. 232.56 ± 43.3 ng/ml, p=0.057). There were no significant differences between groups in adiponectin (8.79 ± 8.67 vs. 7.90 ± 3.71 μg/mL, p=0.46, NS) and ADMA (0.57 ± 0.26 vs. 0.60 ± 0.24 μmol/L, p=0.68, NS) levels. The significant correlation between leptin levels and BMI value was observed only in patients with GH (R = 0.56, p=0.02).

Conclusions

The higher levels of leptin in pregnant women with gestational hypertension may be suggestive of the role of leptin in GH development. As the patients in the GH group had higher BMI, hyperleptinemia may link obesity with gestational hypertension. The significance of leptin as the predictive marker of GH development could be implied. It could be postulated that the higher levels of sICAM-1 in the GH patients, although not statistically significant, could reflect some impairment of the endothelium function occurring in GH regardless of BMI. The comparable adiponectin levels in GH and healthy pregnant patients and the lack of its correlation with BMI may indicate the occurrence of a protective mechanism in pregnancy maintaining its concentration and preserving from the consequences of the decrease in its levels in overweight and obese patients. Since ADMA levels were similar in GH and healthy pregnant women, ADMA seems not to be involved in GH pathogenesis, suggesting that NO synthesis is not impaired in this pregnancy complication. As the data on the gestational hypertension pathogenesis and its correlations with adipokines and markers of the endothelium dysfunction are limited, further studies on this issue are warranted.

Mechanisms of Adiponectin Action in Fertility: An Overview from Gametogenesis to Gestation in Humans and Animal Models in Normal and Pathological Conditions

Adiponectin is the most abundant plasma adipokine. It mainly derives from white adipose tissue and plays a key role in the control of energy metabolism thanks to its insulin-sensitising, anti-inflammatory, and antiatherogenic properties. In vitro and in vivo evidence shows that adiponectin could also be one of the hormones controlling the interaction between energy balance and fertility in several species, including humans. Indeed, its two receptors—AdipoR1 and AdipoR2—are expressed in hypothalamic–pituitary–gonadal axis and their activation regulates Kiss, GnRH and gonadotropin expression and/or secretion. In male gonads, adiponectin modulates several functions of both somatic and germ cells, such as steroidogenesis, proliferation, apoptosis, and oxidative stress. In females, it controls steroidogenesis of ovarian granulosa and theca cells, oocyte maturation, and embryo development. Adiponectin receptors were also found in placental and endometrial cells, suggesting that this adipokine might play a crucial role in embryo implantation, trophoblast invasion and foetal growth. The aim of this review is to characterise adiponectin expression and its mechanism of action in male and female reproductive tract. Further, since features of metabolic syndrome are associated with some reproductive diseases, such as polycystic ovary syndrome, gestational diabetes mellitus, preeclampsia, endometriosis, foetal growth restriction and ovarian and endometrial cancers, evidence regarding the emerging role of adiponectin in these disorders is also discussed.

Adipokine profiles in preeclampsia

Objectives: Hypertensive disorders of pregnancy (HDP), including preeclampsia (PE), are associated with short- and long-term maternal health complications, and obesity is a leading attributable risk factor for HDP. Yet, most women identified as obese [by body mass index (BMI) ≥ 30 kg/m²] do not develop HDP, indicating limited predictability of BMI alone. In nonpregnant populations, increased visceral fat mass (VFM) is an obesity-associated phenotype increasing the risk of developing hypertension. We sought to assess whether, in pregnancy, obese women with PE would have higher circulating levels of adipokines preferential to VFM compared to obese women without PE.Study Design: We performed a case-control study of women with and without PE, including obese (n = 65; BMI ≥ 30 kg/m²) and normal weight (n = 52; BMI 18.4-24.9 kg/m²) women. Plasma concentrations of adipokines preferential to VFM (visfatin, resistin), adipokines reflecting overall adiposity (leptin, adiponectin), and inflammatory cytokines were compared.Results: We found that among obese women, cases had significantly higher levels of VFM-associated adipokines and cytokines compared to controls [visfatin (p < .01, t = -3.8), resistin (p = .002, t = 1.12), IFN gamma (p = .04, t = -2.0), IL-6 (p < .01, t = -2.65), IL1-beta (p < .01, t = -4.1), IL-2 (p < .01, t = -3.9)]. Interestingly, however, obese and normal weight cases had similar VFM-adipokine and cytokine levels [visfatin (p = .34, t = -0.35), resistin (p = .55, t = -0.25)], and inflammatory marker concentrations [IFN gamma (p = .86, t = -0.76), IL-6 (p = .91, t = -0.53), IL-1beta (p = .67, t = 1.18), and IL-2 (p = .45, t = -1.16)]. These data possibly suggest an association between VFM and PE that is present independent of BMI.Conclusion: In summary, we demonstrated that, in normal-weight and obese women, PE was associated with higher concentrations of VFM-preferential adipokines compared to normal-weight and obese controls without PE.

Longitudinal association of 25-hydroxyvitamin D with adipokines and markers of glucose metabolism among Brazilian pregnant women

This study aimed to evaluate the longitudinal association of vitamin D status with glycaemia, insulin, homoeostatic model assessment of insulin resistance, adiponectin and leptin. A prospective cohort with 181 healthy, pregnant Brazilian women was followed at the 5th–13th, 20th–26th and 30th–36th gestational weeks. In this cohort, 25-hydroxyvitamin D (25(OH)D) plasma concentrations were analysed using liquid chromatography–tandem MS. Vitamin D status was categorised as sufficient or insufficient using the Endocrine Society Practice Guidelines (≥75/<75 nmol/l) and the Institute of Medicine (≥50/<50 nmol/l) thresholds. Linear mixed-effect regression models were employed to evaluate the association between vitamin D status and each outcome, considering interaction terms between vitamin D status and gestational age (P<0·1). At baseline, 70·7 % of pregnant women had 25(OH)D levels <75 nmol/l and 16 % had levels <50 nmol/l. Women with sufficient vitamin D status at baseline, using both thresholds, presented lower glycaemia than those with insufficient 25(OH)D. Pregnant women with 25(OH)D concentrations <75 nmol/l showed lower insulin (β=−0·12; 95 % CI −0·251, 0·009;P=0·069) and adiponectin (β=−0·070; 95 % CI −0·150, 0·010;P=0·085) concentrations throughout pregnancy than those with 25(OH)D levels ≥75 nmol/l. Pregnant women with 25(OH)D <50 nmol/l at baseline presented significantly higher leptin concentrations than those with 25(OH)D levels ≥50 nmol/l (β=−0·253; 95 % CI −0·044, 0·550;P=0·095). The baseline status of vitamin D influences the biomarkers involved in glucose metabolism. Vitamin D-sufficient women at baseline had higher increases in insulin and adiponectin changes throughout gestation than those who were insufficient.

Leptin and Adiponectin as markers for preeclampsia in obese pregnant women, a cohort study

OBJECTIVE

Preeclampsia (PE) is a serious complication of pregnancy, the pathogenesis of which is largely unknown. We hypothesize that adipocytokines may play a role in the pathogenesis of PE, particularly in obese women, and evaluate leptin and adiponectin as potential first trimester markers for predicting PE.

STUDY DESIGN

A cohort of 2503 pregnancies, containing 93 PE pregnancies, was divided into women with normal weight, moderate, or severe obesity. All pregnancies had serum adiponectin and leptin measured in first trimester. Logistic regression was used to model PE with maternal characteristics and concentrations of the biomarkers.

RESULTS

In obese women a lower concentration of adiponectin was found in PE pregnancies; the concentration was lowest in the severely obese (p = 0.005). No association was found in normal weight women (p = 0.72). Leptin concentration had no association with PE in normal weight and moderately obese (p = 0.175-0.072), however in women with severe obesity a lower level of leptin was found (p = 0.049). The AUC was 0.73 for the ROC curve of combined maternal characteristics and adiponectin. Using adiponectin in women with moderate to severe obesity the sensitivity was 72.9% and the specificity was 49%.

CONCLUSIONS

In severely obese women, PE is associated with low serum adiponectin and leptin concentrations in first trimester. This indicates that the inability of adipokine regulation to adapt to severe obesity may play a role in the pathogenesis of PE. Adipocytokines may contribute in identification of risk pregnancies among severe obese.

Towards frailty biomarkers: Candidates from genes and pathways regulated in aging and age-related diseases

OBJECTIVE

Use of the frailty index to measure an accumulation of deficits has been proven a valuable method for identifying elderly people at risk for increased vulnerability, disease, injury, and mortality. However, complementary molecular frailty biomarkers or ideally biomarker panels have not yet been identified. We conducted a systematic search to identify biomarker candidates for a frailty biomarker panel.

METHODS

Gene expression databases were searched (http://genomics.senescence.info/genes including GenAge, AnAge, LongevityMap, CellAge, DrugAge, Digital Aging Atlas) to identify genes regulated in aging, longevity, and age-related diseases with a focus on secreted factors or molecules detectable in body fluids as potential frailty biomarkers. Factors broadly expressed, related to several "hallmark of aging" pathways as well as used or predicted as biomarkers in other disease settings, particularly age-related pathologies, were identified. This set of biomarkers was further expanded according to the expertise and experience of the authors. In the next step, biomarkers were assigned to six "hallmark of aging" pathways, namely (1) inflammation, (2) mitochondria and apoptosis, (3) calcium homeostasis, (4) fibrosis, (5) NMJ (neuromuscular junction) and neurons, (6) cytoskeleton and hormones, or (7) other principles and an extensive literature search was performed for each candidate to explore their potential and priority as frailty biomarkers.

RESULTS

A total of 44 markers were evaluated in the seven categories listed above, and 19 were awarded a high priority score, 22 identified as medium priority and three were low priority. In each category high and medium priority markers were identified.

CONCLUSION

Biomarker panels for frailty would be of high value and better than single markers. Based on our search we would propose a core panel of frailty biomarkers consisting of (1) CXCL10 (C-X-C motif chemokine ligand 10), IL-6 (interleukin 6), CX3CL1 (C-X3-C motif chemokine ligand 1), (2) GDF15 (growth differentiation factor 15), FNDC5 (fibronectin type III domain containing 5), vimentin (VIM), (3) regucalcin (RGN/SMP30), calreticulin, (4) PLAU (plasminogen activator, urokinase), AGT (angiotensinogen), (5) BDNF (brain derived neurotrophic factor), progranulin (PGRN), (6) α-klotho (KL), FGF23 (fibroblast growth factor 23), FGF21, leptin (LEP), (7) miRNA (micro Ribonucleic acid) panel (to be further defined), AHCY (adenosylhomocysteinase) and KRT18 (keratin 18). An expanded panel would also include (1) pentraxin (PTX3), sVCAM/ICAM (soluble vascular cell adhesion molecule 1/Intercellular adhesion molecule 1), defensin α, (2) APP (amyloid beta precursor protein), LDH (lactate dehydrogenase), (3) S100B (S100 calcium binding protein B), (4) TGFβ (transforming growth factor beta), PAI-1 (plasminogen activator inhibitor 1), TGM2 (transglutaminase 2), (5) sRAGE (soluble receptor for advanced glycosylation end products), HMGB1 (high mobility group box 1), C3/C1Q (complement factor 3/1Q), ST2 (Interleukin 1 receptor like 1), agrin (AGRN), (6) IGF-1 (insulin-like growth factor 1), resistin (RETN), adiponectin (ADIPOQ), ghrelin (GHRL), growth hormone (GH), (7) microparticle panel (to be further defined), GpnmB (glycoprotein nonmetastatic melanoma protein B) and lactoferrin (LTF). We believe that these predicted panels need to be experimentally explored in animal models and frail cohorts in order to ascertain their diagnostic, prognostic and therapeutic potential.

Adipose tissue and reproductive health

The understanding of adipose tissue role has evolved from that of a depot energy storage organ to a dynamic endocrine organ. While genetics, sexual phenotype and sex steroids can impact the mass and distribution of adipose tissue, there is a counter-influence of white adipocytes on reproduction. This primarily occurs via the secretion of adipokines, the most studied of which- leptin and adiponectin- are highlighted in this article. Leptin, the "satiety hormone" primarily acts on the hypothalamus via pro-opiomelanocortin (POMC), neuropeptide Y (NPY), and agouti-related peptide (AgRP) neurons to translate acute changes in nutrition and energy expenditure, as well as chronic adipose accumulation into changes in appetite and potentially mediate insulin resistance via shared pathway and notably impacting reproductive health via influence on GnRH secreting neurons. Meanwhile, adiponectin is notable for its action in mediating insulin sensitivity, with receptors found at every level of the reproductive axis. Both have been examined in the context of physiologic and pathologic reproductive conditions. Leptin has been shown to influence puberty, pregnancy, hypothalamic amenorrhea, and lipodystrophy, and with a potential therapeutic role for both metabolic and reproductive health. Adiponectin mediates the relative state of insulin resistance in pregnancy, and has been implicated in conditions such as polycystic ovary syndrome and reproductive malignancies. There are numerous other adipokines, including resistin, visfatin, chemerin and retinol binding protein-4, which may also play roles in reproductive health and disease states. The continued examination of these and other adipokines in both normal reproduction and reproductive pathologies represents an important avenue for continued study. Here, we seek to provide a broad, yet comprehensive overview of many facets of these relationships and highlight areas of consideration for clinicians and future study.

Integrated Systems Biology Approach Identifies Novel Maternal and Placental Pathways of Preeclampsia

Preeclampsia is a disease of the mother, fetus, and placenta, and the gaps in our understanding of the complex interactions among their respective disease pathways preclude successful treatment and prevention. The placenta has a key role in the pathogenesis of the terminal pathway characterized by exaggerated maternal systemic inflammation, generalized endothelial damage, hypertension, and proteinuria. This sine qua non of preeclampsia may be triggered by distinct underlying mechanisms that occur at early stages of pregnancy and induce different phenotypes. To gain insights into these molecular pathways, we employed a systems biology approach and integrated different "omics," clinical, placental, and functional data from patients with distinct phenotypes of preeclampsia. First trimester maternal blood proteomics uncovered an altered abundance of proteins of the renin-angiotensin and immune systems, complement, and coagulation cascades in patients with term or preterm preeclampsia. Moreover, first trimester maternal blood from preterm preeclamptic patients in vitro dysregulated trophoblastic gene expression. Placental transcriptomics of women with preterm preeclampsia identified distinct gene modules associated with maternal or fetal disease. Placental "virtual" liquid biopsy showed that the dysregulation of these disease gene modules originates during the first trimester. In vitro experiments on hub transcription factors of these gene modules demonstrated that DNA hypermethylation in the regulatory region of ZNF554 leads to gene down-regulation and impaired trophoblast invasion, while BCL6 and ARNT2 up-regulation sensitizes the trophoblast to ischemia, hallmarks of preterm preeclampsia. In summary, our data suggest that there are distinct maternal and placental disease pathways, and their interaction influences the clinical presentation of preeclampsia. The activation of maternal disease pathways can be detected in all phenotypes of preeclampsia earlier and upstream of placental dysfunction, not only downstream as described before, and distinct placental disease pathways are superimposed on these maternal pathways. This is a paradigm shift, which, in agreement with epidemiological studies, warrants for the central pathologic role of preexisting maternal diseases or perturbed maternal-fetal-placental immune interactions in preeclampsia. The description of these novel pathways in the "molecular phase" of preeclampsia and the identification of their hub molecules may enable timely molecular characterization of patients with distinct preeclampsia phenotypes.

Leptin action in normal and pathological pregnancies

Leptin is now considered an important signalling molecule of the reproductive system, as it regulates the production of gonadotrophins, the blastocyst formation and implantation, the normal placentation, as well as the foeto-placental communication. Leptin is a peptide hormone secreted mainly by adipose tissue, and the placenta is the second leptin-producing tissue in humans. Placental leptin is an important cytokine which regulates placental functions in an autocrine or paracrine manner. Leptin seems to play a crucial role during the first stages of pregnancy as it modulates critical processes such as proliferation, protein synthesis, invasion and apoptosis in placental cells. Furthermore, deregulation of leptin levels has been correlated with the pathogenesis of various disorders associated with reproduction and gestation, including polycystic ovary syndrome, recurrent miscarriage, gestational diabetes mellitus, pre-eclampsia and intrauterine growth restriction. Due to the relevant incidence of the mentioned diseases and the importance of leptin, we decided to review the latest information available about leptin action in normal and pathological pregnancies to support the idea of leptin as an important factor and/or predictor of diverse disorders associated with reproduction and pregnancy.

Performance of first trimester biochemical markers and mean arterial pressure in prediction of early-onset pre-eclampsia

OBJECTIVE

To develop a predictive risk model for early-onset pre-eclampsia (EO-PE) using maternal characteristics, combined screening markers, previously reported biomarkers for PE and mean arterial pressure (MAP).

METHODS

This retrospective study was conducted at Oulu University hospital between 2006 and 2010. Maternal serum from first trimester combined screening was further analyzed for alpha fetoprotein (AFP), placental growth factor (PlGF), soluble tumor necrosis factor receptor-1 (sTNFR1), retinol binding protein-4 (RBP4), a disintegrin and metalloprotease-12 (ADAM12), soluble P-selectin (sP-selectin), follistatin like-3 (FSTL3), adiponectin, angiopoietin-2 (Ang-2) and sex hormone binding globulin (SHBG). First, the training sample set with 29 cases of EO-PE and 652 controls was developed to study whether these biomarkers separately or in combination with prior risk (maternal characteristics, first trimester pregnancy associated plasma protein-A (PAPP-A) and free beta human chorionic gonadotrophin (fβ-hCG)) could be used to predict the development of EO-PE. Second, the developed risk models were validated with a test sample set of 42 EO-PE and 141 control subjects. For the test set MAP data was also available.

RESULTS

Single marker statistically significant (ANOVA p<0.05) changes between control and EO-PE pregnancies were observed with AFP, RBP4 and sTNFR1 with both training and test sample sets. Based on the test sample set performances, the best detection rate, 47% for a 10% false positive rate, was achieved with PlGF and sTNFR1 added with prior risk and MAP.

CONCLUSION

Based on our results, the best first trimester biomarkers to predict the subsequent EO-PE were AFP, PlGF, RBP4 and sTNFR1. The risk models that performed best for the prediction of EO-PE included prior risk, MAP, sTNFR1 and AFP or PlGF or RBP4.

Metabolic markers during pregnancy and their association with maternal and newborn weight status

Background/Aims

Obesity during pregnancy increases the risk of adverse clinical outcomes and is associated with low-grade chronic inflammation. We describe maternal metabolic risk and inflammation by maternal weight status, and evaluate the association of metabolic and inflammatory markers with birthweight in a group of pregnant Mexican women.

Methods

This study derived from a prospective cohort of healthy pregnant women <14 weeks of gestation, receiving prenatal care at National Institute of Perinatology (Mexico, 2009–2013). Metabolic and inflammatory markers were measured in maternal serum in all three pregnancy trimesters (1st: 11.42±1.7; 2nd: 21.06±2.4; 3rd: 32.74±2.3 weeks). Pregestational weight was self-reported, and body mass index (BMI) was calculated. Gestational weight gain was evaluated in the third trimester. Newborn´s weight was measured at birth. We carried out correlations, general mixed linear model and regression analyses, based on pregestational weight (self-reported), body mass index (BMI), gestational weight gain (evaluated in the third trimester) and newborn weight (measured at birth).

Results

Of the 177 women included in the study (mean age = 26.93±8.49), thirty-eight percent (n = 67) were overweight or had obesity, and 32.8% (n = 58) showed excessive gestational weight gain. We found insulin, lipids (including total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides-TG), leptin and interleukin 1b (IL-1b) all increased significantly (p<0.05) during pregnancy. Pregestational maternal weight status altered longitudinal concentrations of insulin, leptin, adiponectin, TG and C reactive protein. Excessive gestational weight gain was associated with higher maternal insulin in the third trimester (p<0.05). Early pregnancy leptin and TNFα were determinants of birthweight in women with normal weight, but not in overweight or obese women.

Conclusions

Maternal weight status affected the concentrations of insulin, leptin, adiponectin, triglycerides and C reactive protein throughout pregnancy. The role of early leptin and TNFα in fetal growth need further study given the association was only observed in normal weight women. This study presents data distribution of metabolic and inflammatory markers of normal weight and overweight/obese women that did not develop GDM, preeclampsia nor macrosomia.

Low-Grade Metabolically-Induced Inflammation Mediators Interleukin-6, Adiponectin, and TNF-α Serum Levels in Obese Pregnant Patients in the Perinatal Period

Background

Obesity is a major clinical problem. The number of obese pregnant women is rising rapidly. The consequences of obesity are significant and affect every aspect of perinatal care for both the mother and the developing fetus. Adipose tissue may be responsible for chronic subclinical inflammation in obesity, being a source of inflammatory mediators. The study was designed to evaluate the analysis of the serum concentration of inflammatory mediators, including interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and adiponectin, in obese pregnant women at full-term pregnancies.

Material/Methods

The study included 40 women with body mass index (BMI) less than 30 and 24 pregnant women with BMI equal to or greater than 30, admitted to the Perinatology and Obstetrics Department of the University Hospital in Cracow in the first stage of labor. Blood samples were taken from patients to detect the serum concentration of cytokines. Ultrasound was used to evaluate the development of the fetus, including estimated fetal weight, Doppler flows, and the amount of amniotic fluid. We also included the history of chronic diseases and other complications of the pregnancy. A p-value <0.05 was considered significant.

Results

The level of adiponectin in obese patients as compared to controls was significantly lower. There was no statistically significant difference in either group when TNF-α and IL-6 were measured. The results of the survey are consistent with previous reports.

Conclusions

The exact role of inflammation in pregnancy is not well understood. Determining the exact functions of the different cytokines in physiological pregnancy and pregnancy complicated by obesity requires further study.

Serum inhibin and leptin: Risk factors for pre-eclampsia?

BACKGROUND

Pre-eclampsia and eclampsia are parts of the broader spectrum of hypertensive disorders complicating pregnancy. This study aims to examine the association between serum inhibin and leptin levels and pre-eclampsia.

METHODS

This study included 98 consecutive cases of pregnant women with pre-eclampsia, together with their 98 pregnant controls, matched for age, gestational week and time period of delivery. Maternal venous blood samples were obtained within 24h before delivery. In addition to serum inhibin and leptin, birth order, multiple pregnancy, maternal age, maternal overweight/obesity, maternal education, maternal smoking and family history of diabetes/hypertension, were examined as risk factors. Multivariate logistic regression analysis was performed.

RESULTS

At the univariate analysis, serum inhibin and leptin levels were significantly higher in cases vs.

CONTROLS

Pre-eclampsia occurred more frequently in primiparous women, whereas overweight and obesity were also associated with pre-eclampsia. At the multivariate analysis, higher serum inhibin levels were associated with pre-eclampsia (multivariate OR=1.09, 95%CI: 1.03-1.17, p=0.004, increase per 0.1ng/mL). On the other hand, leptin was not independently associated with the occurrence of pre-eclampsia (multivariate OR=1.02, 95%CI: 0.95-1.09, p=0.631, increase per 10ng/mL).

CONCLUSIONS

Elevated serum inhibin levels seem to be associated with pre-eclampsia, reflecting placental dysfunction. Increased serum leptin levels may merely reflect an elevated maternal body mass index, which is a well-known risk factor for pre-eclampsia.