Midtrimester amniotic fluid leptin and insulin levels and subsequent gestational diabetes

Is There a Correlation between Apelin and Insulin Concentrations in Early Second Trimester Amniotic Fluid with Fetal Growth Disorders?

INTRODUCTION

Fetal growth disturbances place fetuses at increased risk for perinatal morbidity and mortality. As yet, little is known about the basic pathogenetic mechanisms underlying deranged fetal growth. Apelin is an adipokine with several biological activities. Over the past decade, it has been investigated for its possible role in fetal growth restriction. Most studies have examined apelin concentrations in maternal serum and amniotic fluid in the third trimester or during neonatal life. In this study, apelin concentrations were examined for the first time in early second-trimester fetuses. Another major regulator of tissue growth and metabolism is insulin.

MATERIALS AND METHODS

This was a prospective observational cohort study. We measured apelin and insulin concentrations in the amniotic fluid of 80 pregnant women who underwent amniocentesis in the early second trimester. Amniotic fluid samples were stored in appropriate conditions until delivery. The study groups were then defined, i.e., gestations with different fetal growth patterns (SGA, AGA, and LGA). Measurements were made using ELISA kits.

RESULTS

Apelin and insulin levels were measured in all 80 samples. The analysis revealed statistically significant differences in apelin concentrations among groups (p = 0.007). Apelin concentrations in large for gestational age (LGA) fetuses were significantly lower compared to those in AGA and SGA fetuses. Insulin concentrations did not differ significantly among groups.

CONCLUSIONS

A clear trend towards decreasing apelin concentrations as birthweight progressively increased was identified. Amniotic fluid apelin concentrations in the early second trimester may be useful as a predictive factor for determining the risk of a fetus being born LGA. Future studies are expected/needed to corroborate the present findings and should ideally focus on the potential interplay of apelin with other known intrauterine metabolic factors.

Evaluation of H19, Mest, Meg3, and Peg3 genes affecting growth and metabolism in umbilical cord blood cells of infants born to mothers with gestational diabetes and healthy mothers in Rafsanjan City, Iran

Hyperglycemia during the first trimester leads to an increased risk of innate malformations as well as death at times close to delivery dates. The methylated genes include those from paternal H19 and PEG3 and those from maternal MEST and MEG3 that are necessary for the growth and regulation of the human fetus and its placenta. The aim of this study was to evaluate and compare the expression of these genes in the cord blood of healthy infants born to mothers with gestational diabetes mellitus (GDM) and healthy mothers.This case-control study was conducted on the cord blood of 40 infants born to mothers with GDM and 35 infants born to healthy mothers. Mothers were identified by measuring oral glucose tolerance in the 24th-26th week of pregnancy. Cord blood was obtained post-delivery, and cord blood mononuclear cells were immediately extracted, using Ficoll solution. Then, RNA extraction and cDNA synthesis were performed, and gene expression of MEG3, PEG3, H19, and MEST was assessed through quantitative real-time PCR.Findings show that the expression levels of MEG3, PEG3, H19, and MEST genes were significantly decreased in mononuclear cord blood cells of infants born to mothers with GDM when compared to those of the healthy control group.These findings reveal that the reduction of imprinted genes in mothers with GDM is most likely due to changes in their methylation by an epigenetic process. Considering the importance of GDM due to its high prevalence and its side effects both for mother and fetus, recognizing their exact mechanisms is of high importance. This has to be studied more widely.

Down-Regulated miR-21 in Gestational Diabetes Mellitus Placenta Induces PPAR-α to Inhibit Cell Proliferation and Infiltration

PURPOSE

This study aimed to investigate the role of miR-21 expression in the reduction of placental function in GDM patients.

MATERIALS AND METHODS

qRT-PCR was used to detect the differential expression of miR-21 in the serum of gestational diabetes mellitus (GDM) and normal pregnant women, and to verify the functional target gene PPAR-α of miR-21 by double fluorescence experiments. Cellular experiments were performed to verify the effect of PPAR-α on cell function.

RESULTS

miR-21 is down-regulated in the serum and placenta of GDM patients compared to normal pregnant women. In the case of insulin resistance, miR-21-5p knockdown promoted glucose uptake, but no significant effect was found under physiological condition. Functional studies have shown that reduced PPAR-α expression can restore miR-21 knockdown-mediated cell growth and metastasis inhibition. Additionally, decreased expression of miR-21 but increased expression of -PPAR-α was observed in patients with GDM and GDM rats.

CONCLUSION

The expression of the placental miR-21-5p, which inhibits cell growth and infiltration by up-regulating PPAR-α, is downregulated in pregnant GDM patients, which in turn may affect the placental function.

Leptin, resistin and visfatin as useful predictors of gestational diabetes mellitus

Background

Lipids and adipokines including leptin, resistin and visfatin play various roles in the pathophysiology of Gestational Diabetes Mellitus (GDM). This study was aimed at determining whether serum leptin, resistin and visfatin are significantly altered during the first trimester of pregnancies that subsequently develop GDM and whether such changes are useful in predicting the disease.

Methods

This was a case-case control study which compared first trimester biochemical and anthropometric parameters in 70 pregnant women who subsequently developed GDM and 70 pregnant women without GDM at the Volta Regional Hospital, Ho, Ghana. Lipid profile and some selected adipokines were analyzed and first trimester body mass index (BMI) was determined.

Results

There were significant differences (p < 0.05) in leptin, resistin, and visfatin as well as significant dyslipidemia among those with GDM compared to those without GDM. Furthermore, the area under the Receiver Operating Characteristic Curves (AUCs) for leptin, resistin and visfatin were; 0.812, 0.836 and 0.799 respectively. Increased first trimester leptin (OR = 1.166; CI = 1.104–1.233; p < 0.0001), resistin (p < 0.0001) and visfatin (p < 0.0001) were associated with GDM.

Conclusion

Hyperleptinemia, hyperesistinemia and hypervisfatinemia precede GDM and can serve as good predictive indices for gestational diabetes mellitus.

The role of adipokines in the pathogenesis of gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a complex condition whose physiopathology to date has not been completely clarified. Two major metabolic disorders, insulin resistance and β-cells dysfunction, play currently major role in pathogenesis of GDM. These elements are influenced by the amount of adipose tissue present before and/or during the pregnancy. Consequently, adipokines (adiponectin (APN), leptin (LPT), adipocyte fatty acid-binding protein, resistin, visfatin, omentin, vaspin, apelin, chemerin) secreted by adipose tissue, may contribute directly and/or indirectly, through the enhancement of chronic inflammation, aggravating insulin resistance and promoting GDM onset. This review aims to outline the potential physiopathological and prognostic role in GDM of adipokines, mainly APN and LPT.

Role of insulin, adenosine, and adipokine receptors in the foetoplacental vascular dysfunction in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a disease of pregnancy associated with maternal and foetal hyperglycaemia and altered foetoplacental vascular function. Human foetoplacental microvascular and macrovascular endothelium from GDM pregnancy show increased maximal l-arginine transport capacity via the human cationic amino acid transporter 1 (hCAT-1) isoform and nitric oxide (NO) synthesis by the endothelial NO synthase (eNOS). These alterations are paralleled by lower maximal transport activity of the endogenous nucleoside adenosine via the human equilibrative nucleoside transporter 1 (hENT1) and activation of adenosine receptors. A causal relationship has been described for adenosine-activation of A_2A adenosine receptors, hCAT-1, and eNOS activity (i.e. the Adenosine/l-Arginine/Nitric Oxide, ALANO, signalling pathway). Insulin restores these alterations in GDM via activation of insulin receptor A (IR-A) form in the macrovascular but IR-A and IR-B forms in the microcirculation of the human placenta. Adipokines are secreted from adipocytes influencing the foetoplacental metabolic and vascular function. Various adipokines are dysregulated in GDM, with adiponectin and leptin playing major roles. Abnormal plasma concentration of these adipokines and the activation or their receptors are involved in the pathophysiology of GDM. However, involvement of adipokines, adenosine, and insulin receptors and membrane transporters in the aetiology of this disease of pregnancy is unknown. This review focuses on the pathophysiology of insulin and adenosine receptors and l-arginine and adenosine membranes transporters giving an overview of the key adipokines leptin and adiponectin in the foetoplacental vasculature in GDM. This article is part of a Special Issue entitled: Membrane Transporters and Receptors in Pregnancy Metabolic Complications edited by Luis Sobrevia.

[Promising markers for the risk and prognosis of gestational diabetes mellitus]

The review provides information on the molecular genetic mechanisms for the development gestational diabetes mellitus (GDM). It gives data on the genetic identity of GDM and type 2 diabetes mellitus and considers a role of some adipokines and incretin hormones in the development of GDM. There is evidence for the role of magnesium and vitamin D deficiencies in the pathogenesis of gestational carbohydrate metabolic disturbances.

Adipokine levels during the first or early second trimester of pregnancy and subsequent risk of gestational diabetes mellitus: A systematic review

OBJECTIVE

We aimed to systematically review available literature linking adipokines to gestational diabetes mellitus (GDM) for a comprehensive understanding of the roles of adipokines in the development of GDM.

METHODS

We searched PubMed/MEDLINE and EMBASE databases for published studies on adipokines and GDM through October 21, 2014. We included articles if they had a prospective study design (i.e., blood samples for adipokines measurement were collected before GDM diagnosis). Random-effects models were used to pool the weighted mean differences comparing levels of adipokines between GDM cases and non-GDM controls.

RESULTS

Of 1523 potentially relevant articles, we included 25 prospective studies relating adipokines to incident GDM. Our meta-analysis of nine prospective studies on adiponectin and eight prospective studies on leptin indicated that adiponectin levels in the first or early second trimester of pregnancy were 2.25 μg/ml lower (95% CI: 1.75-2.75), whereas leptin levels were 7.25 ng/ml higher (95% CI 3.27-11.22), among women who later developed GDM than women who did not. Prospective data were sparse and findings were inconsistent for visfatin, retinol binding protein (RBP-4), resistin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and vaspin. We did not identify prospective studies for several novel adipokines, including chemerin, apelin, omentin, or adipocyte fatty acid-binding protein. Moreover, no published prospective studies with longitudinal assessment of adipokines and incident GDM were identified.

CONCLUSION

Adiponectin levels in the first or second trimester of pregnancy are lower among pregnant women who later develop GDM than non-GDM women, whereas leptin levels are higher. Well-designed prospective studies with longitudinal assessment of adipokines during pregnancy are needed to understand the trajectories and dynamic associations of adipokines with GDM risk.

Second trimester maternal plasma and amniotic fluid adipokines in women who will develop gestational diabetes mellitus

OBJECTIVE

To study the adipokines concentration and glucose homoeostasis in the early-second trimester of women who will develop gestational diabetes mellitus (GDM).

MATERIALS AND METHODS

Maternal plasma and fetal amniotic fluid samples were prospectively collected between 2006 and 2007 at the time of mid-trimester amniocentesis. Eight patients found to be affected by GDM were compared with 10 control patients with a normal pregnancy course. Adipokines leptin and adiponectin, as well as insulin and glucose concentration both in amniotic fluid and maternal plasma were compared between cases and controls. HOMA-IR (homeostatic model assessment for insulin resistance) was also calculated both for amniotic fluid and maternal serum.

RESULTS

The amniotic fluid adiponectin concentration was higher in women who would develop GDM than in controls (29.9 ng/ml, 95% CI 26.7-49.8 ng/ml, versus 14.9 ng/ml, 95% CI 13.5-18.8 ng/ml), p < 0.05). No difference was shown for leptin both in amniotic fluid and maternal serum. Insulin concentrations in the amniotic fluid were found to be lower in GDM than in controls, while HOMA-IR-index resulted lower in amniotic fluid and higher maternal serum (p < 0.05).

CONCLUSIONS

Our data suggests that an earlier alteration in the fetal glucose metabolism will precede the glucose dysmetabolism in pregnancies later complicated by GDM.

Potential mechanisms of exercise in gestational diabetes

Gestational diabetes mellitus (GDM) is defined as glucose intolerance first diagnosed during pregnancy. This condition shares same array of underlying abnormalities as occurs in diabetes outside of pregnancy, for example, genetic and environmental causes. However, the role of a sedentary lifestyle and/or excess energy intake is more prominent in GDM. Physically active women are less likely to develop GDM and other pregnancy-related diseases. Weight gain in pregnancy causes increased release of adipokines from adipose tissue; many adipokines increase oxidative stress and insulin resistance. Increased intramyocellular lipids also increase cellular oxidative stress with subsequent generation of reactive oxygen species. A well-planned program of exercise is an important component of a healthy lifestyle and, in spite of old myths, is also recommended during pregnancy. This paper briefly reviews the role of adipokines in gestational diabetes and attempts to shed some light on the mechanisms by which exercise can be beneficial as an adjuvant therapy in GDM. In this regard, we discuss the mechanisms by which exercise increases insulin sensitivity, changes adipokine profile levels, and boosts antioxidant mechanisms.

Leptin, adiponectin and other adipokines in gestational diabetes mellitus and pre-eclampsia

Proteins secreted from adipocytes - so-called adipokines - influence metabolic and vascular function. Recent data suggest that various adipokines are dysregulated in gestational diabetes mellitus (GDM) and pre-eclampsia (PE) and might be of pathophysiological and prognostic significance in these complications of pregnancy. This review gives an overview on the regulation and pathophysiology of leptin and adiponectin in GDM and PE. Furthermore, data on novel adipokines including resistin, visfatin, retinol-binding protein 4 and vaspin are summarized.

Fetal exposure to altered amniotic fluid glucose, insulin, and insulin-like growth factor-binding protein 1 occurs before screening for gestational diabetes mellitus

OBJECTIVE

We explored the possibility that perturbations in amniotic fluid glucose, insulin, and insulin-like growth factor-binding protein 1(IGFBP1) and/or metabolic acids exist before routine screening for GDM.

RESEARCH DESIGN AND METHODS

We selected consenting mother-infant pairs (n = 408) who met our inclusion criteria (singleton pregnancy, no genetic abnormalities, and no preexisting diabetes) and for whom sufficient amniotic fluid and appropriate medical information were available. We compared birth outcomes and second trimester amniotic fluid glucose, insulin, IGFBP1 concentrations, and amniotic fluid lactic, β-hydroxybutyric, and uric acids of mothers with gestational diabetes mellitus (GDM) (n = 52) with those of mothers with no diagnosis of GDM at >24 weeks (n = 356).

RESULTS

Higher amniotic fluid glucose, lactic acid, uric acid, and insulin and lower IGFBP1 concentrations were present by 15.1 ± 0.1 weeks in mothers in whom GDM was subsequently diagnosed. However, logistic regression showed that second trimester amniotic fluid glucose, but not insulin, IGFBP1, or metabolic acids was associated with an increased odds ratio (1.2 [95% CI 1.052-1.338]) for diagnosis of GDM at 24-28 weeks. In addition, probability contour maps that accounted for nonlinear relationships among the dynamically changing amniotic fluid constituents showed an increased risk for GDM with elevated second trimester amniotic fluid glucose in combination with either elevated amniotic fluid insulin or low amniotic fluid IGFBP1

CONCLUSIONS

Fetuses are exposed to increased amniotic fluid glucose before 15 weeks of gestation, suggesting that metabolic perturbations are underway before diagnosis and that earlier screening and intervention may be warranted.

Change in amniotic fluid levels of multiple anti-angiogenic proteins before development of preeclampsia and intrauterine growth restriction

CONTEXT

The cause of preeclampsia remains unknown. Excessive antiangiogenic proteins have been proposed to play a pathogenic role in preeclampsia.

OBJECTIVE

Our objective was to determine the differences in soluble endoglin (sEndoglin), soluble fms-like tyrosine kinase receptor-1 (sFLT1), leptin, adiponectin, and endothelin 1 concentrations between normal and preeclampsia amniotic fluid (AF). Such results may help us understand the pathophysiology of preeclampsia.

METHODS

We performed a nested case-control study. Seventy-one women with preeclampsia were matched to 71 normotensive controls. The preeclamptic women were broken into two subgroups according to the association with fetal intrauterine growth restriction (IUGR). AF concentrations of sEndoglin, sFLT1, leptin, adiponectin, and endothelin 1 were measured by ELISA. Receiver-operating characteristics curve analysis was used to compare the discriminative values of these potential biomarkers. Functional network analysis was performed using MetaCore to reveal the common functions of the interacting proteins.

RESULTS

Increased AF concentrations of sFLT1, sEndoglin, endothelin 1, and leptin were found in women who later developed preeclampsia. sFLT1, sEndoglin, leptin, and adiponectin were significantly higher in the preeclampsia with IUGR than those without IUGR. Leptin has the largest area under the curve (0.753). Network analysis revealed that elevated amniotic proteins are involved in the inflammatory process of the human placenta.

CONCLUSIONS

Significant elevation of leptin can be detected in AF 2 months earlier than the appearance of symptoms; thus, it may be used as a predictive marker for preeclampsia. The increase of these antiangiogenic proteins supports the roles of inflammation and oxidative stress in pathogenesis of preeclampsia.

The change in sex hormone binding globulin and the influence by gestational diabetes mellitus in fetal period

OBJECTIVE

To investigate the influence of gestational diabetes mellitus (GDM) on the change of SHBG in fetus.

METHOD

Forty-eight pregnant women with GDM and 86 women with normal pregnancy were included in the study. The following were measured in the serums of pregnant women, amniotic fluids, and umbilical cord serums: glucose, insulin, peptide-C, SHBG, and sex hormones.

RESULTS

SHBGs in pregnant women's serums were, when compared with the control group: in male fetuses 308.06 +/- 55.64 vs. 445.21 +/- 50.07 (p < 0.01) and in female fetuses 312.38 +/- 56.61 vs. 451.05 +/- 52.87 (p < 0.01). When comparing the levels of SHBGs in amniotic fluids, inclusive of the control group, the following were in male fetuses 8.35 +/- 1.07 vs. 8.41 +/- 1.09 (p = NS) and in female fetuses 8.31 +/- 0.97 vs. 8.39 +/- 0.94 (p = NS). For the levels of SHBGs in umbilical cord serums and comparison to the control group were: in male fetuses 41.44 +/- 8.83 vs. 40.24 +/- 7.50 (p = NS) and in female fetuses 39.93 +/- 7.04 vs. 39.69 +/- 7.16 (p = NS). The concentration of SHBG in amniotic fluid had no significant relationship to glucose, dehydroepiandrosterone (DHEAS), estradiol, and total and free testosterone, but had an extremely negatively correlated to insulin and peptide-C (p < 0.01) in GDM group.

CONCLUSION

Although the concentration of SHBG does not change in fetus when pregnant woman is complicated with GDM, it is already influenced by the fetal regulation on hyperinsulinemia.