Maternal serum resistin at 11 to 13 weeks' gestation in normal and pathological pregnancies

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.

Doppler Indices of the Uterine, Umbilical and Fetal Middle Cerebral Artery in Diabetic versus Non-Diabetic Pregnancy: Systematic Review and Meta-Analysis

Background and Objectives: The aim of this study was to assess the differences in Doppler indices of the uterine (Ut), umbilical (UA), and middle cerebral artery (MCA) in diabetic versus non-diabetic pregnancies by conducting a comprehensive systematic review of the literature with a meta-analysis. Materials and Methods: PubMed, Web of Science, and SCOPUS were searched for studies that measured the pulsatility index (PI), resistance index (RI), and systolic/diastolic ratio index (S/D ratio) of the umbilical artery, middle cerebral artery, and uterine artery in diabetic versus non-diabetic pregnancies. Two reviewers independently evaluated the eligibility of studies, abstracted data, and performed quality assessments according to standardized protocols. The standardized mean difference (SMD) was used as a measure of effect size. Heterogeneity was assessed using the I2 statistic. Publication bias was evaluated by means of funnel plots. Results: A total of 62 publications were included in the qualitative and 43 in quantitative analysis. The UA-RI, UtA-PI, and UtA-S/D ratios were increased in diabetic compared with non-diabetic pregnancies. Subgroup analysis showed that levels of UtA-PI were significantly higher during the third, but not during the first trimester of pregnancy in diabetic versus non-diabetic pregnancies. No differences were found for the UA-PI, UA-S/D ratio, MCA-PI, MCA-RI, MCA-S/D ratio, or UtA-RI between diabetic and non-diabetic pregnancies. Conclusions: This meta-analysis revealed the presence of hemodynamic changes in uterine and umbilical arteries, but not in the middle cerebral artery in pregnancies complicated by diabetes.

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.

Early Identification of the Maternal, Placental and Fetal Dialog in Gestational Diabetes and Its Prevention

Gestational diabetes mellitus (GDM) complicates between 5 and 12% of pregnancies, with associated maternal, fetal, and neonatal complications. The ideal screening and diagnostic criteria to diagnose and treat GDM have not been established and, currently, diagnostic use with an oral glucose tolerance test occurs late in pregnancy and produces poor reproducibility. Therefore, in recent years, significant research has been undertaken to identify a first-trimester biomarker that can predict GDM later in pregnancy, enable early intervention, and reduce GDM-related adverse pregnancy outcomes. Possible biomarkers include glycemic markers (fasting glucose and hemoglobin A1c), adipocyte-derived markers (adiponectin and leptin), pregnancy-related markers (pregnancy-associated plasma protein-A and the placental growth factor), inflammatory markers (C-reactive protein and tumor necrosis factor-α), insulin resistance markers (sex hormone-binding globulin), and others. This review summarizes current data on first-trimester biomarkers, the advantages, and the limitations. Large multi-ethnic clinical trials and cost-effectiveness analyses are needed not only to build effective prediction models but also to validate their clinical use.

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.

Comparison of ultrasound with biomarkers to identify large-for-gestational age in women screened for gestational diabetes mellitus

OBJECTIVE

Large-for-gestational-age (LGA) is associated with both fetal and maternal complications. One of the few modifiable risk factors for LGA is Gestational Diabetes Mellitus (GDM); for this reason, fetal growth is usually monitored by ultrasound in the third trimester. This prospective study compared a panel of ten established biomarkers measured at the time of selective screening for GDM at 26-28 weeks gestation with the ultrasound prediction of LGA.

METHOD

Women were recruited using convenience sampling and consented at the first antenatal visit. Women with maternal risk factors for GDM attended for the one-step 75 g oral glucose tolerance test. An additional blood sample was taken for biomarker measurement. GDM was diagnosed according to the 2013 World Health Organization (WHO) criteria. Fetal biometry, including the abdominal circumference (AC) and the fetal abdominal subcutaneous tissue (FAST) thickness, were measured at 37 weeks gestation.

RESULTS

Of the 195 women included, 105 (53.8%) had GDM. Of the 195 babies, 36 (18.5%) were LGA. Whether the woman had GDM or not, fetal biometry was strongly predictive of LGA but none of the following biomarkers measured at 26-28 weeks gestation alone or in combination were predictive: c-peptide, ghrelin, gastric inhibitory polypeptide, glucagon-like peptide-1 (GLP-1), glucagon, insulin, leptin, plasminogen activator inhibitor-1, resistin and visfatin.

CONCLUSIONS

In women diagnosed with GDM, surveillance of fetal growth to identify LGA by ultrasound should continue in the third trimester. None of the ten established maternal biomarkers measured at the time of the OGTT was as strongly predictive of LGA as ultrasound.

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.

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.

Serum levels of adipokines in gestational diabetes: a systematic review

OBJECTIVE

To determine the difference of serum levels of 10 adipokines (apelin, chemerin, fatty acid-binding protein-4, fibroblast growth factor-21, monocyte chemoattractant protein-1, nesfatin-1, omentin-1, resistin, vaspin, and visfatin) among women with gestational diabetes and healthy pregnant controls.

MATERIALS AND METHODS

Literature search was conducted using the Medline (1966-2018), Scopus (2004-2018), Cochrane Central Register of Controlled Trials (CENTRAL) (1999-2018), Clinicaltrials.gov (2008-2018) and Google Scholar (2004-2018) databases, along with the reference list of the included studies.

RESULTS

Ninety-one studies were included in the present review, with a total number of 11,074 pregnant women. A meta-analysis was not conducted due to the high inter-study heterogeneity. Current evidence suggests that fatty acid-binding protein-4 levels are significantly increased in pregnancies complicated with gestational diabetes, while no association of serum apelin and monocyte chemoattractant protein-1 with the disease can be supported. Data regarding the rest adipokines are conflicting, since the available studies did not unanimously indicate a significant change of their levels in gestational diabetes.

CONCLUSIONS

The findings of the present systematic review suggest the promising role of fatty acid-binding protein-4 in the prediction of gestational diabetes, while inconsistent evidence exists regarding the rest novel adipokines. Future cohorts are needed to assess their predictive efficacy and fully elucidate their contribution in the disease.

Relationship between elevated serum level of placental growth factor and status of gestational diabetes mellitus

Objective: As only limited and confusing evidence about serum placental growth factor (PlGF) level in gestational diabetes mellitus (GDM) exist in the known literature, the aim of this study was to evaluate the association of maternal serum PlGF level with GDM status.Methods: The pregnant women attending the Obstetrics Outpatient Unit of Hitit University Hospital were screened at 24 and 28 weeks of gestation for GDM according to the suggestions of the American College of Obstetricians and Gynecologists (ACOG). Concisely, all of the low-risk pregnant women were evaluated with a 50 g glucose challenge test (GCT). Women with serum glucose ≥140 mg/dL at 1 h after GCT were subjected to a 100 g oral glucose tolerance test (OGTT). According to the criteria of Carpenter and Coustan, the GDM diagnosis was confirmed. Consequently, a total of 158 pregnant women eligible for inclusion criteria were categorized into two main groups; 76 of the GDM group, 82 of the control group. The demographic characteristic and biochemical parameters of the study population including age, body mass index (BMI), gestational age were recorded at the second trimester. The assays for glucose, insulin, and PlGF were carried out.Results: The mean maternal age of control and GDM groups were 27.9 and 30.5 years, respectively. The parameters such as age, BMI, and gestational age were statistically similar in both groups (p>.05, for all). As expected, serum insulin level and homeostasis model assessment-insulin resistance (HOMA-IR) value were significantly elevated in women with GDM (p<.001, for both). Moreover, maternal PlGF concentration was found to be higher in the GDM group compared to the control group (p=.029). Pearson's correlation analysis of PlGF with other study parameters revealed that there was a negative moderate and significant correlation in only control group (r= -0.416, p<.05). However, this correlation was not detected in the GDM group (r = 0.099, p>.05). None of the variables including maternal age, BMI, insulin, and HOMA-IR showed significant correlations in GDM and control groups.Conclusion: Our findings revealed that maternal serum PlGF level is increased in pregnant women complicated with GDM. Early identification of pregnant women who subsequently will pose GDM risk could improve the pregnancy outcomes.

Maternal serum level of resistin is associated with risk for gestational diabetes mellitus: A meta-analysis

BACKGROUND

Resistin is most likely involved in the pathogenesis of gestational diabetes mellitus (GDM), but the existing findings are inconsistent.

AIM

To review the literature investigating the associations of the risk of GDM with serum level of resistin.

METHODS

A systematic literature search was performed using MEDLINE, EMBASE, and Web of Science (all databases). This meta-analysis included eligible studies that: (1) investigated the relationship between the risk of GDM and serum resistin; (2) included GDM cases and controls without GDM; (3) diagnosed GDM according to the oral glucose-tolerance test; (4) were performed in humans; (5) were published as full text articles in English; and (6) provided data with median and quartile range, median and minimum and maximum values, or mean and standard deviation. The pooled standardized mean difference (SMD) and 95% confidence interval (CI) were calculated to estimate the association between the risk of GDM and serum resistin. To analyze the potential influences of need for insulin in GDM patients and gestational age at blood sampling, we performed a subgroup analysis. Meta-regression with restricted maximum likelihood estimation was performed to assess the potentially important covariate exerting substantial impact on between-study heterogeneity.

RESULTS

The meta-analysis for the association between serum resistin level and GDM risk included 18 studies (22 comparisons) with 1041 cases and 1292 controls. The total results showed that the risk of GDM was associated with higher serum resistin level (SMD = 0.250, 95%CI: 0.116, 0.384). The “after 28 wk” subgroup, “no need for insulin” subgroup, and “need for insulin” subgroup indicated that higher serum resistin level was related to GDM risk (“after 28 wk” subgroup: SMD = 0.394, 95%CI: 0.108, 0.680; “no need for insulin” subgroup: SMD = 0.177, 95%CI: 0.018, 0.336; “need for insulin” subgroup: SMD = 0.403, 95%CI: 0.119, 0.687). The “before 14 wk” subgroup, “14-28 wk” subgroup, and “no information of need for insulin” subgroup showed a nonsignificant association between serum resistin level and GDM risk (“before 14 wk” subgroup: SMD = 0.087, 95%CI: -0.055, 0.230; “14-28 wk” subgroup: SMD = 0.217, 95%CI: -0.003, 0.436; “no information of need for insulin” subgroup: SMD = 0.356, 95%CI: -0.143, 0.855). The postpartum subgroup included only one study and showed that higher serum resistin level was related to GDM risk (SMD = 0.571, 95%CI: 0.054, 1.087) The meta-regression revealed that no need for insulin in GDM patients, age distribution similar between cases and controls, and ELISA all had a significant impact on between-study heterogeneity.

CONCLUSION

This meta-analysis supports that the maternal serum resistin level is associated with GDM risk.

The association between adipocytokines and glycemic control in women with gestational diabetes mellitus

Objective: To evaluate the relationship between adipocytokines and glycemic control.Study design: Prospective observational trial of gestations with gestational diabetes mellitus (GDM). Fasting glucose (FG), insulin, adiponectin, leptin, chemerin, retinol-binding protein 4 (RBP-4), osteocalcin, and resistin were measured. HomeOstasis model assessment of insulin resistance (HOMA-IR) and QUantitative insulin sensitivity ChecK Index (QUICKI) were calculated. Women who required medications for glycemic control were compared to women using nutritional therapy only.Results: Overall, 75 women were included -26 (34.7%) required medications to achieve good glycemic control. Factors associated with poor control are as follows: low resistin (aOR 0.84), HOMA-IR (aOR 1.96), QUICKI (aOR 0.62), first trimester FG (aOR 1.43), and maternal age (aOR 1.26). HOMA-IR and QUICKI performed highest for prediction. Resistin, first trimester FG, maternal age, and QUICKI had an AUC of 0.878, sensitivity and specificity of 87.5% for the prediction of the need for medications.Conclusions: Low resistin is associated with poor control. A model utilizing maternal age, first trimester fasting glucose, and first visit QUICKI yields good predictability.

First-trimester irisin and fetuin-A concentration in predicting macrosomia

Objective: We investigated the diagnostic value of first-trimester adipokines and placental markers in predicting macrosomia. Methods: Out of 328 women recruited during the prenatal diagnosis between 11th and 13th week of pregnancy and subjected to follow up until delivery, we selected 26 women who gave birth to macrosomic babies and 34 women who gave birth to normal weight neonates for the evaluation of first trimester serum levels of pregnancy associated plasma protein-A, free β-human chorionic gonadotropin, placental growth factor (PIGF), and selected adipokines. Results: The mothers of macrosomic infants had higher PIGF (p = .049) and irisin concentrations (p = .00003), and lower fetuin-A levels (p = .0002) than had the mothers of normal weight babies. Newborn's weight correlated positively with maternal irisin (R = 0.454, p = .0003) and negatively with fetuin-A concentrations (R = -0.497, p = .00005). Multiple regression analysis showed that only serum irisin concentration was a significant predictor of birth weight (β = 0.329, p = .03), explaining 14% of its variability. The sensitivity and the specificity of irisin concentration in predicting macrosomia were 0.769 and 0.794, respectively (AUC = 0.818 [95%CI: 0.708-0.928], p = .00001) with a proposed cut-off value of 1725.4 ng/ml. Conclusions: Our results suggest that mother's irisin may be an early biomarker of macrosomia.

Ficolin-3/adiponectin ratio for the prediction of gestational diabetes mellitus in pregnant women

AIMS/INTRODUCTION

To establish that the ficolin-3/adiponectin ratio is a predictor for gestational diabetes mellitus (GDM) and is eligible for screening tests for GDM.

MATERIALS AND METHODS

A prospective cohort study of 86 pregnant women who developed GDM and 273 normal glucose tolerance participants was carried out. Maternal serum ficolin-3, adiponectin levels were investigated at 16-18 weeks of gestation using enzyme-linked immunosorbent assay.

RESULTS

Compared with the normal glucose tolerance group, the GDM group showed significantly higher levels of ficolin-3 and the ratio of ficolin-3/adiponectin; and decreased levels of adiponectin between 16-18 weeks of gestation (P < 0.05 or P < 0.01). The cut-off values for the ratio of ficolin-3/adiponectin (≥1.06; sensitivity 90.9%, specificity 96.5%) to discriminate the pregnant women who developed GDM from the non-diabetic cases were identified using receiver operating characteristic analysis. Using binary logistic regression analysis, ficolin-3, retinol-binding protein-4 and adiponectin, but not C-reactive protein, triglyceride and free fatty acids were shown as predictive factors for GDM.

CONCLUSIONS

The ratio of ficolin-3/adiponectin at 16-18 weeks of gestation was changed in pregnant women who subsequently developed GDM, and might provide effective early predicting and screening for GDM.

Early Pregnancy Biochemical Predictors of Gestational Diabetes Mellitus

PURPOSE OF REVIEW

Universal oral glucose tolerance-based screening is employed to identify pregnant women with gestational diabetes mellitus (GDM), as treatment of this condition decreases the risk of associated complications. A simple and accurate blood test which identifies women at low or high risk for GDM in the first trimester would have the potential to decrease costs and improve outcomes through prevention or treatment. This review summarizes published data on early pregnancy biomarkers which have been tested as predictors of GDM.

RECENT FINDINGS

A large number of first-trimester biochemical predictors of GDM have been reported, mostly in small case-control studies. These include glycemic markers (fasting glucose, post-load glucose, hemoglobin A1C), inflammatory markers (C-reactive protein, tumor necrosis factor-alpha), insulin resistance markers (fasting insulin, sex hormone-binding globulin), adipocyte-derived markers (adiponectin, leptin), placenta-derived markers (follistatin-like-3, placental growth factor, placental exosomes), and others (e.g., glycosylated fibronectin, soluble (pro)renin receptor, alanine aminotransferase, ferritin). A few large studies suggest that first-trimester fasting glucose or hemoglobin A1C may be useful for identifying women who would benefit from early GDM treatment. To translate the findings from observational studies of first-trimester biomarkers for GDM to clinical practice, trials or cost-effectiveness analyses of screening and treatment strategies based on these novel biomarkers are needed.

Maternal serum osteocalcin at 11-14 weeks of gestation in gestational diabetes mellitus

BACKGROUND

Recent studies support that osteocalcin (OC), apart from its skeletal role, is implicated in glucose homoeostasis. Aims of this study were to examine the first-trimester maternal serum concentrations of OC in pregnancies that developed gestational diabetes mellitus (GDM) and to create a first-trimester prediction model for GDM.

DESIGN

Case-control study in a prospective cohort of pregnant women. Maternal serum levels of OC were measured in 40 cases that developed GDM and 94 unaffected controls. First-trimester biophysical parameters, biochemical indices, maternal-pregnancy characteristics, and OC concentrations were assessed in relation to GDM occurrence.

RESULTS

In the GDM group, first-trimester OC serum levels were increased compared to the control group (mean = 8·81 ng/mL, SD = 2·59 vs. mean = 7·34 ng/ml, SD = 3·04, P = 0·0058). Osteocalcin was independent of first-trimester biophysical and biochemical indices. Osteocalcin alone (OR = 1·21, CI: 1·02-1·43, P = 0·023) was a significant predictor of GDM [Model R(2) = 0·04, area under the curve (AUC) = 0·61, CI: 0·55-0·72, P < 0·001]. The combination of maternal and pregnancy characteristics with OC resulted in an improved prediction model for GDM (Model R(2) = 0·21, AUC = 0·80, CI: 0·71-0·88, P < 0·001). The combined model yields a sensitivity of 72·2% for 25% false-positive rate.

CONCLUSIONS

First-trimester maternal serum levels of OC are increased in GDM pregnancies. Osteocalcin combined with maternal and pregnancy characteristics provides an effective screening for GDM at 11-14 weeks.

Inflammatory and Other Biomarkers: Role in Pathophysiology and Prediction of Gestational Diabetes Mellitus

Understanding pathophysiology and identifying mothers at risk of major pregnancy complications is vital to effective prevention and optimal management. However, in current antenatal care, understanding of pathophysiology of complications is limited. In gestational diabetes mellitus (GDM), risk prediction is mostly based on maternal history and clinical risk factors and may not optimally identify high risk pregnancies. Hence, universal screening is widely recommended. Here, we will explore the literature on GDM and biomarkers including inflammatory markers, adipokines, endothelial function and lipids to advance understanding of pathophysiology and explore risk prediction, with a goal to guide prevention and treatment of GDM.

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.

Elevated placental growth factor concentrations at 11-14 weeks of gestation to predict gestational diabetes mellitus

OBJECTIVE

To examine maternal serum concentrations of placental growth factor (PlGF) at 11-14 gestational weeks in pregnancies that developed gestational diabetes mellitus (GDM) and to create first trimester prediction models for GDM.

METHODS

Case control study including 40 GDM cases and 94 controls. PlGF, biophysical and biochemical markers and maternal-pregnancy characteristics were analyzed.

RESULTS

Log10 transformed PlGF (log10 PlGF) was not related to maternal factors. Log10 PlGF was increased (p=0.008) in the GDM group compared to the control group. Log10 PlGF was associated with fasting glucose levels (p=0.04) in the oral glucose tolerance test. Log10 PlGF had a strong relation with birth weight adjusted for gestational age in the control but not in the GDM group. Maternal weight and maternal age were the only predictors of GDM among the maternal factors [area under the curve (AUC)=0.73, p<0.001]. Log10 PlGF alone was a significant predictor of GDM (AUC=0.63, p<0.001). Combination of maternal weight, maternal age and log10 PlGF resulted in an improved prediction (DR=71.4%, for 25% FPR, AUC=0.78, Model R(2)=0.17, p<0.001).

CONCLUSION

At 11-14weeks in pregnancies that develop GDM, the maternal serum levels of PlGF are increased. Measurement of serum PlGF at 11-14weeks improves the performance of early screening for GDM provided by maternal factors alone.

First trimester screening can predict adverse pregnancy outcomes

There has been an increasing drive over the last two decades to push the detection of women at risk of adverse pregnancy outcomes into the first trimester. This has led to a plethora of techniques, risk assessments and biomarkers, both fascinating and bewildering in its breadth. Despite the vast amount of knowledge available, it is often difficult to determine what is practicable and valuable for clinical practice. This is especially true as earlier diagnosis does not necessarily equate to improved outcomes for mother and child. We suggest that, at least for preeclampsia, fetal growth restriction, spontaneous preterm birth and gestational diabetes, there are effective first trimester tests available to identify the women at risk of subsequently developing complications. Unfortunately, there are no currently reliable first trimester tests available for identifying women at risk of stillbirth. It is likely that this field will continue to develop over time, and we hope that new and better strategies will continue to emerge to target these clinically important pathologies.

Adipokines in gestational diabetes

Gestational diabetes is characterised by glucose intolerance with onset or first recognition during pregnancy. The disease shows facets of the metabolic syndrome including obesity, insulin resistance, and dyslipidaemia. Adipokines are a group of proteins secreted from adipocytes, which are dysregulated in obesity and contribute to metabolic and vascular complications. Recent studies have assessed the role of various adipokines including leptin, adiponectin, tumour necrosis factor α (TNFα), adipocyte fatty acid-binding protein (AFABP), retinol-binding protein 4 (RBP4), resistin, NAMPT, SERPINA12, chemerin, progranulin, FGF-21, TIMP1, LCN2, AZGP1, apelin (APLN), and omentin in gestational diabetes. This Review provides an overview of these key adipokines, their regulation in, and potential contribution to gestational diabetes. Based on the evidence so far, the adipokines adiponectin, leptin, TNFα, and AFABP seem to be the most probable candidates involved in the pathophysiology of gestational diabetes.

Pregnancy-associated plasma protein A (PAPP-A) and preeclampsia

Pregnancy-associated plasma protein A (PAPP-A) is a key regulator of insulin-like growth factor bioavailability essential for normal fetal development. In maternal blood, this protein increases with gestational age and then rapidly decreases after delivery. It is routinely used for Down syndrome screening in the first trimester of pregnancy, and its decrease compared to a normal pregnancy indicates an increased risk for both chromosomal anomalies and adverse pregnancy outcomes. It belongs to a group of biomarkers that predict later preeclampsia development, primarily early onset preeclampsia; however, it should be combined with a Doppler ultrasonography of the uterine artery (pulsatile index) and other biochemical and maternal factors to achieve a higher detection rate with an acceptable false positivity rate. Some studies have demonstrated an even more pronounced decrease of PAPP-A in the early second trimester of pregnancy in women who subsequently develop preeclampsia compared with women who do not develop preeclampsia. Conversely, during the last trimester of pregnancy, its concentration increases even more in patients with preeclampsia than in patients without. It is also detectable at very low levels in nonpregnant individuals, and a higher concentration indicates an adverse effect in patients with acute coronary syndromes or stable atherosclerotic disease and in patients with end-stage renal disease who are being treated with hemodialysis.

Resistin concentration and gestational diabetes: a systematic review of the literature

Gestational diabetes (GD) exposes mothers and infants to the risk of immediate and later adverse outcomes. Increased insulin resistance is a common feature of GD and obesity. Because of its critical role in regulating insulin sensitivity, resistin has been implicated in the physiopathology of GD. The aim of this study was to review the existing literature on the relationship between circulating maternal resistin levels and GD. Three electronic databases (MEDLINE, EMBASE, and LILACS) were searched for pertinent studies published from 2001 to 2012, without language restrictions. Eleven studies, with a total of 639 participants between 23 and 41 weeks of gestation, were included. The number of GD patients per study ranged from 11 to 81, with varying degrees of disease severity and several different GD diagnostic criteria. Mean concentrations of resistin varied widely both in control women (0.05-22.21 ng/ml) and in GD patients (0.05-62.38 ng/ml). We performed a meta-analysis including a total of 10 studies, and also subgroup analyses according to gestational age at sample collection (up to 32 and >33 weeks). The pooled absolute mean difference (WMD) in resistin levels was slightly lower in GD patients than in controls, but this did not reach statistical significance (WMD=-0.02, 95% CI -0.07 to 0.04). According to the data from the 11 studies analyzed, there was no association between circulating resistin levels and GD. However, this result should be interpreted with caution owing to the large heterogeneity amongst the existing published studies.

Circulating levels of the cytokines IL10, IFNγ and resistin in an obese mouse model of developmental programming

An infant's early developmental environment plays a pivotal role in the programming of its physiological phenotype. The identification of the factors in the maternal environment that mediate the effects of maternal obesity and diet is essential to the development of clinical intervention strategies. Maternal hyperglycaemia, hyperinsulinaemia, hypertriglyceridaemia, hyperleptinaemia and altered inflammatory cytokines concentrations are potentially important predictive factors of her future offspring's susceptibility to metabolic disease. Using a diet-induced obese mouse model, we have investigated which of these maternal factors could induce adverse metabolic programming in the offspring. Female C57Bl/6 mice were fed either laboratory chow (10% fat) or high fat diet (42% fat) for 10 weeks before mating and throughout gestation. At day 18 of pregnancy, maternal body weight, body composition and glucose tolerance were measured, as well as plasma insulin, adiponectin, RBP4, leptin, resistin and the inflammatory cytokines (IL6, IL10, IL12, IL1β, IFNγ, KC, TNF-α). At day 18 of pregnancy, high fat-fed dams were significantly heavier than the chow dams and had increased fat mass. High fat-fed dams had higher 5 h fasting blood glucose than chow dams and elevated plasma insulin. Although the obese dams had both reduced plasma adiponectin and resistin levels compared with lean dams, their plasma IL6, IL10 and IFNγ levels were all increased. High fat feeding in pregnancy leads to altered plasma concentrations of both adipokines and adipocytokines in the dam that may directly pass to the fetus and affect their development.

Early detection of maternal risk for preeclampsia

Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortality. New molecular insights offer new possibilities of early diagnosis of elevated maternal risk. Maternal risk factors, biophysical parameters like Doppler examination of the uterine arteries and biochemical parameters allow early risk calculation. Preventive and effective therapeutic agents like acetylsalicylacid can be started in the early second trimester. This article reviews the diagnostic possibilities of early risk calculation to detect women having high risk for preeclampsia and the potential benefits for them, the offspring and health care systems. We provide risk calculation for preeclampsia as an important and sensible part of first trimester screening.