Adipokine profile and C-reactive protein in pregnancy: effects of glucose challenge response versus body mass index. ACTA ACUST UNITED AC. 2005;12:330-334. [PMID: 15979544 DOI: 10.1016/j.jsgi.2005.02.002]

Fatty acids, inflammation and angiogenesis in women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a metabolic disorder in pregnancy whose prevalence is on the rise. Reports suggest a likely association between inflammation and maternal GDM. A balance between pro and anti-inflammatory cytokines is necessary for the regulation of maternal inflammation system throughout pregnancy. Along with various inflammatory markers, fatty acids also act as pro-inflammatory molecules. However, studies reporting the role of inflammatory markers in GDM are contradictory, suggesting the need of more studies to better understand the role of inflammation in pregnancies complicated by GDM. Inflammatory response can be regulated by angiopoietins suggesting a link between inflammation and angiogenesis. Placental angiogenesis is a normal physiological process which is tightly regulated during pregnancy. Various pro and anti-angiogenic factors influence the regulation of the feto-placental vascular development. Studies evaluating the levels of angiogenic markers in women with GDM are limited and the findings are inconsistent. This review summarizes the available literature on fatty acids, inflammatory markers and angiogenesis in women with GDM. We also discuss the possible link between them and their influence on placental development in GDM.

Markers of inflammation in obese pregnant women: Adenosine deaminase and high sensitive C - reactive protein

Introduction

The worldwide increase in the prevalence of obesity over the years has emerged as a global health concern. The growing rate of obesity in women of child bearing age is particularly a matter of concern. Obesity is considered a risk factor that predisposes an individual to a proinflammatory state through the release of the inflammatory mediators. Recent studies have shown a positive correlation between the severity of inflammation and an increase in adenosine deaminase (ADA) and high sensitivity C- reactive protein (hs-CRP). Obese pregnancy women are at a higher risk for developing inflammation-mediated pregnancy complications like gestational diabetes, preeclampsia, and preterm delivery. Considering the fact that pregnancy, obesity and inflammation are closely linked, this study evaluated the inflammation associated with obesity during pregnancy by estimating changes in ADA and hs-CRP.

Materials and methods

The current study aimed to evaluate the levels of inflammation in obese pregnant women compared to non-obese pregnant women by correlating BMI with levels of ADA / hs-CRP. The study also aimed to examine the change in ADA and hs-CRP levels with gestational age (between the 1^st and the 3^rd trimester) in obese pregnant women as compared to non-obese pregnant women. We also examined whether changes in the levels of ADA correlate with changes in the levels of hs-CRP particularly in obese pregnant women.Blood samples were collected from obese and non-obese pregnant women. ADA activity and hs-CRP levels were estimated by biochemical assays. BMI was evaluated in the 1^st trimester and those women with BMI > 30 kg/m²were considered as obese. Thirty subjects were included in each of the two groups.

Results

ADA and hs-CRP levels were significantly higher in obese pregnant women in both the 1^st and 3^rd trimesters compared to non-obese participants (P value<0.05). Statistically significant higher values of ADA and hs-CRP were seen in obese participants in the 3^rd trimester compared to the 1^st trimester.A significant linear positive correlation was found between BMI and 3^rd trimester ADA, and a linear positive correlation between BMI and hs-CRP both in the 1^st and 3^rd trimester. The relationship between ∆ ADA and ∆ hs-CRP was non- significant.

Conclusions

The observations of this study reveal increased inflammatory responses in obese pregnant women and suggests the importance of ADA and hs-CRP as early indicators of obesity-related complications prevailing thereafter, these markers can be useful for clinical diagnosis of impending maternal and neonatal complications.

Serum concentration of angiogenic (CXCL1, CXCL12) and angiostasis (CXCL9, CXCL10) CXC chemokines are differentially altered in normal and gestational diabetes mellitus associated pregnancies

BACKGROUND

The present study was aimed and designed to determine the serum levels of CXCL1 and CXCL12 as angiogenesis along with CXCL9 and CXCL10 as angiostasis, chemokines in, Gestational diabetes mellitus mothers (GDMM) and normal pregnancy mothers (NPM) and neonates who delivered by them.

METHODS

We have recruited 63 pregnant GDMM and 63 normal pregnant mothers at the third trimester of pregnancy to this cross-sectional study. Cord blood specimens were obtained from neonates who were delivered from GDMM and NPM. The serum and cord blood levels of chemokines were measured by ELISA in studied groups. Data were analyzed by chi-square and student's t test between two groups. The P-values less than 0.05 were considered significant.

RESULTS

Our results revealed that the serum levels of CXCL1, CXCL9 and CXCL12 were increased in GDMM, while no alteration was found in the serum levels of CXCL10 when compared to NPM. We have observed that in neonates the serum levels of angiogeneic chemokines followed an inverse fashion when compared to angiostasis chemokines. Interestingly, CXCL1 and CXCL12 were both increased in neonates who were delivered by GDMM, while, CXCL9 and CXCL10 were decreased in neonates delivered by GDMM.

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.

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.

Body Mass Index as a Measure of Obesity: Racial Differences in Predictive Value for Health Parameters During Pregnancy

BACKGROUND

As a measure of obesity, body mass index (BMI; kg/m²) is an imperfect predictor of health outcomes, particularly among African Americans. However, BMI is used to guide prenatal care. We examined racial differences in the predictive value of maternal BMI for physiologic correlates of obesity, serum interleukin (IL)-6 and C-reactive protein (CRP), as well as cesarean section and infant birth weight.

METHODS

One hundred five pregnant women (40 European American, 65 African American) were assessed during the second trimester. BMI was defined as per prepregnancy weight. Electrochemiluminescence and enzyme-linked immunosorbent assays were used to quantify IL-6 and CRP, respectively. Birth outcomes were determined by medical record review.

RESULTS

Women of both races classified as obese had higher serum IL-6 and CRP than their normal-weight counterparts (ps ≤ 0.01). However, among women with overweight, elevations in IL-6 (p < 0.01) and CRP (p = 0.06) were observed among European Americans, but not African Americans (ps ≥ 0.61). Maternal obesity was a significantly better predictor of cesarean section among European Americans versus African Americans (p = 0.03) and BMI was associated with infant birth weight among European Americans (p < 0.01), but not African Americans (p = 0.94). Effects remained after controlling for gestational age at delivery, gestational diabetes, and gestational weight gain as appropriate.

CONCLUSIONS

BMI may be a less valid predictor of correlates of overweight/obesity among African Americans versus European Americans during pregnancy. This should be considered in epidemiological studies of maternal-child health. In addition, studies examining the comparative validity of alternative/complementary measures to define obesity in pregnancy are warranted to inform clinical care.

Maternal Serum Resistin Is Reduced in First Trimester Preeclampsia Pregnancies and Is a Marker of Clinical Severity

OBJECTIVE

To examine whether resistin levels in first trimester maternal serum are associated with insulin resistance or preeclampsia (PE).

METHODS

A case-control study of maternal serum resistin concentration conducted using 285 normal pregnancies and 123 PE pregnancies matched for gestational age, parity and maternal age. Samples were taken in gestational weeks 10⁺⁰-13⁺⁶.

RESULTS

There was a negative correlation between resistin and clinical severity of PE, but no correlation with IS, TNF-α, body mass index, birth weight and pregnancy length.

CONCLUSIONS

Resistin is reduced in first trimester of PE pregnancies, particularly in severe PE. Inflammation and IS cannot explain this phenomenon.

Is maternal obesity associated with sustained inflammation in extremely low gestational age newborns?

BACKGROUND

The offspring of obese women are at increased risk for systemic inflammation. Blood concentrations of inflammatory proteins in preterm newborns of obese women have not been reported.

AIM

To compare blood concentrations in the highest quartile for gestational age of inflammatory proteins and day of blood specimen collection on two days at least one week apart of newborns of overweight (i.e., BMI 25-29) and obese women (i.e., BMI ≥ 30) with newborns of women with lower BMIs. Because deliveries for spontaneous indications are more likely than those for other indications to be associated with inflammation, we evaluated spontaneous indication deliveries separately from maternal or fetal indications.

STUDY DESIGN

Prospective cohort study.

SUBJECTS AND OUTCOME MEASURES

We measured from 939 children born before the 28th week of gestation 25 inflammation-related proteins in blood obtained on postnatal day 1 (range 1-3), day 7 (range 5-8) and day 14 (range 12-15).

RESULTS

Among infants delivered for spontaneous indications, maternal BMI was not related to elevated concentrations of any protein. Among infants delivered for maternal (i.e., preeclampsia) or fetal indications, those whose mother was overweight or obese were more likely than others to have elevated concentrations of inflammation proteins.

CONCLUSIONS

Maternal pre-pregnancy overweight and obesity appear to contribute to a pro-inflammatory state in very preterm newborns delivered for maternal or fetal indications. Our failure to see a similar pattern among newborns delivered for spontaneous indications, which often have inflammatory characteristics, might reflect competing risks.

Regulation of nutrient transport across the placenta

Abnormal fetal growth, both growth restriction and overgrowth, is associated with perinatal complications and an increased risk of metabolic and cardiovascular disease later in life. Fetal growth is dependent on nutrient availability, which in turn is related to the capacity of the placenta to transport these nutrients. The activity of a range of nutrient transporters has been reported to be decreased in placentas of growth restricted fetuses, whereas at least some studies indicate that placental nutrient transport is upregulated in fetal overgrowth. These findings suggest that changes in placental nutrient transport may directly contribute to the development of abnormal fetal growth. Detailed information on the mechanisms by which placental nutrient transporters are regulated will therefore help us to better understand how important pregnancy complications develop and may provide a foundation for designing novel intervention strategies. In this paper we will focus on recent studies of regulatory mechanisms that modulate placental transport of amino acids, fatty acids, and glucose.

Insulin sensitivity in late gestation and early postpartum period: the role of circulating maternal adipokines

OBJECTIVE

Early postpartum period is characterised by a dramatic decrease in insulin resistance and significant metabolic alterations. The aims of this study were to determine the changes in circulating maternal concentrations of total adiponectin, adiponectin multimers, leptin and resistin before and after the delivery and to explore their relationship with insulin sensitivity.

METHODS

Twenty-seven normal pregnant women at term were included in this longitudinal study. Blood samples were taken before and 4 days after elective caesarean section. Total adiponectin, adiponectin multimers, leptin, resistin, glucose, insulin and prolactin were measured in maternal serum. Adiponectin multimers were measured before and after the delivery in eight women.

RESULTS

(1) The mean maternal serum total adiponectin concentration was significantly higher before than after delivery while the relative distribution of circulating maternal adiponectin multimers did not change after delivery; (2) the median maternal serum concentration of leptin was significantly higher in the antepartum than in the postpartum period; (3) the median maternal serum resistin concentration was comparable before and after delivery; (4) multiple linear regression analysis revealed that antepartum insulin sensitivity was associated with maternal low body mass index, and low glucose concentrations in glucose challenge test, as well as with maternal age and increased leptin concentrations. Postpartum insulin sensitivity was associated with decreased circulating resistin concentrations.

CONCLUSIONS

Despite increase in insulin sensitivity, early postpartum period is characterised by a decrease in maternal circulating total adiponectin and by steady concentrations of resistin and adiponectin multimers compared to the late third trimester.

Placental effects of systemic tumour necrosis factor-α in an animal model of gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) may adversely affect fetoplacental interaction. Numerous reports demonstrate that GDM women have increased circulating tumour necrosis factor-α (TNF), a pro-apoptotic peptide.

OBJECTIVE

To examine whether implantation site apoptosis is increased by exogenous TNF in mice heterozygous for a defective leptin receptor (db/+), a GDM animal model.

STUDY DESIGN

Implantation sites were studied at gestational day (gd)18.5 in 3 groups: saline-treated wild-type (wt) and db/+ mice, and TNF-treated db/+ mice. Saline or TNF (total dose 4 μg) was administered by miniosmotic pump from gd11.5. Immunostaining for cleaved caspase-3, PAS and cytokeratin was performed for quantification of apoptotic cells, uterine natural killer (uNK) cells, and trophoblast invasion, respectively. The mRNA expression of TNF and TNF-induced apoptotic markers in placenta and mesometrial triangle (MT) was measured by quantitative RT-PCR.

RESULTS

The implantation sites from saline-treated wt and db/+ mice showed comparable numbers of apoptotic cells and uNK cells. Compared with the saline-treated groups, TNF-treated db/+ dams had less fetuses; the placental labyrinth and trophospongium contained more apoptotic cells; and the MT contained a higher total number of uNK cells including more cells intensely stained for cleaved caspase-3 as well as cells with negative staining. Trophoblast invasion was shallower in db/+ than in wt mice (14% and 30% of total invasion into MT, respectively) but this was not affected by TNF. The mRNA expression of TNF and apoptotic markers was comparable in the 3 groups.

CONCLUSIONS

TNF treatment in db/+ mice raises the number of apoptotic cells in the placenta, and appears to increase the retention of uNK cells in the MT. Db/+ mice demonstrate shallower trophoblast invasion which is unaffected by exogenous TNF.

Circulating concentrations of adiponectin and tumor necrosis factor-alpha in gestational diabetes mellitus

Adiponectin and tumor necrosis factor-alpha (TNF-alpha) have been implicated in insulin resistance and diabetes mellitus (DM). In the present study we investigated levels of adiponectin and TNF-alpha and their relationships with each other and metabolic factors in women with gestational DM (GDM). Thirty-four pregnant women with GDM and 31 pregnant women with normal glucose tolerance (NGT) were included in the study. Plasma adiponectin levels were lower in GDM than in NGT (36.9 +/- 6.7 vs. 61.3 +/- 13.0 ng/ml, p = 0.028). Serum TNF-alpha levels were increased in GDM compared with NGT (20.5 +/- 2.4 vs. 14.0 +/- 1.5 pg/ml, p = 0.042). After adjustment for pre-pregnancy and current body mass index (BMI), adiponectin levels correlated negatively with insulin resistance by homeostasis model assessment-insulin resistance (HOMA-IR) and 0-h and 1-h glucose both at glucose challenge test and oral glucose tolerance test in GDM. Adiponectin levels were correlated only with very low-density lipoprotein cholesterol and triglyceride levels in NGT. TNF-alpha levels were correlated with glycated hemoglobin in GDM. There was a significant positive correlation between TNF-alpha levels and pre-pregnancy and current BMI in GDM as well as NGT. HOMA-IR for adiponectin and pre-pregnancy BMI for TNF-alpha remained as significant determinants in multiple regression analyses. In conclusion, these data suggest that reduced adiponectin and increased TNF-alpha may be involved in the pathogenesis of GDM.

Resistin: a hormone which induces insulin resistance is increased in normal pregnancy

AIMS

Resistin, a newly discovered adipokine, is thought to play a key role in the regulation of insulin resistance. The objectives of this study were to develop a nomogram of maternal plasma concentrations of resistin from 11 weeks of gestation to term and to determine whether resistin concentrations differ between normal and overweight pregnant women.

METHODS

In this cross-sectional study, plasma concentrations of resistin were determined in normal pregnant women of normal body mass index (BMI 18.5-24.9; n=261), overweight pregnant women (BMI > or =25; n=140), and non-pregnant women of normal BMI (n=40). Blood samples were collected once from each woman between the first trimester and term. Percentiles for resistin concentration were determined for five pre-specified windows of gestational age. Plasma resistin concentration was determined by immunoassay. Non-parametric statistics were used for analysis.

RESULTS

The median maternal plasma concentration of resistin between 11 to 14 weeks of gestation in women of normal weight was significantly higher than non-pregnant women; the plasma concentration of resistin increased with gestational age.

CONCLUSIONS

Normal pregnant women have a higher median plasma concentration of resistin than non-pregnant women and the concentration of this adipokine increases with advancing gestation. Alterations in the maternal plasma concentration of resistin during pregnancy could contribute to metabolic changes of pregnancy.

Adiponectin, Adipocyte Fatty Acid Binding Protein, and Epidermal Fatty Acid Binding Protein: Proteins Newly Identified in Human Breast Milk

Background: Breastfeeding may protect children from developing metabolic syndrome and other diseases later in life. We investigated novel proteins in human breast milk that might play a role in this process.

Methods: We used ELISA to measure adiponectin, adipocyte and epidermal fatty acid binding proteins (AFABP, EFABP), and leptin concentrations in human breast milk obtained from 59 mothers 48 h after initiation of lactation. Using a questionnaire and medical records, we collected information about the mothers and newborns.

Results: Mean (SE) adiponectin concentrations in breast milk were 13.7 (0.8), range 3.9–30.4 μg/L; AFABP concentrations 26.7 (4.4), range 1.2–137.0 μg/L; EFABP concentrations 18.1 (1.4), range 0.8–47.0 μg/L; and leptin concentrations 0.50 (0.05), range 0–1.37 μg/L. We found a significant correlation between AFABP and EFABP concentrations (r = 0.593, P &lt;0.0001). Maternal EFABP concentrations were significantly higher in mothers who delivered boys than in those who delivered girls [21.7 (2.3) vs 15.4 (1.7) μg/L, P = 0.028] and correlated with newborn birth weight (r = 0.266, P = 0.045). Maternal leptin correlated with body weight before pregnancy (r = 0.272, P = 0.043) and at delivery (r = 0.370, P = 0.005), body mass index before pregnancy (r = 0.397, P = 0.003) and at delivery (r = 0.498, P &lt;0.0001), body weight gain during pregnancy (r = 0.267, P = 0.047), and newborn gestational age (r = 0.266, P = 0.048). Leptin was significantly lower in mothers who delivered preterm vs term babies [0.30 (0.09) vs 0.60 (0.05) ug/L, P = 0.026].

Conclusions: Concentrations of adiponectin, AFABP, and EFABP in human breast milk are related to nutritional variables of mothers and newborns and thus may play a role in the protective effects of breastfeeding.

Maternal body size and birth weight: can insulin or adipokines do better?

Overweight gravidas and gravidas with a robust weight gain have an accrued risk of delivering a large-for-gestational age (LGA) baby. Here, we examined whether the measurement of insulin and adipokines--peptides secreted mainly by adipose tissue--at the glucose challenge test (GCT) improves the prediction of birth weight. We studied 631 singleton pregnancies at 24 to 29 weeks' gestational age (GA) with data on height, baseline body weight (BW), and BW change between baseline and the GCT. In addition to glucose and insulin, we measured adiponectin, leptin, soluble leptin receptor (the main leptin-binding protein), and tumor necrosis factor alpha. We found that birth weight was related to maternal height, baseline BW, and BW change, and also--albeit less strongly--to insulin, adiponectin, leptin, and soluble leptin receptor concentrations. In multiple regression analyses, body size parameters explained approximately 10% of the variance in birth weight, of which BW change was the most important correlate, but the metabolic markers added only approximately 2% variance, with leptin alone adding 1.4%. Gravidas carrying a small-for-GA (SGA) fetus were more likely to have a leptin value in the highest quartile than those with an appropriate-for-GA fetus (odds ratio, 2.6; 95% confidence interval, 1.1-6.3; P = .04), but there were no other differences in the metabolic markers between SGA or LGA and appropriate-for-GA pregnancies. In conclusion, measuring insulin and adipokines at the GCT has limited, if any, clinical benefit to predict which fetuses will be SGA or LGA at birth.