Maternal and umbilical resistin levels do not correlate with infant birth weight either in normal pregnancies and or in pregnancies complicated with gestational diabetes

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.

Effect of Lifestyle Interventions during Pregnancy on Maternal Leptin, Resistin and Offspring Weight at Birth and One Year of Life

Lifestyle during pregnancy impacts the health of the mother and child. However, the extent to which physical activity affects maternal biomarkers and factors that might influence birth weight remains unclear. We analysed data from two lifestyle interventions in which the effects of an exercise programme (2x/week, 60-90 min) on the course of pregnancy with regard to adipokines and offspring were evaluated. A total of 70 women participated in this study (45, intervention group; 25, control group). Anthropometric data and maternal fasting serum leptin and resistin levels were measured at three time points (approximately 14th (T1), 24th (T2), and 36th (T3) weeks of gestation). Neonatal/child data were retrieved from screening examinations. Independent of the intervention, we found a positive correlation between the fat mass at T1 and both leptin and resistin levels at all time points. Leptin level was significantly higher in the control group at T3; however, no differences between the groups were found for resistin. The birth weight was influenced by the birth length, fat mass at T1/T3, and resistin level at T2. The BMI-SDS at one year of age was influenced by maternal fat-free mass at T3 and resistin at T1/T2. Even if these results can only be interpreted cautiously, lifestyle interventions during pregnancy are important in promoting maternal and child health. Further randomised controlled trials and translational studies are warranted to clarify the underlying mechanisms.

GDM-complicated pregnancies: focus on adipokines

Gestational diabetes mellitus (GDM) is a serious complication of pregnancy and is defined as a state of glucose intolerance that is first diagnosed and arises during gestation. Although the pathophysiology of GDM has not yet been thoroughly clarified, insulin resistance and pancreatic β-cell dysfunction are considered critical components of its etiopathogenesis. To sustain fetus growth and guarantee mother health, many significant changes in maternal metabolism are required in normal and high-risk pregnancy accompanied by potential complications. Adipokines, adipose tissue-derived hormones, are proteins with pleiotropic functions including a strong metabolic influence in physiological conditions and during pregnancy too. A growing number of studies suggest that various adipokines including adiponectin, leptin, visfatin, resistin and tumor necrosis factor α (TNF-α) are dysregulated in GDM and might have pathological significance and a prognostic value in this pregnancy disorder. In this review, we will focus on the current knowledge on the role that the aforementioned adipokines play in the development and progression of GDM.

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.

Adipokine levels and their association with insulin resistance and fetal outcomes among the newborns of Indian gestational diabetic mothers

OBJECTIVES

To investigate the cord blood levels of adipokine and to assess their association with the fetal insulin resistance and fetal outcomes in newborns of gestational diabetic women (GDM). Methods: This cross-sectional study was performed in 40 GDM women and 40 healthy pregnant women (HPW) in the Department of Obstetrics and Gynecology at Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER) hospital in Puducherry, India, during the period from May 2016 to December 2017. Cord blood samples were collected at delivery from GDM and HPW groups. Cord plasma biochemical parameters such as insulin, C-peptide, adiponectin, leptin, resistin, and visfatin concentrations were measured. Leptin/adiponectin ratio (L/A), homeostasis model assessment of insulin resistance (HOMA2-IR), insulin sensitivity (HOMA2-%S) and beta cell function (HOMA2-%B) were calculated. The pregnancy outcomes such as birth weight (BW), Ponderal index and Apgar scores of the baby were measured. Results: The BW and Ponderal index of the baby were found to be significantly higher in GDM newborns compared to HPW newborns. Cord plasma insulin, C-peptide, HOMA2 -IR, visfatin, leptin, and L/A ratio were significantly higher whereas adiponectin level was lower in GDM compared to HPW. A significant positive correlation was observed between L/A ratio and fetal HOMA2-IR. Conclusion: Altered adipokine levels with increased L/A ratio was observed among the new-borns of Indian gestational diabetic mothers. There was an association between increased L/A ratio, insulin resistance and increased Ponderal index among the new-borns.

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.

Biomarkers for Macrosomia Prediction in Pregnancies Affected by Diabetes

Large birthweight, or macrosomia, is one of the commonest complications for pregnancies affected by diabetes. As macrosomia is associated with an increased risk of a number of adverse outcomes for both the mother and offspring, accurate antenatal prediction of fetal macrosomia could be beneficial in guiding appropriate models of care and interventions that may avoid or reduce these associated risks. However, current prediction strategies which include physical examination and ultrasound assessment, are imprecise. Biomarkers are proving useful in various specialties and may offer a new avenue for improved prediction of macrosomia. Prime biomarker candidates in pregnancies with diabetes include maternal glycaemic markers (glucose, 1,5-anhydroglucitol, glycosylated hemoglobin) and hormones proposed implicated in placental nutrient transfer (adiponectin and insulin-like growth factor-1). There is some support for an association of these biomarkers with birthweight and/or macrosomia, although current evidence in this emerging field is still limited. Thus, although biomarkers hold promise, further investigation is needed to elucidate the potential clinical utility of biomarkers for macrosomia prediction for pregnancies affected by diabetes.

From Placenta to Polycystic Ovarian Syndrome: The Role of Adipokines

Adipokines are cytokines produced mainly by adipose tissue, besides many other tissues such as placenta, ovaries, peripheral-blood mononuclear cells, liver, muscle, kidney, heart, and bone marrow. Adipokines play a significant role in the metabolic syndrome and in cardiovascular diseases, have implications in regulating insulin sensitivity and inflammation, and have significant effects on growth and reproductive function. The objective of this review was to analyze the functions known today of adiponectin, leptin, resistin, and visfatin from placenta throughout childhood and adolescence. It is well known now that their serum concentrations during pregnancy and lactation have long-term effects beyond the fetus and newborn. With regard to puberty, adipokines are involved in the regulation of the relationship between nutritional status and normal physiology or disorders of puberty and altered gonadal function, as, for example, premature pubarche and polycystic ovarian syndrome (PCOS). Cytokines are involved in the maturation of oocytes and in the regular progression of puberty and pregnancy.

Ethnic Differences in Maternal Adipokines during Normal Pregnancy

Two adipokines (adiponectin and resistin) have opposite relations with insulin resistance and inflammation. Our major focus was to determine whether there were detectable ethnic differences in maternal adipokines during pregnancy. We also explored the correlation of the adipokines with maternal glucose homeostasis, blood pressure and anthropometric parameters. Pregnant women (n = 1634) were from a large prospective cohort study in Camden NJ (African-American 36.8%; Hispanic 47.6%; Caucasian 15.6%). Serum adiponectin and resistin were measured at entry (week 16.8) and the 3rd trimester (week 30.7) using the Luminex xMapTechnology. Significant differences were observed among ethnic groups, controlling for confounding variables. African American women were exceptional in that they had decreased adiponectin and increased resistin throughout the course of pregnancy (p < 0.05 to p < 0.0001) and a greater than two fold risk of simultaneously exhibiting low adiponectin (lowest tertile) and high resistin (highest tertile) compared to Caucasians and/or Hispanics. The cohort as a whole and each ethnic group showed similar negative correlations between adiponectin, and glucose homeostasis, blood pressure and anthropometric parameters but there was lesser correspondence with resistin. Our data underscore the need for further research on ethnic variation in adipokines and other physiologic biomarkers during complicated and uncomplicated pregnancy.

Maternal, umbilical arterial and umbilical venous 25-hydroxyvitamin D and adipocytokine concentrations in pregnancies with and without gestational diabetes

OBJECTIVE

Gestational diabetes mellitus (GDM) has been associated with inflammation as well as Vitamin D insufficiency. While Vitamin D has anti-inflammatory properties, relationships between Vitamin D and inflammatory markers remain unexplored in GDM. Therefore, this case--control study investigated adipocytokine and Vitamin D [25(OH)D] concentrations and correlations in GDM and control women, as well as their neonates.

DESIGN/PARTICIPANTS/MEASUREMENTS

seventy-three women participated: 36 GDM and 37 controls. Maternal samples were drawn at 31 weeks. Umbilical arterial and venous samples were collected at birth. 25(OH)D and adipocytokine concentrations were compared for GDM vs control maternal, umbilical arterial and venous samples. Correlations were explored between biochemical results, maternal and neonatal demographics.

RESULTS

Compared with age- and weight-matched control participants, GDM women had significantly lower concentrations of 25(OH)D (77·3 ± 24·3 vs 93·2 ± 19·2 nm/l; P = 0·009); adiponectin (17·5 ± 11·8 vs 34·1 ± 20·3 μg/ml, P < 0·001); resistin (25·4 ± 9·1 vs 31·9 ± 12·1 ng/ml, P = 0·045); and plasminogen activator inhibitor-1 (PAI-1) 13·9 ± 10·0 vs 21·0 ± 12·6 ng/ml, P = 0·038), while delivering 1 week earlier (38·2 ± 1·2 vs 39·5 ± 0·9 weeks, P < 0·001). GDM maternal 25(OH)D concentrations positively correlated with PAI-1, IL-8 and TNF-α concentrations. Umbilical 25(OH)D concentrations were not significantly different in GDM vs control offspring, whereas adiponectin, resistin and PAI-1 concentrations were significantly lower in GDM offspring.

CONCLUSIONS

GDM women had lower 25(OH)D concentrations than controls, while neonatal umbilical concentrations of 25(OH)D did not differ. GDM maternal and GDM offspring had lower adiponectin, resistin and PAI-1 concentrations compared with controls. Results suggest that both GDM women and their offspring demonstrate abnormal adipocytokine patterns.

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.

Adipocytokines and insulin resistance across various degrees of glucose tolerance in pregnancy

OBJECTIVE

Gestational diabetes mellitus is characterized by progressive insulin resistance. Adipocytokines are thought to be associated with insulin resistance. This cross-sectional study evaluated the associations between serum concentrations of several adipocytokines and insulin resistance at different stages of glucose tolerance in pregnancy, using the homeostasis model assessment of insulin resistance (HOMA-IR) as a reference.

METHODS

According to oral glucose tolerance test results, 74 pregnant women were divided into three groups: normal glucose tolerance (n = 25); intermediate glucose tolerance (n = 19); gestational diabetes mellitus (n = 30). Adiponectin, leptin, resistin, visfatin and retinol-binding protein 4 (RBP4) concentrations were measured using enzyme-linked immuno sorbent assays.

RESULTS

Groups were comparable regarding age, week of gestation and body mass index before gestation. There were statistically significant between-group differences in HOMA-IR, but no significant differences regarding serum adipocytokine concentrations.

CONCLUSIONS

Adipo nectin, leptin, resistin, visfatin and RBP4 were not associated with the degree of glucose tolerance in pregnancy. Concentrations of these adipocytokines are not sufficiently sensitive to replace HOMA- IR in pregnancy.

Chemerin is present in human cord blood and is positively correlated with birthweight

OBJECTIVE

Chemerin, a novel adipokine, has been implicated in adipogenesis, inflammation, and metabolism. The aims of this study were to determine the presence of chemerin in cord blood and its association with birthweight.

STUDY DESIGN

This cross-sectional study included the following: (1) twins with (n = 24) or without (n = 28) birthweight discordancy; and (2) singletons subclassified into small-for-gestational-age (SGA; n = 18); appropriate for gestational age (AGA; n = 33); and large-for-gestational-age (LGA; n = 8). Cord blood chemerin was determined. Parametric and nonparametric statistics were used for analysis.

RESULTS

The results of the study included the following: (1) within the discordant twins group, the median chemerin concentration was significantly lower in the SGA group than in their cotwins; (2) within singletons, the median chemerin concentration was significantly higher in the LGA than the AGA newborns; and (3) the regression model revealed that chemerin was independently associated with birthweight.

CONCLUSION

Cord blood chemerin is present in cord blood and its concentrations are positively correlated with birthweight. These novel findings support a role of adipokines in fetal growth.

New insights on glucose pathophysiology in gestational diabetes and insulin resistance

Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy. The definition of GDM does not preclude the possibility that unrecognized glucose intolerance may have existed before the pregnancy, and the definition applies whether insulin, oral antidiabetic agents, or dietary modification is used for treatment. Approximately 7% of all pregnancies in the United States are complicated by gestational diabetes resulting in more than 200,000 cases annually, but the prevalence ranges from 1% to 14% of all pregnancies depending on the population studied and the diagnostic tests used. Despite the better detection of GDM and recognition of its adverse consequences for mother and baby in many countries, there is still no consensus regarding GDM pathophysiology; as a result, diagnosis and treatment of GDM remain controversial. A better understanding of obesity along with new studies in GDM has identified the intra-abdominal metabolically active adipose tissue as a major factor in the pathophysiology of GDM. This review examines recent research regarding the link between obesity and glucose intolerance and highlights studies in the areas of genetics, glucose transport, and adipokines.