Plasma ghrelin and resistin concentrations are suppressed in infants of insulin-dependent diabetic mothers

Distinct cord blood C-peptide, adipokine, and lipidomic signatures by in utero HIV exposure

BACKGROUND

Early-life metabolic derangements in HIV-exposed uninfected (HEU) infants have been reported.

METHODS

Pregnant women with HIV and HIV-uninfected pregnant women were enrolled with their newborns in a US cohort from 2011 to 2015. We measured cord insulin, C-peptide, and metabolic cytokines of HEU and HIV-unexposed uninfected (HUU) newborns using ELISA and metabolites, lipid subspecies, and eicosanoids via liquid chromatography/mass spectrometry. Linear regression was employed to assess the association of intrauterine HIV/ART with insulin and C-peptide. Graphical lasso regression was used to identify differences between metabolite/lipid subspecies networks associated with C-peptide.

RESULTS

Of 118 infants, 56 were HEU, ART exposed. In adjusted analyses, mean cord insulin (β = 0.295, p = 0.03) and C-peptide (β = 0.522, p < 0.01) were significantly higher in HEU vs. HUU newborns. HEU neonates exhibited primarily positive associations between complex lipids and C-peptide, indicative of fuel storage, and augmented associations between cord eicosanoids and cytokines. HUU neonates exhibited negative associations with lipids and C-peptide indicative of increased fuel utilization.

CONCLUSION

Higher cord insulin and C-peptide in HEU vs. HUU newborns as well as differences in cord metabolites, metabolic-related cytokines, and eicosanoids may reflect a propensity for fuel storage and an inflammatory milieu suggestive of fetal metabolic changes associated with in utero HIV/ART exposure.

IMPACT

There is a paucity of studies assessing cord blood and neonatal metabolic health in HIV-exposed uninfected (HEU) newborns, an increasing population worldwide. Compared to HIV-unexposed uninfected (HUU) newborns, HEU newborns exhibit alterations in fuel homeostasis and an inflammatory milieu associated with in utero HIV/antiretroviral therapy (ART) exposure. The long-term implications of these neonatal findings are as yet unknown, but merit continued evaluation as this important and growing population ages into adulthood.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus-pituitary-gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The Role of the Gastric Hormones Ghrelin and Nesfatin-1 in Reproduction

Ghrelin and nesfatin-1 are enteroendocrine peptide hormones expressed in rat X/A-like and human P/D1cells of the gastric mucosa. Besides their effect on food intake, both peptides are also implicated in various other physiological systems. One of these is the reproductive system. This present review illustrates the distribution of ghrelin and nesfatin-1 along the hypothalamus–pituitary–gonadal (HPG) axis, their modulation by reproductive hormones, and effects on reproductive functions as well as highlighting gaps in current knowledge to foster further research.

The possible role of endocrine dysfunction of adipose tissue in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is diabetes that is first diagnosed in the second or third trimester of pregnancy in patients who did not have a history of diabetes before pregnancy. Consequences of GDM include increased risk of macrosomia and birth complications in the infant and an increased risk of maternal type 2 diabetes mellitus (T2DM) after pregnancy. There is also a longer-term risk of obesity, T2DM, and cardiovascular diseases in the child. GDM is the result of impaired glucose tolerance due to pancreatic β-cell dysfunction on a background of insulin resistance that physiologically increases during pregnancy. The strongest clinical predictors of GDM are overweight and obesity. The fact that women with GDM are more likely to be overweight or obese suggests that adipose tissue dysfunction may be involved in the pathogenesis of GDM, similarly to T2DM. Adipose tissue is not only involved in energy storage but also functions as an active endocrine organ secreting adipokines (specific hormones and cytokines) with the ability to alter insulin sensitivity. Recent evidence points to a crucial role of numerous adipokines produced by fat in the development of GDM. The following text summarizes the current knowledge about a possible role of selected adipokines in the development of GDM.

Diabetes during Pregnancy: A Maternal Disease Complicating the Course of Pregnancy with Long-Term Deleterious Effects on the Offspring. A Clinical Review

In spite of the huge progress in the treatment of diabetes mellitus, we are still in the situation that both pregestational (PGDM) and gestational diabetes (GDM) impose an additional risk to the embryo, fetus, and course of pregnancy. PGDM may increase the rate of congenital malformations, especially cardiac, nervous system, musculoskeletal system, and limbs. PGDM may interfere with fetal growth, often causing macrosomia, but in the presence of severe maternal complications, especially nephropathy, it may inhibit fetal growth. PGDM may also induce a variety of perinatal complications such as stillbirth and perinatal death, cardiomyopathy, respiratory morbidity, and perinatal asphyxia. GDM that generally develops in the second half of pregnancy induces similar but generally less severe complications. Their severity is higher with earlier onset of GDM and inversely correlated with the degree of glycemic control. Early initiation of GDM might even cause some increase in the rate of congenital malformations. Both PGDM and GDM may cause various motor and behavioral neurodevelopmental problems, including an increased incidence of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Most complications are reduced in incidence and severity with the improvement in diabetic control. Mechanisms of diabetic-induced damage in pregnancy are related to maternal and fetal hyperglycemia, enhanced oxidative stress, epigenetic changes, and other, less defined, pathogenic mechanisms.

Gestational Diabetes Mellitus and Infant Adiposity at Birth: A Systematic Review and Meta-Analysis of Therapeutic Interventions

Exposure to untreated gestational diabetes mellitus (GDM) in utero increases the risk of obesity and type 2 diabetes in adulthood, and increased adiposity in GDM-exposed infants is suggested as a plausible mediator of this increased risk of later-life metabolic disorders. Evidence is equivocal regarding the impact of good glycaemic control in GDM mothers on infant adiposity at birth. We systematically reviewed studies reporting fat mass (FM), percent fat mass (%FM) and skinfold thicknesses (SFT) at birth in infants of mothers with GDM controlled with therapeutic interventions (IGDMtr). While treating GDM lowered FM in newborns compared to no treatment, there was no difference in FM and SFT according to the type of treatment (insulin, metformin, glyburide). IGDMtr had higher overall adiposity (mean difference, 95% confidence interval) measured with FM (68.46 g, 29.91 to 107.01) and %FM (1.98%, 0.54 to 3.42) but similar subcutaneous adiposity measured with SFT, compared to infants exposed to normal glucose tolerance (INGT). This suggests that IGDMtr may be characterised by excess fat accrual in internal adipose tissue. Given that intra-abdominal adiposity is a major risk factor for metabolic disorders, future studies should distinguish adipose tissue distribution of IGDMtr and INGT.

Altered Resistin Concentrations in Mid-trimester Amniotic Fluid of Fetuses With Trisomies 18 and 13: A Window onto the Pathophysiology of Trisomies 18 and 13

BACKGROUND/AIM

The study aimed to examine whether resistin is present in second trimester amniotic fluid from pregnancies with trisomy 18 and 13 and evaluate its concentration in comparison with euploid pregnancies.

PATIENTS AND METHODS

The study included 37 women who underwent amniocentesis. Eleven fetuses had trisomy 18, 3 had trisomy 13, while 23 had a normal karyotype.

RESULTS

Resistin was detected in all cases. The mean level of resistin in trisomy 18 was statistically significantly lower compared to euploid controls. Resistin levels in all abnormal cases were below its median concentration in euploid controls. ROC analysis showed very good prognostic value for both trisomies.

CONCLUSION

Resistin is a constituent of mid-trimester amniotic fluid of pregnancies with trisomies 13 and 18, exhibiting lower levels than those in euploid fetuses. The reduced levels of resistin in amniotic fluid may be associated with early changes in metabolic pathways and immunoinflammatory responses.

Obesity in Type 1 Diabetes: Pathophysiology, Clinical Impact, and Mechanisms

There has been an alarming increase in the prevalence of obesity in people with type 1 diabetes in recent years. Although obesity has long been recognized as a major risk factor for the development of type 2 diabetes and a catalyst for complications, much less is known about the role of obesity in the initiation and pathogenesis of type 1 diabetes. Emerging evidence suggests that obesity contributes to insulin resistance, dyslipidemia, and cardiometabolic complications in type 1 diabetes. Unique therapeutic strategies may be required to address these comorbidities within the context of intensive insulin therapy, which promotes weight gain. There is an urgent need for clinical guidelines for the prevention and management of obesity in type 1 diabetes. The development of these recommendations will require a transdisciplinary research strategy addressing metabolism, molecular mechanisms, lifestyle, neuropsychology, and novel therapeutics. In this review, the prevalence, clinical impact, energy balance physiology, and potential mechanisms of obesity in type 1 diabetes are described, with a special focus on the substantial gaps in knowledge in this field. Our goal is to provide a framework for the evidence base needed to develop type 1 diabetes-specific weight management recommendations that account for the competing outcomes of glycemic control and weight management.

The role of obesity and adipose tissue dysfunction in gestational diabetes mellitus

Gestational diabetes mellitus is defined as diabetes diagnosed in the second or third trimester of pregnancy in patients with no history of diabetes prior to gestation. It is the most common complication of pregnancy. The underlying pathophysiology shares some common features with type 2 diabetes mellitus (T2DM) combining relatively insufficient insulin secretion with increased peripheral insulin resistance. While a certain degree of insulin resistance is the physiological characteristics of the second half of pregnancy, it is significantly more pronounced in patients with gestational diabetes. Adipose tissue dysfunction and subclinical inflammation in obesity are well-described causes of increased insulin resistance in non-pregnant subjects and are often observed in individuals with T2DM. Emerging evidence of altered adipokine expression and local inflammation in adipose tissue in patients with gestational diabetes suggests an important involvement of adipose tissue in its etiopathogenesis. This review aims to summarize current knowledge of adipose tissue dysfunction and its role in the development of gestational diabetes. We specifically focus on the significance of alterations of adipokines and immunocompetent cells number and phenotype in fat. Detailed understanding of the role of adipose tissue in gestational diabetes may provide new insights into its pathophysiology and open new possibilities of its prevention and treatment.

The Relationship Between Skinfold Thickness and Leptin, Ghrelin, Adiponectin, and Resistin Levels in Infants of Diabetic Mothers

This study aimed to investigate the relationship between skinfold thickness and serum leptin, ghrelin, adiponectin, and resistin levels in infants of diabetic mothers. Biochemical parameters were also similar for the two groups (infants of diabetic mothers and controls) (p > 0.05). We confirmed that there was a negative correlation between birth weight and serum ghrelin level (p < 0.05) in the two groups. When it was evaluated for control newborns, a positive correlation between abdominal circumference and serum resistin level was found in the controls (p < 0.05). Our results indicate that gestational diabetes by appropriate diet or insulin treatment may be effective in the protection of fetuses of diabetic mothers from the negative effects of gestational diabetes. Ghrelin alone was negatively correlated with birth weight. This negative correlation could be potentially advantageous to infants, because a reduction in appetite might prevent excessive food intake and postnatal weight gain.

Diabetes in pregnancy and infant adiposity: systematic review and meta-analysis

OBJECTIVE

Maternal glycaemia and anthropometry-derived newborn adiposity are strongly correlated. The children of mothers with diabetes are at greater risk of adverse metabolic health, and increased adiposity is a plausible mediator. We undertook a systematic review and meta-analysis to compare adiposity in infants of diabetic mothers (IDM) and infants of mothers without diabetes (NIDM).

DESIGN

We identified observational studies reporting adiposity in IDM and NIDM. We searched references, traced forward citations and contacted authors for additional data. We considered all body composition techniques and compared fat mass, fat-free mass, body fat % and skinfold thickness. We used random effects meta-analyses and performed subgroup analyses by maternal diabetes type (type 1, type 2 and gestational) and infant sex. We examined the influence of pre-pregnancy body mass index (BMI) and conducted sensitivity analyses.

RESULTS

We included data from 35 papers and over 24 000 infants. IDM have greater fat mass than NIDM (mean difference (95% CI)): 83 g (49 to 117). Fat mass is greater in infants of mothers with gestational diabetes: 62 g (29 to 94) and type 1 diabetes: 268 g (139 to 397). Insufficient studies reported data for type 2 diabetes separately. Compared with NIDM, fat mass was greater in IDM boys: 87 g (30 to 145), but not significantly different in IDM girls: 42 g (-33 to 116). There was no attenuation after adjustment for maternal BMI.

CONCLUSIONS

IDM have significantly greater adiposity in comparison with NIDM. These findings are justification for studies to determine whether measures to reduce infant adiposity will improve later health.

Lower Plasma Ghrelin Levels are Found in Women with Diabetes-Complicated Pregnancies

OBJECTIVE

To evaluate the associations of glycemic control and gestational age with ghrelin and proinsulin levels in cord blood and mothers' peripheral blood during pregnancy.

METHODS

This is a cross-sectional comparative study of twenty-four pregnant women with gestational diabetes (GD), 18 with type 2 diabetes mellitus (T2DM), and 36 without diabetes, as well as their neonates. Levels of proinsulin, ghrelin, and glycated hemoglobin A1c (HbA1c) were measured from maternal blood during the last week before caesarian delivery and in neonatal umbilical cord blood samples.

RESULTS

Mothers with GD and T2DM had significantly lower ghrelin levels compared to the healthy mothers (p<0.001). Maternal proinsulin was lower in women with GD than in women without diabetes (p<0.001). Proinsulin was significantly elevated in the neonates of women with GD and in women with HbA1c ≥6.5% (p<0.001). However, maternal ghrelin levels were higher (p=0.031) and neonate proinsulin levels lower in the pre-term offspring of mothers with GD (p=0.033). There was a negative correlation between HbA1c levels and birth weight (r=-0.407, p<0.001).

CONCLUSION

Ghrelin levels were lower in pregnant women with diabetes, although pre-term birth appeared to reverse this trend in GD. Proinsulin levels were also low in pregnant women with diabetes and even lower in pre-term vs. at-term births. Both ghrelin and proinsulin levels were lower in pregnant women with diabetes and HbA1c of <6.5%. Thus, ghrelin participates in the adaptation to the caloric imbalance of diabetic pregnancy and may play a similar role in pregnancy-related complications, since high ghrelin concentrations may be necessary for normal fetal development.

Newborn Adipokines and Birth Outcomes

BACKGROUND

Adipokines can serve as a measure of adipose tissue activity. Although birthweight correlates with neonatal adiposity, findings for cord blood levels of adipokines and birth outcomes have been conflicted. Therefore, we determined the cross-sectional associations between adipokines measured in newborn dried blood spots (DBS) and birth outcomes.

METHODS

The Upstate KIDS study enrolled mothers and infants from 2008 to 2010. Among infants whose parents consented to the use of residual DBS from newborn screening, 2397 singletons and 1240 twins had adipokine measurements from the Human Obesity Panel (R&D Systems) by Luminex. Odds ratios were estimated by multivariable logistic regression for risk of birth outcomes of preterm delivery (<37 weeks for singletons, <32 for twins) and small-for-gestational age (SGA <10th for singletons and <3rd for twins age- and sex-specific percentiles) by adipokine quintiles. Generalised estimating equations were applied to account for correlations between twins.

RESULTS

Singletons in the lowest compared with the highest quintile of adiponectin were more likely preterm (adjusted odds ratio 3.26; 95% confidence interval [CI] 1.99, 5.34) and SGA (1.81; [95% CI 1.18, 2.77]). Similar associations were observed among twins. Resistin was associated with preterm birth (Q1 vs. Q5: 2.08; [95% CI 1.20, 3.62]) only among singletons. Adipsin had inconsistent associations after adjustment.

CONCLUSIONS

This large population-based study demonstrates that newborn DBS-measured adipokines are associated with birth outcomes, particularly preterm birth and SGA among those with lower adiponectin levels regardless of plurality.

Effect of maternal diabetes on the embryo, fetus, and children: congenital anomalies, genetic and epigenetic changes and developmental outcomes

INTRODUCTION

Pregestational and gestational diabetes mellitus (PGDM; GDM) are significant health concerns because they are associated with an increased rate of malformations and maternal health complications.

METHODS

We reviewed the data that help us to understand the effects of diabetes in pregnancy.

RESULTS

Diabetic embryopathy can affect any developing organ system, but cardiovascular and neural tube defects are among the most frequent anomalies. Other complications include preeclampsia, preterm delivery, fetal growth abnormalities, and perinatal mortality. Neurodevelopmental studies on offspring of mothers with diabetes demonstrated increased rate of Gross and Fine motor abnormalities, of Attention Deficit Hyperactivity Disorder, learning difficulties, and possibly also Autism Spectrum Disorder. The mechanisms underlying the effects of maternal hyperglycemia on the developing fetus may involve increased oxidative stress, hypoxia, apoptosis, and epigenetic changes. Evidence for epigenetic changes are the following: not all progeny are affected and not to the same extent; maternal diet may influence pregnancy outcomes; and maternal diabetes alters embryonic transcriptional profiles and increases the variation between transcriptomic profiles as a result of altered gene regulation. Research in animal models has revealed that maternal hyperglycemia is a teratogen, and has helped uncover potential therapeutic targets which, when blocked, can mitigate or ameliorate the negative effects of diabetes on the developing fetus.

CONCLUSIONS

Tight metabolic control, surveillance, and labor management remain the cornerstone of care for pregnant women with diabetes, but advances in the field indicate that new treatments to protect the mother and baby are not far from becoming clinical realities.

Gut hormone activity of children born to women with and without gestational diabetes

What is already known about this subject Children born to women with gestational diabetes have greater risk for obesity. Obesity in adults and children is associated with blunted postprandial gut hormone responses. What this study adds Children of women with gestational diabetes have a blunted postprandial response of GLP-1. Children of women with gestational diabetes have high fasting PYY concentrations.

BACKGROUND

Intrauterine exposure to gestational diabetes mellitus (GDM) increases risk for obesity. Obesity is associated with a blunted postprandial gut hormone response, which may impair satiety and thereby contribute to weight gain. The postprandial response of gut hormones among children of women with GDM has not previously been investigated.

OBJECTIVE

To examine whether children of women with GDM have suppressed peptide-tyrosine-tyrosine (PYY) and glucagon-like-peptide-1 (GLP-1), and higher concentrations of ghrelin, following a meal challenge. A secondary objective was to investigate associations of these hormones with children's free-living energy intake.

METHODS

Children (n = 42) aged 5-10 years were stratified into two groups: offspring of GDM mothers (OGD) and of non-diabetic mothers (CTRL). Body composition was measured by dual-energy X-ray absorptiometry, and circulating PYY, GLP-1 and total ghrelin were measured during a liquid meal challenge. Energy intake was assessed by three 24-h diet recalls.

RESULTS

Between-groups analyses of fasting and incremental area under the curve (AUC) found no differences in ghrelin. Incremental AUC for GLP-1 was greater among the CTRL vs. OGD (P < 0.05), and fasting PYY, but not incremental AUC, was higher among OGD vs. CTRL (P < 0.01). Associations of fasting and incremental AUC for each gut hormone with children's usual energy intake did not differ significantly by group.

CONCLUSIONS

Further research is needed to more fully examine the potential role of postprandial GLP-1 suppression and high-fasting PYY concentrations on the feeding behaviour and risk for obesity among children exposed to GDM in utero.

Resistin in mid-trimester amniotic fluid in trisomy 21

OBJECTIVE

The aim of this study was to examine whether resistin is present in second trimester amniotic fluid from trisomy 21 (also known as Down's syndrome) pregnancies and whether its concentration differs compared with euploid pregnancies.

METHODS

The study cohort consisted of 58 women in the mid-trimester of pregnancy who underwent amniocentesis for prenatal diagnosis, 31 of whom carried a single fetus with diagnosed trisomy 21 (study group) and the rest with normal karyotype (control group, n = 27). Groups were matched for maternal and gestational age. Levels of resistin in amniotic fluid were measured by a commercially available enzyme-linked immunosorbent assay (ELISA) kit.

RESULTS

Resistin was detected in all amniotic fluid samples. Its median concentration in the second trimester amniotic fluid of trisomy 21 pregnancies (2.1 ng/ml) was statistically significantly lower (p value <0.001) in comparison with that in euploid pregnancies (3.3 ng/ml).

CONCLUSIONS

Resistin is a physiologic constituent of second trimester amniotic fluid. Lower levels of amniotic fluid resistin in pregnancies with trisomy 21 may reflect altered metabolic pathways in utero that could possibly be related with phenotypic features of the syndrome.

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.

Resistin and leptin in breast milk and infants in early life

BACKGROUND

The role of adipokines in early life is considered an emerging topic issue in nutritional researches.

AIMS

To evaluate serum resistin and leptin concentrations and their relations in infants and in breast milk.

STUDY DESIGN

We enrolled 41 term, AGA, healthy infants, of which 23 exclusively breast-fed (BF) and 18 formula-fed (FF), aged less than 6 months. Breast milk (BM) samples were collected from 23 breastfeeding mothers of the infants enrolled. Resistin concentration in serum and BM was determined by ELISA test (Human-Resistin-ELISA, Mediagnost, Reutlingen, Germany). Leptin concentration was determined by Radioimmunoassay method (LEP-R40, Mediagnost, Reutlingen, Germany). Infants weight, length and body mass index were measured. We used Mann-Whitney test. Spearman correlation was applied. Statistical significance was set at p<0.05. Data are reported as median and interquartile range (IR).

RESULTS

Infants serum resistin concentration was 9.30 (5.02) ng/ml. Breast milk resistin concentration (n=23) was 0.18 (0.44) ng/ml. Leptin concentration was 3.04 (3.68) ng/ml in infants serum and in BM was 2.34 (5.73) ng/ml. Serum resistin concentrations in BF infants correlated positively with BM resistin (r=0.636, p=0.035). We have shown a positive correlation between resistin and leptin in total group of infants (r=0.44, p=0.05), confirmed in breastfed subjects (r=0.65, p=0.02). No correlations were found between serum hormones and anthropometric parameters of infants.

CONCLUSION

Our findings show interestingly a positive correlation between resistin concentrations in BF infants serum and in BM and between resistin and leptin in infants.

Breast milk hormones and regulation of glucose homeostasis

Growing evidence suggests that a complex relationship exists between the central nervous system and peripheral organs involved in energy homeostasis. It consists in the balance between food intake and energy expenditure and includes the regulation of nutrient levels in storage organs, as well as in blood, in particular blood glucose. Therefore, food intake, energy expenditure, and glucose homeostasis are strictly connected to each other. Several hormones, such as leptin, adiponectin, resistin, and ghrelin, are involved in this complex regulation. These hormones play a role in the regulation of glucose metabolism and are involved in the development of obesity, diabetes, and metabolic syndrome. Recently, their presence in breast milk has been detected, suggesting that they may be involved in the regulation of growth in early infancy and could influence the programming of energy balance later in life. This paper focuses on hormones present in breast milk and their role in glucose homeostasis.

Maternal serum resistin concentrations in gestational diabetes mellitus and normal pregnancies

AIM

To investigate changes in maternal serum resistin levels during pregnancy and postpartum and clarify their relationship to insulin resistance.

METHODS

Thirty normal pregnant women were compared to 30 women diagnosed with gestational diabetes mellitus (GDM). Serum resistin levels were collected at the time of glucose challenge test (26-28 weeks), at 38 gestational weeks and at the third postpartum day and measured with enzyme immunoassay. Correlation of resistin to the homeostatic model assessment-insulin resistance (HOMA-IR) was performed.

RESULTS

Maternal serum resistin levels at 38 weeks were significantly higher in pregnant women with GDM compared to the control group (0.28 vs 0.21 ng/mL, P = 0.02) and the same was true for the immediate puerperium (0.25 vs 0.19 ng/mL, P = 0.03). A significant increase in resistin levels was observed in GDM women from 26-28 weeks to 38 weeks (0.21 vs 0.28 ng/mL, P = 0.02), but not in controls. A decrease in serum resistin levels was noted in both the GDM and control groups, at 38 weeks and the immediate postpartum period, but this decrease did not reach statistical significance in either of the two groups. Resistin levels were positively correlated to HOMA-IR at 26-28 weeks of gestation (r = +0.253, P = 0.05).

CONCLUSION

GDM is associated with increased resistin serum levels in term pregnancy as well as postpartum. Resistin is positively correlated to HOMA-IR at 26-28 weeks of gestation. A reduction in maternal resistin after delivery indicates a significant placental or fetal contribution in the production of resistin.

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

OBJECTIVE

To evaluate the role of resistin in the pathophysiology of insulin resistance during pregnancy and on the birth weight of infants born from women with gestational diabetes (GDM).

MATERIAL AND METHODS

Thirty women diagnosed with GDM were compared to 30 normal pregnant controls. Maternal serum resistin and insulin levels were measured at the time of the oral glucose tolerance test screening. In addition, umbilical levels of resistin and insulin were measured at the time of delivery.

RESULTS

There was no difference in maternal serum resistin levels in women with GDM as compared to normal controls at 24-26 weeks. There was no difference in umbilical resistin levels between the infants born in the two groups. There was no correlation between infant weight and either maternal resistin at 24-26 week or umbilical resistin levels.

CONCLUSION

There were no significant differences in umbilical resistin levels between infants born of women with GDM as compared to normal pregnant women. In addition, there was no correlation between resistin levels during pregnancy, as well as between umbilical resistin levels and neonatal birth weight. In conclusion, resistin seems to play a rather minor role in the pathophysiology of GDM and the energy metabolism during fetal life.

The role of adipocytokines in fetal growth

Cumulative evidence suggests that the origins of obesity may occur during fetal development. In this respect, the concept of "developmental programming" was introduced and supported by experimental and epidemiological data. This concept supports the idea that the nutritional and hormonal status during pregnancy could irreversibly interfere in metabolism control. The mechanisms responsible for this developmental programming remain poorly documented. However, recent research indicates that adipocytokines may play a critical role in this process. Thus, leptin, adiponectin, and the recently identified resistin, visfatin, and apelin, all exert effects on fat, muscle, and liver cells early in life. The aforementioned adipocytokines are secreted by adipocytes and human placenta during fetal life and may play a major role in the etiopathogenesis of the metabolic syndrome. This review will focus on the intrauterine expression of adipocytokines, their contribution to the hormonal control of fetal growth, and their role in restricted and exaggerated intrauterine growth.

Cord blood resistin and adiponectin in term newborns of diabetic mothers

INTRODUCTION

Adipose tissue can release hormones into the blood stream in response to specific extracellular stimuli or changes in metabolic status. Resistin, an adipose-secreted factor, is primarily involved in the modulation of insulin sensitivity and adipocyte differentiation. Adiponectin, an adipocyte-specific hormone with insulin sensitizing, anti-inflammatory and anti-atherogenic effects, is reduced in obesity and type II diabetes. The aim of the study was to assess the influence of maternal pre-existing diabetes on cord blood resistin and adiponectin at birth in relation to neonatal anthropometric parameters and cord blood insulin levels.

MATERIAL AND METHODS

A total of 60 term newborns were prospectively enrolled and categorized into three groups: 20 were macrosomic infants of pre-gestational diabetic mothers (group I), 20 were non-macrosomic infants of pre-gestational diabetic mothers (group II) and 20 were healthy non-macrosomic infants born to non-diabetic mothers serving as controls (group III). Infants' anthropometric indices were recorded. Cord blood samples for glucose, insulin, resistin and adiponectin assay, together with maternal glycosylated haemoglobin were obtained.

RESULTS

Serum insulin was increased while resistin and adiponectin were significantly decreased in infants of diabetic mothers (IDMs) compared to the control group. Serum glucose, insulin, resistin and adiponectin were comparable in group I and II. Cord serum resistin correlated positively with cord blood glucose in IDMs in both macrosomic and non-macrosomic groups. Cord serum insulin correlated positively with triceps skinfold thickness in all studied neonates. Cord serum resistin and adiponectin showed no correlation with neonatal anthropometric indices. Multiple regression analysis demonstrated that insulin, resistin and adiponectin together were highly correlated with birth weight, with adiponectin as the one responsible for this positive correlation.

CONCLUSIONS

Infants of diabetic mothers had elevated levels of cord serum insulin and suppressed levels of cord serum resistin and adiponectin, suggesting that the regulation of these metabolic pathways is probably operational before birth. Levels were comparable in both macrosomic and non-macrosomic neonates.

Umbilical cord ghrelin in term and preterm newborns and its relation to metabolic hormones and anthropometric measurements

The aim of the study was to assess umbilical cord ghrelin level in term and preterm newborns and its relation to other metabolic hormones and anthropometric measurements. A cross sectional comparative study included 50 normal appropriate-for-gestational-age newborns (25 full-terms; 25 preterm). Assessment of anthropometric measurements, cord levels of ghrelin, leptin, insulin and glucose were done to all newborns. Umbilical cord ghrelin was detected in all newborns. There was no significant difference between term and preterm groups regarding ghrelin, insulin and glucose. Leptin was significantly lower in preterm than term group. Sex and mode of delivery had no effects regarding all studied variables. There was no overall correlation between ghrelin and gestational age, anthropometric measurements, leptin, insulin or glucose in all newborns. Preterm group demonstrated significant correlations between ghrelin and weight, body mass index and abdominal circumference. An overall significant correlation was found between leptin and gestational age and anthropometric measurements in all newborns. In preterm group leptin correlated with weight, length, subscapular skin-fold thickness and abdominal circumference. To conclude the umbilical cord ghrelin was relatively invariable at birth between 30 and 41 weeks gestation showing no gestational age-related variation, unlike leptin, which was lower in preterm group indicating increased adipose mass and placental maturation with increased gestational age.

Ghrelin levels are decreased in non-obese prepubertal children born large for gestational age

BACKGROUND

Ghrelin is the natural ligand of GH secretagogue receptor. It has several metabolic functions including regulation of food intake, energy homeostasis, and body weight. An inverse relationship between fasting plasma ghrelin and insulin concentrations has been shown. Being born large for gestational age (LGA) has an increased risk of developing insulin resistance.

OBJECTIVE

The aim of this study was to evaluate ghrelin levels in LGA born children who have no obesity at prepubertal ages and the effect of intrauterine and postnatal growth on ghrelin levels. Patients and methods Thirty-two (17F, 15M) LGA born non-obese children (mean (+/-s.e.m.) age 4.4+/-0.3 years) were evaluated with respect to glucose, insulin, and ghrelin levels. Their data were compared with that of non-obese 45 (19F, 26M) appropriate for gestational age (AGA) children (mean (+/-s.e.m.) age 4.0+/-0.1 years).

RESULTS

LGA children, who had similar age and body mass index (BMI) standard deviation score (SDS) as AGA children, had significantly higher insulin (P=0.044) and at a borderline significance higher homeostasis model assessment-insulin resistance levels (P=0.054) than AGA children. Ghrelin level was significantly lower in LGA born than AGA born children (P=0.001) even after controlling for age, sex, and BMI (P=0.006). There were no differences between genders in insulin and ghrelin levels. Multivariate analysis revealed that birth weight was the only significant parameter influencing ghrelin levels (R(2)=0.13, B=-0.007, P=0.002).

CONCLUSIONS

LGA born non-obese prepubertal children have lower ghrelin levels when compared with age and BMI matched AGA children. Birth weight seems to have the only significant effect on the reduced ghrelin levels.

Serum levels of resistin and its correlation with adiponectin and insulin in healthy full term neonates

Resistin and adiponectin are two adipokines involved in the regulation of insulin sensitivity, and have been suggested as mediators of adult metabolic syndrome.

AIM

The aim of this study was to investigate cord blood levels of resistin, and their postnatal changes in full-term appropriate for gestational age (AGA) neonates. Interrelations between resistin, adiponectin, and insulin, and between resistin and neonatal and maternal anthropometric parameters were also assessed.

DESIGN

Blood samples were obtained from 30 full term AGA neonates at birth and on the 4th day of life. Anthropometric variables studied included birth weight, length, body mass index (BMI), neonatal weight loss, and mother's BMI. Resistin and adiponectin were determined by ELISA, and insulin by radioimmunoassay method. Data were analyzed using Wilcoxon test and Spearman's correlation coefficient.

RESULTS

Resistin levels were high at birth and did not change on the 4th day of life. Resistin levels were not correlated to insulin, nor adiponectin levels, nor any anthropometric parameter of neonates or their mothers. Instead, adiponectin levels increased on the 4th day of life, and were correlated to insulin levels.

CONCLUSION

High levels of resistin in full-term AGA neonates suggest that this hormone may play a role in maintenance of metabolic neonatal homeostasis, but its physiological significance needs further investigation.

Resistin in amniotic fluid and its association with intra-amniotic infection and inflammation

OBJECTIVE

Intra-amniotic infection/inflammation (IAI) is one of the most important mechanisms of disease in preterm birth. Resistin is an adipocytokine that has been linked to insulin resistance, diabetes, obesity and inflammation. The objective of this study was to determine if resistin is present in amniotic fluid (AF) and if its concentration changes with gestational age, in the presence of labour, and in IAI in patients with spontaneous preterm labour (PTL) and intact membranes, preterm prelabour rupture of membranes (PPROM) and clinical chorioamnionitis.

STUDY DESIGN

This cross-sectional study included 648 patients in the following groups: (1) women in the mid-trimester of pregnancy (14-18 weeks) who underwent amniocentesis for genetic indications and delivered a normal neonate at term (n = 61); (2) normal pregnant women at term with (n = 49) and without (n = 50) spontaneous labour; (3) patients with an episode of PTL and intact membranes who were classified into: (a) PTL who delivered at term (n = 153); (b) PTL who delivered preterm (<37 weeks gestation) without IAI (n = 108); and (c) PTL with IAI (n = 84); (4) women with PPROM with (n = 47) and without (n = 44) IAI; and (5) patients with clinical chorioamnionitis at term with (n = 22) and without (n = 30) microbial invasion of the amniotic cavity. Resistin concentration in AF was determined by enzyme-linked immunoassay. Non-parametric statistics were used for analyses.

RESULTS

(1) Resistin was detected in all AF samples; (2) the median AF resistin concentration at term was significantly higher than in the mid-trimester (23.6 ng/mL vs. 10 ng/mL; p < 0.001); (3) among patients with PTL, the median AF resistin concentration was significantly higher in patients with IAI than in those without IAI (144.9 ng/mL vs. 18.7 ng/mL; p < 0.001) and those with PTL and intact membranes who delivered at term (144.9 ng/mL vs. 16.3 ng/mL; p < 0.001); (4) patients with PPROM with IAI had a significantly higher median AF resistin concentration than those without IAI (132.6 ng/mL vs. 13 ng/mL; p < 0.001); (5) no significant differences were observed in the median AF resistin concentration between patients with spontaneous labour at term and those at term not in labour (28.7 ng/mL vs. 23.6 ng/mL; p = 0.07); and (6) AF resistin concentration > or =37 ng/mL (derived from a receiver-operating characteristic curve) had a sensitivity of 85.4% and a specificity of 94.3% for the diagnosis of intra-amniotic inflammation.

CONCLUSIONS

Resistin is a physiologic constituent of the AF, and its concentrations in AF: (1) are significantly elevated in the presence of IAI; (2) increase with advancing gestation; and (3) do not change in the presence of spontaneous labour at term. We propose that resistin may play a role in the innate immune response against intra-amniotic infection.

Comparison of maternal ghrelin and leptin in healthy mothers and mothers with Type 1 diabetes

AIMS

Maternal leptin affects placental growth hormone (GH), whereas ghrelin, a natural ligand of the growth-hormone-secretagogue receptor, modulates GH action. Both hormones may affect fetal growth, and dysregulation in diabetes may lead to fetal growth disturbances. The aim was to investigate changes in maternal ghrelin during pregnancy with diabetes and to establish reference leptin levels.

METHODS

Twelve healthy non-diabetic (ND) and 12 pregnant women with Type 1 diabetes (T1DM) were recruited. Age and body mass index (BMI) [ND: age 29.9 +/- 4.7 years (mean +/- sd), BMI 25.2 +/- 3.7 kg/m2; T1DM: age 31 +/- 5.5 years, BMI 27 +/- 3.1 kg/m2] were similar in the groups. HbA1c in T1DM was 6.2 +/- 1.1% at 20 weeks, 6.3 +/- 1.1% at 30 weeks' gestation and 7.8 +/- 2.1% postpartum. Fasting plasma ghrelin, total leptin, free leptin (FL) and soluble leptin receptor (sOB-R) levels were measured at 20 and 30 weeks' gestation and postpartum and determined by radioimmunoassay.

RESULTS

All pregnancies resulted in full-term singleton births with no differences in birth weight between groups [T1DM: 3.4 +/- 0.56 kg (mean +/- SE); ND: 3.6 +/- 0.3 kg, P = NS]. Ghrelin levels were lower in T1DM when corrected for age and mothers' weight (T1DM: 458 +/- 36 pg/ml and 432.9 +/- 26.6 pg/ml; ND: 562 +/- 52 pg/ml and 515.8 +/- 63 pg/ml at 20 and 30 weeks, respectively, P < 0.05). T1DM mothers had higher levels of sOB-R and FL levels declined at 30 weeks' gestation in T1DM (P = 0.04) but not in ND.

CONCLUSION

In a population of pregnant women with expected changes in leptin levels as previously reported, ghrelin levels were lower in T1DM pregnancies at 20 and 30 weeks. This may have implications for fetal development and requires further study in diabetes, particularly in pregnancies that result in macrosomia.

Catalytic antibody degradation of ghrelin increases whole-body metabolic rate and reduces refeeding in fasting mice

Obesity is a chronic, costly, and globally prevalent condition, with excess caloric intake a suspected etiologic factor. Nonsurgical treatments are modestly efficacious, and weight loss maintenance is hampered by anti-famine homeostatic mechanisms. Ghrelin, a gastric hormone linked to meal initiation, energy expenditure, and fuel partitioning, is hypothesized to facilitate weight gain and impede weight loss. Unique among known animal peptides, the serine-3 residue of ghrelin is posttranslationally acylated with an n-octanoic acid, a modification important for the peptide's active blood-brain transport and growth hormone secretagogue receptor-1 agonist activity. Pharmacological degradation of ghrelin would be hypothesized to reduce ghrelin's biological effects. To study endogenous ghrelin's role in appetite and energy expenditure, we generated antibodies that hydrolyze the octanoyl moiety of ghrelin to form des-acyl ghrelin. The most proficient antibody catalyst, GHR-11E11, was found to display a second-order rate constant of 18 M(-1) x s(-1) for the hydrolysis of ghrelin to des-acyl ghrelin. I.v. administration of GHR-11E11 (50 mg/kg) maintained a greater metabolic rate in fasting C57BL/6J mice as compared with mice receiving a control antibody and suppressed 6-h refeeding after 24 h of food deprivation. Indirect respiratory measures of metabolism after refeeding and relative fuel substrate utilization were unaffected. The results support the hypothesis that acylated ghrelin stimulates appetite and curbs energy expenditure during deficient energy intake, whereas des-acyl ghrelin does not potently share these functions. Catalytic anti-ghrelin antibodies might thereby adjunctively aid consolidation of caloric restriction-induced weight loss and might also be therapeutically relevant to Prader-Willi syndrome, characterized after infancy by hyperghrelinemia, hyperphagia, and obesity.

Milk and blood ghrelin level in diabetics

OBJECTIVE

Besides its presence in various tissues, ghrelin has recently been shown to be present in blood and breast milk. No previous studies, however, have evaluated the level of this hormone under the condition of pregestational and gestational diabetes mellitus (P-GDM and GDM, respectively). This study was undertaken to show whether a relation exists between serum and milk ghrelin levels in lactating mothers with and without diabetes.

METHODS

Venous blood was obtained from four groups of women (age range 22-37 y): GDM lactating (n = 12), P-GM lactating (n = 3), healthy non-diabetic lactating (n = 14), and healthy non-lactating (n = 14). Colostrum and mature milk samples were collected just before suckling. The ghrelin level was determined by radioimmunoassay and high-performance liquid chromatography.

RESULTS

Radioimmunoassay results showed that women with GDM and P-GDM had greater than two-fold lower colostrum and serum levels of ghrelin than did lactating women with no GDM at 2 d after parturition. The GDM and non-diabetic groups at 15 d after delivery, however, showed similar levels of ghrelin in mature milk and serum. High-performance liquid chromatographic results indicated that in serum the deacylated form of ghrelin was 18-fold higher than the acylated form. Furthermore, in milk the acylated form of ghrelin was 24-fold that of the active form.

CONCLUSION

These results indicate that mothers with GDM have a substantial (greater than two-fold) decrease in their serum and colostral ghrelin levels. This is, however, a temporary effect lasting only up to early postparturition (2 d after delivery). This peptide hormone restores to completely normal levels at day 15 of parturition, but not P-GDM. The significance of these results in terms of the health of the mother and her newborn, however, has yet to be determined.

Perinatal changes of plasma resistin concentrations in pregnancies with normal and restricted fetal growth

BACKGROUND

The adipocytokine resistin inhibits adipogenesis and induces insulin resistance. Intrauterine growth-restricted (IUGR) neonates have reduced fat mass and changes of endocrine/metabolic mechanisms, predisposing to insulin resistance and metabolic syndrome in adult life.

OBJECTIVES

To investigate plasma resistin concentrations in maternal, fetal and neonatal samples from IUGR and appropriate-for-gestational-age (AGA) pregnancies and correlate them with respective insulin concentrations.

METHODS

Plasma resistin and insulin concentrations were determined in 40 mothers and their 20 IUGR and 20 AGA singleton full-term fetuses and neonates on postnatal day 1 (N1) and day 4 (N4).

RESULTS

No significant differences in resistin concentrations were observed between AGA and IUGR groups. In the AGA group, maternal resistin concentrations were significantly lower compared to fetal, N1 and N4 ones (p = 0.003, p = 0.017 and p = 0.039, respectively). Maternal resistin concentrations positively correlated with fetal ones (r = 0.527, p = 0.02). In the IUGR group, maternal resistin concentrations were significantly lower compared to N1 (p < 0.001) and positively correlated with N4 concentrations (r = 0.626, p = 0.007). In both groups, the effect of gender, mode of delivery, parity and adjusted birth weight (customized centiles) on resistin concentrations was not significant. No correlation between resistin and insulin concentrations was documented.

CONCLUSIONS

Lack of difference in resistin concentrations between IUGR and AGA groups, and lack of correlation between resistin and insulin concentrations as well as customized centiles, possibly suggests that resistin may not be directly involved in the regulation of insulin sensitivity and adipogenesis in the perinatal period. Mode of delivery and parity are not associated with circulating resistin concentrations.

Elevated serum acylated (biologically active) ghrelin and resistin levels associate with pregnancy-induced weight gain and insulin resistance

AIM

To study fasting biologically active serum ghrelin (RIA) and resistin (ELISA) levels in different trimesters of pregnancy (HP, n=45, 15 in each) and in gestational diabetes mellitus (GDM, n=30) compared to non-pregnant healthy women (NP, n=40) in correlation with TNF-alpha, soluble (s)TNF-receptor (R)-1, -2, leptin (ELISA), C-peptide (Cp, RIA) and Cp/blood glucose ratio (bg).

STUDY DESIGN

Cross-sectional case control study.

RESULTS

Acylated ghrelin levels were significantly increased (p<0.0001) in the 2nd (377+/-38pg/ml, X+/-S.D.) and decreased in the 3rd trimester (252+/-36) and in GDM (226+/-21) compared to NP controls (309+/-20) and HP women in the 1st trimester (314+/-41). Serum resistin levels were higher in the 1st (8.5+/-2.6ng/ml), 2nd (10.2+/-2.1) and 3rd (13.1+/-3.6) trimesters of pregnancy and in GDM (15.7+/-3.5) than in NP controls (6.5+/-2.3). Significant (p<0.01) negative linear correlations were found among fasting serum ghrelin and body mass index (BMI), the fasting C-peptide (Cp) level, C-peptide/blood glucose (Cp/bg) ratio, TNF-alpha, soluble (s)TNFR-2, leptin and resistin concentrations in both, HP and GDM groups. Significant positive correlations were observed between serum acylated ghrelin and adiponectin, and between BMI and fasting Cp, Cp/bg, TNF-alpha, sTNFR-1, -2 and leptin levels in both pregnant groups.

CONCLUSION

Increased fasting serum acylated ghrelin concentrations in the 2nd trimester may associate with weight gain during pregnancy. Hyperresistinemia may also be associated with the pregnancy-induced insulin resistance. A negative regulatory feed-back mechanism between resistin, TNF-alpha and ghrelin may be hypothesized.

Maternal and foetal resistin and adiponectin concentrations in normal and complicated pregnancies

OBJECTIVE

The aim of this study was to evaluate how resistin and adiponectin (ApN) are involved in maternal energy metabolism and foetal growth.

DESIGN

A cross-sectional study.

PATIENTS AND MEASUREMENTS

Resistin and ApN were measured in 30 healthy nonpregnant women, 73 pregnant women [10-41 weeks of gestation; 18 with gestational diabetes mellitus (GDM), five with pregnancy-induce hypertension (PIH), nine with pre-eclampsia (PE), eight with chronic hypertension (CH) and 33 normal] and 40 foetal samples (20-41 weeks of gestation; 18 from GDM mothers and 22 from normal mothers).

RESULTS

Resistin levels were significantly higher in normal pregnant women than in nonpregnant controls (13.7 +/- 2.1 vs. 6.3 +/- 1.6 ng/ml; P < 0.005) and showed a negative correlation with gestational age (P < 0.0001, r = -0.7). Only women with PE presented resistin levels significantly lower than normotensive women of the same gestational age (8.2 +/- 1.2 vs. 17.9 +/- 4.3 ng/ml; P < 0.005). ApN levels, although similar in normal pregnant women to those in nonpregnant controls, were significantly lower in women with GDM (37-41 weeks; 5.2 +/- 0.5 vs. 8.2 +/- 0.8 mg/l; P < 0.0001) and PE (20-37 weeks; 5.0 +/- 0.7 vs. 9.5 +/- 0.7 mg/l; P = 0.008) than those found in normal women matched for gestational age. Resistin was detected in the umbilical venous blood in foetuses from 20 to 41 weeks of gestation. In all newborns, both resistin and ApN levels were significantly higher than those recorded in adult life and did not correlate with maternal levels (P = ns, r = 0.03 for resistin and P = ns, r = -0.3 for ApN). Foetuses from diabetic mothers had ApN significantly lower than normal foetuses (26.8 +/- 2.6 vs. 37.5 +/- 3.5 mg/l; P = 0.02), while resistin levels were similar (17.3 +/- 3.7 vs. 18.2 +/- 1.5 ng/ml; P = ns).

CONCLUSION

The secretion pattern of ApN in normal and complicated pregnancies strongly suggests an involvement of ApN in insulin resistance during gestation, while resistin seems to have a minor role. Moreover, the detection of high levels of resistin and ApN in cord blood during gestation is consistent with a regulatory action of these adipokines on tissue differentiation and foetal growth.

Maternal and Cord Blood Ghrelin in the Pregnancies of Smoking Mothers: Possible Markers of Nutrient Availability for the Fetus

AIMS

To investigate the role of ghrelin in maternal and fetal metabolism, we determined its value in maternal smoking, a specific cause of reduced placenta function and fetal growth.

METHODS

In 85 normal term pregnancies, 42 in smoking and 43 in non-smoking mothers, we measured ghrelin in the maternal blood at the onset of labor and in the cord blood of their 85 singletons immediately after birth. We determined the relationships between ghrelin and placental GH (PGH), pituitary GH (pitGH), and IGF-I.

RESULTS

The newborns of smoking mothers weighed 0.24 kg less (p < 0.05) than those of non-smoking mothers. Cord blood ghrelin was 71% higher and PGH and cord blood IGF-I were 34% and 32% lower, respectively, in the pregnancies of smoking compared with non-smoking mothers (p < 0.05). Cord blood ghrelin was unrelated to pitGH and cord blood IGF-I. Maternal ghrelin was unchanged in smoking mothers, increased with maternal fasting duration (r = 0.26, p < 0.05), showed no correlation with PGH and negative correlation with cord blood IGF-I (r = -0.42, p < 0.01).

CONCLUSION

The decrease in placental function and fetal growth in smoking mothers is associated with an increase in cord blood ghrelin, and no change in maternal ghrelin. Maternal ghrelin concentration increases with fasting, and is negatively correlated with cord blood IGF-I: it may signal a reduction in the level of nutrients available for placental transfer. No correlation supports a role for ghrelin in PGH or pitGH secretion.

Discordant gene expression in skeletal muscle and adipose tissue of patients with type 2 diabetes: effect of interleukin-6 infusion

AIMS/HYPOTHESIS

We compared metabolic gene expression in adipose tissue and skeletal muscle from patients with type 2 diabetes and from well-matched healthy control subjects. We hypothesised that gene expression would be discordantly regulated when comparing the two groups. Our secondary aim was to determine the effect of Interleukin-6 (IL6) infusion on circulating adipokines and on gene expression in human adipose tissue. To do this we used real-time RT-PCR.

METHODS

Both diabetic and control subjects underwent basal skeletal muscle and subcutaneous adipose tissue biopsies. A subset of these individuals underwent a 3-h infusion of recombinant human IL6 and had adipose tissue samples taken before and after infusion.

RESULTS

The mRNA gene expression of suppressor of cytokine signalling (SOCS) 3, peroxisome proliferative activated receptor (PPAR) alpha/delta, PPAR gamma, coactivator 1, alpha (PPARGC1A), carnitine palmitoyltransferase 1B and solute carrier family 2 (facilitated glucose transporter), member 4 (formerly known as glucose transporter 4/GLUT4), was higher in adipose tissue, but lower in skeletal muscle of diabetic patients than in that of control subjects. In addition, uncoupling protein 1 (UCP1) gene was detected in the adipose tissue of some of the diabetic patients, but not in the control subjects. The following genes were increased by infusion of recombinant human IL6 in both groups: SOCS1/3, resistin, adiponectin, AMP-activated protein kinase-alpha-1 and PPARA. Plasma tumour necrosis factor alpha, adiponectin and resistin were all unaffected by IL6 infusion, but plasma resistin was lower in the diabetic subjects than in control subjects.

CONCLUSIONS/INTERPRETATION

The observation that PPARGC1A and the PPARs were upregulated in the adipose tissue of type 2 diabetic patients, along with the finding that adipose tissue from some patients with type 2 diabetes can express UCP1 mRNA, suggests that in these patients white adipose tissue may move towards a brown adipose tissue phenotype.

Resistin in preterm and term newborns: relation to anthropometry, leptin, and insulin

This study aimed to investigate 1) the plasma resistin concentration at birth, 2) the relationship of resistin with leptin and insulin, and 3) the association of resistin with anthropometric indexes in newborn infants. Blood samples for hormonal assay were obtained from preterm and term newborns within the first 2 h of life and before milk feeding or energy intake. Although these infants required blood sampling for clinical reasons, all were proved to be noninfected. Plasma resistin was significantly higher in term than in preterm infants. It was also significantly correlated with serum leptin, and both hormones were significantly associated with gestational age and anthropometric indexes. Infants who were born vaginally were found to have significantly higher plasma resistin levels compared with those who were born by cesarean section. In the multivariate forward stepwise regression models, resistin was found to be significantly associated with the mode of delivery and gestational age or birth weight. The association among resistin, leptin, and anthropometric indexes suggested that both hormones might be gestation related. A high circulating resistin level at term gestation could be advantageous to the infant by promoting hepatic glucose production and preventing hypoglycemia after birth. Infants who were born vaginally had significantly higher plasma resistin levels, suggesting that this hormone might also be associated with stress or inflammation induced by the birth process.

Ghrelin in preterm and term newborns: relation to anthropometry, leptin and insulin

AIMS

This study aimed to investigate (i) the plasma ghrelin concentration at birth, (ii) the relationship of ghrelin with metabolic hormones, including leptin and insulin, and (iii) its association with anthropometric parameters, in appropriately grown preterm (23-36 weeks gestation) and term (37-42 weeks gestation) newborns.

PATIENTS AND METHODS

Blood samples for hormonal assay were obtained from preterm (n = 81) and term newborns (n = 40) within the first 2 h of life and before milk feeding or energy intake. The relationship between plasma ghrelin and other metabolic hormones or anthropometric parameters was evaluated.

RESULTS

Plasma ghrelin was detectable in all studied infants and the concentrations did not differ significantly between term and preterm infants [median (interquartile range): 1.21 (0.86-1.48) nmol/l vs. 1.04 (0.71-1.51) nmol/l, P = 0.52, respectively]. There was no overall significant correlation between plasma ghrelin and gestational age, anthropometric parameters and leptin or insulin. However, when term and preterm infants were analysed independently, plasma ghrelin was inversely correlated with birth weight (r = -0.31, P = 0.05) and body length (r = -0.33, P = 0.04) in the term infant group.

CONCLUSIONS

Our findings suggested that plasma ghrelin concentrations were relatively constant at birth, between 23 and 42 weeks gestation, and ghrelin secretion did not appear to undergo gestational age-related variations. An inverse relationship between plasma ghrelin and anthropometric indices in term infants raised the possibility that ghrelin might adopt its physiological role in regulating growth and metabolism at a late stage of gestation (> or = 37 weeks gestation). This phenomenon could be beneficial to term newborns by stimulating their appetite and maintaining an adequate blood sugar level at the most critical period when nutrients from mothers are abruptly terminated after birth.