Adiponectin expression in human fetal tissues during mid- and late gestation

Regulated adipose tissue-specific expression of human AGPAT2 in lipodystrophic Agpat2-null mice results in regeneration of adipose tissue

Genetic loss of Agpat2 in humans and mice results in congenital generalized lipodystrophy with near-total loss of adipose tissue and predisposition to develop insulin resistance, diabetes mellitus, hepatic steatosis, and hypertriglyceridemia. The mechanism by which Agpat2 deficiency results in loss of adipose tissue remains unknown. We studied this by re-expressing human AGPAT2 (hAGPAT2) in Agpat2-null mice, regulated by doxycycline. In both sexes of Agpat2-null mice, adipose-tissue-specific re-expression of hAGPAT2 resulted in partial regeneration of both white and brown adipose tissue (but only 30%-50% compared with wild-type mice), which had molecular signatures of adipocytes, including leptin secretion. Furthermore, the stromal vascular fraction cells of regenerated adipose depots differentiated ex vivo only with doxycycline, suggesting the essential role of Agpat2 in adipocyte differentiation. Turning off expression of hAGPAT2 in vivo resulted in total loss of regenerated adipose tissue, clear evidence that Agpat2 is essential for adipocyte differentiation in vivo.

Hormonal Determinants of Growth and Weight Gain in the Human Fetus and Preterm Infant

The factors controlling linear growth and weight gain in the human fetus and newborn infant are poorly understood. We review here the changes in linear growth, weight gain, lean body mass, and fat mass during mid- and late gestation and the early postnatal period in the context of changes in the secretion and action of maternal, placental, fetal, and neonatal hormones, growth factors, and adipocytokines. We assess the effects of hormonal determinants on placental nutrient delivery and the impact of preterm delivery on hormone expression and postnatal growth and metabolic function. We then discuss the effects of various maternal disorders and nutritional and pharmacologic interventions on fetal and perinatal hormone and growth factor production, growth, and fat deposition and consider important unresolved questions in the field.

Programming of metabolism by adipokines during development

The intrauterine and early postnatal periods represent key developmental stages in which an organism is highly susceptible to being permanently influenced by maternal factors and nutritional status. Strong evidence indicates that either undernutrition or overnutrition during development can predispose individuals to disease later in life, especially type 2 diabetes mellitus and obesity, a concept known as metabolic programming. Adipose tissue produces important signalling molecules that control energy and glucose homeostasis, including leptin and adiponectin. In addition to their well-characterized metabolic effects in adults, adipokines have been associated with metabolic programming by affecting different aspects of development. Therefore, alterations in the secretion or signalling of adipokines, caused by nutritional insults in early life, might lead to metabolic diseases in adulthood. This Review summarizes and discusses the potential role of several adipokines in inducing metabolic programming through their effects during development. The identification of the endocrine factors that act in early life to permanently influence metabolism represents a key step in understanding the mechanisms behind metabolic programming. Thus, future strategies aiming to prevent and treat these metabolic diseases can be designed, taking into consideration the relationship between adipokines and the developmental origins of health and disease.

Associations of perfluoroalkyl substances with adipocytokines in umbilical cord serum: A mixtures approach

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS), a kind of emerging environmental endocrine disruptors, may interfere with the secretion of adipokines and affect fetal metabolic function and intrauterine development. However, the epidemiological evidence is limited and inconsistent. We examined the associations of single and multiple PFAS exposures in utero with adipocytokine concentrations in umbilical cord serum.

METHODS

This study included 1111 mother-infant pairs from Sheyang Mini Birth Cohort Study (SMBCS), and quantified 12 PFAS and two adipokine in umbilical cord serum. Generalized linear models (GLMs) and Bayesian Kernel Machine Regression (BKMR) models were applied to estimate the associations of single- and mixed- PFAS exposure with adipokines, respectively. Furthermore, sex-stratification was done in each model to assess the sexually dimorphic effects of PFAS.

RESULTS

10 PFAS were detected with median concentrations (μg/L) ranging from 0.04 to 3.97, (except 2.7% for PFOSA and 1.7% for PFDS, which were excluded). In GLMs, for each doubling increase in PFBS, PFHpA, PFHxS, PFHpS, PFUnDA and PFDoDA, leptin decreased between 14.04% for PFBS and 22.69% for PFHpS (P < 0.05). PFAS, except for PFNA, were positively associated with adiponectin, and for each doubling of PFAS, adiponectin increased between 3.27% for PFBS and 12.28% for PFHxS (P < 0.05). In addition, infant gender modified the associations of PFAS with adipokines, especially the associations of PFBS, PFOA and PFHxS with adiponectin. Similarly, significant associations of PFAS mixtures with leptin and adiponectin were observed in the BKMR models. PFDA, PFOS, PFNA and PFHpS were identified as important contributors. In the sex-stratified analysis of BKMR models, the associations between PFAS mixtures and adipokines were more pronounced in males.

CONCLUSIONS

PFAS levels were significantly associated with adipokines in cord serum, suggesting that intrauterine mixture of PFAS exposure may be related to decreased fetal leptin level but increased fetal adiponectin level and the associations may be sex-specific.

Serum adiponectin levels and adiponectin +276 G/T gene polymorphism in newborns with large and small birth weights

PURPOSE

Adiponectin may be an important indicator in the regulation of fetal and neonatal growth due to its metabolism, energy balance, and insulin-sensitizing action. The current study's goal was to determine if there is a link between adiponectin +276 G/T gene polymorphism and serum adiponectin level in newborns classified as appropriate for gestational age (AGA), small for gestational age (SGA), or large for gestational age (LGA).

METHODS

The study included newborns classified as AGA (n = 65), SGA (n = 65), or LGA (n = 65) according to their gestational age or birth weight. To determine the presence of adiponectin +276 G/T gene polymorphism, genotyping was done using polymerase chain reaction-restriction fragment length polymorphism. Enzyme-linked immunosorbent assay was used to determine the level of adiponectin in the blood.

RESULTS

The SGA newborns had significantly lower levels of serum adiponectin than the AGA and LGA newborns. There were statistically significant differences between the genotype frequencies (GG, GT, TT) of the SGA newborns (29.9%, 45.1%, 13.9%), the AGA newborns (41.6%, 20.7%, 44.4%), and the LGA newborns (28.6%, 34.1%, 41.7%) (chi-square = 15.8; degree of freedom = 4; p = .003). The newborns carrying the GT genotype had an increased risk of being SGA compared to those carrying the GG and TT genotypes (odds ratio [OR] = 3.07; confidence interval [CI] = 95% (1.38-6.64); p = .005 and OR = 6.96; CI = 95% (2.19-22.1); p < .001, respectively). The newborns carrying the GG and TT genotypes had better protection against being SGA than those carrying the GT genotype (OR = 0.33; CI = 95% (0.15-0.72); p = .005 and OR = 0.14; CI = 95% (0.05-0.46); p < .001, respectively). The newborns carrying the GT genotype had lower birth weights, head circumferences, and ponderal indices than those carrying the TT genotype (p < .001). The serum adiponectin levels between adiponectin +276 G/T genotypes did not differ significantly (p = .429). In addition, serum adiponectin level showed a significant positive correlation with birth weight, birth length, head circumference, and ponderal index in all newborns.

CONCLUSION

The results of the current study suggest that the adiponectin +276 G/T gene polymorphism was associated with an increased chance of being born SGA or LGA. The effect of this polymorphism on newborn birth size was independently associated with serum adiponectin levels. Adiponectin may play a role in fetal growth.

Cytokines and parturition: investigating adiponectin, TNF-α, and IL-6 in mother-newborn pairs

OBJECTIVE

Cytokines are reported to be associated with various pregnancy complications and health outcomes of the offspring. However, reference values during pregnancy have not been established, effects of clinical and obstetric factors have not been examined, and interactions between different cytokines have not yet been reported.

METHODS

In this cross-sectional study, we recruited 120 mother-newborn pairs. Maternal venous blood samples (6 mL) were taken on admission to the labor ward; newborn venous blood samples (6 mL) were drawn from the placental part of the umbilical cord (UC). Adiponectin, TNF-α, and IL-6 serum concentrations were measured by commercial immunoassays. Clinical and obstetric variables were analyzed for their association with maternal and UC cytokine concentrations.

RESULTS

Forty-six adiponectin pairs, 55 TNF-α pairs, and 14 IL-6 pairs were available for analysis. Correlation between UC and maternal adiponectin-, IL-6-, and TNF-α levels was low. We found a significant correlation of UC adiponectin with maternal brain-derived neurotrophic factor (BDNF) and maternal adiponectin, and between maternal leptin and maternal TNF-α.

CONCLUSIONS

Clinical and obstetric variables as well as interactions between cytokines may have an impact on serum concentrations of the respective cytokines in maternal and UC blood. Further studies are required to confirm our findings.

Lycopene supplementation of maternal and weanling high-fat diets influences adipose tissue development and metabolic outcomes of Sprague-Dawley offspring

Dietary patterns high in fat contribute to the onset of cardiometabolic disease through the accrual of adipose tissue (AT). Lycopene, a carotenoid shown to exert multiple health benefits, may disrupt these metabolic perturbations. The purpose of the present study was to evaluate AT development and obesity-associated metabolic outcomes in the neonate and weanling offspring of Sprague-Dawley mothers fed a high-fat diet (HFD = 50 % fat) with and without lycopene supplementation. Sprague-Dawley rats consumed either a normal fat diet (NFD; 25 % fat) or HFD throughout gestation. Upon delivery, half of HFD mothers were transitioned to an HFD supplemented with 1 % lycopene (HFDL). At postnatal day 14 (P14), P25, and P35, pups were euthanised, body weight was recorded, and visceral white AT (WAT) and brown AT (BAT) mass were determined. Serum redox status, adipokines, glucose and inflammatory biomarkers were evaluated, as well as BAT mRNA expression of uncoupling protein 1 (UCP1). The HFD was effective in inducing weight gain as evident by significantly greater BW and WAT in the HFD group compared to the NFD group across all time points. Compared to HFD, the HFDL group exhibited significantly greater BAT with concomitant reductions in WAT mass, serum lipid peroxides and serum glucose. No significant differences were observed in serum adipokines, inflammatory markers or UCP1 expression despite the aforementioned alterations in AT development. Results suggest that dietary lycopene supplementation may influence metabolic outcomes during the weaning and post-weaning periods. Additional research is warranted to elucidate molecular mechanisms by which lycopene influences AT biology.

Mediators Linking Maternal Weight to Birthweight and Neonatal Fat Mass in Healthy Pregnancies

CONTEXT

Lifestyle interventions have not efficaciously reduced complications caused by maternal weight on fetal growth, requiring insight into explanatory mediators.

OBJECTIVE

We hypothesized that maternal mediators, including adiponectin, leptin, insulin, and glucose, mediate effects of pregestational BMI (pBMI) and gestational weight gain (GWG) on birthweight and neonatal fat mass percentage (FM%) through placental weight and fetal mediators, including insulin levels (Ifv) and venous-arterial glucose difference (ΔGfva). Hypothesized confounders were maternal age, gestational age, and parity.

METHODS

A cross-sectional study of healthy mother-offspring-pairs (n = 165) applying the 4-vessel in vivo sampling method at Oslo University Hospital, Norway. We obtained pBMI, GWG, birthweight, and placental weight. FM% was available and calculated for a subcohort (n = 84). We measured circulating levels of adiponectin, leptin, glucose, and insulin and performed path analysis and traditional mediation analyses based on linear regression models.

RESULTS

The total effect of pBMI and GWG on newborn size was estimated to be 30 g (range, 16-45 g) birthweight and 0.17 FM% (range, 0.04-0.29 FM%) per kg∙m-2 pBMI and 31 g (range, 18-44 g) and 0.24 FM% (range, 0.10-0.37 FM%) per kg GWG. The placental weight was the main mediator, mediating 25-g birthweight and 0.11 FM% per kg∙m-2 pBMI and 25-g birthweight and 0.13 FM% per kg GWG. The maternal mediators mediated a smaller part of the effect of pBMI (3.8-g birthweight and 0.023 FM% per kg∙m-2 pBMI) but not GWG.

CONCLUSION

Placental weight was the main mediator linking pBMI and GWG to birthweight and FM%. The effect of pBMI, but not GWG, on birthweight and FM%, was also mediated via the maternal and fetal mediators.

Does exercise during pregnancy impact organs or structures of the maternal-fetal interface?

Exercise during pregnancy has been shown to be associated with improved health outcomes both during and after pregnancy for mother and fetus across the lifespan. Increasing physical activity and reducing sedentary behaviour during pregnancy have been recommended by many researchers and clinicians-alike. It is thought that the placenta plays a central role in mediating any positive or negative pregnancy outcomes. The positive outcomes obtained through prenatal exercise are postulated to result from exercise-induced regulation of maternal physiology and placental development. Considerable research has been performed to understand the placenta's role in pregnancy-related diseases, such as preeclampsia, fetal growth restriction, and gestational diabetes mellitus. However, little research has examined the potential for healthy lifestyle and behavioural changes to improve placental growth, development, and function. While the placenta represents the critical maternal-fetal interface responsible for all gas, nutrient, and waste exchange between the mother and fetus, the impact of exercise during pregnancy on placental biology and function is not well known. This review will focus on prenatal exercise and its promising influence on the structures of the maternal-fetal interface, with particular emphasis on the placenta. Potential molecular mechanistic hypotheses are presented to aid future investigations of prenatal exercise and placental health.

Cord Blood Adipocytokines and Body Composition in Early Childhood: A Systematic Review and Meta-Analysis

Childhood obesity is a growing epidemic. Early identification of high-risk groups will allow for the development of prevention strategies. Cord blood adipocytokines have been previously examined as biomarkers predicting future obesity. We conducted a systematic review looking at the association between cord blood leptin and adiponectin with adiposity up to 5 years of age. A literature review was performed between January 1994 and August 2020 using two bibliographic databases (Medline/Pubmed and EMBASE) and was registered on PROSPERO (CRD42017069024). Studies using skinfold thickness and direct methods of assessing body composition in full term neonates were considered. Partial correlation and multiple regression models were used to present the results. Meta-analysis was performed, were possible, using a random effects model. Cochran’s Q test was used to assess heterogeneity and I² statistics to calculate the percentage of variation across studies. The potential for publication bias was assessed using funnel plots. Data from 22 studies were retrieved and reviewed by two independent reviewers. Cord blood leptin was positively associated with adiposity at birth (r = 0.487; 95% CI: 0.444, 0.531) but was inversely related to adiposity up to 3 years of age. The association was not sustained at 5 years. There was a weak positive association between adiponectin in cord blood and adiposity at birth (r = 0.201; 95% CI: 0.125, 0.277). No correlation was found between cord blood adiponectin in young children, but data were limited. This review supports that cord blood leptin and adiponectin are associated with adiposity at birth. The results of this study provide insight into the role of adipocytokines at birth on future metabolic health and their potential use as risk stratification tools.

Characteristics of the Oxidative Status in Dairy Calves Fed at Different Milk Replacer Levels and Weaned at 14 Weeks of Age

A paradigm shift in the way of rearing heifer calves from restricted feeding and early weaning towards greater feed allowances and later weaning ages is ongoing. We aimed at characterizing the oxidative status in Holstein heifer calves fed with milk replacer (MR) at either a restrictive (RES) or a high (HIGH) level for 14 weeks. We compared two groups: HIGH (10 L MR/d, n = 18) and RES (5.7 L/d, n = 19) from day five until week 14 of life. In blood samples collected at birth, and then fortnightly from week 8–16, and in week 20, the antioxidative capacity measured as ferric reducing ability of plasma (FRAP), oxidative damage of lipids measured as thiobarbituric acid reactive substances (TBARS) and oxidative damage of proteins measured as advanced oxidation products of proteins (AOPP), free radicals measured as reactive oxidative metabolites (dROM), and the glutathione peroxidase (GSH-Px) activity, as well as leptin, adiponectin and haptoglobin were assessed. The time course of these variables during the first 20 weeks of life showed characteristic patterns; group differences were limited to adiponectin, AOPP, and FRAP. RES calves had lower growth rates, showed signs of hunger, but did not differ from HIGH in their intake of solid starter feed and in health status. This work characterizes the changes in oxidative status of dairy calves with increasing age and confirms the benefits of a high feeding plane with regard to welfare and development.

Adipose tissue development and lipid metabolism in the human fetus: The 2020 perspective focusing on maternal diabetes and obesity

During development, the human fetus accrues the highest proportion of fat of all mammals. Precursors of fat lobules can be found at week 14 of pregnancy. Thereafter, they expand, filling with triacylglycerols during pregnancy. The resultant mature lipid-filled adipocytes emerge from a developmental programme of embryonic stem cells, which is regulated differently than adult adipogenesis. Fetal triacylglycerol synthesis uses glycerol and fatty acids derived predominantly from glycolysis and lipogenesis in liver and adipocytes. The fatty acid composition of fetal adipose tissue at the end of pregnancy shows a preponderance of palmitic acid, and differs from the mother. Maternal diabetes mellitus does not influence this fatty acid profile. Glucose oxidation is the main source of energy for the fetus, but mitochondrial fatty acid oxidation also contributes. Indirect evidence suggests the presence of lipoprotein lipase in fetal adipose tissue. Its activity may be increased under hyperinsulinemic conditions as in maternal diabetes mellitus and obesity, thereby contributing to increased triacylglycerol deposition found in the newborns of such pregnancies. Fetal lipolysis is low. Changes in the expression of genes controlling metabolism in fetal adipose tissue appear to contribute actively to the increased neonatal fat mass found in diabetes and obesity. Many of these processes are under endocrine regulation, principally by insulin, and show sex-differences. Novel fatty acid derived signals such as oxylipins are present in cord blood with as yet undiscovered function. Despite many decades of research on fetal lipid deposition and metabolism, many key questions await answers.

Placental Regulation of Energy Homeostasis During Human Pregnancy

Successful pregnancies rely on sufficient energy and nutrient supply, which require the mother to metabolically adapt to support fetal needs. The placenta has a critical role in this process, as this specialized organ produces hormones and peptides that regulate fetal and maternal metabolism. The ability for the mother to metabolically adapt to support the fetus depends on maternal prepregnancy health. Two-thirds of pregnancies in the United States involve obese or overweight women at the time of conception. This poses significant risks for the infant and mother by disrupting metabolic changes that would normally occur during pregnancy. Despite well characterized functions of placental hormones, there is scarce knowledge surrounding placental endocrine regulation of maternal metabolic trends in pathological pregnancies. In this review, we discuss current efforts to close this gap of knowledge and highlight areas where more research is needed. As the intrauterine environment predetermines the health and wellbeing of the offspring in later life, adequate metabolic control is essential for a successful pregnancy outcome. Understanding how placental hormones contribute to aberrant metabolic adaptations in pathological pregnancies may unveil disease mechanisms and provide methods for better identification and treatment. Studies discussed in this review were identified through PubMed searches between the years of 1966 to the present. We investigated studies of normal pregnancy and metabolic disorders in pregnancy that focused on energy requirements during pregnancy, endocrine regulation of glucose metabolism and insulin resistance, cholesterol and lipid metabolism, and placental hormone regulation.

Adipokines underlie the early origins of obesity and associated metabolic comorbidities in the offspring of women with pregestational obesity

Maternal pregestational obesity is a well-known risk factor for offspring obesity, metabolic syndrome, cardiovascular disease and type 2 diabetes. The mechanisms by which maternal obesity can induce alterations in fetal and later neonatal metabolism are not fully elucidated due to its complexity and multifactorial causes. Two adipokines, leptin and adiponectin, are involved in fetal and postnatal growth trajectories, and both are altered in women with pregestational obesity. The placenta synthesizes leptin, which goes mainly to the maternal circulation and in lesser amount to the developing fetus. Maternal pregestational obesity and hyperleptinemia are associated with placental dysfunction and changes in nutrient transporters which directly affect fetal growth and development. By the other side, the embryo can produce its own leptin from early in development, which is associated to fetal weight and adiposity. Adiponectin, an insulin-sensitizing adipokine, is downregulated in maternal obesity. High molecular weight (HMW) adiponectin is the most abundant form and with most biological actions. In maternal obesity lower total and HMW adiponectin levels have been described in the mother, paralleled with high levels in the umbilical cord. Several studies have found that cord blood adiponectin levels are related with postnatal growth trajectories, and it has been suggested that low adiponectin levels in women with pregestational obesity enhance placental insulin sensitivity and activation of placental amino acid transport systems, supporting fetal overgrowth. The possible mechanisms by which maternal pregestational obesity, focusing in the actions of leptin and adiponectin, affects the fetal development and postnatal growth trajectories in their offspring are discussed.

Maternal cardiometabolic markers are associated with fetal growth: a secondary exploratory analysis of the LIMIT randomised trial

BACKGROUND

To determine the association between maternal cardiometabolic and inflammatory markers with measures of fetal biometry and adiposity.

METHODS

Women included in this exploratory analysis were randomised to the 'Standard Care' group (N = 911) from the LIMIT randomised trial involving a total of 2212 pregnant women who were overweight or obese (ACTRN12607000161426, Date of registration 9/03/2007, prospectively registered). Fetal biometry including abdominal circumference (AC), estimated fetal weight (EFW), and adiposity measurements (mid-thigh fat mass, subscapular fat mass, abdominal fat mass) were obtained from ultrasound assessments at 28 and 36 weeks' gestation. Maternal markers included C reactive protein (CRP), leptin and adiponectin concentrations, measured at 28 and 36 weeks' gestation and fasting triglycerides and glucose concentrations measured at 28 weeks' gestation.

RESULTS

There were negative associations identified between maternal serum adiponectin and fetal ultrasound markers of biometry and adiposity. After adjusting for confounders, a 1-unit increase in log Adiponectin was associated with a reduction in the mean AC z score [- 0.21 (- 0.35, - 0.07), P = 0.004] and EFW [- 0.23 (- 0.37, - 0.10), P < 0.001] at 28 weeks gestation. Similarly, a 1-unit increase in log Adiponectin was association with a reduction in the mean AC z score [- 0.30 (- 0.46, - 0.13), P < 0.001] and EFW [- 0.24 (- 0.38, - 0.10), P < 0.001] at 36 weeks gestation. There were no consistent associations between maternal cardiometabolic and inflammatory markers with measurements of fetal adiposity.

CONCLUSION

Adiponectin concentrations are associated with measures of fetal growth. Our findings contribute to further understanding of fetal growth in the setting of women who are overweight or obesity.

Adiponectin and Cardiovascular Risk. From Pathophysiology to Clinic: Focus on Children and Adolescents

Adiponectin (Ad) is a cytokine produced by adipocytes that acts on specific receptors of several tissues through autocrine, paracrine, and endocrine signaling mechanisms. Ad is involved in the regulation of cell survival, cell growth, and apoptosis. Furthermore, Ad plays an important pathophysiological role in metabolic activities by acting on peripheral tissues involved in glucose and lipid metabolism such as skeletal muscle, and the liver. Adiponectin has anti-inflammatory, anti-atherogenic, and insulin-sensitizing effects. For this reason, low levels of Ad are associated with the development of cardiovascular complications of obesity in adulthood. Numerous studies have shown that, even in children and adolescents, Ad is associated with risk factors for cardiovascular diseases. In obese children, reduced levels of Ad have been reported and Ad plasma levels are inversely related with abdominal obesity. Moreover, lower Ad concentrations are associated with the development of metabolic syndrome, insulin resistance and hypertension in pediatric subjects. In addition to a higher prevalence of cardiovascular risk factors, plasma values of Ad are also inversely associated with early organ damage, such as an increase in carotid intima-media thickness. It has been suggested that low Ad levels in childhood might predict the development of atherosclerosis in adulthood, suggesting the possibility of using Ad to stratify cardiovascular risk in obese children. Some evidence suggests that lifestyle modification may increase Ad plasma levels. The aim of this review is to summarize the evidence on the relationship between Ad, obesity, metabolic alterations and hypertension in children and adolescents, and to address the possibility that Ad represents an early marker of cardiovascular risk in pediatric subjects. Furthermore, the effects of non-pharmacological treatment (weight loss and physical activity) on Ad levels are considered.

How are maternal dietary patterns and maternal/fetal cytokines associated with birth weight? A path analysis

The aim of the study was to investigate how maternal dietary patterns and maternal/fetal cytokines are associated with birth weight and whether cytokines mediate the association. A total of 469 pregnant women and their children were recruited for this prospective study. Dietary patterns in pregnancy were identified using factor analysis of data from three consecutive 24 h dietary recalls. Maternal and umbilical blood serum cytokines (adiponectin (APN), IL-6 and interferon-γ) were measured via ELISA. Path analysis was used to explore the relationships between maternal diet, cytokines and birth weight. Four dietary patterns were identified: a mainly fruit, dairy products and poultry diet (FDP); a mainly vegetables, beans and pork diet (VBP); a mainly fish, shrimp and soup diet (FS) and a mainly tuber and egg diet (TE). Path analysis showed the order of effects of dietary patterns on birth weight was FS>FDP>TE>VBP (β=0·130, 0·109, –0·094 and 0·046, respectively). Only the TE pattern’s effect was negative. Maternal and fetal APN were positively associated with birth weight (β=0·045 and 0·226, respectively), and they mediated the association between the TE pattern and birth weight (indirect effect was 5·3 %). Maternal IL-6 was negatively associated with birth weight (β=–0·067) and mediated the association between maternal FDP and VBP patterns and birth weight (indirect effects were 10·1 and 100·0 %, respectively). All variables in the path explained 33·6 % of variation. These results suggested that maternal dietary patterns in pregnancy are associated with birth weight and mediated directly and indirectly through some maternal/fetal serum cytokines.

Alterations of adiponectin gene expression and DNA methylation in adipose tissues and blood cells are associated with gestational diabetes and neonatal outcome

Background

Adiponectin critically contributes to metabolic homeostasis, especially by insulin-sensitizing action. Gestational diabetes mellitus (GDM) is characterized by insulin resistance leading to materno-fetal hyperglycemia and detrimental birth outcomes. By investigating paired subcutaneous (SAT) and visceral adipose tissue (VAT) as well as blood (cell) samples of GDM-affected (n = 25) vs. matched control (n = 30) mother-child dyads of the prospective “EaCH” cohort study, we addressed whether alterations of adiponectin plasma, mRNA, and DNA methylation levels are associated with GDM and offspring characteristics.

Results

Hypoadiponectinemia was present in women with GDM, even after adjustment for body mass index (BMI). This was accompanied by significantly decreased mRNA levels in both SAT and VAT (P < 0.05), independent of BMI. Maternal plasma adiponectin showed inverse relations with glucose and homeostatic model assessment of insulin resistance (both P < 0.01). In parallel to reduced mRNA expression in GDM, significant (P < 0.05) yet small alterations in locus-specific DNA methylation were observed in maternal fat (~ 2%) and blood cells (~ 1%). While newborn adiponectin levels were similar between groups, DNA methylation in GDM offspring was variously altered (~ 1–4%; P < 0.05).

Conclusions

Reduced adiponectin seems to be a pathogenic co-factor in GDM, even independent of BMI, affecting materno-fetal metabolism. While altered maternal DNA methylation patterns appear rather marginally involved, functional, diagnostic, and/or predictive implications of cord blood DNA methylation should be further evaluated.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0567-z) contains supplementary material, which is available to authorized users.

Adiponectin regulates glycogen metabolism at the human fetal–maternal interface

Throughout the entire first trimester of pregnancy, fetal growth is sustained by endometrial secretions, i.e. histiotrophic nutrition. Endometrial stromal cells (EnSCs) accumulate and secrete a variety of nutritive molecules that are absorbed by trophoblastic cells and transmitted to the fetus. Glycogen appears to have a critical role in the early stages of fetal development, since infertile women have low endometrial glycogen levels. However, the molecular mechanisms underlying glycogen metabolism and trafficking at the fetal–maternal interface have not yet been characterized. Among the various factors acting at the fetal–maternal interface, we focused on adiponectin – an adipocyte-secreted cytokine involved in the control of carbohydrate and lipid homeostasis. Our results clearly demonstrated that adiponectin controls glycogen metabolism in EnSCs by (i) increasing glucose transporter 1 expression, (ii) inhibiting glucose catabolism via a decrease in lactate and ATP productions, (iii) increasing glycogen synthesis, (iv) promoting glycogen accumulation via phosphoinositide-3 kinase activation and (v) enhancing glycogen secretion. Furthermore, our results revealed that adiponectin significantly limits glycogen endocytosis by human villous trophoblasts. Lastly, we demonstrated that once glycogen has been endocytosed into placental cells, it is degraded into glucose molecules in lysosomes. Taken as a whole, the present results demonstrate that adiponectin exerts a dual role at the fetal–maternal interface by promoting glycogen synthesis in the endometrium and conversely reducing trophoblastic glycogen uptake. We conclude that adiponectin may be involved in feeding the conceptus during the first trimester of pregnancy by controlling glycogen metabolism in both the uterus and the placenta.

Correlation of adipokines and markers of oxidative stress in women with gestational diabetes mellitus and their newborns

AIM

We have shown that some markers of oxidative stress were higher in women with gestational diabetes mellitus (GDM). This study examines the relationship between adipokines and oxidative stress and their potential effects in pregnant women.

METHODS

Three markers of oxidative stress (malondialdehyde, 8-isoprostane and xanthine oxidase) and three adipokines (leptin, adiponectin and resistin) were measured in maternal plasma, cord plasma and placenta of 208 pregnant women.

RESULTS

Among all these women, 105 were diagnosed with GDM while the other 103 were controls. Leptin, resistin, malondialdehyde, xanthine oxidase and 8-isoprostane in maternal plasma, cord plasma and placenta were significantly higher while maternal adiponectin significantly lower in women with GDM (P < 0.05). Adipokines in maternal plasma, cord plasma and placenta were positively correlated with markers of oxidative stress. Both markers of oxidative stress and adipokines were correlated inversely with homeostasis model assessment of insulin resistance whereas positively with quantitative insulin sensitivity check index (P < 0.01). Adiponectin is negatively correlated with leptin and resistin. Placental/cord leptin and cord resistin levels were higher in the macrosomia while maternal adiponectin level was lower (P < 0.05) than normal birthweight newborns. Both markers of oxidative stress and adipokines in maternal and cord plasma are negatively correlated with newborn birthweight (P < 0.05).

CONCLUSION

Adipokines interact with markers of oxidative stress, both of which lead to insulin resistance, GDM and macrosomia. It has long been known that placenta involves in the development of GDM. Adipokines might participate in this process and need to be confirmed by further studies.

Disparity in fetal growth between twin and singleton gestation: the role of adipokines

OBJECTIVE

Twin pregnancies are characterized by unique pattern of attenuated fetal weight gain during late gestation compared with singleton gestation. The mechanism(s) responsible for regulating twin growth has not yet elucidated. Leptin and adiponectin are two adipocytokines implicated in metabolism and energy balance of fetuses, newborns and adults. Moreover, these hormones have been suggested to play a role in fetal growth. The objective of the study was to determine cord blood adiponectin and leptin in twins and singletons, with and without growth impairment.

STUDY DESIGN

This was a case-control study. It included two groups of newborns, matched for gestational age and birth weight percentile: singleton (n=60 newborns) and twins (n=44 newborns). Adiponectin and leptin were determined in cord blood, and compared between the groups according to clinical and demographic characteristics. Non-parametric and parametric statistical methods were employed.

RESULTS

Median adiponectin and leptin concentrations were lower in twins vs singletons (P<0.001 for both comparisons). Among small for gestational age newborns (SGA), median concentration of adiponectin (P=0.04), but not leptin (P=0.1), was lower in twins compared to singletons. In pooled analysis (singleton plus twins), cord blood adiponectin and leptin were strongly correlated with gestational age (P<0.001 and P=0.005, respectively) and birth weight (P<0.001 and P<0.001, respectively). Regression analysis revealed that plurality (P=0.02) was significantly and independently associated with cord blood adiponectin concentrations, after adjustment for confounding variables. Similar regression in which leptin was the independent variable revealed that only birth weight (P=0.01) was significantly and independently associated with cord blood leptin concentrations.

CONCLUSIONS

Twin pregnancies are associated with lower cord blood concentrations of adiponectin and leptin compared with singleton gestations. However, only cord blood adiponectin, but not leptin, was lower in SGA neonates. Collectively, these data suggest that adiponectin may be implicated in the mechanism accounting for the growth disparity between twins and singletons.

Expression, function, and regulation of the embryonic transcription factor TBX1 in parathyroid tumors

Transcription factors active in embryonic parathyroid cells can be maintained in adult parathyroids and be involved in tumorigenesis. TBX1, the candidate gene of 22q11.2-DiGeorge syndrome, which includes congenital hypoparathyroidism, is involved in parathyroid embryogenesis. The study aimed to investigate expression, function, and regulation of the parathyroid embryonic transcription factor TBX1 in human parathyroid adult normal and tumor tissues. TBX1 transcripts were detected in normal parathyroids and were deregulated in parathyroid tumors. Using immunohistochemistry, TBX1 protein was detected, mainly at the nuclear level, in a consistent proportion of cells in normal adult parathyroids, whereas TBX1 immunoreactivity was absent in fetal parathyroids. TBX1-expressing cells were markedly reduced in about a half of adenomas (PAds) and two-thirds of carcinomas and the proportion of TBX1-expressing cells negatively correlated with the serum albumin-corrected calcium levels in the analyzed tumors. Moreover, a subset of TBX1-expressing tumor cells coexpressed PTH. TBX1 silencing in HEK293 cells, expressing endogenous TBX1, increased the proportion of cells in the G0/G1 phase of cell cycle; concomitantly, CDKN1A/p21 and CDKN2A/p16 transcripts increased and ID1 mRNA levels decreased. TBX1 silencing exerted similar effects in PAd-derived cells, suggesting cell cycle arrest. Moreover, in PAd-derived cells GCM2 and PTH mRNA levels were unaffected by TBX1 deficiency, whereas it was associated with reduction of WNT5A, an antagonist of canonical WNT/β-catenin pathway. WNT/β-catenin activation by lithium chloride inhibited TBX1 expression levels both in HEK293 and PAd-derived cells. In conclusion, TBX1 is expressed in adult parathyroid cells and deregulated in parathyroid tumors, where TBX1 deficiency may potentially contribute to the low proliferative nature of parathyroid tumors.

Cord blood and child plasma adiponectin levels in relation to childhood obesity risk and fat distribution up to 5 y

BACKGROUND

Few human studies have explored the role of adiponectin in early life on growth and adipose tissue development.

METHODS

High molecular weight (HMW) and total adiponectin levels from 141 cord blood samples and plasma blood samples from 40 3-y-old children were analyzed. Associations between adiponectin levels in cord blood and child plasma, and infant/child growth and fat mass measurements up to the age of 5 y were assessed using linear regression models.

RESULTS

HMW cord blood adiponectin was positively associated with weight, BMI percentiles, and lean body mass at birth only. At 3 and 4 y, positive associations were found with cord blood adiponectin and sum of four skinfold thickness measures and percentage of body fat following adjustment for maternal and child covariates, but did not persist at 5 y. There was no significant evidence of an association between child plasma HMW adiponectin and growth or body composition characteristics at 3-5 y.

CONCLUSION

Our results do not support the hypothesis that HMW cord blood adiponectin is a useful biomarker for the prediction of adiposity at the age of 5 y. Additionally, there is no evidence that plasma HMW adiponectin levels predict body fat distribution between 3-5 y.

Maternal and fetal lipid metabolism under normal and gestational diabetic conditions

Maternal lipids are strong determinants of fetal fat mass. Here we review the overall lipid metabolism in normal and gestational diabetes mellitus (GDM) pregnancies. During early pregnancy, the increase in maternal fat depots is facilitated by insulin, followed by increased adipose tissue breakdown and subsequent hypertriglyceridemia, mainly as a result of insulin resistance (IR) and estrogen effects. The response to diabetes is variable as a result of greater IR but decreased estrogen levels. The vast majority of fatty acids (FAs) in the maternal circulation are esterified and associated with lipoproteins. These are taken up by the placenta and hydrolyzed by lipases. The released FAs enter various metabolic routes and are released into fetal circulation. Although these determinants are modified in maternal GDM, the fetus does not seem to receive more FAs than in non-GDM pregnancies. Long-chain polyunsaturated FAs are essential for fetal development and are obtained from the mother. Mitochondrial FA oxidation occurs in fetal tissue and in placenta and contributes to energy production. Fetal fat accretion during the last weeks of gestation occurs very rapidly and is sustained not only by FAs crossing the placenta, but also by fetal lipogenesis. Fetal hyperinsulinemia in GDM mothers promotes excess accretion of adipose tissue, which gives rise to altered adipocytokine profiles. Fetal lipoproteins are low at birth, but the GDM effects are unclear. The increase in body fat in neonates of GDM women is a risk factor for obesity in early childhood and later life.

The roles of leptin and adiponectin at the fetal-maternal interface in humans

Infertility now affects one in seven couples, and the prevalence of this condition continues to increase. Ovulatory defects and unknown causes account for more than half of the cases of infertility. It has been postulated that a significant proportion of these cases are directly or indirectly related to obesity, since the presence of excess adipose tissue has a variety of effects on reproductive function. Here, we review on the effects of the two major adipokines (leptin and adiponectin) on fertility, with a focus on the first steps in embryo implantation and the key components of fetal-maternal interface (the placenta and the endometrium). These adipokines are reportedly involved in the regulation of cell proliferation and differentiation, and as such affect local angiogenesis, immune tolerance and inflammatory processes in placental and endometrial tissues. In placental cells, leptin and adiponectin also modulate trophoblast invasiveness and the nutrient supply. These observations strongly suggest by interfering with the placenta and endometrium, adipokines can create a favorable environment for embryo implantation and have a key role in fetal-maternal metabolism, fetal-maternal communication, and gestation. Given that reproductive functions are tightly coupled to the energy balance, metabolic abnormalities may lead to the development of complications of pregnancy and changes in fetal growth. In this context, we suggest that the leptin/adiponectin ratio may be a clinically valuable marker for detecting a number of pathologies in pregnancy.

Adiponectin Concentrations in Maternal Serum: Elevated in Preeclampsis But Unrelated to Insulin Sensitivity

OBJECTIVE

Adiponectin is an adipocyte-derived protein with profound insulin-sensitizing, anti-inflammatory, and antiatherogenic effects. Surprisingly, recent evidence suggests that adiponectin concentrations are increased during preeclampsia, which is characterized by insulin resistance. We studied whether serum adiponectin is related to insulin sensitivity in preeclamptic and normotensive pregnant women.

METHODS

We measured serum adiponectin concentrations and insulin sensitivity (intravenous glucose tolerance test/minimal model) in 22 women with preeclampsia and 15 normotensive controls with similar pre-pregnancy body mass index (BMI) (range 18-29 kg/m(2)) between 29 and 39 weeks of gestation. Fourteen cases and 10 controls were also studied 6-22 weeks after delivery. No subject had gestational diabetes.

RESULTS

During pregnancy, the mean adiponectin concentration in preeclamptic women was 10.3 (SD 4.2) mug/mL as compared to 7.9 (SD 2.9) microg/mL in normotensive controls (95% confidence interval [CI] for difference 0.1-5.3 microg/mL; P = .04). Adiponectin concentrations were unrelated to insulin sensitivity both in preeclamptic and normotensive subjects; insulin sensitivity was decreased in preeclampsia (P = .01). After delivery, mean adiponectin concentration was lower than during pregnancy: 7.4 (SD 3.0) microg/mL in preeclamptic subjects (P = .001) and 7.1 (SD 1.6) microg/mL in normotensive controls (P = .06) and similar in cases and controls (95% CI for difference -1.7-2.3 microg/mL, P = .7).

CONCLUSIONS

Despite their reduced insulin sensitivity, preeclamptic women have higher adiponectin concentrations than normotensive pregnant women. These concentrations are unrelated to insulin sensitivity. After pregnancy, the difference in adiponectin concentrations is no longer present between the two groups. These findings are consistent with a role of adiponectin in the pathophysiology of preeclampsia.

Maternal and cord blood adiponectin levels in relation to post-natal body size in infants in the first year of life: a prospective study

Background

Adiponectin is an adipocyte hormone involved in energy homeostasis and metabolism. However, its role in early infancy is poorly understood.

Methods

We recruited a total of 443 pregnant women and their children in this prospective study. Cord blood samples were successfully obtained from 331 neonates. Maternal and umbilical blood serum adiponectin were measured. The weight-, height- and BMI-for-age Z scores of infants at birth and at 3, 6 and 12 months of age were assessed.

Results

Multiple linear regression analysis indicated that cord blood but not maternal serum adiponectin was positively associated with all of the anthropometric measures at birth (P < 0.01). Using Generalized Estimating Equation model after adjustment for sex, time, maternal age, gestational age, prepregnancy BMI, weight gain during pregnancy, maternal education, parity, history of miscarriage and mode of delivery, for every 1-μg/ml increment of maternal serum adiponectin, the height-for-age Z score during the first year of life increased by 0.026 (P =0.013) on average, and the height-for-age Z score of infants in the highest quartile of maternal serum adiponectin was 0.270 (95 % CI: 0.013–0.527) higher than those in the lowest quartile. The changes in weight-for-age Z score from birth decreased by 0.67 × 10⁻² on average with every 1-μg/ml additional increase of cord blood adiponectin (P = 0.047). The infants in the highest quartile of cord blood adiponectin showed a −0.368 (95 % CI, −0.701–−0.035) decrease in weight-for-age Z score change from birth compared with those in the lowest quartile.

Conclusions

Cord blood adiponectin concentration is a determinant of infant birth size and weight gain in the first year of life. Circulating maternal adiponectin during pregnancy may predict postnatal height growth.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0978-9) contains supplementary material, which is available to authorized users.

Endogenous and exogenous factors influencing the concentrations of adiponectin in body fluids and tissues in the bovine

Adiponectin, one of the messenger molecules secreted from adipose tissue that are collectively termed adipokines, has been demonstrated to play a central role in lipid and glucose metabolism in humans and laboratory rodents; it improves insulin sensitivity and exerts antidiabetic and antiinflammatory actions. Adiponectin is synthesized as a 28 kDa monomer but is not secreted as such; instead, it is glycosylated and undergoes multimerization to form different molecular weight multimers before secretion. Adiponectin is one of the most abundant adipokines (μg/mL range) in the circulation. The concentrations are negatively correlated with adipose depot size, in particular with visceral fat mass in humans. Adiponectin exerts its effects by activating a range of different signaling molecules via binding to 2 transmembrane receptors, adiponectin receptor 1 and adiponectin receptor 2. The adiponectin receptor 1 is expressed primarily in the skeletal muscle, whereas adiponectin receptor 2 is predominantly expressed in the liver. Many of the functions of adiponectin are relevant to growth, lactation, and health and are thus of interest in both beef and dairy production systems. Studies on the role of the adiponectin protein in cattle have been impeded by the lack of reliable assays for bovine adiponectin. Although there are species-specific bovine adiponectin assays commercially available, they suffer from a lack of scientific peer-review of validity. Quantitative data about the adiponectin protein in cattle available in the literature emerged only during the last 3 yr and were largely based on Western blotting using either antibodies against human adiponectin or partial peptides from the bovine sequence. Using native bovine high-molecular-weight adiponectin purified from serum, we were able to generate a polyclonal antiserum that can be used for Western blot but also in an ELISA system, which was recently validated. The objective of this review is to provide an overview of the literature about the adiponectin protein in cattle addressing the following aspects: (1) the course of the adiponectin serum concentrations during development in both sexes, during inflammation, nutritional energy deficit and energy surplus, and lactation-induced changes including the response to supplementation with conjugated linoleic acids and with niacin, (2) the concentrations of adiponectin in subcutaneous vs visceral fat depots of dairy cows, (3) the protein expression of adiponectin in tissues other than adipose, and (4) the concentrations in different body fluids including milk.

Extrauterine growth and adipocytokines in appropriate-for-gestational-age preterm infants

BACKGROUND

Extra-uterine growth retardation in preterm infants is associated with an increased risk for cardiometabolic diseases later in life. Adipocytokines are also associated with the development of cardiometabolic diseases. We examined the relationship between extra-uterine growth and serum concentrations of adipocytokines and metabolic hormones in preterm infants.

METHODS

Serum concentrations of leptin, adiponectin, insulin, IL-6, TNF-α, C-peptide, GIP, GLP-1 and glucagon were measured in 38 appropriate-for-gestational-age preterm infants at birth, and at 33 and 38 weeks of postmenstrual age using a Bio-Plex 200^TM suspension array system.

RESULTS

Serum concentrations of leptin were not correlated with body weight at any time point. However, serum concentrations of adiponectin were correlated with body weight at all time points. Serum concentrations of IL-6 were decreased from birth to 33 and 38 weeks. Serum concentrations of TNF-α were not changed. Serum concentrations of C-peptide, GIP and glucagon increased from birth to 33 weeks, and decreased from 33 to 38 weeks. Serum concentrations of insulin and GLP-1 were not changed.

CONCLUSION

Changes in serum concentrations of leptin and adiponectin showed unique profiles, thereby suggesting maldevelopment of white adipose tissue. This may affect the future development of adipose tissue and lead to increased risk for cardio-metabolic disorders. This article is protected by copyright. All rights reserved.

The rapid increase of circulating adiponectin in neonatal calves depends on colostrum intake

Adiponectin, an adipokine, regulates metabolism and insulin sensitivity. Considering that the transplacental transfer of maternal proteins of high molecular weight is hindered in ruminants, this study tested the hypothesis that the blood concentration of adiponectin in neonatal calves largely reflects their endogenous synthesis whereby the intake of colostrum might modify the circulating concentrations. We thus characterized the adiponectin concentrations in neonatal and young calves that were fed either colostrum or formula. Three trials were performed: in trial 1, 20 calves were all fed colostrum for 3 d, and then formula until weaning. Blood samples were collected on d 0 (before colostrum feeding), and on d 1, 3, 11, 22, 34, 43, 52, 70, 90, and 108 postnatum. In trial 2, 14 calves were studied for the first 4 d of life. They were fed colostrum (n=7) or formula (n=7), and blood samples were taken right after birth and before each morning feeding on d 2, 3, and 4. In trial 3, calves born preterm (n=7) or at term received colostrum only at 24 h postnatum. Blood was sampled at birth, and before and 2 h after feeding. Additionally, allantoic fluid and blood from 4 Holstein cows undergoing cesarean section were sampled. Adiponectin was quantified by ELISA. In trial 1, the serum adiponectin concentrations recorded on d 3 were 4.7-fold higher than before colostrum intake. The distribution of the molecular weight forms of adiponectin differed before and after colostrum consumption. In trial 2, the colostrum group had consistently greater plasma adiponectin concentrations than the formula group after the first meal. In trial 3, the preterm calves tended to have lower concentrations of plasma adiponectin than the term calves at birth and before and 2 h after feeding. Furthermore, the adiponectin concentrations were substantially lower in allantoic fluid than in the sera from neonatal calves and from cows at parturition. Our results show that calves are born with very low blood concentrations of adiponectin and placental transfer of adiponectin to the bovine fetus is unlikely. In conclusion, colostrum intake is essential for the postnatal increase of circulating adiponectin in newborn calves.

Direct effects of leptin and adiponectin on peripheral reproductive tissues: a critical review

Obesity is a risk factor for infertility and adverse reproductive outcomes. Adipose tissue is an important endocrine gland that secretes a host of endocrine factors, called adipokines, which modulate diverse physiologic processes including appetite, metabolism, cardiovascular function, immunity and reproduction. Altered adipokine expression in obese individuals has been implicated in the pathogenesis of a host of health disorders including diabetes and cardiovascular disease. It remains unclear whether adipokines play a significant role in the pathogenesis of adverse reproductive outcomes in obese individuals and, if so, whether the adipokines are acting directly or indirectly on the peripheral reproductive tissues. Many groups have demonstrated that receptors for the adipokines leptin and adiponectin are expressed in peripheral reproductive tissues and that these adipokines are likely, therefore, to exert direct effects on these tissues. Many groups have tested for direct effects of leptin and adiponectin on reproductive tissues including the testis, ovary, uterus, placenta and egg/embryo. The hypothesis that decreased fertility potential or adverse reproductive outcomes may result, at least in part, from defects in adipokine signaling within reproductive tissues has also been tested. Here, we present a critical analysis of published studies with respect to two adipokines, leptin and adiponectin, for which significant data have been generated. Our evaluation reveals significant inconsistencies and methodological limitations regarding the direct effects of these adipokines on peripheral reproductive tissues. We also observe a pervasive failure to account for in vivo data that challenge observations made in vitro. Overall, while leptin and adiponectin may directly modulate peripheral reproductive tissues, existing data suggest that these effects are minor and non-essential to human or mouse reproductive function. Current evidence suggests that direct effects of leptin or adiponectin on peripheral reproductive tissues are unlikely to factor significantly in the adverse reproductive outcomes observed in obese individuals.

Early Surge in Circulatory Adiponectin Is Associated With Improved Growth at Near Term in Very Preterm Infants

CONTEXT

Adiponectin enhances insulin sensitivity and may play a role in fetal and postnatal growth.

OBJECTIVE

This study aimed to determine whether early postnatal adiponectin concentration change is related to postnatal growth in very preterm infants.

SETTING, DESIGN, AND PATIENTS

This was an in-hospital, prospective, longitudinal cohort study of 52 preterm infants with a gestational age (GA) of 26.0 ± 1.9 (SD) weeks and birth weight (BW) of 889 ± 284 g.

INTERVENTIONS

An analysis of adiponectin was performed on cord blood at birth and peripheral blood at 72 hours, day 7, and then weekly until postmenstrual age (PMA) 40 weeks. Weight, length, and head circumference (HC) measurement was performed weekly and SD scores (SDS) calculated. Energy and protein intake was calculated daily from birth until PMA 35 weeks.

RESULTS

Mean adiponectin concentration increased from 6.8 ± 4.4 μg/mL at 72 hours to 37.4 ± 22.2 μg/mL at 3 weeks; during days 3-21, it was 21.4 ± 12 μg/mL and correlated with GA at birth (r = 0.46, P = .001; BW: r = 0.71, P < .001; BW(SDS): r = 0.42, P = .003). Furthermore, mean adiponectin during days 3-21 correlated with weight(SDS), length(SDS), and HC(SDS) (r = 0.62, 0.65, and 0.62, respectively; all P < .001) at PMA 35 wk). Energy intake (kcal/kg/d) correlated with mean adiponectin during days 3-21 (r = 0.35, P < .013).

CONCLUSIONS

In very preterm infants, adiponectin concentrations increased markedly in the first 3 weeks, and a greater increase was associated with improved postnatal growth.

Omentin, an adipokine with insulin-sensitizing properties, is negatively associated with insulin resistance in normal gestation

OBJECTIVE

Omentin, a newly identified adipokine, enhances insulin mediated glucose uptake in human adipocytes, thus, inducing systemic insulin-sensitizing effect. The aims of this study were to determine whether circulating maternal omentin levels are associated with insulin resistance indices and to assess which compartment, maternal, fetal, or placental, is the source of omentin in maternal circulation.

METHODS

Fasting serum glucose, insulin, and omentin were determined in 25 healthy pregnant women at the third trimester, before and 3 days after elective cesarean section. Cord blood omentin was measured in the 25 term neonates. Homeostasis model assessment (HOMA) was used to evaluate insulin sensitivity before and after delivery.

RESULTS

Antepartum maternal omentin levels were negatively correlated with insulin levels (r=-0.41, P=0.04) and positively correlated with insulin sensitivity (HOMA%S; r=0.4, P=0.04). Postpartum omentin levels were negatively correlated with maternal body mass index (r=-0.44, P=0.02). Median maternal omentin levels was comparable before and after delivery (57.2, inter-quartile range: 38.2-76.2 ng/mL vs. 53.4, 39.8-69.4 ng/mL, respectively, P=0.25) and highly correlated (r=0.83, P<0.001). Antepartum maternal and neonatal omentin levels did not differ significantly (fetal: 62.2, 44.3-74.2 ng/mL, P=0.77) and did not correlate (P=0.6).

CONCLUSIONS

Circulating maternal omentin levels are correlated with insulin resistance indices, suggesting that this adipokine may play a role in metabolic adaptations of normal gestation. The strong correlation between anteparum and postpartum maternal omentin levels, as well as the lack of association between maternal and neonatal omentin levels, suggest that placental or fetal compartments are unlikely as the main source of circulating maternal omentin.

Maternal obesity and metabolic risk to the offspring: why lifestyle interventions may have not achieved the desired outcomes

Obesity during pregnancy is associated with an increased risk of short- and long-term metabolic dysfunction in the mother and her offspring. Both higher maternal pregravid body mass index (kg m(-2)) and excessive gestational weight gain (GWG) have been associated with adverse pregnancy outcomes such as gestational diabetes, preeclampsia and fetal adiposity. Multiple lifestyle intervention trials consisting of weight management using various diets, increased physical activity and behavioral modification techniques have been employed to avoid excessive GWG and improve perinatal outcomes. These randomized controlled trials (RCTs) have achieved modest success in decreasing excessive GWG, although the decrease in GWG was often not within the current Institute of Medicine guidelines. RCTs have generally not had any success with decreasing the risk of maternal gestational diabetes (GDM), preeclampsia or excessive fetal growth often referred to as macrosomia. Although the lack of success for these trials has been attributed to lack of statistical power and poor compliance with study protocols, our own research suggests that maternal pregravid and early pregnancy metabolic condition programs early placenta function and gene expression. These alterations in maternal/placental function occur in the first trimester of pregnancy prior to when most intervention trials are initiated. For example, maternal accrural of adipose tissue relies on prior activation of genes controlling lipogenesis and low-grade inflammation in early pregnancy. These metabolic alterations occur prior to any changes in maternal phenotype. Therefore, trials of lifestyle interventions before pregnancy are needed to demonstrate the safety and efficacy for both the mother and her offspring.

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.

Tumour-associated fibroblasts contribute to neoangiogenesis in human parathyroid neoplasia

Components of the tumour microenvironment initiate and promote cancer development. In this study, we investigated the stromal component of parathyroid neoplasia. Immunohistochemistry for alpha-smooth muscle actin (α-SMA) showed an abundant periacinar distribution of α-SMA(+) cells in normal parathyroid glands (n=3). This pattern was progressively lost in parathyroid adenomas (PAds; n=6) where α-SMA(+)cells were found to surround new microvessels, as observed in foetal parathyroid glands (n=2). Moreover, in atypical adenomas (n=5) and carcinomas (n=4), α-SMA(+) cells disappeared from the parenchyma and accumulated in the capsula and fibrous bands. At variance with normal glands, parathyroid tumours (n=37) expressed high levels of fibroblast-activation protein (FAP) transcripts, a marker of tumour-associated fibroblasts. We analysed the ability of PAd-derived cells to activate fibroblasts using human bone-marrow mesenchymal stem cells (hBM-MSCs). PAd-derived cells induced a significant increase in FAP and vascular endothelial growth factor A (VEGFA) mRNA levels in co-cultured hBM-MSCs. Furthermore, the role of the calcium-sensing receptor (CASR) and of the CXCL12/CXCR4 pathway in the PAd-induced activation of hBM-MSCs was investigated. Treatment of co-cultures of hBM-MSCs and PAd-derived cells with the CXCR4 inhibitor AMD3100 reduced the stimulated VEGFA levels, while CASR activation by the R568 agonist was ineffective. PAd-derived cells co-expressing parathyroid hormone (PTH)/CXCR4 and PTH/CXCL12 were identified by FACS, suggesting a paracrine/autocrine signalling. Finally, CXCR4 blockade by AMD3100 reduced PTH gene expression levels in PAd-derived cells. In conclusion, i) PAd-derived cells activated cells of mesenchymal origin; ii) PAd-associated fibroblasts were involved in tumuor neoangiogenesis and iii) CXCL12/CXCR4 pathway was expressed and active in PAd cells, likely contributing to parathyroid tumour neoangiogenesis and PTH synthesis modulation.

Adiponectin protects against paraquat-induced lung injury by attenuating oxidative/nitrative stress

The specific mechanisms underlying paraquat (PQ)-induced lung injury remain unknown, which limits understanding of its cytotoxic potential. Although oxidative stress has been established as an important mechanism underlying PQ toxicity, multiple antioxidants have proven ineffective in attenuating the deleterious effects of PQ. Adiponectin, which shows anti-oxidative and antinitrative effects, may have the potential to reduce PQ-mediated injury. The present study determined the protective action of globular domain adiponectin (gAd) on PQ-induced lung injury, and attempted to elucidate the underlying mechanism or mechanisms of action. BALB/c mice were administered PQ, with and without 12 or 36 h of gAd pre-treatment. The pulmonary oxidative/nitrative status was assessed by measuring pulmonary O₂^•−, superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO) and 8-hydroxy-2-dydeoxy guanosine (8-OHdG) production, and blood 3-Nitrotyrosine (3-NT). At a dose of 20 mg/kg, PQ markedly increased O₂^•−, SOD, MDA, NO and 8-OHdG production 3 h post-administration, but did not significantly increase 3-NT levels until 12 h. gAd inhibited these changes in a dose-dependent manner, via transient activation of MDA, followed by attenuation of MDA formation from 6 h onwards. Histological analysis demonstrated that gAd decreased interstitial edema and inflammatory cell infiltration. These results suggest that gAd protects against PQ-induced lung injury by mitigating oxidative/nitrative stress. Furthermore, gAd may be a potential therapeutic agent for PQ-induced lung injury, and further pharmacological studies are therefore warranted.

Patterns of adiponectin expression in term pregnancy: impact of obesity

CONTEXT

Adiponectin (adpN) production is down-regulated in several situations associated with insulin resistance. The hypoadiponectinemia, which develops in late pregnancy, suggests a role of adpN in pregnancy-induced insulin resistance.

OBJECTIVE

In obese pregnancy there is a decreased systemic adpN, which results from down-regulation of gene expression in adipose tissue.

SETTING AND DESIGN

One hundred and thirty-three women with uncomplicated pregnancies and a wide range in pre-gravid body mass index (18-62 kg/m(2)) were recruited at term for a scheduled cesarean delivery. Maternal blood, placenta, and sc abdominal adipose tissue were obtained in the fasting state. DNA methylation was analyzed by MBD-based genome-wide methylation sequencing and methyl-specific PCR of placenta and maternal adipose tissue. mRNA and protein expression were characterized by real-time RT-PCR and immunodetection. Plasma adpN, leptin, and insulin were assayed by ELISA.

RESULTS

Maternal adipose tissue was the prominent site of adpN gene expression with no detectable mRNA or protein in placenta. In obese women, adipose tissue adpN mRNA was significantly decreased (P < .01) whereas DNA methylation was significantly increased (P < .001) compared with lean women. The decreased adipose tissue expression resulted in normal-weight women having significantly greater plasma adpN compared with the severely obese (12.8 ± 4.3 ng/mL vs 8.6 ± 3.1, P < .001). Plasma adpN was negatively correlated with maternal body mass index (r = -0.28, P < .001) and homeostasis model assessment indices of insulin sensitivity (r = -0.32, P < .001) but not with gestational weight gain.

CONCLUSIONS

Maternal adipose tissue is the primary source of circulating adpN during pregnancy. Further, based on our results, the placenta does not synthesize adiponectin at term. Obesity in pregnancy is associated with negative regulation of adpN adipose expression with increase in adpN DNA methylation associated with lower mRNA concentrations and hypoadiponectinemia. Maternal hypoadiponectinemia may have functional consequences in down-regulating biological signals transmitted by adpN receptors in various tissues, including the placenta.

The effect of antenatal factors and postnatal growth on serum adiponectin levels in children

Low levels of serum adiponectin (i.e. hypoadiponectinaemia) are a marker of cardiometabolic risk in overweight children. It is not clear whether early-life factors may play a role in the development of hypoadiponectinaemia. We investigated whether antenatal factors and postnatal growth are associated with childhood adiponectin levels. This was an observational study in a birth cohort (Vulnerable Windows Cohort Study). Anthropometry was measured at birth, at 6 weeks, every 3 months up to 2 years and then every 6 months. Fasting glucose, insulin, lipids and adiponectin were measured at a mean age 11.5 years. Data on 323 children were analysed with age- and sex-adjusted multivariate analyses. The sizes of mother, placenta, fetus and newborn were not significantly associated with adiponectin levels. Current weight, body mass index (BMI), fat mass, waist circumference, glucose, insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)], triglycerides and systolic blood pressure were inversely related to adiponectin (P < 0.05). Faster growth in BMI during late infancy and childhood was associated with lower adiponectin levels (P < 0.05). After adjusting for current waist circumference, faster growth in BMI during early infancy was positively associated with adiponectin (P < 0.01). Faster growth in BMI during childhood was inversely associated (P < 0.001). These associations were similar after adjusting for HOMA-IR. We concluded that antenatal factors are not determinants of childhood adiponectin levels. Faster growth in BMI during infancy is associated with higher levels, whereas faster rates during childhood are associated with hypoadiponectinaemia. Hypoadiponectinaemia is a marker of a more adverse cardiometabolic profile in Afro-Caribbean children.

Molecular mechanisms and new treatment strategies for non-alcoholic steatohepatitis (NASH)

Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD), in which most patients exhibit non-progressive, non-alcoholic fatty liver (NAFL) attributable to simple steatosis. Multiple hits, including genetic differences, fat accumulation, insulin resistance and intestinal microbiota changes, account for the progression of NASH. NAFLD is strongly associated with obesity, which induces adipokine secretion, endoplasmic reticulum (ER) and oxidative stress at the cellular level, which in turn induces hepatic steatosis, inflammation and fibrosis. Among these factors, gut microbiota are acknowledged as having an important role in initiating this multifactorial disease. Oxidative stress is considered to be a key contributor in the progression from NAFL to NASH. Macrophage infiltration is apparent in NAFL and NASH, while T-cell infiltration is apparent in NASH. Although several clinical trials have shown that antioxidative therapy with vitamin E can effectively control hepatitis pathology in the short term, the long-term effects remain obscure and have often proved to be ineffective in many other diseases. Several long-term antioxidant protocols have failed to reduce mortality. New treatment modalities that incorporate current understanding of NAFLD molecular pathogenesis must be considered.

Adipokines and the female reproductive tract

It is well known that adipose tissue can influence puberty, sexual maturation, and fertility in different species. Adipose tissue secretes molecules called adipokines which most likely have an endocrine effect on reproductive function. It has been revealed over the last few years that adipokines are functionally implicated at all levels of the reproductive axis including the gonad and hypothalamic-pituitary axis. Many studies have shown the presence and the role of the adipokines and their receptors in the female reproductive tract of different species. These adipokines regulate ovarian steroidogenesis, oocyte maturation, and embryo development. They are also present in the uterus and placenta where they could create a favorable environment for embryonic implantation and play a key role in maternal-fetal metabolism communication and gestation. Reproductive functions are strongly dependent on energy balance, and thereby metabolic abnormalities can lead to the development of some pathophysiologies such as polycystic ovary syndrome (PCOS). Adipokines could be a link between reproduction and energy metabolism and could partly explain some infertility related to obesity or PCOS.

Correlation of high-molecular-weight adiponectin and leptin concentrations with anthropometric parameters and insulin sensitivity in newborns

Objective. High-molecular-weight adiponectin (HMW-adiponectin) and leptin are two important adipokines. The aim of this study was to examine the association between the two adipokines and anthropometric measurements of neonates at birth. Furthermore, we would like to explore whether HMW-adiponectin and leptin correlate with insulin sensitivity in neonates. Methods. Venous cord blood samples were obtained from 266 full-term healthy neonates consecutively born at Peking Union Medical College Hospital. HMW-adiponectin, leptin, blood glucose, and insulin concentrations were measured. Results. HMW-adiponectin and leptin were significantly higher in females compared with males (P = 0.031 and P = 0.000, resp.). Univariate correlation analysis showed that leptin concentrations in cord blood were positively associated with gestational age, birth weight, body length, ponderal index, placenta weight, insulin, and insulin sensitivity (all P < 0.001). However, there was no correlation between cord blood HMW-adiponectin levels and foetal anthropometric measurements or foetal insulin sensitivity indicators (all P > 0.05). Multivariate linear regression analysis indicated that leptin (B = -0.126, P = 0.045) in cord blood was independently associated with insulin sensitivity. Conclusions. Leptin concentrations, but not HMW-adiponectin, were positively associated with foetal anthropometric measurements. Leptin concentrations are significantly associated with foetal insulin sensitivity, and there were no significant correlations between HMW-adiponectin levels and foetal insulin sensitivity.

Multiple hits, including oxidative stress, as pathogenesis and treatment target in non-alcoholic steatohepatitis (NASH)

Multiple parallel hits, including genetic differences, insulin resistance and intestinal microbiota, account for the progression of non-alcoholic steatohepatitis (NASH). Multiple hits induce adipokine secretion, endoplasmic reticulum (ER) and oxidative stress at the cellular level that subsequently induce hepatic steatosis, inflammation and fibrosis, among which oxidative stress is considered a key contributor to progression from simple fatty liver to NASH. Although several clinical trials have shown that anti-oxidative therapy can effectively control hepatitis activities in the short term, the long-term effect remains obscure. Several trials of long-term anti-oxidant protocols aimed at treating cerebrovascular diseases or cancer development have failed to produce a benefit. This might be explained by the non-selective anti-oxidative properties of these drugs. Molecular hydrogen is an effective antioxidant that reduces only cytotoxic reactive oxygen species (ROS) and several diseases associated with oxidative stress are sensitive to hydrogen. The progress of NASH to hepatocellular carcinoma can be controlled using hydrogen-rich water. Thus, targeting mitochondrial oxidative stress might be a good candidate for NASH treatment. Long term clinical intervention is needed to control this complex lifestyle-related disease.

Neonatal cord blood adiponectin and insulin levels in very low birth weight preterm and healthy full-term infants

BACKGROUND

There are few studies concerning adiponectin and insulin concentration in cord blood of very low birth weight (VLBW) preterm and full-term newborns, small and appropriate for gestational age (GA).

AIM

To compare adiponectin and insulin concentrations between preterm and full-term infants, and to determine their relation with birth weight (BW) and size for GA.

METHODS

A cross-sectional study of VLBW preterm newborns with GA < 32 weeks and BW < 1500 g, and full-term newborns with GA > 37 weeks born at our hospital between January 2010 and May 2011, was conducted.

EXCLUSION CRITERIA

major congenital malformation, inborn errors of metabolism, chromosomal anomalies. Adiponectin was determined by enzimoimunoassay with ELISA kits (R&D Systems, Minneapolis, MN) and insulin was assayed by chemiluminescence method.

RESULTS

A total of 127 newborns were studied, 55 VLBW preterm (28 SGA), and 72 full-term (7 SGA). Insulin cord blood concentrations in preterm and full-term newborns were similar. Adiponectin concentrations were significantly lower in preterm than in full-term infants: 1.57 ± 0.74 pg/ml versus 2.4 ± 0.22 pg/ml (p < 0.001), respectively. Regression analyses showed that, after controlling for several neonatal and maternal factors, preterm birth was the only significant predictor of adiponectin concentrations.

CONCLUSION

Being born prematurely is the main determinant factor for lower adiponectin concentration in umbilical cord blood of newborns.

Adiponectin increases secretion of rat submandibular gland via adiponectin receptors-mediated AMPK signaling

Adiponectin and adiponectin receptors (AdipoR1/2) are expressed in various tissues and are involved in the regulation of multiple functions such as energy metabolism and inflammatory responses. However, the effect of adiponectin and AdipoRs in submandibular glands has not been fully evaluated. In the present study, we found that mRNA and protein of both adiponectin and AdipoR1/2 were expressed in rat submandibular glands and in the SMG-C6 cell line, as evidenced by RT-PCR and Western blot analysis. Immunofluorescence staining showed that adiponectin was diffused in the cytoplasm, while AdipoR1/2 was concentrated in the membrane of acinar cells. Saliva flow was significantly increased by full length adiponectin (fAd) or globular adiponectin (gAd) perfusion in isolated rat submandibular glands. 5-Aminoimidazole-4-carboxamide-1-4-ribofuranoside (AICAR), an adenosine monophosphate activated protein kinase (AMPK) activator, also increased saliva secretion. fAd, gAd, and AICAR all increased the average width of apical tight junctions in perfused submandibular glands, and decreased transepithelial electrical resistance (TER) in SMG-C6 cells, suggesting that adiponectin promoted secretion by modulating paracellular permeability. fAd and gAd increased p-AMPK levels, while AraA, an AMPK antagonist, abolished fAd- and gAd-induced changes in secretion, tight junction ultrastructure, and TER. Moreover, both AdipoR1 and AdipoR2 were required for fAd- or gAd-induced p-AMPK and TER responses, suggesting from their inhibition following AdipoR1 or AdipoR2 knockdown, and co-knockdown of AdipoRs by RNA interference. Our results suggest that adiponectin functions as a promoter of salivary secretion in rat submandibular glands via activation of AdipoRs, AMPK, and paracellular permeability.

PKA regulatory subunit R2B is required for murine and human adipocyte differentiation

ADIPOGENESIS IS A COMPLEX PROCESS MODULATED BY SEVERAL FACTORS, INCLUDING CAMP SIGNALING. THE MAIN CAMP TARGET IS PROTEIN KINASE A (PKA), A TETRAMERIC ENZYME WITH FOUR REGULATORY SUBUNITS SHOWING TISSUE-SPECIFIC EXPRESSION AND FUNCTION: PRKAR2B is the main regulatory subunit in adipose tissue in mice and in adult humans. This study aimed to evaluate the expression of PKA regulatory subunits in human adipose tissue during fetal development and to investigate their role in the differentiation of 3T3-L1 and primary human preadipocytes. The expression of PKA regulatory subunits was evaluated in fetal adipose tissue (immunohistochemistry) and in cultured 3T3-L1 and primary human preadipocytes (western blot analysis). Cultured cells were transiently transfected with siRNA against PRKAR2B and induced to differentiate. Differentiation was evaluated by intracellular triglyceride staining (Oil Red O) and expression of molecular markers of adipocyte differentiation. In this study, we found that PRKAR2B is the main regulatory subunit in human adipose tissue during fetal development, from 12 weeks of gestation to the end of gestation, as well as in 3T3-L1 and primary human preadipocytes. The expression of PRKAR2B increases progressively during in vitro differentiation. The silencing of PRKAR2B abolishes the increase in the expression of peroxisome proliferator-activated receptor gamma (PPARγ (PPARG)), fatty acid synthase, aP2 (FABP4), and lipoprotein lipase, as well as intracellular triglyceride accumulation, resulting in impaired adipocyte differentiation in both mouse and human cell systems. In conclusion, PRKAR2B is the key PKA regulatory subunit involved in mouse and human adipose tissue development. The physiological increase in the expression of PRKAR2B is an essential event in adipogenesis in both mice and humans, and it might represent a possible target for future strategies for obesity treatment.

Review: Adiponectin--the missing link between maternal adiposity, placental transport and fetal growth?

Adiponectin has well-established insulin-sensitizing effects in non-pregnant individuals. Pregnant women who are obese or have gestational diabetes typically have low circulating levels of adiponectin, which is associated with increased fetal growth. Lean women, on the other hand, have high circulating levels of adiponectin. As a result, maternal serum adiponectin is inversely correlated to fetal growth across the full range of birth weights, suggesting that maternal adiponectin may limit fetal growth. In the mother, adiponectin is predicted to promote insulin sensitivity and stimulate glucose uptake in maternal skeletal muscle thereby reducing nutrient availability for placental transfer. Adiponectin prevents insulin-stimulated amino acid uptake in cultured primary human trophoblast cells by modulating insulin receptor substrate phosphorylation. Furthermore, chronic administration of adiponectin to pregnant mice inhibits placental insulin and mammalian target of rapamycin complex 1 (mTORC1) signaling, down-regulates the activity and expression of key placental nutrient transporters and decreases fetal growth. Preliminary findings indicate that adiponectin binds to the adiponectin receptor-2 on the trophoblast cell and activates p38 MAPK and PPAR-α, which inhibits the insulin/IGF-1 signaling pathway. In contrast to maternal adiponectin, recent reports suggest that fetal adiponectin may promote expansion of adipose tissue and stimulate fetal growth. Regulation of placental function by adiponectin constitutes a novel physiological mechanism by which the endocrine functions of maternal adipose tissue influence fetal growth. These findings may help us better understand the factors determining birth weight in normal pregnancies and in pregnancy complications associated with altered maternal adiponectin levels such as obesity and gestational diabetes.