TNF-alpha is a predictor of insulin resistance in human pregnancy

Relationship between circulating adipokines and insulin resistance during pregnancy and postpartum in women with gestational diabetes

BACKGROUND AND AIMS

We undertook this study to assess the relationship between circulating adipokines and insulin resistance during pregnancy and postpartum in women with gestational diabetes mellitus (GDM).

METHODS

This was a prospective study including 60 women with GDM and 60 subjects with normal gestation who were evaluated at gestational week 30, 6 weeks and 6 months postpartum. Circulating adipokines that were evaluated during the study were leptin, adiponectin, retinol-binding protein-4 (RBP4), and tumor necrosis factor-alpha (TNF-α).

RESULTS

Women with GDM showed higher insulin resistance measured by HOMA-IR than subjects with normal gestation (2.3 ± 2.3 vs. 1.3 ± 0.95). There was no difference between groups in adipokines; however, in women with a healthy pregnancy, RBP4 was associated with insulin resistance (r = 0.47, p <0.05). At 6 weeks and 6 months postpartum, women with previous GDM exhibited persistent elevated leptin and insulin resistance. RBP4 was associated with insulin resistance only in women with a previous healthy pregnancy (r = 0.51, p <0.05). In addition, progressively impaired glucose tolerance was observed after delivery in women with previous GDM.

CONCLUSIONS

It was demonstrated that GDM is associated with greater insulin resistance than observed in normal pregnancy; however, adipokines are similar in both groups. RBP4 levels are significantly associated with insulin resistance in healthy women during pregnancy and postpartum. After a pregnancy complicated by GDM, leptin and insulin resistance remain elevated and glucose tolerance worsens.

Placental hormones and the control of maternal metabolism and fetal growth

PURPOSE OF REVIEW

To examine the roles of the placental and pituitary hormones in the control of maternal metabolism and fetal growth.

RECENT FINDINGS

In addition to promoting growth of maternal tissues, placental growth hormone (GH-V) induces maternal insulin resistance and thereby facilitates the mobilization of maternal nutrients for fetal growth. Human placental lactogen (hPL) and prolactin increase maternal food intake by induction of central leptin resistance and promote maternal beta-cell expansion and insulin production to defend against the development of gestational diabetes mellitus. The effects of the lactogens are mediated by diverse signaling pathways and are potentiated by glucose. Pathologic conditions of pregnancy are associated with dysregulation of GH-V and hPL gene expression.

SUMMARY

The somatogenic and lactogenic hormones of the placenta and maternal pituitary gland integrate the metabolic adaptations of pregnancy with the demands of fetal and neonatal development. Dysregulation of placental growth hormone and/or placental lactogen in pathologic conditions of pregnancy may adversely impact fetal growth and postnatal metabolic function.

Differences in preterm and term milk fatty acid compositions may be caused by the different hormonal milieu of early parturition

INTRODUCTION

The hormonal milieus of pregnancy and lactation are driving forces of nutrient fluxes supporting infant growth and development. The decrease of insulin sensitivity with compensatory hyperinsulinemia with advancing gestation, causes adipose tissue lipolysis and hepatic de novo lipogenesis (DNL).

SUBJECTS AND METHODS

We compared fatty acid (FA) contents and FA-indices for enzyme activities between preterm (28-36 weeks) and term (37-42) milks, and between colostrum (2-5 days), transitional (6-15) and mature (16-56) milks. We interpreted FA differences between preterm and term milks, and their changes with lactation, in terms of the well known decrease of insulin sensitivity during gestation and its subsequent postpartum restoration, respectively.

RESULTS

Compared with term colostrum, preterm colostrum contained higher indices of DNL in the breast (DNL-breast) and medium chain saturated-FA (MCSAFA), and lower DNL-liver and monounsaturated-FA (MUFA). Preterm milk also had higher docosahexaenoic acid (DHA) in colostrum and transitional milk and higher arachidonic acid (AA) in mature milk. Most preterm-term differences vanished with advancing lactation. In both preterm and term milks, DNL-breast and MCSAFA increased with advancing lactation, while DNL-liver, MUFA, long chain SAFA and AA decreased. DHA decreased in term milk. MUFA was inversely related to MCSAFA in all samples, correlated inversely with PUFA in colostrum and transitional milks, but positively in mature milk. MCSAFA correlated inversely with PUFA in mature milk.

CONCLUSION

Higher maternal insulin sensitivity at preterm birth may be the cause of lower MUFA (a proxy for DNL-liver) and higher MCSAFA (a proxy for DNL-breast) in preterm colostrum, compared with term colostrum. Restoring insulin sensitivity after delivery may be an important driving force for milk FA-changes in early lactation.

Implication of low level inflammation in the insulin resistance of adipose tissue at late pregnancy

Insulin resistance is a characteristic of late pregnancy, and adipose tissue is one of the tissues that most actively contributes to the reduced maternal insulin sensitivity. There is evidence that pregnancy is a condition of moderate inflammation, although the physiological role of this low-grade inflammation remains unclear. The present study was designed to validate whether low-grade inflammation plays a role in the development of insulin resistance in adipose tissue during late pregnancy. To this end, we analyzed proinflammatory adipokines and kinases in lumbar adipose tissue of nonpregnant and late pregnant rats at d 18 and 20 of gestation. We found that circulating and tissue levels of adipokines, such as IL-1β, plasminogen activator inhibitor-1, and TNF-α, were increased at late pregnancy, which correlated with insulin resistance. The observed increase in adipokines coincided with an enhanced activation of p38 MAPK in adipose tissue. Treatment of pregnant rats with the p38 MAPK inhibitor SB 202190 increased insulin-stimulated tyrosine phosphorylation of the insulin receptor (IR) and IR substrate-1 in adipose tissue, which was paralleled by a reduction of IR substrate-1 serine phosphorylation and an enhancement of the metabolic actions of insulin. These results indicate that activation of p38 MAPK in adipose tissue contributes to adipose tissue insulin resistance at late pregnancy. Furthermore, the results of the present study support the hypothesis that physiological low-grade inflammation in the maternal organism is relevant to the development of pregnancy-associated insulin resistance.

Gastric bypass surgery reduces plasma ceramide subspecies and improves insulin sensitivity in severely obese patients

Bariatric surgery is associated with near immediate remission of type 2 diabetes and hyperlipidemia. The mechanisms underlying restoration of normal glucose tolerance postoperatively are poorly understood. Herein, we examined the effect of Roux-en-Y gastric bypass surgery (RYGB) on weight loss, insulin sensitivity, plasma ceramides, proinflammatory markers, and cardiovascular risk factors before and at 3 and 6 months after surgery. Thirteen patients (10 female; age 48.5 ± 2.7 years; BMI, 47.4 ± 1.5 kg/m(2)) were included in the study, all of whom had undergone laparoscopic RYGB surgery. Insulin sensitivity, inflammatory mediators and fasting lipid profiles were measured at baseline, 3 and 6 months postoperatively, using enzymatic analysis. Plasma ceramide subspecies (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0, and C24:1) were quantified using electrospray ionization tandem mass spectrometry after separation with HPLC. At 3 months postsurgery, body weight was reduced by 25%, fasting total cholesterol, triglycerides, low-density lipoproteins, and free fatty acids were decreased, and insulin sensitivity was increased compared to presurgery values. These changes were all sustained at 6 months. In addition, total plasma ceramide levels decreased significantly postoperatively (9.3 ± 0.5 nmol/ml at baseline vs. 7.6 ± 0.4 at 3 months, and 7.3 ± 0.3 at 6 months, P < 0.05). At 6 months, the improvement in insulin sensitivity correlated with the change in total ceramide levels (r = -0.68, P = 0.02), and with plasma tumor necrosis factor-α (TNF-α) (r = -0.62, P = 0.04). We conclude that there is a potential role for ceramide lipids as mediators of the proinflammatory state and improved insulin sensitivity after gastric bypass surgery.

Carotid intimal-medial thickness is not increased in women with previous gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is known to increase the risk of cardiovascular diseases. Measuring the carotid artery intimal-medial thickness (CIMT) is a non-invasive technique used to evaluate early atherosclerosis and to predict future cardiovascular diseases. We examined the association between CIMT and cardiovascular risk factors in young Korean women with previous GDM.

METHODS

One hundred one women with previous GDM and 19 women who had normal pregnancies (NP) were recruited between 1999 and 2002. At one year postpartum, CIMT was measured using high-resolution B-mode ultrasonography, and oral glucose tolerance tests were performed. Fasting glucose, glycated hemoglobin A1c (HbA1c), insulin levels and lipid profiles were also measured. CIMTs in the GDM and NP groups were compared, and the associations between CIMT and cardiovascular risk factors were analyzed in the GDM group.

RESULTS

CIMT results of the GDM group were not significantly different from those of the NP group (GDM, 0.435±0.054 mm; NP, 0.460±0.046 mm; P=0.069). In the GDM group, a higher HbA1c was associated with an increase in CIMT after age adjustment (P=0.011). CIMT results in the group with HbA1c >6.0% were higher than those of the normal HbA1c (HbA1c ≤6.0%) (P=0.010). Nine of the patients who are type 2 diabetes mellitus converters within one year postpartum but showed no significant difference in CIMT results compared to NP group.

CONCLUSION

Higher HbA1c is associated with an increase in CIMT in women with previous GDM. However, CIMT at one year postpartum was not increased in these women compared to that in NP women.

Third trimester plasma adiponectin and leptin in gestational diabetes and normal pregnancies

The aim of this study was to compare pregnant women with and without gestational diabetes (GDM) with regard to third trimester adiponectin, leptin and insulin resistance, as well as to investigate their relation to fetal growth and macrosomia. 134 pregnant women were enrolled in the study: 86 with GDM and 48 controls. Maternal plasma adiponectin, leptin, fasting insulin, glucose and fetal biometry were measured between 27 and 32 weeks of gestation. Birthweight and delivery data were also assessed. Adiponectin in GDM patients was lower when compared to non-diabetic women while mean leptin concentration was not different. In GDM group only mothers' weight gain until third trimester was significantly different between the groups of patients with normal and accelerated fetal growth. No correlation of adiponectin and leptin with fetal growth was shown. Mothers' weight gain until third trimester and mean fasting glucose between 33 and 34 weeks of gestation were associated with neonatal macrosomia. There were no differences in adiponectin and leptin between mothers of macrosomic and non-macrosomic neonates. Fetal growth seems not to be related to third trimester adiponectin and leptin concentrations, while increased third trimester fasting glucose may be an independent risk factor of macrosomia.

Gestational Diabetes Mellitus with Diabetic Ketoacidosis in a Yorkshire Terrier Bitch

A 6 yr old pregnant Yorkshire terrier bitch presented 62 days after mating with an acute history of vomiting and coughing. The owners also reported that the dog was polyuric and polydypsic for the last 2 weeks. Complete blood count, serum biochemistry, and urinalysis revealed hyperglycemia, ketonemia, ketonuria, and metabolic acidosis. Diabetic ketoacidosis was diagnosed and after emergency treatment, including fluid therapy, prophylactic antibiotics, and regular insulin, the bitch whelped six healthy normal puppies. Two weeks after treatment, the bitch was clinically normal with normal fructosamine levels. To the authors' knowledge, this is the first reported case of gestational diabetes mellitus in a small breed dog.

Maternal high-fat feeding through pregnancy and lactation predisposes mouse offspring to molecular insulin resistance and fatty liver

The exposure to an increased supply of nutrients before birth may contribute to offspring obesity. Offspring from obese dams that chronically consume a high-fat diet present clinical features of metabolic syndrome, liver lipid accumulation and activation of c-Jun N-terminal kinases (JNK) consistent with the development of nonalcoholic fatty liver disease (NAFLD). However, in spite of the importance of the resistance to insulin for the development of NAFLD, the molecular alterations in the liver of adult offspring of obese dams are yet to be investigated. In this study, we tested the hypothesis that the consumption of excessive saturated fats during pregnancy and lactation contributes to adult hepatic metabolic dysfunction in offspring. Adult male offspring of dams fed a high-fat diet (HN) during pregnancy and lactation exhibited increased fat depot weight; increased serum insulin, tumor necrosis factor α and interleukin 1β; and reduced serum triglycerides. Liver showed increased JNK and I kappa B kinase phosphorylation and PEPCK expression in the adult. In addition, liver triglyceride content in the offspring 1 week after weaning and in the adult was increased. Moreover, basal ACC phosphorylation and insulin signaling were reduced in the liver from the HN group as compared to offspring of dams fed a standard laboratory chow (NN). Hormone-sensitive lipase phosphorylation (Ser565) was reduced in epididymal adipose tissue from the HN group as compared to the NN group. It is interesting that all changes observed were independent of postweaning diet in 14-week-old offspring. Therefore, these data further reinforce the importance of maternal nutrition to adult offspring health.

Chronically increased S6K1 is associated with impaired IRS1 signaling in skeletal muscle of GDM women with impaired glucose tolerance postpartum

CONTEXT

The rapidly increasing prevalence of gestational diabetes mellitus (GDM) globally places a growing population at risk for developing type 2 diabetes mellitus (T2DM), particularly those with persistent impaired glucose tolerance (IGT) postpartum.

OBJECTIVE

We sought to 1) identify dynamic insulin signaling abnormalities in vivo in a prospective, longitudinal study of GDM women compared to weight-matched pregnant controls both antepartum and postpartum; and 2) determine abnormalities that might distinguish GDM women who normalize their glucose tolerance postpartum from those with persistent IGT.

DESIGN

Skeletal muscle biopsies were obtained before and after a 75-g glucose load in nine overweight to obese GDM women and 10 weight-matched pregnant controls antepartum and postpartum. Postpartum biopsies were collected in five weight-matched GDM women with IGT (GDM/IGT).

RESULTS

GDM women had decreased skeletal muscle insulin-stimulated insulin receptor and insulin receptor substrate 1 (IRS1) tyrosine activation and reduced IRS1, concomitant with increased basal IRS1 serine phosphorylation and basal p70 S6-kinase (S6K1) activation, which resolved postpartum. However, GDM/IGT subjects had a persistent impairment in IRS1 activation and increased S6K1 phosphorylation compared to GDM subjects with normal glucose tolerance.

CONCLUSIONS

This study reveals that women with GDM demonstrate impaired IRS1 signaling associated with increased S6K1 activation in skeletal muscle in vivo. This defect is maintained postpartum in GDM/IGT subjects, despite similar body weights and cytokine levels. Given that GDM women with persistent IGT are at a high risk of developing T2DM, understanding how the nutrient-sensitive mammalian target of rapamycin/S6K1 pathway is chronically activated in GDM may lead to important therapies that could prevent the progression to T2DM.

Circulating interleukin-6 concentrations during and after gestational diabetes mellitus

OBJECTIVE

Recent studies have shown that high interleukin-6 (IL-6) secretion may aggravate insulin resistance in pregnancy and participate in the pathogenesis of gestational diabetes mellitus (GDM). The aim of this study was to determine whether the presence of GDM is associated with elevated IL-6 concentrations and whether this association remains after delivery, independent of body mass index.

DESIGN

Longitudinal study.

SETTING

Hospital-based.

SAMPLE

Forty-seven women were screened for GDM with a 75g oral glucose tolerance test at 26.1±3.7 weeks of pregnancy following the Canadian Diabetes Association guidelines (20 GDM, 27 control subjects).

MAIN OUTCOME MEASURES

Interleukin-6 levels were measured by ELISA at the time of GDM screening and two months post-partum.

RESULTS

Interleukin-6 concentrations were significantly higher in women with GDM compared with control women at the time of GDM screening (1.47±0.72 vs. 0.90±0.32pg/mL, p≤0.01). Similar results were obtained two months post-partum, where IL-6 levels remained significantly higher in women with GDM compared with control women (1.88±0.85 vs. 1.41±0.87pg/mL, p≤0.05). Interleukin-6 concentrations were significantly correlated with the Matsuda insulin sensitivity index, measured at the two time points (r=-0.60, p≤0.01 and r=-0.34, p≤0.05). The Matsuda insulin sensitivity index was an independent and significant predictor of IL-6 concentrations at the time of GDM screening, explaining 35.6% of the variance (p≤0.0001) in this variable. IL-6 concentration measured at GDM screening was identified as an independent and significant predictor of post-partum IL-6 concentrations, explaining 28.6% of the variance (p≤0.001).

CONCLUSIONS

These results show that GDM is associated with elevated IL-6 levels independent of obesity levels, both during pregnancy and after delivery.

Mechanisms in the adaptation of maternal β-cells during pregnancy

Pancreatic β-cell mass adapts to changing insulin demands in the body. One of the most amazing reversible β-cell adaptations occurs during pregnancy and postpartum conditions. During pregnancy, the increase in maternal insulin resistance is compensated by maternal β-cell hyperplasia and hyperfunctionality to maintain normal blood glucose. Although the cellular mechanisms involved in maternal β-cell expansion have been studied in detail in rodents, human studies are very sparse. A summary of these studies in rodents and humans is described below. Since β-cell mass expands during pregnancy, unraveling the endocrine/paracrine/autocrine molecular mechanisms responsible for these effects can be of great importance for predicting and treating gestational diabetes and for finding new cues that induce β-cell regeneration in diabetes. In addition to the well known implication of lactogens during maternal β-cell expansion, additional participants are being discovered such as serotonin and HGF. Transcription factors, such as hepatocyte nuclear factor-4α and the forkhead box protein-M1, and cell cycle regulators, such as menin, p27 and p18, are important intracellular signals responsible for these effects. In this article, we summarize and discuss novel studies uncovering molecular mechanisms involved in the maternal β-cell adaptive expansion during pregnancy.

Diabetes mellitus in elkhounds is associated with diestrus and pregnancy

BACKGROUND

Female Elkhounds are shown to be at increased risk for diabetes mellitus, and occurrence of diabetes during pregnancy has been described in several cases.

HYPOTHESIS

Onset of diabetes mellitus in Elkhounds is associated with diestrus.

ANIMALS

Sixty-three Elkhounds with diabetes mellitus and 26 healthy controls.

METHODS

Medical records from 63 Elkhounds with diabetes were reviewed and owners were contacted for follow-up information. Blood samples from the day of diagnosis were available for 26 dogs. Glucose, fructosamine, C-peptide, growth hormone (GH), insulin-like growth factor-1, progesterone, and glutamate decarboxylase isoform 65-autoantibodies were analyzed and compared with 26 healthy dogs. Logistic models were used to evaluate the association of clinical variables with the probability of diabetes and with permanent diabetes mellitus after ovariohysterectomy (OHE).

RESULTS

All dogs in the study were intact females and 7 dogs (11%) were pregnant at diagnosis. The 1st clinical signs of diabetes mellitus occurred at a median of 30 days (interquartile range [IQR], 3-45) after estrus, and diagnosis was made at a median of 46 days (IQR, 27-62) after estrus. Diabetes was associated with higher concentrations of GH and lower concentrations of progesterone compared with controls matched for time after estrus. Forty-six percent of dogs that underwent OHE recovered from diabetes with a lower probability of remission in dogs with higher glucose concentrations (odds ratio [OR], 1.2; P=.03) at diagnosis and longer time (weeks) from diagnosis to surgery (OR, 1.5; P=.05).

CONCLUSIONS

Diabetes mellitus in Elkhounds develops mainly during diestrus and pregnancy. Immediate OHE improves the prognosis for remission of diabetes.

Association of Insulin Resistance with Serum Interleukin-6 and TNF-α Levels During Normal Pregnancy

Overview:

The purpose of this study was to evaluate the role of Tumor Necrosis Factor-α (TNF-α) in insulin resistance (IR) during normal pregnancy.

Approach:

This cross sectional study was carried out on 86 healthy pregnant women including 26, 23 and 37 individuals in the 1st, 2nd and 3rd trimesters, respectively, and in 21 healthy non pregnant women. Serum TNF-α concentration was measured by Enzyme Linked Immunosorbent Assay (ELISA) method.

Results:

There were significant differences between serum TNF-α and IL-6 levels in pregnant women as compared with maternal healthy controls. There was significant correlation between gestational age and Body Mass Index (BMI) (r = 0.28, P = 0.01). There was no significant correlation between gestational age and insulin resistance (IR). We also did not find correlations between IR and TNF-α and IR and IL-6 in pregnant women.

Conclusion:

In conclusion, our findings suggest that TNF-α and IL-6 are not greatly contributed to pregnancy induced insulin resistance in normal pregnancy.

Retinol-binding protein 4 and insulin resistance in preeclampsia

Preeclampsia is characterized by the onset of high blood pressure and proteinuria during pregnancy, which results in substantial maternal and neonatal morbidity and mortality. Insulin resistance has been observed before the onset of preeclampsia, and is implicated in its pathophysiology. Recently, retinol-binding protein 4 (RBP4), which carries retinol in circulation, has been shown to be a potential regulator of insulin resistance originating from adipose tissue. Here we measured insulin resistance and RBP-4 levels in patients with preeclampsia and in women with normal pregnancies matched for gestational age and body mass index at Okayama University Hospital. Our aim was to examine the potential role of RBP4 in the pathophysiology of this disorder. There were no significant differences in RBP4 levels between all patients with preeclampsia and controls. However, the RBP4 level and homeostasis model assessment as an index of insulin resistance (HOMA-IR) in overweight patients with late-onset preeclampsia were significantly higher than in overweight controls carrying normal pregnancies and in normal weight women with late-onset preeclampsia. In contrast, there were no significant differences between the overweight and normal weight groups among patients with early-onset preeclampsia and in healthy pregnant women. These data suggest that RBP4 might act in the pathophysiology of late-onset preeclampsia via increased insulin resistance in obese women.

Maternal serum levels of TNF-alpha and IL-6 long after delivery in preeclamptic and normotensive pregnant women

AIM

To evaluate maternal TNF-alpha and IL-6 plasma levels in normotensive pregnant women, women with preeclampsia, and to examine the temporal changes in their levels from the antepartum to the postpartum period correlated with the regression of preeclampsia.

METHOD

A prospective study was performed in the 2nd Department of Obstetrics and Gynecology, University of Athens. Blood samples were obtained: (1) antepartum at the time of clinical diagnosis of the syndrome, 2. 12-14 weeks postpartum.

RESULTS

No statistically significant differences were found in IL-6 levels, whereas a difference was found in TNF-alpha levels between preeclamptic and controls in antepartum period (0.80 pg/ml versus 0.60 pg/ml, P : .04). Long after delivery, TNF-alpha levels were significantly higher in preeclamptic compared to normotensive controls (0.86 pg/ml versus 0.60 pg/ml, P : .004). No difference was observed in TNF-alpha before and after delivery in both groups. No difference was noticed in IL-6 levels in women of normotensive group long after delivery compared to that before delivery. Long after delivery IL-6 levels were statistically significant higher in preeclamptic women compared to normal controls (3.53 ± 0.52 pg/ml versus 1.69 ± 0.48 pg/ml, P : .02).

CONCLUSION

Preeclamptic women remain under a status of increased inflammatory stress up to 12-14 weeks postpartum despite the fact that all the other signs of preeclampsia are resolved.

Gestational diabetes: emerging concepts in pathophysiology

Gestational diabetes affects 3 to 5% of pregnancies in the United Kingdom, contributing to significant maternal and fetal morbidity. Understanding the pathophysiology is important as it guides diagnostic screening and treatment. The insulin resistance of normal pregnancy facilitates provision of metabolic substrates to the fetus and is multifactorial in origin. Recent identification of hepatic and skeletal muscle lipid deposition in Type 2 diabetics, demonstrated by novel magnetic resonance spectroscopy techniques, is likely to be the underlying cause of pathological insulin resistance. Similar mechanisms almost certainly underlie gestational diabetes, although further studies are required to prove this. Women who develop gestational diabetes have demonstrable insulin resistance prior to pregnancy that is part of a chronic process of lipid accumulation ultimately leading to type 2 diabetes later in life. The importance of lifestyle advice and dietary modification and the rationale behind the use of metformin are thus explained.

Longitudinal study of prepregnancy cardiometabolic risk factors and subsequent risk of gestational diabetes mellitus: The CARDIA study

This study examined prepregnancy cardiometabolic risk factors and gestational diabetes mellitus (GDM) in subsequent pregnancies. The authors selected 1,164 women without diabetes before pregnancy who delivered 1,809 livebirths between 5 consecutive examinations from 1985 to 2006 in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The authors measured prepregnancy cardiometabolic risk factors and performed multivariate repeated-measures logistic regression to compute the odds of GDM adjusted for race, age, parity, birth order, and other covariates. Impaired fasting glucose (100-125 vs. <90 mg/dL), elevated fasting insulin (>15-20 and >20 vs. <10 μU/mL), and low levels of high-density lipoprotein cholesterol (<40 vs. >50 mg/dL) before pregnancy were directly associated with GDM: The odds ratios = 4.74 (95% confidence interval (CI): 2.14, 10.51) for fasting glucose, 2.19 (95% CI: 1.15, 4.17) for middle insulin levels and 2.36 (95% CI: 1.20, 4.63) for highest insulin levels, and 3.07 (95% CI: 1.62, 5.84) for low levels of high-density lipoprotein cholesterol among women with a negative family history of diabetes; all P < 0.01. Among overweight women, 26.7% with 1 or more cardiometabolic risk factors developed GDM versus 7.4% with none. Metabolic impairment exists before GDM pregnancy in nondiabetic women. Interconceptual metabolic screening could be included in routine health assessments to identify high-risk women for GDM in a subsequent pregnancy and to potentially minimize fetal exposure to metabolic abnormalities that program future disease.

The possible role of epigenetics in gestational diabetes: cause, consequence, or both

Gestational diabetes mellitus (GDM) is defined as the glucose intolerance that is not present or recognized prior to pregnancy. Several risk factors of GDM depend on environmental factors that are thought to regulate the genome through epigenetic mechanisms. Thus, epigenetic regulation could be involved in the development of GDM. In addition, the adverse intrauterine environment in patients with GDM could also have a negative impact on the establishment of the epigenomes of the offspring.

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

The changes of visfatin in serum and its expression in fat and placental tissue in pregnant women with gestational diabetes

OBJECTIVES

To elucidate the main source of circulating visfatin and its potential roles in pathogenesis of gestational diabetes mellitus (GDM).

METHODS

We examined serum concentrations of visfatin with ELISA and its expression in subcutaneous adipose tissue, visceral adipose tissue and placenta with RT-PCR and western blot both in women with GDM and normal pregnant controls at term. Moreover, BeWo cells were treated with tumor necrosis factor-alpha (TNF-alpha) and then the intra- and extra-cellular changes of visfatin expression were measured.

RESULTS

Serum visfatin concentrations were significantly higher in women with GDM than controls, which reduced obviously three days after delivery compared with antepartum. Visfatin expressions in placenta were significantly higher in GDM women than controls but there was no difference in its expressions in adipose tissue between the two groups. Moreover, serum visfatin concentrations correlated positively with its expressions in placenta, rather than adipose tissue. We demonstrated that visfatin secretion from BeWo cells was significantly increased but the intracellular expression was decreased at 48h incubation with TNF-alpha in a dose-depended way.

CONCLUSIONS

The oversecretion of visfatin from placenta, probably induced by the elevated TNF-alpha level, contributes to the increased serum visfatin concentrations in women with GDM.

Is there a genetic variation association in the IL-10 and TNF alpha promoter gene with gestational diabetes mellitus?

Gestational diabetes mellitus (GDM), defined as carbohydrate intolerance diagnosed for the first time during pregnancy, affects both maternal and fetal health. Possession of a specific genetic polymorphism can be a predisposing factor for susceptibility to some diseases. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNP) in the promoter gene of interleukin-10 (IL-10) as well as tumor necrosis factor-alpha (TNF alpha) with the development of GDM. Two hundred and twelve consecutive series of eligible normal pregnant women (controls) and gestational diabetes mellitus women were selected based on the study's inclusion and exclusion criteria. DNA was extracted from blood and genotyped for IL-10 at three positions and TNF alpha for gene polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma levels of IL-10 and TNF alpha at different gestational periods as well as postpartum were quantified using enzyme linked immunosorbent assay (ELISA). The results of the study showed that the difference in the frequency of SNP at position -597 in the promoter of the human IL-10 gene between the control and GDM groups was statistically significant (p < 0.05). In contrast, there was no significant difference in the frequency of SNP at the other two sites in the promoter region of the human IL-10 gene (-824 and -1082) as well as position -308 in the promoter of the human TNF-alpha (p > 0.05). In addition, there was no significant difference between the two groups in terms of plasma levels of IL-10 as well as TNF alpha in different stages of pregnancy. SNP at position -597 was significantly associated with the development of GDM and shows potential for use as a predictive marker for GDM.

Obesity, insulin resistance, and pregnancy outcome

There has been a significant increase over the past few decades in the number of reproductive age women who are either overweight or obese. Overweight and obese women are at increased risk for having decreased insulin sensitivity as compared with lean or average weight women. The combination of obesity and decreased insulin sensitivity increases the long-term risk of these individuals developing the metabolic syndrome and associated problems of diabetes, hypertension, hyperlipidemia, and cardiovascular disorders. Because of the metabolic alterations during normal pregnancy, particularly the 60% decrease in insulin sensitivity, overweight and obese women are at increased risk of metabolic dysregulation in pregnancy, i.e. gestational diabetes, preeclampsia, and fetal overgrowth. Hence, pregnancy can be considered as a metabolic stress test for the future risk of the metabolic syndrome. In this review, we will review the underlying pathophysiology related to these disorders. Most importantly, an understanding of these risks provides an opportunity for prevention. For example, a planned pregnancy offers an opportunity to address weight control prior to conception. At the very least, by avoiding excessive weight gain during pregnancy, this may prevent excessive weight retention post partum. Finally, based on the concept of in utero programming, these lifestyle measures may not only have short- and long-term benefits for the woman but also for her offspring as well.

Asymmetric dimethylarginine concentrations are elevated in women with gestational diabetes

As shown in the previous studies, asymmetric dimethylarginine (ADMA) is related to endothelial dysfunction, whereas high-sensitive C-reactive protein (hCRP) is the marker of inflammation. In our study, we investigated ADMA, hCRP, and homocysteine concentrations in women with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT) during late pregnancy. Fifty-four women with GDM and 69 women with NGT between 32 and 39 weeks of gestation were included in this study. ADMA, hCRP, homocysteine, lipid parameters, glycated hemoglobin (HbA1c) levels, insulin, and homeostasis model assessment for insulin resistance (HOMA-IR) were measured. The plasma ADMA concentrations were significantly higher in GDM patients than in NGT subjects (P = 0.03) and the hCRP levels were also significantly increased in GDM group when compared with those in the NGT group (P = 0.008). However, plasma homocysteine levels did not differ between the groups (P = 0.4), while HOMA-IR, insulin, and triglyceride levels were higher in the GDM group than in the NGT group (P = 0.001, 0.002, and 0.02, respectively). The ADMA concentrations in the third trimester were positively correlated with the glucose levels the 50-g glucose challenge test (GCT) during 24-28 weeks in the whole group (r = 0.21, P = 0.02). Our results demonstrate that ADMA and hCRP are elevated in women with GDM during late pregnancy. Further studies are needed to clarify the significance and the underlying mechanisms of the elevated ADMA and hCRP levels in women with GDM.

Pregnancy and the endocrine regulation of the baroreceptor reflex

The purpose of this review is to delineate the general features of endocrine regulation of the baroreceptor reflex, as well as specific contributions during pregnancy. In contrast to the programmed changes in baroreflex function that occur in situations initiated by central command (e.g., exercise or stress), the complex endocrine milieu often associated with physiological and pathophysiological states can influence the central baroreflex neuronal circuitry via multiple sites and mechanisms, thereby producing varied changes in baroreflex function. During pregnancy, baroreflex gain is markedly attenuated, and at least two hormonal mechanisms contribute, each at different brain sites: increased levels of the neurosteroid 3alpha-hydroxy-dihydroprogesterone (3alpha-OH-DHP), acting in the rostral ventrolateral medulla (RVLM), and reduced actions of insulin in the forebrain. 3alpha-OH-DHP appears to potentiate baroreflex-independent GABAergic inhibition of premotor neurons in the RVLM, which decreases the range of sympathetic nerve activity that can be elicited by changes in arterial pressure. In contrast, reductions in the levels or actions of insulin in the brain blunt baroreflex efferent responses to increments or decrements in arterial pressure. Although plasma levels of angiotensin II are increased in pregnancy, this is not responsible for the reduction in baroreflex gain, although it may contribute to the increased level of sympathetic nerve activity in this condition. How these different hormonal effects are integrated within the brain, as well as possible interactions with additional potential neuromodulators that influence baroreflex function during pregnancy and other physiological and pathophysiological states, remains to be clearly delineated.

The impact of gestational diabetes and maternal obesity on the mother and her offspring

The in utero maternal metabolic environment is important relative to both short and long term development of the offspring. Although poor fetal growth remains a significant factor relative to long-term outcome, fetal overgrowth is assuming greater importance because of the increase in obesity in the world's populations. Maternal obesity and gestational diabetes are the most common metabolic complications of pregnancy related to fetal overgrowth and more specifically adiposity. Women with gestational diabetes have increased insulin resistance and inadequate insulin response compared with weight-matched controls. Gestational diabetes increases the risk of maternal hypertensive disease (preeclampsia) as well as cesarean delivery. At birth the neonate has increased adiposity and is at risk for birth injury. Multiple studies have reported that children of women with gestational diabetes have a greater prevalence childhood obesity and glucose intolerance; even at glucose concentrations less than currently used to define gestational diabetes, compared with normoglycemic women. Obese women also have increased insulin resistance, insulin response and inflammatory cytokines compared with average weight women both before and during pregnancy. They too are at increased risk for the metabolic syndrome-like disorders during pregnancy that is hypertension, hyperlipidemia, glucose intolerance and coagulation disorders. Analogous to women with gestational diabetes, neonates of obese women are heavier at delivery because of increased fat and not lean body mass. Similarly, these children have an increased risk of childhood adiposity and metabolic dysregulation. Hence, the preconceptional and perinatal period offers a unique opportunity to modify both short and long term risks for both the woman and her offspring.

Could alterations in maternal plasma visfatin concentration participate in the phenotype definition of preeclampsia and SGA?

OBJECTIVE

Women with preeclampsia and those who delivered a small-for-gestational-age (SGA) neonate share several mechanisms of disease, including chronic uteroplacental ischemia and failure of physiologic transformation of the spiral arteries. However, the clinical manifestation of these obstetrical syndromes is remarkably different. It has been proposed that an altered maternal metabolic state, as well as a unique circulating cytokines milieu, predispose women to develop either preeclampsia or SGA. Compelling evidence suggests that adipose tissue orchestrates both metabolic pathways and immunological responses via the production of adipokines. Visfatin is a novel adipocytokine with metabolic and immunomodulating properties. The objective of this study was to determine whether preeclampsia and SGA are associated with alterations in maternal circulating visfatin concentrations.

METHODS

This cross-sectional study included pregnant women in the following groups: (1) normal pregnancy (n = 158); (2) patients with preeclampsia (n = 43) of which 32 had an AGA and 11 had an SGA neonate; (3) patients without preeclampsia who delivered an SGA neonate (n = 55). Maternal plasma visfatin concentrations were measured by ELISA. Nonparametric tests and multiple linear regression analysis were used.

RESULTS

(1) Women who delivered an SGA neonate had a higher median maternal plasma visfatin concentration than those with a normal pregnancy (20.0 ng/ml, interquartile range: 17.2-24.6 vs. 15.2 ng/ml, 12.1-19.2, respectively; P < 0.001) and than those with preeclampsia (14.5 ng/ml, 12.5-18.7; P < 0.001); (2) the median maternal plasma visfatin concentration did not differ significantly between patients with preeclampsia and those with a normal pregnancy (P = 0.8); (3) among patients with preeclampsia, there was no significant difference in the median maternal plasma visfatin concentration between those with or without an SGA neonate (P = 0.5); (4) in a linear regression model, delivery of an SGA neonate and pregestational body mass index were independently associated with increased visfatin concentration after adjustment for confounding factors (maternal age, smoking, gestational age at blood collection and the presence of preeclampsia or SGA).

CONCLUSION

(1) Patients with SGA, but not those with preeclampsia, had a higher maternal plasma visfatin concentration than those with a normal pregnancy; (2) this finding suggests differential involvement of visfatin in SGA and preeclampsia; (3) we propose that changes in circulating maternal visfatin concentration may be implicated in the phenotypic definitions and distinction of preeclampsia and SGA.

Beta-cell function and insulin resistance in pregnancy and their relation to fetal development

BACKGROUND

Insulin resistance in pregnancy is consequent to the physiological adaptation necessary to provide glucose to the growing fetus. Disturbance in the maternal metabolism can induce structural and functional adaptations during fetal development.

METHODS

Pregnant women with duration of conception between 24 and 28 weeks were assessed for insulin resistance (IR) and beta-cell function by using homeostatic model assessment IR (HOMA-IR) and homeostatic model assessment of beta-cell function (HOMA-B) models, respectively. One hundred pregnant women and 42 age-matched controls were taken for the study. Fourteen pregnant women were diagnosed as gestational diabetes mellitus (GDM) as per World Health Organization (WHO) criteria.

RESULTS

Pregnant women with normal glucose tolerance (NGT) did not reveal significant IR as compared to controls but the HOMA-B was higher (268.91 +/- 197.16 vs 188.6 +/- 88.83, P < 0.01), suggesting excessive beta-cell function to maintain glucose homeostasis. The subset of pregnant women who presented with GDM had significantly higher HOMA-IR values (6.59 +/- 2.93 vs. 1.77 +/- 1.49, P < 0.001) and similar HOMA-B values as compared to pregnant women with NGT. Pregnant women with severe IR manifested as GDM, even without any previous history of dysglycemia.

CONCLUSIONS

With regard to fetal outcome, HOMA-IR is an independent predictor in pregnant women with NGT (biparietal diameter r(2) = 0.204, P < 0.01; weight r(2) = 0.097, P < 0.01), whereas beta-cell function (HOMA-B) is a strong independent predictor of fetal outcome in pregnant GDM (biparietal diameter r(2) = 0.58, P < 0.05; FL r(2) = 0.71, P < 0.01 AC r(2) = 0.79, P < 0.001; weight r(2) = 0.57, P < 0.01).

Is there evidence of separate inflammatory or metabolic forms of preeclampsia?

OBJECTIVES

To examine whether high insulin resistance versus high inflammation identifies subtypes of preeclampsia.

METHODS

A cytokine panel, glucose and insulin were measured in 37 preeclampsia plasma samples. Wilcoxon rank sum assessed median concentration of HOMA(IR) by pro-inflammatory:anti-inflammatory ratio. Regression stratifying by BMI and preterm birth was conducted.

RESULTS

There was no difference in median HOMA(IR) by the pro-inflammatory:anti-inflammatory ratio (p = 0.16). No subsets scatterplot clusters emerged. A positive correlation between HOMAlog and the ratio was significant (p = 0.04).

CONCLUSIONS

No dichotomous subsets of preeclampsia by inflammation versus insulin resistance were detected. Contrary to our hypothesis, insulin resistance was higher as inflammation increased in preeclampsia.

Association between polymorphisms in human tumor necrosis factor-alpha (--308) and -beta (252) genes and development of gestational diabetes mellitus

OBJECTIVE

The aim of this study is to investigate if an association exists between single nucleotide polymorphism (SNP) in the tumor necrosis factor-alpha (TNF-alpha) and TNF-beta genes.

METHODS

The DNA was extracted and SNP in the human TNF-alpha and TNF-beta genes at positions -308 (G/A) and 252 (A/G), respectively, was analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma levels of TNF-alpha in different stages of pregnancy were quantified using enzyme linked immunosorbent assay (ELISA).

RESULTS

There was no significant difference in genotype and allele frequency of SNP at position -308 (G/A) in the promoter region of the human TNF-alpha gene as well as the SNP at position 252 (A/G) in the human TNF-beta gene between the GDM and control subjects. Using the logistic regression model, it was found that the SNP in the TNF-alpha as well as TNF-beta were not associated with development of GDM. In addition, the TNF-alpha levels in the plasma of GDM and control mothers were not significantly different.

CONCLUSIONS

In the population studied, the SNP in position -308 (G/A) of the human TNF-alpha or in position 252 (A/G) of the human TNF-beta gene is not an independent risk factor or a predictor for GDM.

Progesterone inhibits glucose uptake by affecting diverse steps of insulin signaling in 3T3-L1 adipocytes

Maternal insulin resistance is essential for efficient provision of glucose to the fetus. Although elevation of placental hormones is known to relate to the development of insulin resistance, the precise underlying mechanism of maternal insulin resistance is unknown. Therefore, we examined the molecular mechanisms of progesterone causing insulin resistance in 3T3-L1 adipocytes. Progesterone at 10(-4) M, but not 10(-5) M, reduced the amount of IRS-1. As a result, insulin-induced phosphorylation of IRS-1, the association of IRS-1 with p85alpha, and subsequent phosphorylation of Akt1 and -2 was decreased moderately by 10(-4) M progesterone. Subsequently, insulin-induced translocation of GLUT4 to the plasma membrane evaluated by immunostaining on the plasma membrane sheet by confocal laser microscope was also decreased by 10(-4) M progesterone. In contrast, 2-[(3)H]deoxyglucose (2DG) uptake was markedly inhibited by both 10(-5) and 10(-4) M progesterone in a dose-dependent manner. Surprisingly, 2DG uptake elicited by adenovirus-mediated expression of constitutive-active mutant of PI 3-kinase (myr-p110) and Akt (myr-Akt) was suppressed by progesterone. Interestingly, insulin-induced tyrosine phosphorylation of Cbl and activation of TC10 were inhibited by progesterone at 10(-5) M. These results indicate that progesterone is implicated in insulin resistance during pregnancy by inhibiting the PI 3-kinase pathway at the step of 1) IRS-1 expression and 2) distal to Akt and 3) by suppressing the PI 3-kinase-independent pathway of TC10 activation by affecting Cbl phosphorylation.

YKL-40 concentrations are not elevated in gestational diabetes

BACKGROUND

Gestational diabetes (GDM) is an increasing and common complication of pregnancy. The involvement of inflammatory mechanisms in GDM remains unclear. YKL-40 is a novel inflammatory marker that has been recently found to be associated with type 2 diabetes. This is the first study to investigate YKL-40 in GDM.

MATERIAL AND METHODS

A total of 58 subjects were included, 28 patients with GDM (BMI 33.2 +/- 6.1 kg m(-(2)), 33 +/- 6 years) and 30 healthy pregnant controls (BMI 28.4 +/- 5.2 kg m(-(2)), 33 +/- 4 years; mean +/- SD). Standard risk factors for GDM (weight and BMI prior to pregnancy, family history, former GDM, high birthweight offspring) were evaluated. A 2-h 75-g oral glucose tolerance test (oGTT) and measurement of YKL-40 were conducted in gestational week 28 +/- 4, as well as 8 weeks after delivery.

RESULTS

YKL-40 was not different between GDM and controls, neither during (65.8 +/- 44.4 vs. 60.3 +/- 30.1 ng mL(-1)), nor after pregnancy (63.4 +/- 30.5 vs. 66.9 +/- 32.7 ng mL(-1)). YKL-40 was correlated with insulin, HOMA and BMI. GDM had higher fasting insulin (14.1 +/- 7.4 vs. 8.3 +/- 4.3 muU mL(-1)) and glucose (88 +/- 13 - 200 +/- 31 - 160 +/- 33 vs. 76 +/- 10 - 146 +/- 37 - 112 +/- 28 mg dL(-1) for fasting, 1- and 2-h-concentrations in the oGTT, respectively), higher HbA1c (5.3 +/- 0.4 vs. 5.0 +/- 0.5%;), HOMA (3.1 +/- 1.7 vs. 1.6 +/- 0.9), and BMI (33.2 +/- 6.1 vs. 28.5 +/- 5.2 kg m(-2)) (means +/- SD, all P < 0.01).

CONCLUSIONS

No difference in YKL-40 between GDM and controls suggests similar inflammatory status at the time of measurements. The short duration of metabolic changes during GDM might explain this finding, which is in contrast to results in type 2 diabetes.

First-trimester follistatin-like-3 levels in pregnancies complicated by subsequent gestational diabetes mellitus

OBJECTIVE To determine whether maternal levels of follistatin-like-3 (FSTL3), an inhibitor of activin and myostatin involved in glucose homeostasis, are altered in the first trimester of pregnancies complicated by subsequent gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS This was a nested case-control study of subjects enrolled in a prospective cohort of pregnant women with and without GDM (> or =2 abnormal values on a 100-g glucose tolerance test at approximately 28 weeks of gestation). We measured FSTL3 levels in serum collected during the first trimester of pregnancy. Logistic regression analyses were used to determine the risk of GDM. RESULTS Women who developed GDM (n = 37) had lower first-trimester serum levels of FSTL3 compared with women who did not (n = 127) (median 10,789 [interquartile range 7,013-18,939] vs. 30,670 [18,370-55,484] pg/ml, P < 0.001). When subjects were divided into tertiles based on FSTL3 levels, women with the lowest levels demonstrated a marked increase in risk for developing GDM in univariate (odds ratio 11.2 [95% CI 3.6-35.3]) and multivariate (14.0 [4.1-47.9]) analyses. There was a significant negative correlation between first-trimester FSTL3 levels and approximately 28-week nonfasting glucose levels (r = -0.30, P < 0.001). CONCLUSIONS First-trimester FSTL3 levels are associated with glucose intolerance and GDM later in pregnancy.

Insulin requirements throughout pregnancy in women with type 1 diabetes mellitus: three changes of direction

AIMS/HYPOTHESIS

The aim of the study was to analyse the insulin requirements of women with type 1 diabetes mellitus throughout pregnancy.

METHODS

We have examined the weekly mean blood glucose (mmol/l), insulin requirements (U kg(-1) day(-1)) and total insulin requirements (U/day) in 65 women with type 1 diabetes mellitus and tight metabolic control since before pregnancy (HbA(1c) < or =6.0%).

RESULTS

Both insulin requirement and total insulin requirement displayed a peak in week 9, a nadir in week 16 and a second peak in week 37. For the change in insulin requirement (4.08% per week) and in total insulin requirement (5.19% per week), the sharpest slope was observed from week 16 to week 37. However, two changes of direction took place in the first 11 weeks and eight out of nine episodes of severe hypoglycaemia requiring treatment with glucagon or i.v. glucose took place in the first 16 weeks.

CONCLUSIONS/INTERPRETATION

Pregnant women with type 1 diabetes mellitus and tight metabolic control since before pregnancy displayed changes in insulin requirement and total insulin requirement with successive changes of direction. The sharpest slope was observed between 16 and 37 weeks, but insulin requirements were more unstable in the first 16 weeks. This information could help patients and physicians to react to changes in glycaemic pattern in a prompt and adequate way.

Hormonal and metabolic factors associated with variations in insulin sensitivity in human pregnancy

OBJECTIVE

The objective of this study was to determine maternal hormonal and metabolic factors associated with insulin sensitivity in human pregnancy.

RESEARCH DESIGN AND METHODS

This was a prospective observational cross-sectional study of 180 normal pregnant women, using samples collected at the time of a blinded oral glucose tolerance test (OGTT) between 24 and 32 weeks' gestation as an ancillary to the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study. The study was conducted at two public university teaching hospitals, Cleveland, Ohio, and Brisbane, Australia. Fasting maternal serum cholesterol, triglycerides, free fatty acids, insulin, leptin, tumor necrosis factor-alpha, placental growth hormone (PGH), insulin-like growth factors (IGFs) 1 and 2, and insulin-like growth factor binding proteins (IGFBPs) 1 and 3 were assayed. Correlation and multiple regression analyses were used to determine factors associated with maternal insulin sensitivity (IS) estimated using both OGTT-derived (IS(OGTT)) and fasting (using the homeostasis model assessment [HOMA]; IS(HOMA)) insulin and glucose concentrations.

RESULTS

Insulin sensitivity correlated (r = x and y for IS(OGTT) and IS(HOMA,) respectively) with fasting maternal serum leptin (-0.44 and -0.52), IGFBP1 (0.42 and 0.39), and triglycerides (-0.31 and -0.27). These factors were significantly associated with insulin sensitivity in multiple regression analyses (adjusted R(2) 0.44 for IS(OGTT) and IS(HOMA)). These variables explained more than 40% of the variance in estimates of insulin sensitivity.

CONCLUSIONS

Maternal hormonal and metabolic factors related to the placenta, adipose tissue, and the growth hormone axis are associated with the variation in insulin sensitivity seen during normal human pregnancy.

Development of macrosomia resulting from gestational diabetes mellitus: physiology and social determinants of health

This integrative review sought to advance understanding of the literature pertaining to gestational diabetes mellitus (GDM) and subsequent lifestyle changes in Canadian and American populations. Gestational diabetes mellitus includes glucose intolerance identified during pregnancy and affects approximately 7% of all pregnancies worldwide or more than 200,000 cases annually. Depending upon the population studied and the diagnostic tests employed, the prevalence may range from 1% to 14% of all pregnancies. The article comprises 2 parts in which internal and external factors are discussed concerning pathophysiologic pathways and psychosocial influences. Social determinants of health affect the development of GDM. Gestational diabetes mellitus is increasing in all socioeconomic strata, particularly because of stress, sedentary lifestyle, and poor nutritional choices. Questions are raised about future research directions.

Gestational Diabetes Mellitus: An Opportunity to Prevent Type 2 Diabetes and Cardiovascular Disease in Young Women

In women with previous gestational diabetes (pGDM), the risk of developing Type 2 diabetes is greatly increased, to the point that GDM represents an early stage in the natural history of Type 2 diabetes. In addition, in the years following the index pregnancy, women with pGDM exhibit an increased cardiovascular risk profile and an increased incidence of cardiovascular disease. This paper will review current knowledge on the metabolic modifications that occur in normal pregnancy, underlining the mechanism responsible for GDM, the link between these alterations and the associated long-term maternal complications. In women with pGDM, accurate follow-up and prevention strategies (e.g., weight control and regular physical exercise) are needed to reduce the subsequent development of overt diabetes and other metabolic abnormalities related to cardiovascular disease. Therefore, our paper will provide arguments in favor of performing follow-up programs aimed at modifying risk factors involved in the pathogenesis of Type 2 diabetes and cardiovascular disease.

Periodontal disease is associated with gestational diabetes mellitus: a case-control study

BACKGROUND

Few studies have specifically examined the relationship between periodontal disease and gestational diabetes mellitus (GDM). The objective of this study was to examine whether maternal periodontal disease is associated with GDM.

METHODS

A case-control study was conducted of 53 pregnant women with GDM and 106 pregnant women without GDM at Woman's Hospital, Baton Rouge, Louisiana. The periodontal examinations were performed by a calibrated dentist who was masked to the diabetic status of the pregnant women. Periodontitis was defined as the presence of any site with a probing depth (PD) >or=4 mm or a clinical attachment loss (AL) >or=4 mm. The severity of periodontal disease was measured in quartiles of PD and clinical AL. Univariable analysis and multivariable logistic regression were used to examine the relationships between periodontal disease and GDM.

RESULTS

The percentage of periodontitis was 77.4% in women with GDM and 57.5% in women without GDM, with an odds ratio (OR) of 2.5 and a 95% confidence interval (CI) of 1.2 to 5.3. After adjusting for confounding variables of maternal age, parity, race, marital status, education, family income, smoking, alcohol consumption, systemic antibiotics during pregnancy, family history of diabetes, income, dental insurance coverage, and body mass index, the adjusted OR (95% CI) was 2.6 (1.1 to 6.1). The adjusted ORs (95% CIs) of GDM comparing the highest-to-lowest quartiles of PD and clinical AL were 3.8 (1.0 to 14.0) and 4.5 (1.2 to 16.9).

CONCLUSION

This study supports the hypothesis of an association between periodontal disease and GDM.

Profile of peripheral blood neutrophil cytokines in diabetes type 1 pregnant women and its correlation with selected parameters in the newborns

PROBLEM

Interleukin (IL)-12, IL-10, tumor necrosis factor-alpha (TNF-alpha), IL-6 and IL-8 alter as pregnancy progresses, implying continuous immune regulation associated with the maintenance of pregnancy. We aimed to evaluate the peripheral blood neutrophil-derived production of these cytokines in the course of pregnancy complicated by type 1 diabetes.

METHOD

of study These parameters were measured in samples from healthy non-pregnant (C), diabetic non-pregnant (D), healthy pregnant (P) and pregnant diabetic (PD) women.

RESULTS

Neutrophil-derived secretion of TNF-alpha and IL-12 increased along with progression of pregnancy in PD and P groups. The concentration of IL-10 from lipopolysaccharide (LPS)-stimulated neutrophils increased during the course of uncomplicated pregnancy but decreased in diabetic pregnancy. Concentration of IL-8 decreased with the advancing gestational age in P and PD groups. LPS-stimulated neutrophil-derived IL-6 concentration increased only in PD patients.

CONCLUSION

Our results show that diabetes creates pro-inflammatory environment thus potentially influencing the outcome of pregnancy. We conclude that neutrophil-derived cytokine production could contribute to the complications seen in pregnant women with type 1 diabetes.

Review: Diabetes in pregnancy: insulin resistance, obesity and placental dysfunction

Obesity in pregnancy is linked to increased morbidity and mortality for mother and baby. The incidence of gestational diabetes is increased approximately two to six-fold in women who are overweight-obese and the presence of diabetes is a further metabolic challenge which is associated with adverse outcomes. Herein the role of obesity is discussed in the generation of insulin resistance and inflammation and its contribution to placental dysfunction.

Dysregulation of maternal serum adiponectin in preterm labor

OBJECTIVE

Intra-amniotic and systemic infection/inflammation have been causally linked to preterm parturition and fetal injury. An emerging theme is that adipose tissue can orchestrate a metabolic response to insults, but also an inflammatory response via the production of adipocytokines, and that these two phenomenons are interrelated. Adiponectin, an insulin-sensitising, anti-inflammatory adipocytokine, circulates in multimeric complexes including low-molecular weight (LMW) trimers, medium-molecular weight (MMW) hexamers and high-molecular weight (HMW) isoforms. Each of these complexes can exert differential biological effects. The aim of this study was to determine whether spontaneous preterm labor (PTL) with intact membranes and intra-amniotic infection/inflammation (IAI) is associated with changes in maternal serum circulating adiponectin multimers.

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) normal pregnant women (n=158); (2) patients with an episode of preterm labor and intact membranes without IAI who delivered at term (n=41); (3) preterm labor without IAI who delivered preterm (n=27); and (4) preterm labor with IAI who delivered preterm (n=36). Serum adiponectin multimers (total, HMW, MMW and LMW) concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

(1) Preterm labor leading to preterm delivery or an episode of preterm labor that does not lead to preterm delivery was associated with a lower median maternal serum concentration of total and HMW adiponectin, a lower median HMW/total adiponectin ratio and a higher median LMW/total adiponectin ratio than normal pregnancy; (2) among patients with preterm labor, those with IAI had the lowest median concentration of total and HMW adiponectin, as well as the lowest median HMW/total adiponectin ratio; (3) the changes in maternal adiponectin and adiponectin multimers remained significant after adjusting for confounding factors such as maternal age, BMI, gestational age at sampling and parity.

CONCLUSION

(1) Preterm labor is characterised by a change in the profile of adiponectin multimers concentrations and their relative isoforms. These changes were observed in patients with an episode of preterm labor not leading to preterm delivery, in patients with intra-amniotic inflammation, or in those without evidence of intra-amniotic inflammation. (2) The changes in adiponectin multimer concentrations reported in preterm labor are different from those previously reported in spontaneous labor at term, suggesting that there is a fundamental difference between preterm labor and labor at term. (3) The findings reported herein provide the first evidence for the participation of adiponectin multimer in preterm parturition. We propose that adiponectins and adipokines in general provide a mechanism to organise the metabolic demands generated by the process of preterm parturition regardless of the nature of the insult (intra-amniotic inflammation or not).

Feto-placental adaptations to maternal obesity in the baboon

Maternal obesity is present in 20-34% of pregnant women and has been associated with both intrauterine growth restriction and large-for-gestational age fetuses. While fetal and placental functions have been extensively studied in the baboon, no data are available on the effect of maternal obesity on placental structure and function in this species. We hypothesize that maternal obesity in the baboon is associated with a maternal inflammatory state and induces structural and functional changes in the placenta. The major findings of this study were: 1) decreased placental syncytiotrophoblast amplification factor, intact syncytiotrophoblast endoplasmic reticulum structure and decreased system A placental amino acid transport in obese animals; 2) fetal serum amino acid composition and mononuclear cells (PBMC) transcriptome were different in fetuses from obese compared with non-obese animals; and 3) maternal obesity in humans and baboons is similar in regard to increased placental and adipose tissue macrophage infiltration, increased CD14 expression in maternal PBMC and maternal hyperleptinemia. In summary, these data demonstrate that in obese baboons in the absence of increased fetal weight, placental and fetal phenotype are consistent with those described for large-for-gestational age human fetuses.

Insulin resistance and C-reactive protein in preeclampsia

Preeclampsia is referred to as the "disease of the theories" because of the multiple hypotheses proposed to explain is occurrence. Despite considerable research, the causes of preeclampsia remain unclear. Preeclampsia is likely to be multifactorial in origin, and recent research has focused on endothelial dysfunction as a central abnormality in preeclampsia. Insulin resistance and inflammation may contribute to the onset of preeclampsia. They could also be correlated. The aim of the study was to evaluate the presence and relationship between insulin resistance and its markers and C-reactive protein as a marker of inflammation. During their third trimester, 17 preeclamptic women and 20 normotensive controls underwent oral glucose tolerance test, basic biochemical analyses and SHBG. Preeclamptic women were more insulin resistant (p=0,004), and they had higher triglycerides levels (p=0,006), uric acid (p=0,002). However, the study groups did not differ in C-reactive protein (CRP), sex hormone-binding globulin (SHBG), high and low-density lipoproteins (HDL-cholesterol and LDL-cholesterol). In multiple regression analysis only SHBG (p=0,014) and triglycerides (p=0,003) were associated with insulin sensitivity independently of the body mass index (BMI), weight gain, HDL and LDL, and CRP. Preeclampsia is a state of increased insulin resistance, and CRP as the marker of inflammation was not increased in our research, and not associated with established preeclampsia.

Maternal obesity, inflammation, and fetal skeletal muscle development

Maternal obesity coupled with Western-style high-energy diets represents a special problem that can result in poor fetal development, leading to harmful, persistent effects on offspring, including predisposition to obesity and type 2 diabetes. Mechanisms linking maternal obesity to the increased incidence of obesity and other metabolic diseases in offspring remain poorly defined. Because skeletal muscle is the principal site for glucose and fatty acid utilization and composes 40%-50% of total body mass, changes in the properties of offspring skeletal muscle and its mass resulting from maternal obesity may be responsible for the increase in type 2 diabetes and obesity. Fetal stage is crucial for skeletal muscle development because there is no net increase in the muscle fiber number after birth. Fetal skeletal muscle development involves myogenesis, adipogenesis, and fibrogenesis, which are all derived from mesenchymal stem cells (MSCs). Shifting commitment of MSCs from myogenesis to adipogenesis and fibrogenesis will result in increased intramuscular fat and connective tissue, as well as reduced numbers of muscle fiber and/or diameter, all of which have lasting negative effects on offspring muscle function and properties. Maternal obesity leads to low-grade inflammation, which changes the commitment of MSCs in fetal muscle through several possible mechanisms: 1) inflammation downregulates wingless and int (WNT) signaling, which attenuates myogenesis; 2) inflammation inhibits AMP-activated protein kinase, which promotes adipogenesis; and 3) inflammation may induce epigenetic modification through polycomb group proteins. More studies are needed to further explore the underlying mechanisms associated with maternal obesity, inflammation, and the commitment of MSCs.