Autoimmune gestational diabetes mellitus: a distinct clinical entity?

Presence of diabetes-specific autoimmunity in women with gestational diabetes mellitus (GDM) predicts impaired glucose regulation at follow-up

PURPOSE

Gestational diabetes mellitus (GDM) is the most frequent complication of pregnancy; around 10% of GDM cases may be determined by autoimmunity, and our aims were to establish the role of autoimmunity in a population of Sardinian women affected by GDM, to find predictive factors for autoimmune GDM, and to determine type 1 diabetes (T1D) auto-antibodies (Aabs) together with glucose tolerance after a mean 21.2 months of follow-up.

METHODS

We consecutively recruited 143 women affected by GDM and 60 without GDM; clinical data and pregnancy outcomes were obtained by outpatient visit or phone recall. T1D auto-antibodies GADA, IA2-A, IAA, ZnT8-A were measured in the whole population at baseline, and in the Aab-positive women at follow-up.

RESULTS

The overall prevalence of autoimmunity was 6.4% (13/203). No significant difference was found in the prevalence of auto-antibodies between GDM (5.6%) and control (8.3%) women, neither in antibody titres. Highest titres for GADA and ZnT8-A were observed in the control group; no phenotypic factors were predictive for autoimmune GDM. Diabetes-related autoantibodies were still present in all the GDM women at follow-up, and their presence was associated with a 2.65 (p < 0.0016) relative risk (RR) of glucose impairment.

CONCLUSION

We observed a low prevalence (5.6%) of diabetes-related autoimmunity in our GDM cohort, consistent with the prevalence reported in previous studies. It was not possible to uncover features predictive of autoimmune GDM. However, given the significant risk of a persistent impaired glycemic regulation at follow-up, it is advisable to control for glucose tolerance in GDM women with diabetes-related autoimmunity.

Microarray analysis of differentially expressed genes and their functions in omental visceral adipose tissues of pregnant women with vs. without gestational diabetes mellitus

Increasing evidence has shown that insulin resistance in omental visceral adipose tissue (OVAT) is a characteristic of gestational diabetes mellitus (GDM). The present study aimed to identify differentially expressed genes (DEGs) and their associated functions and pathways involved in the pathogenesis of GDM by comparing the expression profiles of OVATs obtained from pregnant Chinese women with and without GDM during caesarian section. A total of 935 DEGs were identified, including 450 downregulated and 485 upregulated genes. In the gene ontology category cellular components, the DEGs were predominantly associated with functions of the extracellular region, while receptor binding was predominant in the molecular function category and biological process terms included antigen processing and presentation, extracellular matrix organization, positive regulation of cell-substrate adhesion, response to nutrients and response to dietary excess. Functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed and a functional interaction network was constructed. Functions of downregulated genes included antigen processing and presentation as well as cell adhesion molecules, while those of upregulated genes included transforming growth factor (TGF)-β-signaling, focal adhesion, phosphoinositide-3 kinase-Akt-signaling, P53 signaling, extracellular matrix-receptor interaction and regulation of actin cytoskeleton pathway. The five main pathways associated with GDM were antigen processing and presentation, cell adhesion molecules, Type 1 diabetes mellitus, natural killer cell-mediated cytotoxicity and TGF-β signaling. These pathways were included in the KEGG pathway categories of ‘signaling molecules and interaction’, ‘immune system’ and ‘inflammatory response’, suggesting that these processes are involved in GDM. The results of the present study enhanced the present understanding of the mechanisms associated with insulin resistance in OVATs of GDM.

The relationships between HLA class II alleles and antigens with gestational diabetes mellitus: A meta-analysis

Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset or first recognition during pregnancy. It is associated with an increased risk of pregnancy complications. Susceptibility to GDM is partly determined by genetics and linked with type 1 diabetes-associated high risk HLA class II genes. However, the evidence for this relationship is still highly controversial. In this study, we assessed the relationship between HLA class II variants and GDM. We performed meta-analysis on all of literatures available in PubMed, Embase, Web of Science and China National Knowledge Infrastructure databases. The odds ratio and 95% confidence interval of each variant were estimated. All statistical analyses were conducted using the Comprehensive Meta Analysis 2.2.064 software. At the allelic analysis, DQB1*02, DQB1*0203, DQB1*0402, DQB1*0602, DRB1*03, DRB1*0301 and DRB1*1302 reached a nominal level of significance, and only DQB1*02, DQB1*0602 and DRB1*1302 were statistically significant after Bonferroni correction. At the serological analysis, none of DQ2, DQ6, DR13 and DR17 was statistically significant following Bonferroni correction although they reached a nominal level of significance. In sum, our meta-analysis demonstrated that there were the associations between HLA class II variants and GDM but more studies are required to elucidate how these variants contribute to GDM susceptibility.

Heterogeneity of maternal characteristics and impact on gestational diabetes (GDM) risk-Implications for universal GDM screening?

OBJECTIVE

To study the incidence of gestational diabetes mellitus (GDM) in relation to phenotypic characteristics and gestational weight gain (GWG) among women at high risk for GDM.

MATERIALS AND METHODS

This is a secondary analysis of a GDM prevention study (RADIEL), a randomized controlled trial conducted in Finland. 269 women with a history of GDM and/or a pre-pregnancy body mass index (BMI) ≥ 30 kg/m(2) were enrolled before 20 weeks of gestation and divided into four groups according to parity, BMI and previous history of GDM. The main outcome was incidence of GDM.

RESULTS

There was a significant difference in incidence of GDM between the groups (p < 0.001). Women with a history of GDM and BMI <30 kg/m(2) showed the highest incidence (35.9%). At baseline they had fewer metabolic risk factors and by the second trimester they gained more weight. There was no interaction between GWG and GDM outcome and no significant difference in the prevalence of diabetes-associated antibodies.

CONCLUSION

Despite a healthier metabolic profile at baseline the non-obese women with a history of GDM displayed a markedly higher cumulative incidence of GDM. GWG and the presence of diabetes-associated antibodies were not associated with GDM occurrence among these high-risk women. Key message Despite a healthier metabolic profile at baseline the non-obese women with previous gestational diabetes mellitus display a markedly higher cumulative incidence of gestational diabetes mellitus.

Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex

Background

Gestational diabetes mellitus (GDM) affects approximately 10 % of pregnancies in the United States and increases the risk of adverse health outcomes in the offspring. These adult disease propensities may be set by anatomical and molecular alterations in the placenta associated with GDM.

Results

To assess the mechanistic aspects of fetal programming, we measured genome-wide methylation (Infinium HumanMethylation450 BeadChips) and expression (Affymetrix transcriptome microarrays) in placental tissue of 41 GDM cases and 41 matched pregnancies without maternal complications from the Harvard Epigenetic Birth Cohort. Specific transcriptional and epigenetic perturbations associated with GDM status included alterations in the major histocompatibility complex (MHC) region, which were validated in an independent cohort, the Rhode Island Child Health Study. Gene ontology enrichment among gene regulation influenced by GDM revealed an over-representation of immune response pathways among differential expression, reflecting these coordinated changes in the MHC region. This differential methylation and expression may be capturing shifts in cellular composition, reflecting physiological changes in the placenta associated with GDM.

Conclusions

Our study represents the largest investigation of transcriptomic and methylomic differences associated with GDM, providing comprehensive insight into how GDM shapes the intrauterine environment, which may have implications for fetal (re)programming.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0116-y) contains supplementary material, which is available to authorized users.

Gestational diabetes mellitus and later cardiovascular disease: a Swedish population based case-control study

Objective

To identify if gestational diabetes mellitus (GDM) is a clinically useful marker of future cardiovascular disease (CVD) risk and if GDM combined with other risks (smoking, hypertension or body mass) identifies high-risk groups.

Design

Population-based matched case–control study.

Setting

National Swedish register data from 1991 to 2008.

Population

A total of 2639 women with a cardiovascular event and matched controls.

Methods

Conditional logistic regression examined associations with CVD before and after adjustment for conventional risk factors and confounders. Effect modification for the association of GDM with CVD by body mass index (BMI), smoking and chronic hypertension was assessed by stratification and interaction testing. Adjustment for diabetes post-pregnancy evaluated its mediating role.

Main outcome measures

Inpatient diagnoses or causes of death identifying ischemic heart disease, ischemic stroke, atherosclerosis or peripheral vascular disease.

Results

The adjusted odds ratios (and 95% confidence intervals) for the association of CVD with GDM are 1.51 (1.07–2.14), 2.23 (2.01–2.48) for smoking, 1.98 (1.71–2.29) for obesity and 5.10 (3.18–8.18) for chronic hypertension. In stratified analysis the association of CVD with GDM was only seen among women with BMI ≥25, with an odds ratio of 2.39 (1.39–4.10), but only women with a BMI <30 accounted for this increased risk. Adjustment for post-pregnancy diabetes attenuated it somewhat to 1.99 (1.13–3.52).

Conclusions

In the absence of other recognised cardiovascular risk factors, such as smoking, obesity or chronic hypertension, GDM is a useful marker of raised CVD risk among women with BMI between 25 and 29.

Caspase 3 activation and PARP cleavage in lymphocytes from newborn babies of diabetic mothers with unbalanced glycaemic control

Several epidemiological studies showed that gestational diabetes mellitus is the most frequent metabolic disorder of pregnancy, the pathogenesis of which has yet to be completely clarified. The aim of this study was to investigate the presence and processing of caspase 3 (Casp3) and poly(ADP-ribose) polymerase 1 (PARP1) in cord blood lymphocytes as markers of apoptosis in relation to glycaemic control during intrauterine life. Our results showed a specific positive correlation between the levels of active Casp3 (17-19 kDa) and the inactive form of PARP1 (89 kDa) in lymphocytes isolated from newborn babies of diabetic women with unbalanced glycaemic control, with a direct correlation between the activation of casp3 and the inactivation of PARP1, that makes lymphocytes unresponsive towards lipopolysaccharide stimulation, highlighting an altered functional response. Besides more studies are required to fully correlate the activation of the apoptotic process during the intrauterine life with the foetal health later in life, our study indicates that a cord blood lymphocyte, an easily accessible source, is informative about the activation of apoptotic stimuli in circulating cells of newborn babies in relation to the glycaemic control reached by the mother during pregnancy.

Outcomes in women with a history of gestational diabetes. Screening and prevention of type 2 diabetes. Literature review

Women with a history of gestational diabetes mellitus (GDM) are characterized by a high risk of type 2 diabetes mellitus (T2DM) (x 7), metabolic syndrome (x 2 to 5) and cardiovascular diseases (x 1,7). Women with lesser degrees of glucose intolerance share the same risks. T2DM may occur from post-partum (5 to 14%) to several years later, up to 25 years. Some factors associated with T2DM are identified: obesity, early diagnosis of GDM before 24 weeks gestation, high pregnancy OGTT blood glucose or insulin-therapy during GDM. Screening for T2DM only with fasting glucose provides less sensibility than with OGTT; HbA1c may supplant these dosages. The recurrence rate of GDM is between 30 and 84%, non-white ethnicity and insulinotherapy during GDM being the best proven predictors. High risk women need repeated life-long screenings for glycaemic abnormalities, or when another pregnancy is planned. Among obese women with history of GDM who show minor glycoregulation disturbances, modifications of lifestyle in intensive programs or metformin halve the risk of DT2. However, studies analysing practices show low adhesion to screening; without an intensive program, few women implement lifestyle modifications. These intensive programs should be implemented and proposed to high-risk women. Their therapeutic education should also include prevention of cardiovascular risk factors.

Genomic expression profiles of blood and placenta reveal significant immune-related pathways and categories in Chinese women with gestational diabetes mellitus

AIMS

We used microarray as well as quantitative real-time PCR (Q-RT-PCR) validation to define the genes and/or pathways that are involved in gestational diabetes mellitus (GDM) in patients of Chinese ethnicity.

METHODS

We used the Illumina microarray platform to obtain comprehensive gene expression profiles of blood and placenta taken from GDM-positive and GDM-negative women.

RESULTS

We found 5197 genes in blood and 243 genes in placenta, which had significantly altered expression profiles attributable to GDM. Genes previously known to have altered expressions as a result of GDM (such as TNF, IL1B, LEP, IFNG and HLA-G) were also validated. In addition, we identified a number of previously unreported genes: VAV3, PTPN6, CD48 and IL15, which had expression patterns that were significantly different from our GDM and control samples, as determined by both microarray and Q-RT-PCR assays. Two significant pathways were identified as GDM-associated pathways through integrated functional annotation. These pathways were: 'Natural killer cell mediated cytotoxicity' in blood and 'Cytokine-cytokine receptor interaction' in placenta. Furthermore, despite differences between blood and placenta in terms of the quantity of gene expression, we nonetheless observed similar functional distributions in both tissues in terms of immune-related genes.

CONCLUSIONS

These newly identified key genes and pathways may provide valuable information about the pathogenesis of GDM and can be used to improve early diagnosis, prevention, medication design and clinical treatment.

[Outcomes in women with history of gestational diabetes mellitus. Screening and prevention of type 2 diabetes mellitus. Literature review]

Women with a history of gestational diabetes mellitus (GDM) are characterized by a high risk of type 2 diabetes mellitus (T2DM) (X 7), metabolic syndrome (X 2 to 5) and cardiovascular diseases (X 1,7). Women with lesser degrees of glucose intolerance share the same risks. T2DM may occur from postpartum (5 to 14%) to several years later, up to 25 years. Some factors associated with T2DM are identified: obesity, early diagnostic before 24 weeks, high pregnancy OGTT blood glucose or insulinotherapy. Screening for T2DM only with fasting glucose provides less sensibility than with OGTT; HbA1c may supplant these dosages. The recurrence rate of GDM is between 30 and 84%, non-white ethnicity and insulinotherapy during GDM being the best proven predictors. High risk women need repeated life-long screenings for glycemic abnomalies, or when another pregnancy is planned. Among overweight or obese women with history of GDM who show minor glycoregulation disturbances, it is proved that modifications of lifestyle in intensive programs or metformin halve the risk of DT2. However, studies analysing practices show low adhesion to screening; without an intensive program, few women implement lifestyle modifications. These intensive programs should be implemented and proposed to high-risk women. Their therapeutic education should also include prevention of cardiovascular risk factors.

Autoantibodies against aminoacyl-tRNA synthetase: novel diagnostic marker for type 1 diabetes mellitus

OBJECTIVES

To investigate whether or not antiaminoacyl-tRNA synthetase (aaRS) autoantibodies could be detected in patients with type 1 diabetes mellitus (DM) and be used as a diagnostic marker for type 1 DM, autoantibodies against aaRSs were measured in the plasma of normal subjects, patients with type 1 DM and patients with type 2 DM.

METHODS

An enzyme-linked immunosorbent assay was performed to detect anti-aaRS autoantibodies in the plasma of normal subjects, and patients with type 1 DM, and patients with type 2 DM.

RESULTS

From the 65 (normal), 58 (type 1 DM) and 57 (type 2 DM) subjects, anti-aaRS autoantibodies were found in 37.9% of patients with type 1 DM compared with 1.54% of the non-diabetic controls, and 5.26% of the patients with type 2 DM (p <0.0001). In addition, anti-aaRS autoantibodies were identified in 30% of patients with type 1 DM without classical type 1 DM autoantibodies.

CONCLUSION

Anti-aaRS autoantibodies were identified in 37.9% of patients with type 1 DM. The results of this study demonstrate for the first time that autoantibodies against aaRSs are specifically associated with type 1 DM.

Retinol-binding protein 4: a novel adipokine implicated in the genesis of LGA in the absence of gestational diabetes mellitus

OBJECTIVE

Adipokines (cytokines produced by adipose tissue) play a major role in the control of body weight and energy distribution. Retinol-binding protein 4 (RBP4), only recently recognized as an adipokine, has been proposed to modulate systemic insulin sensitivity. The goal of this study was to determine whether there is an association between maternal plasma RBP4 concentration and the birth of a large-for-gestational-age (LGA) newborn in women with and without gestational diabetes mellitus (GDM).

STUDY DESIGN

This cross-sectional study included pregnant women at term in the following groups: 1) normal pregnancy with an appropriate-for-gestational-age (AGA) neonate (n=64); 2) normal pregnancy with an LGA neonate (n=44); 3) GDM with an AGA neonate (n=55); and 4) GDM with an LGA neonate (n=42). Maternal plasma RBP4 concentration was determined by ELISA. Parametric and non-parametric statistics were used for analyses.

RESULTS

1) Patients with GDM, either with AGA or LGA neonates, had a higher median plasma concentration of RBP4 than normal pregnant women who delivered an AGA neonate (P=0.01 and P=0.008, respectively); 2) mothers without GDM but with LGA neonates had a higher median plasma concentration of RBP4 than those with normal pregnancy and AGA newborns (P=0.001); 3) these findings remained significant after adjusting for maternal age, body mass index and gestational age at blood sampling.

CONCLUSION

GDM is characterized by alterations in maternal circulating RBP4 concentrations akin to those of Type 2 diabetes mellitus. RBP4 concentrations in maternal plasma may play a role in accelerated fetal growth in the absence of overt carbohydrate intolerance.

Early impairment of beta-cell function and insulin sensitivity characterizes normotolerant Caucasian women with previous gestational diabetes

BACKGROUND AND AIMS

Women with previous gestational diabetes (pGDM) are at high risk of developing type 2 diabetes mellitus. The aim of this study was to evaluate insulin action and insulin secretion in women with pGDM.

METHODS AND RESULTS

One hundred and fifty-three pGDM women and 45 with normal glucose tolerance during pregnancy (controls) were studied 1-3years after delivery. Insulin sensitivity (ISI) and beta-cell secretory capacity (beta-index) were derived from 75-g OGTT. Disposition Index was calculated as the product of beta-index and ISI. One hundred and twenty-two pGDM were normotolerant (NGT) and 31 had impaired glucose regulation (IGR) i.e. impaired glucose tolerance and/or impaired fasting glucose. NGT-pGDM, as compared to controls, had significant impairment in insulin action (ISI: 5.46+/-2.81 vs. 7.38+/-3.68, P<0.01) and insulin secretion (beta-index: 4.68+/-1.01 vs. 5.24+/-0.82 pmol/min/m(2); P<0.01). A further impairment was apparent in IGR-pGDM for beta-index (4.16+/-1.09; P<0.05). The disposition index was reduced in NGT-pGDM as compared to controls (33.9%) and further reduced in IGR-pGDM (28.6%, vs. NGT-pGDM; ANOVA P<0.001). In women of normal weight, ISI and beta-index were significantly (P<0.01) impaired in NGT-pGDM compared to controls and further reduced in IGR-pGDM, although a more pronounced defect in insulin secretion was apparent in these women (beta-index: 4.02+/-0.9; P<0.05).

CONCLUSIONS

Normotolerant women with pGDM show both impairment in insulin secretion and action irrespective of body weight. A more pronounced defect in insulin secretion seems to characterize normal weight women while a more prominent defect in insulin action is found in overweight women.

Thyroid function abnormalities and antithyroid antibody prevalence in pregnant women at high risk for gestational diabetes mellitus

Both gestational diabetes mellitus (GDM) and thyroid dysfunction in pregnancy compromise maternal and fetal health. The aim of the present study was to determine the prevalence of abnormal thyroid function and antithyroid antibodies during early pregnancy in a population at high risk for GDM. Serum free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured in 301 pregnant women who underwent routine 'universal screening' for GDM. The antithyroid peroxidase antibody (antiTPOAb) was also quantified in 255 of these women. GDM was confirmed by a 75-g oral glucose tolerance test using World Health Organization criteria. No statistically significant difference was found between the 80 (26.6%) women with GDM and the 221 (73.4%) women without GDM for any of the thyroid function tests. In the cohort tested for antiTPOAb, the 51 (20.0%) women who were positive for antiTPOAb had higher mean TSH (1.57 +/- 2.49 mIU/l; p < 0.001) than the women negative for antiTPOAb. Seventeen (5.6%) women had low FT4 while 12 (4.0%) women had high TSH; 28 (9.3%) women had low serum TSH, among whom three (1.0%) also had high FT4. The significantly higher prevalence of hypothyroxinemia and antiTPOAb titers than generally reported warrants routine screening for thyroid abnormalities. This screening, which can be effectively and easily incorporated into screening practices already in place for GDM, would result in improved obstetric care.

Lymphocyte subsets and cytokines in women with gestational diabetes mellitus and their newborn

This study aimed to identify potential immunological markers for predicting type 1 diabetes in patients with gestational diabetes mellitus (GDM) and any immunological impairment in their newborn. In 62 GDM patients and 74 women with normal glucose tolerance (NGT), and their babies, we assessed total lymphocytes, T lymphocyte subsets CD3 and CD8 expressing T cell receptor (TCR) alpha/beta or gamma/delta, CD16 and CD19, pancreatic autoantibodies and cytokines (IL-5, IL-2, soluble receptor IL-2). At delivery, umbilical cord blood samples were taken for lymphocyte subpopulations and cytokine measurements. GDM mothers had higher levels of total lymphocytes, CD8 expressing TCR gamma/delta, and lower levels of CD3 expressing TCR alpha/beta than NGT controls. Insulin-treated GDM mothers had lower CD4 and CD4/CD8 ratios, and higher CD8 and IL-5 than diet-treated GDM or controls. Five women were positive for pancreatic autoantibodies, with lower CD4 (p<0.01) and CD4/CD8 ratios (p<0.05), and higher CD8 (p<0.03) and CD19 than GDM and control mothers negative for autoantibodies. GDM newborn had higher CD8 gamma/delta and lower CD16 than NGT babies. There were no significant differences in TNF-alpha concentrations in the cord blood obtained from the GDM and NGT newborn. In conclusion, GDM women and their newborn have lymphocyte subset impairments, which are more important in patients positive for autoantibodies and/or treated with insulin.

Autoimmunity and familial risk of type 1 diabetes

There is evidence that the process leading to type I diabetes may start in early infancy or already in utero. Even though diabetes-associated antibodies can be detected in up to half of the pregnancies of mothers with type I diabetes, pregnancy itself has no major effect on these antibodies. If such antibodies are present in the mother, they are transferred to the fetal circulation and are detectable in cord blood. Most of the transplacentally transferred antibodies disappear by 6 months of age, but may persist even longer. Antibodies present in cord blood may represent true induction of beta-cell autoimmunity, but such a phenomenon is extremely rare. The offspring of affected mothers have a 2% to 3% risk of type I diabetes, which is about one third of that in the offspring of affected fathers. A novel conceivable explanation is that exogenous insulin transplacentally transferred in immune complexes might lead to the induction of tolerance to insulin, which may be the primary autoantigen in type I diabetes. The possible protective or predisposing effect of diabetes-associated antibodies detectable at birth on progression to clinical type I diabetes later will be assessed in ongoing prospective birth cohort studies.