Prevalence and predictive value of islet cell antibodies and insulin autoantibodies in women with gestational diabetes

The Prognosis of Glutamic Acid Decarboxylase Antibodies in Women With Hyperglycemia in Pregnancy

CONTEXT

We recently reported that the presence of glutamic acid decarboxylase antibodies (GADA) was not associated with large-for-gestational-age infants in women with hyperglycemia in pregnancy (HIP).

OBJECTIVE

We explored the association between the presence of GADA and other HIP-related adverse pregnancy outcomes.

METHODS

This observational prospective study, conducted at a university hospital in a suburb of Paris, France, included 1182 consecutive women with HIP measured for GADA at HIP care initiation between 2012 and 2017. Post hoc analyses for outcomes included gestational weight gain, insulin therapy, cesarean delivery, hypertensive disorders, small-for-gestational-age infant, prematurity, and neonatal hypoglycemia.

RESULTS

Of the 1182 women studied, 87 (7.4%) had positive (≥ 1 IU/mL) GADA. Although socioeconomic, clinical, and biological characteristics were similar across women in the positive and negative GADA groups, higher fasting plasma glucose values during early HIP screening were observed in the former (5.5 ± 1.5 vs 5.2 ± 0.7 mmol/L respectively, P < .001). At HIP care initiation, fructosamine levels were higher in women with positive GADA (208 ± 23 vs 200 ± 18 µmol/L; P < .05). In the homeostatic model assessment, insulin resistance (HOMA-IR) and beta secretion (HOMA-B) rates were similar in both groups. Gestational weight gain and the rates of all adverse outcomes were similar in both groups except for cesarean delivery (18.4 and 27.3% for positive and negative GADA, respectively; adjusted odds ratio 0.49 [95% CI, 0.26-0.92], P = .026).

CONCLUSION

Universal measurement of GADA in women with HIP highlighted that 7.4% had positive GADA. No association was observed between GADA and HIP-related adverse pregnancy outcomes, except a lower risk of cesarean delivery.

Autoantibodies predict type 1 diabetes after gestational diabetes - a 23-year cohort study

Objective

To study the predictive value of autoantibodies for type 1 (T1DM) and type 2 (T2DM) diabetes morbidity after gestational diabetes (GDM) in a 23-year follow-up study.

Design

Prospective population-based cohort study.

Methods

We studied 391 women with GDM, and 391 age- and parity-matched controls, who delivered in 1984-1994. Four autoantibodies were analysed in first-trimester blood samples: islet cell autoantibodies (ICAs), glutamic acid decarboxylase autoantibodies (GADAs), insulin autoantibodies (IAAs) and insulinoma-associated antigen-2 autoantibodies (IA-2As). Two follow-up questionnaires (1995-1996, 2012-2013) were sent to assess development of T1DM and T2DM. Predictive value of autoantibodies and clinical factors were analysed by conditional linear regression and ROC analyses.

Results

Single autoantibody positivity was detected in 12% (41/342) of the GDM cohort and in 2.3% (8/353) of the control cohort. In the GDM cohort, 2.6% (9/342) tested positive for two autoantibodies and 2.3% (8/342) for three autoantibodies, whereas only one subject in the control cohort had two autoantibodies. ICA positivity was found in 12.5% of the cases, followed by GADA (6.0%), IA-2A (4.9%) and IAA (1.2%). In the control cohort, GADA positivity was found in 1.4%, IA-2A in 0.8%, IAA in 0.6%, and ICA in 0.3% of the subjects. Detection of ICA, GADA and/or IA-2A autoantibodies decreased T1DM-free survival time and time to diagnosis. All subjects with three positive autoantibodies developed T1DM within seven years from the GDM pregnancy. Development of T2DM after GDM occurred independent of autoantibody positivity.

Conclusion

Development of T1DM can be reliably predicted with GADA and ICA autoantibodies during early pregnancy.

Risk of type 2 diabetes mellitus after gestational diabetes mellitus: A systematic review & meta-analysis

Background &objectives:

Women with gestational diabetes are at an increased risk of being diagnosed as type 2 diabetes, but the postpartum screening rate is low. To provide evidence-based data for health providers and promote postpartum screening, this systematic review and meta-analysis was conducted to access the risks of type 2 diabetes mellitus (T2DM) diagnosis after gestational diabetes mellitus (GDM) in different demographic and maternal subgroups.

Methods:

MEDLINE, Embase and Cochrane Library were searched systematically. Unadjusted relative risks (RRs) and 95 per cent confidence intervals (CIs) were calculated and pooled using a random-effects model. Heterogeneity was assessed with Cochrane’s Q text and by calculating I² values. Subgroup analyses were conducted to address the disparities of type 2 diabetes conversion after gestational diabetes in different demographic and maternal subgroups.

Results:

1809 publications were screened and 39 cohort studies including 2,847,596 women were selected. In these studies, 78,893 women were diagnosed as T2DM at six weeks or later after delivery. The unadjusted RRs of women diagnosed T2DM at six weeks or later after delivery ranged from 1.32 (95% CI, 0.46-3.37) to 47.25 (95% CI, 2.95-758.01) with a pooled unadjusted RR of 8.92 (95% CI, 7.84-10.14). Older women, women with a family history of diabetes, Black and non-Hispanic White women and women living in Europe and South-East Asia had a higher risk of developing T2DM after GDM.

Interpretation & conclusionsxs:

It is suggested that healthcare providers may focus on older women with GDM and women with GDM and a family history of diabetes. Black and non-Hispanic White women with GDM may receive more attention, and healthcare providers, especially those in Europe and South-East Asia, may pay more attention to preventive measures for postpartum T2DM.

Metabolomic Biomarkers in Gestational Diabetes Mellitus: A Review of the Evidence

Gestational diabetes mellitus (GDM) is the fastest growing type of diabetes, affecting between 2 to 38% of pregnancies worldwide, varying considerably depending on diagnostic criteria used and sample population studied. Adverse obstetric outcomes include an increased risk of macrosomia, and higher rates of stillbirth, instrumental delivery, and birth trauma. Metabolomics, which is a platform used to analyse and characterise a large number of metabolites, is increasingly used to explore the pathophysiology of cardiometabolic conditions such as GDM. This review aims to summarise metabolomics studies in GDM (from inception to January 2021) in order to highlight prospective biomarkers for diagnosis, and to better understand the dysfunctional metabolic pathways underlying the condition. We found that the most commonly deranged pathways in GDM include amino acids (glutathione, alanine, valine, and serine), carbohydrates (2-hydroxybutyrate and 1,5-anhydroglucitol), and lipids (phosphatidylcholines and lysophosphatidylcholines). We also highlight the possibility of using certain metabolites as predictive markers for developing GDM, with the use of highly stratified modelling techniques. Limitations for metabolomic research are evaluated, and future directions for the field are suggested to aid in the integration of these findings into clinical practice.

A case of newly diagnosed autoimmune diabetes in pregnancy presenting after acute onset of diabetic ketoacidosis

Objectives

We present a case of immune-mediated diabetes mellitus, diagnosed in pregnancy upon presentation with diabetic ketoacidosis, found to have normal glucose control postpartum.

Case presentation

A 28-year-old medically uncomplicated G1P0 presented in diabetic ketoacidosis at 28.2 weeks gestation. Workup for pancreatic autoantibodies revealed indeterminate anti-islet cell antibodies and positive anti-glutamic acid antibodies. She was stabilized with intravenous fluids and insulin, and transitioned to long and short acting subcutaneous insulin. Her insulin requirements decreased over the course of her pregnancy. Spontaneous vaginal delivery occurred at 37 weeks. Her postpartum glucose control was normal without re-initiation of insulin.

Conclusions

The diagnosis of diabetic ketoacidosis during pregnancy should prompt further investigation into an underlying diagnosis of immune mediated diabetes. These patients should be followed closely in the postpartum period.

The Incidence of Glutamic Acid Decarboxylase Autoantibodies and its Association With Clinical Features in Pregnant Women With Gestational Diabetes Mellitus

Introduction: The association between the incidence of glutamic acid decarboxylase antibodies(GADAs) and risk of diabetes in pregnant women is controversial. Here, our aim was to investigate the incidence and clinical relevance of GADA and its association with development of post-delivery diabetes in women with gestational diabetes mellitus (GDM).Methods: This cohort study was conducted in Torbat–e Heydarieh (Khorasan Razavi, Iran) from October 2015 to March 2017. A total of 147 pregnant women with GDM were included in case group. The control group consisted of 147 healthy controls. A GAD diagnostic kit (Diametra Co.,Italy) was used for diagnosis of GADA. The history of insulin therapy and the development of diabetes one year after delivery were investigated.Results: Of 147 pregnant women with GDM, 9 (6.1%) had GADA in their sera. 14.3% (21 out of 147) of women with GDM had history of insulin therapy. 33.3% (7 of 21) of women who had received insulin developed diabetes one year after delivery. Type 1 and type 2 diabetes were observed in, respectively, 1 (0.7%) and 7 (4.8%) of women with GDM at one year after delivery.At one year after delivery, no women in GADA negative women was diagnosed with type 1 diabetes. However, type 2 diabetes was observed in 2.9% of GADA negative pregnant women.Type 1 and type 2 diabetes were also noticed in, respectively, 11.1% and 33.3% of GADA positive mothers at one year after delivery.Conclusion: The prevalence of GADA was 6.1% in diabetic pregnant women. The GADA positivity and history of insulin therapy during pregnancy were significant risk factors for diabetes at one year after delivery. In addition, development of type 1 diabetes was higher in GADA positive pregnant women with GDM than GADA negative women.

Testing for type 1 diabetes autoantibodies in gestational diabetes mellitus (GDM): is it clinically useful?

Gestational Diabetes Mellitus (GDM) is the most common metabolic disorder in pregnancy, and it is associated with increased risk of morbidity in maternal-fetal outcomes. GDM is also associated with a higher risk to develop diabetes in the future. Diabetes-related autoantibodies (AABs) have been detected in a small percentage (usually less than 10%) of women with gestational diabetes. The prevalence in gestational diabetes of these autoimmune markers of type 1 diabetes (T1D) has been assessed in many studies, together with the risk of progression of AABs-positive GDM towards impaired glucose regulation (IFG or IGT) and overt diabetes after pregancy. The question whether it is necessary to test for T1D autoantibodies in all pregnancies with GDM is still debated. Here we examine the epidemiology of T1D autoantibodies in GDM, their clinical relevance in term of future risk of diabetes or impaired glucose regulation and in term of maternal-fetal outcomes, and discuss when it may be the most appropriate time to search for T1D autoantibodies in women with gestational diabetes.

The Pathophysiology of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a serious pregnancy complication, in which women without previously diagnosed diabetes develop chronic hyperglycemia during gestation. In most cases, this hyperglycemia is the result of impaired glucose tolerance due to pancreatic β-cell dysfunction on a background of chronic insulin resistance. Risk factors for GDM include overweight and obesity, advanced maternal age, and a family history or any form of diabetes. Consequences of GDM include increased risk of maternal cardiovascular disease and type 2 diabetes and macrosomia and birth complications in the infant. There is also a longer-term risk of obesity, type 2 diabetes, and cardiovascular disease in the child. GDM affects approximately 16.5% of pregnancies worldwide, and this number is set to increase with the escalating obesity epidemic. While several management strategies exist-including insulin and lifestyle interventions-there is not yet a cure or an efficacious prevention strategy. One reason for this is that the molecular mechanisms underlying GDM are poorly defined. This review discusses what is known about the pathophysiology of GDM, and where there are gaps in the literature that warrant further exploration.

Long-term risk of diabetes in women at varying durations after gestational diabetes: a systematic review and meta-analysis with more than 2 million women

This study aims to investigate the impact of gestational diabetes mellitus (GDM) on the long-term risks of diabetes in women with prior GDM, including the effect at different time periods after GDM. We searched PubMed and other databases to retrieve articles which were published prior to February 28, 2017. Cohort studies which evaluated the risk and time of onset of diabetes postpartum in women with and without GDM were included. Meta-analysis with random effects models was used to obtain pooled relative risks and 95% confidence intervals for the risk of diabetes. Subgroup analyses were performed to check for different effect sizes as well as consistency across groups. Multivariable logistic regression was used to adjust for confounders. Thirty cohort studies with 2,626,905 pregnant women were included. Women with prior GDM had 7.76-fold (95% confidence intervals: 5.10-11.81) unadjusted pooled risk of diabetes as compared with women without GDM, whilst the adjusted risk was 17.92-fold (16.96-18.94). The adjusted ORs of GDM for diabetes among women at <3, ≥3 - <6 and ≥6 - <10 years after GDM were 5.37 (3.51-9.34), 16.55 (16.08-17.04) and 8.20 (4.53-14.86), respectively. Women with prior GDM had substantially increased risk of diabetes, with the risk highest during the 3-6 years after GDM.

Prevention of type 2 diabetes mellitus in women with previous gestational diabetes mellitus

Gestational diabetes mellitus (GDM), defined as any degree of glucose intolerance with onset or first recognition during pregnancy, is characterized by underlying maternal defects in the β-cell response to insulin during pregnancy. Women with a previous history of GDM have a greater than 7-fold higher risk of developing postpartum diabetes compared with women without GDM. Various risk factors for postpartum diabetes have been identified, including maternal age, glucose levels in pregnancy, family history of diabetes, pre-pregnancy and postpartum body mass index, dietary patterns, physical activity, and breastfeeding. Genetic studies revealed that GDM shares common genetic variants with type 2 diabetes. A number of lifestyle interventional trials that aimed to ameliorate modifiable risk factors, including diet, exercise, and breastfeeding, succeeded in reducing the incidence of postpartum diabetes, weight retention, and other obesity-related morbidities. The present review summarizes the findings of previous studies on the incidence and risk factors of postpartum diabetes and discusses recent lifestyle interventional trials that attempted to prevent postpartum diabetes.

Postpartum development of type 1 diabetes in Asian Indian women with gestational diabetes

AIM

To study the postpartum conversion of gestational diabetes mellitus (GDM) to different types of diabetes among Asian Indian women.

MATERIALS AND METHODS

Using data from electronic medical records, 418 women with GDM seen at a tertiary diabetes care center for diabetes in Chennai in South India between 1991 and 2014 were evaluated for development of diabetes postpartum.

RESULTS

Of the 418 GDM women followed up postpartum, 388 progressed to diabetes. Of these 359 (92.5%) developed type 2 diabetes (T2DM) and 29 women (7.5%) developed type 1 diabetes (T1DM). The median time to development of T1DM was 2 years (interquartile range 2 [IQR]) while for T2DM it was 5 years (IQR 6). Women who developed T1DM had significantly lower mean body mass index (BMI) (20.4 ± 2.8 vs. 27.5 ± 4.4 kg/m², P = 0.001), and higher fasting plasma glucose (222 ± 105 vs. 165 ± 62 mg/dl P = 0.008) and glycated hemoglobin levels (10.2 ± 2.7 vs. 8.5 ± 2.1% P < 0.001) compared to those who developed T2DM. Glutamic acid decarboxylase (GAD) autoantibodies were present in 24/29 (82.7%) of women who developed T1DM.

CONCLUSION

A small but significant proportion of women with GDM progress to T1DM postpartum. Measurement of GAD antibodies in leaner women with more severe diabetes could help to identify women who are likely to develop T1DM and thus prevent their presentation with acute hyperglycemic emergencies after delivery.

Prevalence of Gestational Diabetes and Risk of Progression to Type 2 Diabetes: a Global Perspective

Despite the increasing epidemic of diabetes mellitus affecting populations at different life stages, the global burden of gestational diabetes mellitus (GDM) is not well assessed. Systematically synthesized data on global prevalence estimates of GDM are lacking, particularly among developing countries. The hyperglycemic intrauterine environment as exemplified in pregnancies complicated by GDM might not only reflect but also fuel the epidemic of type 2 diabetes mellitus (T2DM). We comprehensively reviewed available data in the past decade in an attempt to estimate the contemporary global prevalence of GDM by country and region. We reviewed the risk of progression from GDM to T2DM as well. Synthesized data demonstrate wide variations in both prevalence estimates of GDM and the risk of progression from GDM to T2DM. Direct comparisons of GDM burden across countries or regions are challenging given the great heterogeneity in screening approaches, diagnostic criteria, and underlying population characteristics. In this regard, collaborative efforts to estimate global GDM prevalence would be a large but important leap forward. Such efforts may have substantial public health implications in terms of informing health policy makers and healthcare providers for disease burden and for developing more targeted and effective diabetes prevention and management strategies globally.

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.

Evaluation of thyroid dysfunction and autoimmunity in gestational diabetes mellitus and its relationship with postpartum thyroiditis

AIMS

To evaluate thyroid dysfunction and autoimmunity in women with gestational diabetes and to investigate the frequency of postpartum thyroiditis in women with gestational diabetes.

MATERIALS AND METHODS

A total of 350 women with gestational diabetes and 350 healthy pregnant women were enrolled in the study. We studied the thyroid hormone profiles of the women in each group during pregnancy (at 24-28 weeks' gestation) and after delivery (at 6 weeks, 3, 6 and 9 months, and 1 year postpartum).

RESULTS

A total of 342 women with gestational diabetes and 313 healthy pregnant women completed the follow-up during pregnancy and 1 year after delivery. Of the women with gestational diabetes, 16.6% had thyroid dysfunction, while of the healthy pregnant women, 6.1% had thyroid dysfunction. The prevalence of postpartum thyroiditis was higher in the women with a history of gestational diabetes (19.6%) than in the healthy pregnant women (10.2%), and this difference was statistically significant.

CONCLUSION

According to the results of the present study, the prevalence of postpartum thyroiditis was higher in women with a history of gestational diabetes than in healthy women. We recommend that all women with gestational diabetes and women who have previous thyroid dysfunction should be screened for thyroid hormonal abnormalities during pregnancy and for 1 year after pregnancy.

A community-based survey for different abnormal glucose metabolism among pregnant women in a random household study (SAUDI-DM)

OBJECTIVE

To assess the prevalence and risk factors of gestational diabetes mellitus (GDM) in a population known to have a high prevalence of abnormal glucose metabolism.

METHODS

A household random population-based cross-sectional study of 13,627 women in the childbearing age, who were subjected to fasting plasma glucose if they were not known to have been diagnosed before with any type of diabetes. GDM cases were diagnosed using the International Association of Diabetes and Pregnancy Study Group (IAPSG) criteria.

RESULTS

The overall GDM prevalence was 36.6%, categorised into 32.4% new cases and 4.2% known cases. Another 3.6% had preconception type 1 or 2 diabetes. GDM cases were older and had a significantly higher body mass index, in addition to a higher rate of macrocosmic baby and history of GDM. Monthly income, educational level, living in urban areas and smoking were not found to be significantly different between normal and GDM cases. The most important and significant risk factors for GDM were history of GDM, macrosomic baby, obesity and age >30 years. However, hypertension, low high-density lipoprotein, family history of diabetes and increased triglycerides did not show any significant effect on GDM prevalence in this cohort.

CONCLUSIONS

This society is facing a real burden of abnormal glucose metabolism during pregnancy, where almost half of the pregnant women are subjected to maternal and neonatal complications. Early screening of pregnant women, especially those at a high risk for GDM, is mandatory to identify and manage those cases.

Prevalence of zinc transporter 8 antibodies in gestational diabetes mellitus

AIMS

Gestational diabetes mellitus affects approximately 7% of all pregnant women. Some of these women develop autoantibodies that are generally characteristic of Type 1 diabetes. Autoantibodies targeting glutamic acid decarboxylase and tyrosine phosphatase-like protein are the most frequently reported. A recently identified autoantigen in Type 1 diabetes is zinc transporter 8. Some reports suggest that the frequency of zinc transporter 8 antibodies is as high as glutamic acid decarboxylase antibodies in Type 1 diabetes and thus a good diagnostic marker for autoimmune diabetes. There are currently no reports of zinc transporter 8 antibodies in gestational diabetes. The aim of this pilot study was to investigate the frequency of zinc transporter 8 antibodies in patients at clinical onset of gestational diabetes mellitus.

METHODS

  Subjects included in this pilot study were all diagnosed with gestational diabetes at Skåne University Hospital, Lund, Sweden, 2009-2010 (n = 193). Sera samples were analysed for antibodies using a commercial enzyme-linked immunosorbent assay according to the manufacturers' instructions.

RESULTS

We found that 19/193 patients with gestational diabetes, diagnosed in 2009-2010, were positive for at least one autoantibody. Glutamic acid decarboxylase was the most common single autoantibody (52.6%; 10/19), followed by zinc transporter 8 (21.1%; 4/19) and tyrosine phosphatase-like protein (15.8%; 3/19). Combinations of two or more antibodies were rare (10.5%; 2/19).

CONCLUSIONS

In this study, we found that zinc transporter 8 added 2.1% (4/193) of autoantibody positivity in women with gestational diabetes who were negative for glutamic acid decarboxylase and tyrosine phosphatase-like protein antibodies. Glutamic acid decarboxylase was still the most prevalent autoantibody in gestational diabetes, but, as zinc transporter 8 was present even in the absence of glutamic acid decarboxylase, this autoantibody could be an important independent marker of autoimmunity in gestational diabetes.

Comprehensive intensive therapy for Chinese gestational diabetes benefits both newborns and mothers

OBJECTIVE

This study identified the impact of intensive therapy on neonatal outcomes in women with gestational diabetes mellitus (GDM) and determined the effects on the postpartum metabolic status of the mothers.

RESEARCH DESIGN AND METHODS

In total, 127 pregnant women with GDM were randomly selected to receive an intensive treatment regimen, which included one-to-one education, lifestyle intervention, scheduled clinic visits, strict glucose control, and frequent glucose self-monitoring. Meanwhile, 148 age-matched pregnant women with GDM were selected as controls and given the standard treatment regimen. Pregnancy outcomes including parameters related to the GDM mothers and to their neonates were comparatively analyzed between the two treatment groups. GDM patient follow-up (range, 1-3 years after delivery) included an oral glucose tolerance test and measurements of lipid concentration and insulin secretion. The insulinogenic index (ΔInsulin(30 min)/ΔBlood glucose(30 min)) and homeostasis model assessment index of β-cell function and insulin resistance were calculated. The patients' demographic and anthropometric data were also recorded for comparative analysis.

RESULTS

Compared with GDM patients receiving standard treatment, GDM patients receiving intensive treatment had lower instances of premature delivery (2.4% vs. 8.3%, P<0.05) and neonatal care unit admission (21.3% vs. 33.3%, P<0.05) and lower neonatal birth weight (3.26±0.53 vs. 3.45±0.55 kg, P<0.0001). At follow-up, GDM patients from the intensive treatment group had a smaller waist circumference (75.83±3.11 vs. 78.34±4.20 cm, P<0.01), lower 30-min glucose levels after a 75-g glucose load (8.26±1.85 vs. 9.46±2.74 mmol/L, P<0.05), and higher high-density lipoprotein levels (1.30±0.24 vs. 1.18±0.23 mmol/L, P<0.05).

CONCLUSIONS

The intensive GDM treatment regimen led to healthier outcomes for the women, the neonates, and the birth event and was associated with better maternal metabolic situations in the months and years after delivery.

HLA-DQB1 genotypes and islet cell autoantibodies against GAD65 and IA-2 in relation to development of diabetes post partum in women with gestational diabetes mellitus

AIMS

To study HLA-DQB1 genes and islet cell autoantibodies against glutamic acid decarboxylase 65 (GADA) and insulinoma antigen-2 (IA-2A) in relation to diabetes post partum in mothers with diagnosed gestational diabetes mellitus (GDM).

METHODS

During 2003-2004, women undergoing a 75 g oral glucose tolerance test (OGTT) during pregnancy were invited to participate in the Mamma Study. Cut-off level defining GDM was a 2-h capillary blood glucose of 7.8 mmol/L. 1-2 years after delivery a 75 g OGTT was performed, GADA and IA-2A were measured and HLA-DQB1 genes analysed. Data were available for 452 mothers with previous GDM and 168 randomly selected control subjects.

RESULTS

HLA-DQB1*0602 was negatively associated with GDM (p=0.033) and with development of diabetes post partum (p=0.017), whereas high risk HLA were not associated with GDM or with diabetes. The presence of GADA post partum was positively associated with diabetes post partum (p=0.0009), but not with impaired glucose tolerance.

CONCLUSIONS

Mothers with GDM and HLA-DQB1*0602 were less likely to develop diabetes after pregnancy, and type 1 diabetes associated high risk HLA genes did not predict type 1 diabetes post partum. Additionally, GADA were positively associated with diabetes development.

Gestational diabetes and thyroid autoimmunity

Background. About 10% of pregnancies are complicated by previously unknown impairment of glucose metabolism, which is defined as gestational diabetes. There are little data available on prevalence of thyroid disorders in patients affected by gestational diabetes, and about their postgestational thyroid function and autoimmunity. We therefore investigated pancreatic and thyroid autoimmunity in gestational diabetic patients and in women who had had a previous gestational diabetic pregnancy. Methods. We investigated 126 pregnant women at the time of a 100-g oral glucose tolerance test: 91 were classified as gestational diabetics, and 35 were negative (controls). We also studied 69 women who had delivered a baby 18-120 months prior to this investigation and who were classified at that time gestational diabetics (38 women) or normally pregnant (31 women; controls). Results. Our data show no differences for both thyroid function and prevalence of autoimmune disorders during pregnancy; however, a significant increase in thyroid autoimmunity was seen in women previously affected by gestational diabetes. This increased prevalence of thyroid autoimmunity was not associated with the development of impaired glucose metabolism after pregnancy. Conclusions. Our data suggest that maternal hyperglycemia is a risk factor for the development of thyroid autoimmunity, a conclusion that should now be confirmed in a larger cohort of patients.

Gestational diabetes mellitus is associated with TCF7L2 gene polymorphisms independent of HLA-DQB1*0602 genotypes and islet cell autoantibodies

AIMS

To test whether the TCF7L2 gene was associated with gestational diabetes, whether the association between TCF7L2 and gestational diabetes was independent of HLA-DQB1*0602 and islet cell autoantibodies, as well as maternal age, number of pregnancies, family history of diabetes and the HLA-DQB1 genotypes, and to test whether the distribution of HLA-DQB1 alleles was affected by country of birth.

METHODS

We genotyped the rs7903146, rs12255372 and rs7901695 single nucleotide polymorphisms of the TCF7L2 gene in 826 mothers with gestational diabetes and in 1185 healthy control subjects in the Diabetes Prediction in Skåne Study. The mothers were also typed for HLA-DQB1 genotypes and tested for islet cell autoantibodies against GAD65, insulinoma-associated antigen-2 and insulin.

RESULTS

The heterozygous genotypes CT, GT and TC of the rs7903146 (T is risk for Type 2 diabetes), rs12255372 (T is risk for Type 2 diabetes) and rs7901695 (C is risk for Type 2 diabetes), respectively, as well as the homozygous genotypes TT, TT and CC of the rs7903146, rs12255372 and rs7901695, respectively, were strongly associated with gestational diabetes (P < 0.0001). These associations remained statistically significant after adjusting for maternal age, number of pregnancies, family history of diabetes and HLA-DQ genotypes and were independent of the presence of islet cell autoantibodies. No interaction was observed between TCF7L2 and HLA-DQB1*0602, which was shown to be negatively associated with gestational diabetes in mothers born in Sweden (P = 0.010).

CONCLUSIONS

The TCF7L2 was associated with susceptibility for gestational diabetes independently of the presence of HLA-DQB1*0602 and islet cell autoantibodies and other factors such as maternal age, number of pregnancies, family history of diabetes and other HLA-DQ genotypes. The HLA-DQB1*0602 was negatively associated with gestational diabetes in mothers born in Sweden.

Onset of autoimmune type 1 diabetes during pregnancy: Prevalence and outcomes

Although this has been recently challenged, gestational diabetes mellitus (gestational diabetes) is still defined as an "impairment of glucose tolerance with onset or first recognition during pregnancy". According to this definition, all pathophysiological conditions leading to beta cell deficiency may reveal as gestational diabetes, due to the physiological insulin resistance associated with pregnancy. In rare patients, gestational diabetes is associated with the presence of islet autoantibodies and with a high risk of progression to overt type 1 diabetes after delivery. This condition has often been compared to the Latent Autoimmune Diabetes in Adults. The frequency of islet autoantibodies in gestational diabetes has been assessed in many studies, but data about the clinical presentation of this subtype and about its prognosis are few. We review these studies and discuss the links of autoimmune gestational diabetes with type 1 diabetes mellitus.

Diabetes related autoimmunity in gestational diabetes mellitus: is it important?

Some GDM women show autoantibody positivity during and after pregnancy and pancreatic autoantibodies can appear for the first time in some patients after delivery. Autoantibody positivity is often accompanied by a high frequency of DR3 and DR4 alleles, which are classically related to the development of type 1 diabetes and, although not all studies agree on this point, by an immunological imbalance expressed by the behaviour of the lymphocyte subpopulation, which can be seen as diabetic anomalies overlapping with the immunological changes that occur during pregnancy. It is worth emphasizing that such patients may develop classical type 1 diabetes during and/or after their pregnancy or they may evolve, often some years after their pregnancy, into cases of latent autoimmune diabetes of adulthood (LADA). Autoimmune GDM accounts for a relatively small number of cases (about 10% of all GDM) but the risk of these women developing type 1 diabetes or LADA is very high, so these patients must be identified in order to prevent the severe maternal and fetal complications of type 1 diabetes developing in pregnancy, or its acute onset afterwards. Since women with autoimmune GDM must be considered at high risk of developing type 1 diabetes in any of its clinical forms, these women should be regarded as future candidates for the immunomodulatory strategies used in type 1 diabetes.

The type 1 diabetes protective HLA DQB1*0602 allele is less frequent in gestational diabetes mellitus

AIMS/HYPOTHESIS

We tested whether gestational diabetes mellitus (GDM) is associated with HLA-DQ genotypes.

METHODS

A total of 764 mothers with non-autoimmune (GAD65, insulinoma-associated protein 2 [IA-2] and insulin autoantibody-negative) GDM were ascertained between September 2000 and August 2004 in the population-based Diabetes Prediction in Skåne (DiPiS) study. HLA-DQB1 genotypes were determined in these mothers and in 1191 randomly selected non-diabetic control mothers also negative for islet autoantibodies. The data were analysed in relation to maternal age, country of birth, number of pregnancies/siblings and pregnancy weight gain.

RESULTS

The frequency of type 1 diabetes high-risk HLA-DQ alleles (DQB1*0201, DQB1*0302) did not differ between GDM mothers and controls. In contrast, the low-risk DQB1*0602 allele was less prevalent (OR 0.64, 95% CI = 0.51-0.80, p = 0.0006) in GDM than in control mothers. The difference in DQB1*0602 frequency between GDM mothers and controls remained after multiple logistic regression analysis correcting for maternal age, country of birth, number of pregnancies/siblings and weight gain during pregnancy (OR 0.67, 95% CI 0.51-0.88, p = 0.009).

CONCLUSIONS/INTERPRETATION

The negative association between mothers who have non-autoimmune GDM and HLA-DQ*0602 suggest that this allele may protect not only from type 1 diabetes but also from GDM.

Type 2 diabetes mellitus after gestational diabetes: a systematic review and meta-analysis

BACKGROUND

Women with gestational diabetes are at increased risk of developing type 2 diabetes, but the risk and time of onset have not been fully quantified. We therefore did a comprehensive systematic review and meta-analysis to assess the strength of association between these conditions and the effect of factors that might modify the risk.

METHODS

We identified cohort studies in which women who had developed type 2 diabetes after gestational diabetes were followed up between Jan 1, 1960, and Jan 31, 2009, from Embase and Medline. 205 relevant reports were hand searched. We selected 20 studies that included 675 455 women and 10 859 type 2 diabetic events. We calculated and pooled unadjusted relative risks (RRs) with 95% CIs for each study using a random-effects model. Subgroups analysed were the number of cases of type 2 diabetes, ethnic origin, duration of follow-up, maternal age, body-mass index, and diagnostic criteria.

FINDINGS

Women with gestational diabetes had an increased risk of developing type 2 diabetes compared with those who had a normoglycaemic pregnancy (RR 7.43, 95% CI 4.79-11.51). Although the largest study (659 164 women; 9502 cases of type 2 diabetes) had the largest RR (12.6, 95% CI 12.15-13.19), RRs were generally consistent among the subgroups assessed.

INTERPRETATION

Increased awareness of the magnitude and timing of the risk of type 2 diabetes after gestational diabetes among patients and clinicians could provide an opportunity to test and use dietary, lifestyle, and pharmacological interventions that might prevent or delay the onset of type 2 diabetes in affected women.

FUNDING

None.

The prevalence of GAD antibodies in Korean women with gestational diabetes mellitus and their clinical characteristics during and after pregnancy

BACKGROUND

We conducted this research in order to evaluate the prevalence of glutamic acid decarboxylase antibodies (GADA) in Korean women with gestational diabetes mellitus (GDM), to identify the clinical characteristics of these women, and to gauge the prevalence of diabetes among them after childbirth.

METHODS

We studied 887 Korean women with GDM who were screened for GADA, and assessed their antepartum clinical characteristics and the outcomes of their pregnancies. At 6 weeks' postpartum, 75 g oral glucose tolerance tests were performed to determine the diabetic status of GDM women with GADA.

RESULTS

The prevalence of GADA in Korean women with GDM was 1.7%. Plasma glucose levels at 0- and 3-h during oral glucose tolerance tests were significantly different between GADA-positive and GADA-negative women with GDM. There were no significant differences between them in terms of age, body mass index, family history of diabetes, fasting insulin, and lipid profiles. However, GADA-positive women with GDM required insulin treatment during pregnancy more frequently than GADA-negative patients. The development of diabetes at early postpartum was significantly higher in GADA-positive women with GDM than those who were GADA negative.

CONCLUSIONS

The prevalence of GADA in Korean women with GDM was low. However, GADA-positive women with GDM are more susceptible to subsequently developing type 1 diabetes, even in the early postpartum period. Long-term follow up studies and intervention to prevent type 1 diabetes among GADA-positive GDM women are needed.

Maternal type 1 and gestational diabetes: postnatal differences in insulin secretion in offspring at preschool age

BACKGROUND

It is well known that children born to mothers with diabetes in pregnancy are more likely to develop metabolic abnormalities in later life. Most prior studies have not differentiated between offspring of mothers with type 1 diabetes (T1DM) and gestational diabetes (GDM) or lack a control group of non-exposed offspring.

SUBJECTS

Offspring of T1DM (n = 16), GDM (n = 22) and mothers without diabetes (n = 25) born at Oulu University Hospital.

AIM

To assess insulin secretion and insulin resistance in the offspring of T1DM and GDM at preschool age in comparison with offspring of non-diabetic mothers.

METHODS

Anthropometric measurements and intravenous glucose tolerance testing were performed. First-phase insulin response (FPIR) and homoeostasis model assessment (HOMA) values were calculated. Pregnancy and birth data were analysed in relation to later metabolic parameters in all three groups using one-way analysis of variance (ANOVA) and analysis of covariance (ANCOVA).

RESULTS

At a mean age of 4.9 yr, offspring of T1DM had increased fasting serum insulin concentrations (p = 0.044), FPIR (p = 0.034) and HOMA-B values (p = 0.008) compared with offspring of GDM or with offspring of healthy controls (statistically non-significant). The GDM gained least weight during pregnancy, and when adjusted for maternal weight gain during pregnancy, there were no statistically significant differences between study groups.

CONCLUSIONS

Prenatal exposures to maternal type 1 and gestational diabetes may have different effects on postnatal glucose metabolism in the offspring assessed at a mean age close to 5 yr. Maternal weight gain in pregnancy may affect the postnatal glucose metabolism in the offspring.

GESTATIONAL DIABETES MELLITUS

Gestational diabetes (GDM) is defined as “carbohydrate intolerance of variable severity with onset or first recognition during pregnancy.” The definition is applicable regardless of whether insulin is used for treatment or the condition persists after pregnancy. It does not exclude the possibility that unrecognized glucose intolerance may have antedated the pregnancy”. GDM complicates 3–15% of all pregnancies and is a major cause of perinatal morbidity and mortality, as well as maternal long term morbidity. Of all types of diabetes, gestational diabetes (GDM) accounts for approximately 90–95% of all cases of diabetes in pregnancy.

Autoimmunity in gestational diabetes mellitus in Sardinia: a preliminary case-control report

BACKGROUND

We previously reported a high prevalence (22.3%) of gestational diabetes mellitus (GDM) in a large group of Sardinian women, in contrast with the prevalence of Type 2 diabetes. Sardinia has an unusual distribution of haplotypes and genotypes, with the highest population frequency of HLA DR3 in the world, and after Finland, the highest prevalence of Type 1 diabetes and Autoimmune-related Diseases. In this study we preliminarily tested the prevalence of serological markers of Type 1 diabetes in a group of Sardinian GDM patients.

METHODS

We determined glutamic decarboxylase antibodies (anti-GAD65), protein tyrosine phosphatase ICA 512 (IA2) antibodies (anti-IA2), and IAA in 62 GDM patients, and in 56 controls with matching age, gestational age and parity.

RESULTS

We found a high prevalence and very unusual distribution of antibodies in GDM patients (38.8%), the anti-IA2 being the most frequent antibody. Out of all our GDM patients, 38.8% (24 of 62) were positive for at least one antibody. Anti-IA2 was present in 29.0 % (18 out of 62) vs. 7.1% (4 out of 56) in the controls (P < 0.001). IAA was present in 14.5% (9 out of 62) of our GDM patients, and absent in the control subjects (P < 0.001). Anti-GAD65 was also present in GDM patients, with a prevalence of 3.2% (2 out of 62) while it was absent in the control group (P = NS). Pre-gestational weight was significantly lower (57.78 +/- 9.8 vs 65.9 +/- 17.3 P = 0.04) in auto-antibodies- positive GDM patients.

CONCLUSION

These results are in contrast with the very low prevalence of all antibodies reported in Italy. If confirmed, they could indicate that a large proportion of GDM patients in Sardinia have an autoimmune origin, in accordance with the high prevalence of Type 1 diabetes.

Presence of GAD antibodies during gestational diabetes mellitus predicts type 1 diabetes

OBJECTIVE

We sought to study the frequency of beta-cell-specific autoantibody markers in women with gestational diabetes mellitus (GDM) and to follow these women to estimate the risk of later development of type 1 diabetes.

RESEARCH DESIGN AND METHODS

Of 385 pregnant women with GDM during 1995-2005 in the district of Lund, 24 (6%) women were found positive for at least one of the following: islet cell antibody (ICA), GAD antibody (GADA), or tyrosine phosphatase antibody (IA-2A). The women were followed and autoantibodies reanalyzed. Those who had not developed diabetes did an oral glucose tolerance test. The frequencies of known risk factors for GDM were compared in women with GDM with and without pancreatic autoantibodies.

RESULTS

Among the autoantibody-positive women, 50% had developed type 1 diabetes compared with none among the GDM control subjects (P = 0.001), 21% had impaired fasting glucose or impaired glucose tolerance compared with 12.5% among control subjects (P = 0.3), and none had developed type 2 diabetes compared with 12.5% among control subjects (P = 0.1).

CONCLUSIONS

Autoantibody screening in pregnant women with GDM and follow-up after delivery should be considered for early recognition of type 1 diabetes.

Gestational diabetes identifies women at risk for permanent type 1 and type 2 diabetes in fertile age: predictive role of autoantibodies

OBJECTIVE

Our aim was to evaluate the predictive value of gestational diabetes mellitus (GDM), diabetes-associated autoantibodies, and other factors for development of clinical diabetes later in life.

RESEARCH DESIGN AND METHODS

In this case-control study the presence of autoantibodies was studied in 435 women with GDM and in healthy matched control subjects. The need for exogenous insulin during GDM was recorded. In the GDM group, the mean follow-up period was 5.7 years and in the control group 6.1 years.

RESULTS

Among the subjects with GDM, 20 (4.6%) developed type 1 diabetes and 23 (5.3%) developed type 2 diabetes, whereas none of the control subjects became diabetic. Two-thirds of those who developed type 1 diabetes tested positive initially for islet cell antibodies (ICAs), whereas 56% of them had autoantibodies to GAD (GADAs) and 38% to the protein tyrosine phosphatase-related IA-2 molecule. Only 2 of the 23 women who presented later with type 2 diabetes tested positive for autoantibodies. According to multivariate analysis, initial age < or =30 years, the need for insulin treatment for GDM, and antibody positivity for ICAs and GADAs were associated with increased risk for clinical type 1 diabetes.

CONCLUSIONS

Pregnancy seems to identify women who are at risk of developing diabetes later in life. About 10% of Finnish women with GDM will develop diabetes over the next 6 years; nearly half of them develop type 1 diabetes and the other half type 2 diabetes. Age < or =30 years, the need for insulin treatment during pregnancy, and positivity for ICAs and GADAs confer a high risk of subsequent progression to type 1 diabetes in women affected by GDM.

Predictors of postpartum diabetes in women with gestational diabetes mellitus

The aim of this study was to stratify risk for postpartum diabetes in women who have gestational diabetes. Women with gestational diabetes were recruited between 1989 and 1999, and 302 were followed with oral glucose tolerance tests at 9 months and 2, 5, 8, and 11 years postpregnancy. The 8-year postpartum diabetes risk was 52.7% (130 diabetic cases). Risk was increased in women with autoantibodies to GAD and/or insulinoma antigen-2 (adjusted hazard ratio 4.1; P < 0.0001), women who required insulin during pregnancy (4.7; P < 0.0001), women with BMI >30 kg/m2 (1.5; P = 0.04), and women with more than two prior pregnancies (2.5; P = 0.02). Women without these risk factors had a postpartum diabetes risk of 14% by 8 years, and risk rose incrementally to 96% by 8 years in autoantibody-positive women. Parity status, C-reactive protein concentration, a diabetes family history, maternal age, weeks of gestation, and the child's birth weight did not significantly affect risk in multivariate analysis. Prospective diabetes assessment is indicated and intervention should be considered in women with gestational diabetes who are autoantibody positive, require insulin treatment during pregnancy, or are obese.

Different HLA-DR-DQ and MHC class I chain-related gene A (MICA) genotypes in autoimmune and nonautoimmune gestational diabetes in a Swedish population

The genetic susceptibility for gestational diabetes (GDM) was estimated by comparisons of genotypes within human leukocyte antigen (HLA) and major histocompatibility complex class I chain-related gene A (MICA) in 199 women with GDM and 213 healthy women. At least one of ICA, glutamic acid decarboxylase antibodies, or islet cell antigen-2 antibodies/tyrosine phosphatase antibodies was found in 6.0% (12/199) of women with GDM and were considered as autoimmune GDM, whereas the remaining 187 were considered as nonautoimmune GDM. HLA genotyping was done with polymerase chain reaction and sequence-specific oligonucleotides. MICA polymorphism was determined with polymerase chain reaction and fragment size determination. HLA-DR3-DQ2/x or DR4-DQ8/x and MICA5.0/5.1 were more frequent in autoimmune GDM compared with controls; 92% versus 46% and 42% versus 13% and conferred increased risk (odds ratio [OR] = 13; 95% confidence interval [CI] 1.7-104) and (OR = 4.7; 95%CI 1.4-16). Four other genotypes were more frequent in nonautoimmune GDM compared with controls: HLA-DR7-DQ2/y, 24% versus 14%; DR9-DQ9/y, 9.6% versus 1.9%; DR14-DQ5/y, 7.5% versus 0.94%; and MICA5.0/z, 24% versus 13% and gave increased risk: OR = 2.0; 95%CI 1.2-3.4, OR = 5.6; 95%CI 1.8-17, OR = 8.5; 95%CI 1.9-38, and OR = 2.0; 95%CI 1.2-3.4, respectively. We concluded that autoimmune diabetes with onset during pregnancy is associated with the type 1 diabetes-associated genotypes and also with MICA5.0/5.1, whereas DR7-DQ2/y, DR9-DQ9/y, DR14-DQ5/y, and MICA5.0/z are risk factors for nonautoimmune GDM.

Prevalence of gestational diabetes mellitus in Kashmiri women from the Indian subcontinent

This prospective study was carried out to determine the prevalence of gestational diabetes mellitus (GDM) in Kashmiri women and to assess the effect of various demographic factors. Two thousand pregnant women (divided into groups A and B, being the first and last 1000 consecutive women) attending various antenatal clinics in six districts of Kashmir valley were screened for GDM by 1 h 50 g oral glucose challenge test. Four hundred and fourteen (20.8%) women (216 from group A and 198 from group B) had an abnormal screening test and proceeded to oral glucose tolerance testing. Women from group A had a 3 h 100 gram oral glucose tolerance test (OGTT) and GDM was as classified by Carpenter and Coustan. A 2 h 75 g OGTT was performed on group B subjects and WHO criteria applied for diagnosis of GDM. The overall prevalence of GDM was 3.8% (3.1% in group A versus 4.4% in group B-P-value 0.071). GDM prevalence steadily increased with age (from 1.7% in women below 25 years to 18% in women 35 years or older). GDM occurred more frequently in women who were residing in urban areas, had borne three or more children, had history of abortion(s) or GDM during previous pregnancies, had given birth to a macrosomic baby, or had a family history of diabetes mellitus. Women with obesity, hypertension, osmotic symptoms, proteinuria or hydramnios had a higher prevalence of GDM.

Immune responses to glutamic acid decarboxylase and insulin in patients with gestational diabetes

Pregnancy is a natural state of immunoprotection and tolerance. We studied subjects with gestational diabetes (GDM) to evaluate the influence of pregnancy on the humoral immune response to the autoantigen GAD and to injected insulin. Antibodies against glutamic acid decarboxylase (GADA) subclasses and epitope reactivity were determined in 34 GADA-positive pregnant patients with GDM, in 20 GADA-positive relatives of people with TID and in 25 GADA-positive patients with newly diagnosed TID. Partum levels of insulin antibodies (IA), IgG1- and IgG4-IA were measured in 131 women with GDM treated with human insulin from the time of diabetes diagnosis (including 22 with GADA) and were compared to 19 patients with TID after 3 months of insulin treatment. GADA titre and subclasses were similar among all groups. GADA in GDM patients bound fewer epitopes than GADA in relatives of patients with TID (all epitopes being present in 23%versus 65%, P < 0.01). In particular, antibodies to the minor GADA epitopes GAD6596-249, GAD651-100 and GAD67 were less frequent in patients with GDM compared to relatives (P < 0.01). Antibodies to insulin (IA) were found in 17% of patients with GDM. They were more frequent in GDM patients with GADA compared to GADA-negative patients (41%versus 12%, P < 0.005). IgG1 was the dominant insulin antibody subclass response in both patients with GDM and TID but levels of IgG1-IA and IgG4-IA were significantly lower in patients with GDM compared to patients with TID (P < 0.004). Antibody responses in women with gestational diabetes appear to be dampened and restricted, but without change in subclass usage.

Epidemiology of gestational diabetes mellitus and its association with Type 2 diabetes

Gestational diabetes (GDM) is defined as carbohydrate intolerance that begins or is first recognized during pregnancy. Although it is a well-known cause of pregnancy complications, its epidemiology has not been studied systematically. Our aim was to review the recent data on the epidemiology of GDM, and to describe the close relationship of GDM to prediabetic states, in addition to the risk of future deterioration in insulin resistance and development of overt Type 2 diabetes. We found that differences in screening programmes and diagnostic criteria make it difficult to compare frequencies of GDM among various populations. Nevertheless, ethnicity has been proven to be an independent risk factor for GDM, which varies in prevalence in direct proportion to the prevalence of Type 2 diabetes in a given population or ethnic group. There are several identifiable predisposing factors for GDM, and in the absence of risk factors, the incidence of GDM is low. Therefore, some authors suggest that selective screening may be cost-effective. Importantly, women with an early diagnosis of GDM, in the first half of pregnancy, represent a high-risk subgroup, with an increased incidence of obstetric complications, recurrent GDM in subsequent pregnancies, and future development of Type 2 diabetes. Other factors that place women with GDM at increased risk of Type 2 diabetes are obesity and need for insulin for glycaemic control. Furthermore, hypertensive disorders in pregnancy and afterwards may be more prevalent in women with GDM. We conclude that the epidemiological data suggest an association between several high-risk prediabetic states, GDM, and Type 2 diabetes. Insulin resistance is suggested as a pathogenic linkage. It is possible that improving insulin sensitivity with diet, exercise and drugs such as metformin may reduce the risk of diabetes in individuals at high risk, such as women with polycystic ovary syndrome, impaired glucose tolerance, and a history of GDM. Large controlled studies are needed to clarify this issue and to develop appropriate diabetic prevention strategies that address the potentially modifiable risk factors.

Intermediate metabolism in normal pregnancy and in gestational diabetes

Complex though integrated hormonal and metabolic changes characterize pregnancy. In the face of progressive decline in insulin action, glucose homeostasis is maintained through a compensatory increase in insulin secretion. This switches energy production from carbohydrates to lipids, making glucose readily available to the fetus. This precise and entangled hormonal and metabolic condition can, however, be disrupted and diabetic hyperglycemia can develop (gestational diabetes). The increase in plasma glucose level is believed to confer significant risk of complications to both the mother and the fetus and the newborn. Moreover, exposition of fetal tissues to the diabetic maternal environment can translate into an increased risk for development of diabetes and/or the metabolic syndrome in the adult life. In women with previous gestational diabetes, the risk of developing type 2 diabetes is greatly enhanced, to the point that GDM represents an early stage in the natural history of type 2 diabetes. In these women, accurate follow-up and prevention strategies are needed to reduce the subsequent development of overt diabetes. This paper will review current knowledge on the modifications occurring in normal pregnancy, while outlining the mechanisms. In this paper, we will review the changes of intermediary metabolism occurring during pregnancy. In particular, we will outline the mechanisms responsible for gestational diabetes; the link between these alterations and associated maternal and neonatal morbidity will be examined.

Diabetes and abnormal glucose tolerance in women with previous gestational diabetes

OBJECTIVE

In Spanish women with gestational diabetes mellitus (GDM), we aimed to study the progression to diabetes and abnormal glucose tolerance (AGT) and identify predictive factors.

RESEARCH DESIGN AND METHODS

In 696 women with GDM and 70 control women, glucose tolerance was evaluated postpartum and at 5-year intervals.

RESULTS

In the GDM group, the cumulative risk for diabetes and AGT was 13.8 and 42.4% after 11 years compared with 0 and 2.8% in control women, respectively (P < 0.05). Independent predictive factors for diabetes were previous hyperglycemia, four abnormal glucose values on the diagnostic oral glucose tolerance test (OGTT) or overt diabetes during pregnancy, 2-h blood glucose on the diagnostic OGTT >/=11.7 mmol/l, gestational age at diagnosis <24 weeks, and prepregnancy BMI >/=26.4 kg/m(2). All of these factors (some with different cutoff points) in addition to fasting glycemia were predictors of AGT also. The risk was nonlinear. Four abnormal glucose values on the diagnostic OGTT or overt diabetes during pregnancy was the strongest predictive factor for diabetes (relative risk 3.92), and prepregnancy BMI was the predictive factor with the highest attributable fraction in the whole group (13.3%). When first postpartum OGTT data were included in the analysis, predictors changed, but the overall prediction was similar.

CONCLUSIONS

Spanish women with GDM have an increased risk of diabetes and AGT. Predictive factors display a nonlinear relationship. The strongest predictive factor for diabetes was four abnormal glucose values on the diagnostic OGTT or overt diabetes during pregnancy; the factor with the highest attributable fraction in the whole group was prepregnancy BMI.

Clinical characteristics and outcome of pregnancy in women with gestational hyperglycaemia with and without antibodies to beta-cell antigens

AIMS

To evaluate the prevalence of beta-cell autoantibodies in women with gestational diabetes and impaired glucose tolerance, and identify clinical characteristics differentiating hyperglycaemic patients with and without autoantibodies.

METHODS

One hundred and twenty-three pregnant patients with gestational diabetes, 84 with impaired glucose tolerance and 290 with normoglycaemia were evaluated for anti-islet cell antibodies, glutamic acid decarboxylase (GAD) autoantibodies, and the components of the metabolic syndrome.

RESULTS

Autoantibody positivity was 8.9%, 17.9% and 0.3% in patients with diabetes, impaired tolerance and normoglycaemia, respectively. Hyperglycaemic patients with autoantibodies had lower body mass index, waist, weight gain at the time of the screening test and a lower percentage of previous pregnancies than those without autoantibodies. In addition, their fasting insulin values were significantly lower and inversely related to the presence of autoantibodies (odds ratio (OR) = 0.64; 95% confidence interval (CI) 0.42-0.96), the lowest values being found in anti-GAD+ patients. Autoantibody-positive women with diabetes were more frequently treated with insulin than negative patients (OR = 7.21; 95% CI 1.85-28.08).

CONCLUSIONS

Autoantibody-positive women with gestational hyperglycaemia displayed fewer features of insulin resistance and required more frequent insulin therapy than negative women and presumably had presymptomatic Type 1 diabetes. If this conclusion is corroborated by the follow-up of larger series, clinical and immunological distinction of types of gestational hyperglycaemia would be useful.

Islet abnormalities in the pathogenesis of autoimmune diabetes

Type 1 diabetes mellitus is a T-cell-mediated autoimmune disease that results in the destruction of the insulin-producing beta cells in the pancreatic islets of Langerhans. In spite of extensive genetic and immunological studies, mainly performed in the non-obese diabetic (NOD) spontaneous mouse model, the etiology of the autoimmune attack remains unknown. Several autoantigens have been identified and numerous studies have suggested a role for defective regulation of immune function. However, this account does not explain why the autoimmune process specifically affects the insulin-producing beta cells. Thus, abnormal immune regulation might explain the predisposition to autoimmunity in general, but additional factors should then determine the target of the autoimmune attack. Here, we review the evidence that abnormalities in islet cell differentiation and function exist that might trigger the immune system towards beta-cell autoimmunity in humans and NOD mice.

Low frequency of autoantibodies to islet cell, glutamic acid decarboxylase, and second-islet antigen in patients with gestational diabetes mellitus: a follow-up study

The aim of the study was to determine the frequency of patients with gestational diabetes mellitus (GDM) who have serological markers typical of autoimmune type 1 DM. The specific pancreatic markers, ICAs, glutamic decarboxylase (GADAbs), and second islet antigen (IA2Abs), were measured in 70 women with GDM during the pregnancy and after delivery. ICAs were measured by indirect immunofluorescence and GADAbs and IA2Abs were determined by a radiobinding assay with recombinant antigens. On entering the study, 1 of 70 (1.4%) patients was positive for both ICAs (80 JDF-U) and GADAbs (167 U/mL), while another (1.4%) was positive for ICAs (40 JDF-U). None of the patients was positive for IA2Abs. During follow-up, positivity was maintained unchanged in the two positive patients. Four previously negative patients had seroconversion: one for both ICAs (20 JDF-U) and GADAbs (49.3 U/mL) and the other three for GADAbs (1.8, 1.4, and 15.3 U/mL, respectively). The IA2Abs remained negative in all patients. Overall, during the observation period 6 of 70 (8.6%) patients had or developed autoantibodies against endocrine pancreas. During follow-up 15 patients developed clinical DM (10 type 2, 5 type 1) and 7 demonstrated impaired glucose tolerance (IGT) after OGTT. No correlations were demonstrated between the immunological patterns and the evolution in DM. In patients with GDM, the frequency of pancreatic autoantibodies varies during the pregnancy and after delivery, but a small subgroup of patients bearing these markers is identifiable. GDM is a complex syndrome, constituted by different types of diabetes mellitus where the autoimmune form is very rare.

Predictive factors of developing diabetes mellitus in women with gestational diabetes

BACKGROUND

To investigate which factors during gestational diabetes pregnancies correlate with the risk of developing impaired glucose tolerance or diabetes 1 year postpartum and to compare this risk in women with gestational diabetes and women with a normal oral glucose tolerance test during pregnancy.

METHODS

Of 315 women with gestational diabetes, defined as a 2-hr blood glucose value of at least 9.0 mmol/l at a 75-g oral glucose tolerance test, who delivered in Lund 1991-99, 229 (73%) performed a new test 1 year postpartum. We compared maternal and fetal factors during pregnancy with the test value at follow up. A control group of 153 women with a 2-hr test value below 7.8 mmol/l during pregnancy were invited to a new test 1 year postpartum and 60 (39%) accepted.

RESULTS

At 1 year follow up, 31% of the women with gestational diabetes but only one of the 60 controls showed pathologic glucose tolerance and one had developed diabetes. The following factors in women with gestational diabetes were identified as predicting impaired glucose tolerance or diabetes at 1 year follow up: maternal age over 40 and--in a multiple regression analysis, independent of each other--a high 2-hr value at oral glucose tolerance test during pregnancy and insulin treatment during pregnancy.

CONCLUSION

The risk of developing manifest diabetes after gestational diabetes may be high enough to justify a general screening or diagnostic procedure in all pregnant women to identify women with gestational diabetes and a postpartum follow up program for them. This study did not identify any particular factor during pregnancy with enough precision to predict a later progression to diabetes.

Type 1 diabetes islet autoantibody markers

The diagnosis of type 1 diabetes versus other forms of diabetes such as type 2 diabetes is paramount to guiding proper therapy. Several islet autoantibodies have been identified that serve to diagnose immune-mediated, type 1a diabetes in clinically ambiguous cases. These autoantibodies also serve to predict type 1 diabetes in nondiabetic individuals. The most useful islet autoantibodies include islet cell cytoplasmic autoantibodies, insulin autoantibodies, glutamic acid decarboxylase autoantibodies, and insulinoma-associated-2 autoantibodies. Once type 1 diabetes can be safely and reliably prevented, large-scale islet autoantibody screening programs of the general pediatric population may be warranted. It is controversial whether islet autoantibodies influence the course of type 1 diabetes following diagnosis.

Screening for MODY mutations, GAD antibodies, and type 1 diabetes--associated HLA genotypes in women with gestational diabetes mellitus

OBJECTIVE

To investigate whether genetic susceptibility to type 1 diabetes or maturity-onset diabetes of the young (MODY) increases susceptibility to gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

We studied mutations in MODY1-4 genes, the presence of GAD antibodies, and HLA DQB1 risk genotypes in 66 Swedish women with GDM and a family history of diabetes. An oral glucose tolerance test was repeated in 46 women at 1 year postpartum.

RESULTS

There was no increase in type 1 diabetes-associated HLA-DQB1 alleles or GAD antibodies when compared with a group of type 2 diabetic patients (n = 82) or healthy control subjects (n = 86). Mutations in known MODY genes were identified in 3 of the 66 subjects (1 MODY2, 1 MODY3, and 1 MODY4). Of the 46 GDM subjects, 2 had diabetes (4%) and 17 had impaired glucose tolerance (IGT) (37%) at 1 year postpartum. Of the two subjects who developed manifest diabetes, one carried a MODY3 mutation (A203H in the hepatocyte nuclear factor-1alpha gene). There was no increase in high-risk HLA alleles or GAD antibodies in the women who had manifest diabetes or IGT at 1 year postpartum.

CONCLUSIONS

MODY mutations but not autoimmunity contribute to GDM in Swedish women with a family history of diabetes and increase the risk of subsequent diabetes.

Autoimmune gestational diabetes mellitus: a distinct clinical entity?

This review gives an update of the present knowledge on what is defined here as autoimmune gestational diabetes mellitus (GDM). Autoimmune phenomena associated with type 1 diabetes mellitus (DM) can be detected in a subgroup of women with GDM. Islet autoantibodies are present in sera from women with GDM with variable frequency. Distinct phenotypic and genotypic features may be recognised in this subset of women with GDM, which are representative of a distinct clinical entity. Furthermore, these women are at increased risk of developing type 1 DM after pregnancy. However, the eventual progression of the autoimmune destruction of beta-cells in these subjects may follow different time-course patterns thus leading to variable forms of presentation of autoimmune DM. As a high-risk group for type 1 diabetes, women with previous autoimmune GDM may be candidates for potential immune intervention strategies.