Prevalence of zinc transporter 8 antibodies in gestational diabetes mellitus

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.

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.

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.

Immune checkpoint molecule PD-1 acts as a novel biomarker for the pathological process of gestational diabetes mellitus

AIM

Accumulating evidence suggested that challenge of the maternal-fetal interaction during pregnancy might cause the impairment of immunological hemostasis and lead to gestational diabetes mellitus (GDM) pathological process. Immune checkpoint molecule PD-1 is one of the critical molecule balancing immune response and immunological tolerance.

METHODS

PD-1 expressions on T-cell subsets of GDM patients and control groups were measured via flow cytometric analysis and followed up.

RESULTS

Downregulation of PD-1 acted as an indicator for GDM occurrence in the third trimester of pregnancy. With the recovery of GDM, PD-1 expression restored to normal level.

CONCLUSION

PD-1 expression on T-cell subsets is a novel biomarker for the occurrence and recovery of GDM.

Clinical Recommendations for the Use of Islet Cell Autoantibodies to Distinguish Autoimmune and Non-Autoimmune Gestational Diabetes

Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance that begins or is first recognized during pregnancy. The prevalence of GDM is highly variable, depending on the population studied, and reflects the underlying pattern of diabetes in the population. GDM manifests by the second half of pregnancy and disappears following delivery in most cases, but is associated with the risk of subsequent diabetes development. Normal pregnancy induces carbohydrate intolerance to favor the availability of nutrients for the fetus, which is compensated by increased insulin secretion from the maternal pancreas. Pregnancy shares similarities with adiposity in metabolism to save energy, and both conditions favor the development of insulin resistance (IR) and low-grade inflammation. A highly complicated network of modified regulatory mechanisms may primarily affect carbohydrate metabolism by promoting autoimmune reactions to pancreatic β cells and affecting insulin function. As a result, diabetes development during pregnancy is facilitated. Depending on a pregnant woman's genetic susceptibility to diabetes, autoimmune mechanisms or IR are fundamental to the development autoimmune or non-autoimmune GDM, respectively. Pregnancy may facilitate the identification of women at risk of developing diabetes later in life; autoimmune and non-autoimmune GDM may be early markers of the risk of future type 1 and type 2 diabetes, respectively. The most convenient and efficient way to discriminate GDM types is to assess pancreatic β-cell autoantibodies along with diagnosing diabetes in pregnancy.

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.

The prevalence and predictive value of the SLC30A8 R325W polymorphism and zinc transporter 8 autoantibodies in the development of GDM and postpartum type 1 diabetes

The objectives were to evaluate possible associations between the SLC30A8 R325W polymorphism and gestational diabetes mellitus (GDM) as well as postpartum development of type 2 diabetes. Furthermore, we wanted to confirm the prevalence of zinc transporter 8 autoantibodies (ZnT8A), as previously reported, in a larger population and study its predictive value in relation to other β cell specific autoantibodies in postpartum development of type 1 diabetes. Women diagnosed with GDM (n = 776) and women without diabetes (n = 511) were included in the study. Autoantibodies were analyzed in all women using enzyme-linked immunosorbent assay. DNA was extracted when possible from women with GDM (n = 536) and all of the controls. R325W was detected through polymerase chain reaction and specific restriction digestion. The R325W C-allele were more frequent in women with GDM compared to in controls (OR 1.47, 95 % CI 1.16-1.88, p = 0.0018) but not significantly increased in women with GDM and postpartum development of type 2 diabetes. Autoantibodies were found in 6.8 % (53/776) of the women with GDM and approximately 3.2 % (25/776) were ZnT8A positive. Approximately 19 % (10/53) of the autoantibody positive women with GDM developed postpartum type 1 diabetes. In conclusion, this is the first study to report a significant association between the R325W C-allele and increased risk of developing GDM. All of the autoantibody positive women with GDM who developed postpartum type 1 diabetes were positive for autoantibodies against glutamic acid decarboxylase (GADA). Thus ZnT8A did not have any additional predictive value in postpartum development of type 1 diabetes.

Zinc transporter 8 autoantibodies: what is their clinical relevance in gestational diabetes?

AIMS

To investigate the prevalence, clinical significance and antepartum to postpartum trajectory of zinc transporter 8 autoantibodies, a novel marker of islet autoimmunity, in women with gestational diabetes mellitus.

METHODS

A total of 302 consecutive women attending a multi-ethnic Australian gestational diabetes clinic were prospectively studied. Zinc transporter 8 autoantibodies were measured at gestational diabetes diagnosis and 3 months postpartum using an enzyme-linked immunosorbent assay, and were correlated with maternal phenotype, antepartum and postpartum glucose tolerance, treatment and perinatal outcomes.

RESULTS

Of the 302 women, 30 (9.9%) were positive for one islet autoantibody antepartum. No participant had multiple islet autoantibodies. Zinc transporter 8 autoantibodies were the most prevalent autoantibody [zinc transporter 8 autoantibodies: 13/271 women (4.8%); glutamic acid decarboxylase 7/302 women (2.3%); insulinoma-associated antigen-2: 6/302 women (2.0%); insulin: 4/302 women (1.3%)]. Zinc transporter 8 autoantibody positivity was associated with a higher fasting glucose level on the antepartum oral glucose tolerance test, but not with BMI, insulin use, perinatal outcomes or postpartum glucose intolerance. Five of the six women who tested positive for zinc transporter 8 autoantibodies antepartum were negative for zinc transporter 8 autoantibodies postpartum, which corresponded to a significant decline in titre antepartum to postpartum (26.5 to 3.8 U/ml; P=0.03). This was in contrast to the antepartum to postpartum trajectory of the other islet autoantibodies, which remained unchanged.

CONCLUSIONS

Zinc transporter 8 autoantibodies were the most common islet autoantibody in gestational diabetes. Zinc transporter 8 autoantibody positivity was associated with slightly higher fasting glucose levels and, unlike other islet autoantibodies, titres declined postpartum. Zinc transporter 8 autoantibodies may be a marker for islet autoimmunity in a proportion of women with gestational diabetes, but the clinical relevance of zinc transporter 8 autoantibodies in pregnancy and gestational diabetes requires further investigation.

Insulin production hampered by intermittent hypoxia via impaired zinc homeostasis

Without zinc, pancreatic beta cells cannot either assemble insulin molecules or precipitate insulin crystals; thus, a lack of zinc concentration in the beta cells would result in a decreased insulin production. ZIP8 is one of the zinc uptake transporters involved in zinc influx into the cytosol of beta cells. Thus, if ZIP8 is down-regulated, a decreased insulin production would result. We assumed that intermittent hypoxic exposure to the beta cells may result in a decreased production of insulin due to a lack of zinc. To test this hypothesis we harvested pancreatic islets from the rats conditioned under intermittent hypoxia (IH) (fluctuating between 20.5% and 10% every 4 min for 1 h) and compared the results with those from control animals and islets. We also compared their insulin and glucose homeostasis using glucose tolerance tests (GTT) after 3 weeks. GTT results show a significant delay (P<0.05) in recovery of the blood glucose level in IH treated pups. ZIP8 expression in the beta cell membrane was down-regulated. The zinc concentration in the cell as well as insulin production was significantly decreased in the islets harvested from IH animals. However, mRNA for insulin and C-peptide/insulin protein levels in the total cell lysates remained the same as those of controls. When we treated the beta cells using siRNA mediated ZIP8, we observed the commensurate results from the IH-treated islets. We conclude that a transient IH exposure could knockdown ZIP8 transporters at mRNA as well as protein levels in the beta cells, which would decrease the level of blood insulin. However, the transcriptional activity of insulin remains the same. We conclude that the precipitation process of insulin crystal may be disturbed by a lack of zinc in the cytosol that is modulated by mainly ZIP8 after IH exposure.