Association between the ferritin level and risk of gestational diabetes mellitus: A meta-analysis of observational studies

Insights into the pathogenesis of gestational and hepatic diseases: the impact of ferroptosis

Ferroptosis, a distinct form of non-apoptotic cell death characterized by iron dependency and lipid peroxidation, is increasingly linked to various pathological conditions in pregnancy and liver diseases. It plays a critical role throughout pregnancy, influencing processes such as embryogenesis, implantation, and the maintenance of gestation. A growing body of evidence indicates that disruptions in these processes can precipitate pregnancy-related disorders, including pre-eclampsia (PE), gestational diabetes mellitus (GDM), and intrahepatic cholestasis of pregnancy (ICP). Notably, while ICP is primarily associated with elevated maternal serum bile acid levels, its precise etiology remains elusive. Oxidative stress induced by bile acid accumulation is believed to be a significant factor in ICP pathogenesis. Similarly, the liver's susceptibility to oxidative damage underscores the importance of lipid metabolism dysregulation and impaired iron homeostasis in the progression of liver diseases such as alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), cholestatic liver injury, autoimmune hepatitis (AIH), acute liver injury, viral hepatitis, liver fibrosis, and hepatocellular carcinoma (HCC). This review discusses the shared signaling mechanisms of ferroptosis in gestational and hepatic diseases, and explores recent advances in understanding the mechanisms of ferroptosis and its potential role in the pathogenesis of gestational and hepatic disorders, with the aim of identifying viable therapeutic targets.

Iron Deficiency Anaemia in Pregnancy: A Narrative Review from a Clinical Perspective

Anaemia in pregnancy is a global problem of significance in all settings. The most common cause is iron deficiency. Large numbers of women are affected, ranging up to 25-30% antenatally and 20-40% postnatally. It is associated with serious adverse outcomes for both the mother and her baby. The risk of low birth weight, preterm birth, postpartum haemorrhage, stillbirth, and neonatal death are all increased in the presence of anaemia. For the infants of affected pregnancies, complications may include neurocognitive impairment. Making an accurate diagnosis during pregnancy has its challenges, which include the choice of thresholds of haemoglobin below which a diagnosis of anaemia in each trimester of pregnancy can be made and, aligned with this question, which are the most appropriate biomarkers to use to define iron deficiency. Treatment with oral iron supplements increases the haemoglobin concentration and corrects iron deficiency. But high numbers of women fail to respond, probably due to poor adherence to medication, resulting from side effects. This has resulted in an increased use of more expensive intravenous iron. Doubts remain about the optimal regimen to of oral iron for use (daily, alternate days, or some other frequency) and the cost-effectiveness of intravenous iron. There is interest in strategies for prevention but these have yet to be proven clinically safe and effective.

The Role of Maternal Serum Ferritin in Gestational Diabetes Mellitus in Southeast Asia

Introduction Gestational diabetes mellitus (GDM) poses a significant health concern due to the numerous risks it presents to both the mother and fetus. While serum ferritin typically declines in cases of iron deficiency anemia, which is common during pregnancy, it may increase in the presence of inflammation. This study aims to evaluate the significance of serum ferritin in the context of GDM, considering its multifaceted role in these interconnected conditions. Methodology This cross-sectional study included pregnant women attending an obstetrics clinic for an oral glucose tolerance test at Hospital Canselor Tuanku Muhriz in Kuala Lumpur, Malaysia. With consent, demographic data, risk factors for GDM, and blood samples were collected. Blood samples were analyzed for serum ferritin, fasting blood glucose, two-hour post-glucose levels, and full blood count. The assessment of risk factors for GDM and the diagnosis of GDM adhered to Malaysian guidelines. The Mann-Whitney U test was employed to compare variables between the GDM and non-gestational diabetes mellitus (non-GDM) groups. Additionally, univariate and multivariate regression analyses were conducted to investigate the role of serum ferritin in GDM. All analyses were performed using IBM SPSS Statistics for Windows, Version 28.0 (Released 2021; IBM Corp., Armonk, NY, USA), with statistical significance set at p < 0.05. Results Among 172 pregnant women with an average gestational age of 23.6 weeks, the incidence of GDM was higher in those with risk factors (84.8%) compared to non-GDM participants (75.5%). Women with GDM had a slightly higher mean serum ferritin level (50.24 ± 29.00 ng/mL) than those without GDM (45.00 ± 58.69 ng/mL). However, ferritin levels did not significantly differ between the GDM and non-GDM groups (p = 0.669) or between those with and without risk factors (p = 0.374). While a higher BMI (OR: 0.832, p = 0.017) and ferritin (OR: 1.022, p = 0.031) levels independently predicted GDM, the predictive value of ferritin was borderline significant when combined with glucose tests (area under the curve = 0.689, p = 0.051). Conclusions Higher maternal serum ferritin levels in the mid-trimester are associated with increased BMI and GDM. However, maternal serum ferritin is most effective at predicting the incidence of GDM when used alongside standard glucose measurements, especially in women with elevated BMI.

Association of apolipoprotein levels with all-cause and cardiovascular mortality

AIMS

Research has shown that apolipoproteins (Apos) are potential indicators of heart health and death. We investigated the associations of Apo levels with all-cause and cardiovascular mortality.

METHODS AND RESULTS

We systematically searched the Cochrane Library, PubMed, and Web of Science for English language studies up to 28 November 2022. We used Stata 17.0 to summarize the estimated effects with 95% confidence intervals (CIs). We also conducted subgroup analyses according to study location, year of publication, individual age, follow-up years, and sample size. Moreover, we performed a sensitivity analysis to evaluate bias in our study. This study included 23 studies with 152 854 individuals in total. The level of ApoA was negatively related to cardiovascular mortality [odds ratio (OR) = 0.69, 95% CI = 0.52-0.93]. An increased ratio of ApoB/A1 was a risk factor for cardiovascular mortality (OR = 2.13, 95% CI = 1.48-3.07) and all-cause mortality (OR = 2.05, 95% CI = 1.52-2.77). The level of ApoB was positively related to cardiovascular mortality (OR = 1.12, 95% CI = 0.85-1.47), but the difference was not statistically significant. However, the associations between ApoB or ApoA1 and all-cause mortality were not obvious. Our subgroup analyses showed that the location, year of publication, individual age, and follow-up years of the studies affected the heterogeneity of our study to varying degrees. The sensitivity analysis showed that our results were almost robust, apart from excluding the article by Nomikos (OR = 0.77, 95% CI = 0.65-0.92) and Zeng (OR = 0.77, 95% CI = 0.65-0.91), when investigating the relationship between ApoA1 and all-cause mortality.

CONCLUSION

In this study, we found that Apo levels were linked to cardiovascular and all-cause mortality. Our study strengthens the evidence on the association between the level of Apos and cardiac health and may provide ideas for regulating the level of Apos to promote public health.

Association between prenatal perfluorinated compounds exposure and risk of pregnancy complications: A meta-analysis

BACKGROUND AND OBJECTIVE

Per- and polyfluoroalkyl substances (PFASs) have been shown to be persistent and bioaccumulative. An elevated danger of pregnancy complications perhaps connected with exposure to PFASs, but the potential effects remain elusive. The objective of this study is to investigate the possible association between PFASs exposure and pregnancy complications, drawing upon existing evidence.

METHODS

Electronic databases of PubMed, Qvid Medline, Embase, and Web of Science were searched thoroughly to identify eligible research published prior to November 28, 2023, examining the relationship between PFASs and pregnancy-related complications. To evaluate the quality of observational studies incorporated into the article, the Strengthening Reporting of Observational Studies in Epidemiology (STROBE) tool was utilized. The main outcomes assessed in this study included gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), gestational hypertension (GH), and preeclampsia (PE).

RESULTS

Twenty-five relevant studies involving 30079 participants were finally selected from four databases. The combined estimates indicate that prenatal exposure to perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS), and perfluoroenanthic acid (PFHpA) is associated with gestational diabetes mellitus (GDM) (PFOA: OR = 1.45, 95%CI: 1.07-1.94, P = 0.015; PFHxS: OR = 1.16, 95%CI: 1.00-1.36, P = 0.055; PFBS: OR = 1.44, 95%CI: 1.16-1.79, P = 0.001; PFHpA: OR = 1.41, 95%CI: 1.10-1.82, P = 0.008). The exposure to PFBS is positively associated with HDP (OR = 1.27, 95%CI: 1.14-1.41, P < 0.001), while both PFOA and PFHpA demonstrate statistically significant positive correlations with GH (PFOA: OR = 1.09, 95%CI: 1.00-1.19, P = 0.049; PFHpA: OR = 1.43, 95%CI: 1.15-1.78, P = 0.001). Negative correlations were observed for prenatal perfluorododecanoic acid (PFDoA) exposure and GH (OR = 0.71, 95%CI: 0.57-0.87, P = 0.001). However, no compelling evidence was identified to link PFASs exposure with the risk of PE.

CONCLUSION

According to the meta-analysis findings, exposure to PFASs may be linked to GDM, HDP, and GH, but it does not significantly raise the risk of PE alone. Further research with larger sample size is required to verify this potential association and explore the biological mechanisms.

Ferritin and iron supplements in gestational diabetes mellitus: less or more?

Iron metabolism has been found to be closely related to gestational diabetes mellitus (GDM). Excessive ferritin levels were shown to be related to an increased risk of GDM because of iron overload which may lead to insulin resistance and β-cell injury by enhancing oxidative stress and inflammatory responses. On the contrary, insufficient ferritin levels can cause a number of obstetric complications, such as high incidence rates of anaemia and gestational hypertension. Therefore, high or low ferritin levels may have adverse effects on the mother and the foetus, putting clinicians in a dilemma when giving pregnant women iron supplements. This also explains why there have been more conflicting findings in the studies on dietary or oral iron supplementation during pregnancy. Hence, there is an urgent need for more evidence and strategies for appropriate recommendations for ferritin levels and iron supplementation during pregnancy to prevent iron insufficiency without causing iron overload and increasing the risk of GDM. Therefore, we gave an updated review on the association of GDM with ferritin metabolism, ferritin levels and iron supplementation based on the summary of the latest research.

Ferroptosis and its potential role in gestational diabetes mellitus: updated evidence from pathogenesis to therapy

Background

Studies have demonstrated that high iron status is positively associated with gestational diabetes mellitus (GDM), implying that iron overload and ferroptosis play important roles in the development of GDM. The aim of this study was to explore effective therapeutic drugs from traditional Chinese medicine (TCM)formulas for the treatment of GDM based on ferroptosis.

Methods

In this study, the presence of ferroptosis in the placenta was verified through clinical and experimental data, and key genes were subsequently screened for association with ferroptosis in the development of GDM. The analysis was based on transcriptome sequencing of datasets combined with differentially expressed genes (DEGs) analysis and weighted gene correlation network analysis (WGCNA); functional enrichment analysis was also performed. A protein-protein interaction (PPI) network was constructed and pivotal genes were identified using Cytoscape. Finally, traditional Chinese medicine (TCM)formulas related to treating GDM were collected, then the proteins corresponding to the key genes were molecularly docked with the small molecular structures of clinically proven effective herbal tonics, and molecular dynamic simulations were performed to select the best candidates for pharmacological compounds.

Results

Elevated ferritin levels in patients with GDM were verified using clinical data. The presence of ferroptosis in placental tissues of patients with GDM was confirmed using electron microscopy and western blotting. Ninety-nine key genes with the highest correlation with ferroptosis were identified from DEGs and weighted gene co-expression network analysis (WGCNA). Analysis using the Kyoto Encyclopedia of Genes and Genomes demonstrated that the DEGs were primarily involved in the oxidative phosphorylation pathway. The key genes were further screened by PPI; two key genes, SF3B14 and BABAM1, were identified by combining the gene corresponding to protein structure and function, followed by molecular docking and molecular dynamic simulation. Coptis chinensis was proposed as the best candidate for herbal treatment at the molecular level.

Conclusion

This data revealed the presence of ferroptosis in patients with GDM and identified possible modulatory roles of ferroptosis-related genes involved in the molecular mechanisms of GDM, providing new insights into the pathogenesis of GDM, which also provided new directions for the systematic optimization of TCM formulas for the management and targeted treatment of GDM.

Maternal hemoglobin change from early pregnancy to second trimester is associated with risk of gestational diabetes mellitus: a retrospective cohort study

Introduction

The accrual of iron that is reflected in high maternal hemoglobin (Hb) status is increasingly recognized as a risk factor for gestational diabetes mellitus (GDM). Changes in maternal Hb level could also implicate glycemic status in pregnancy. This study aimed to determine the associations between maternal Hb levels and their changes with GDM.

Methods

In this retrospective cohort study, a total of 1,315 antenatal records of mothers with singleton pregnancies from eight health clinics of a district in the northern region of Peninsular Malaysia who delivered between 1st January 2016-31st December 2017 were analyzed. Data extracted from the records were socio-demographic, anthropometric, obstetrical, and clinical data. Hb levels were extracted at booking (<14 weeks) and second trimester (14-28 weeks). Change in Hb was determined by subtracting the Hb level in the second trimester from the booking Hb level and was categorized as decreased, unchanged, and increased Hb. The associations between maternal Hb levels and their changes with GDM risk were analyzed using multiple regression, adjusting for covariates in four different models. Model 1: maternal age and height. Model 2: covariates of Model 1 added with parity, history of GDM, and family history of diabetes. Model 3: covariates of Model 2 added with iron supplementation at booking. Model 4: covariates of Model 3 added with Hb level at booking.

Results and Discussions

Unchanged Hb level from booking to second trimester was significantly associated with GDM risk in Model 1 (AOR: 2.55; 95% CI: 1.20, 5.44; p < 0.05), Model 2 (AOR: 2.45, 95% CI: 1.13, 5.34; p < 0.05) Model 3 (AOR: 2.42; 95% CI: 1.11, 5.27; p < 0.05), and Model 4 (AOR: 2.51; 95% CI: 1.15, 5.49; p < 0.05). No significant associations were observed between maternal Hb levels and GDM in the study.

Conclusion

Unchanged Hb levels from the booking (<14 weeks of gestation) to the second trimester (14-28 weeks) increased GDM risk. Further investigation is warranted to evaluate the associations between changes in maternal Hb and GDM risk and to identify potential factors influencing this relationship.

Impact of iron supplementation on gestational diabetes mellitus: A literature review

Gestational diabetes mellitus (GDM) is a common complication of pregnancy, affecting 14% of pregnancies worldwide, and the prevention of pathological hyperglycaemia during pregnancy is meaningful for global public health. The role of iron supplementation in the progression of GDM has been of significant interest in recent years. Iron is a micronutrient that is vital during pregnancy; however, given the toxic properties of excess iron, it is probable that prophylactic iron supplementation will increase the risk of adverse pregnancy outcomes, including GDM. It is critical to clarify the effect of iron supplementation on the risk of GDM. Therefore, in this review, we comprehensively assess the role of iron in pregnancy. This review aimed to analyse the necessity of iron supplementation and maintenance of iron homeostasis during pregnancy, particularly reviewing the role and function of iron in beta cells and examining the mechanisms of excess iron contributing to the pathogenesis of GDM. Moreover, we aimed to discuss the association of haemoglobin and ferritin with GDM and identify priority areas for research.

Associations between whole blood trace elements concentrations and HbA1c levels in patients with type 2 diabetes

Previous researches have been conducted to study the associations of trace elements on Type 2 diabetes (T2D) risk. The present study focuses on the evaluation of potential associations between trace elements and Hemoglobin A1c (HbA1c) in patients with T2D, via the determination of their levels in human whole blood. 100 diabetes without complications, 75 prediabetes and 40 apparently healthy subjects were studied. The levels of eleven trace elements including lithium (Li), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), selenium (Se), strontium (Sr) and molybdenum (Mo) were measured using inductively coupled plasma mass spectrometry (ICP-MS). The levels of fasting glucose, HbA1c, Hemoglobin, lipid, liver function, kidney function, thyroid function and demographic data were obtained from the Laboratory Information System. Nonparametric correlation (Spearman) was used to analyze the relationship between trace elements and HbA1c. The contents of V, Cr, Mn, Fe, Co, Cu, Zn and Mo in diabetes increased comparing with the healthy subject while Li decreased. But the levels of Li, V, Cr, Mn, Co, Se and Mo negatively correlated with HbA1c in the diabetes subjects (r value: - 0.2189, - 0.2421, - 0.3260, - 0.2744, - 0.2812, - 0.2456, - 0.2240; 95% confidence interval - 0.4032 to - 0.0176, - 0.4235 to - 0.0420, - 0.4955 to - 0.1326, - 0.4515 to - 0.0765, - 0.4573 to - 0.0838, - 0.4266 to - 0.0458, - 0.4076 to - 0.0229; p < 0.05, p < 0.05, p < 0.001, p < 0.01, p < 0.01, p < 0.05, p < 0.05). Accordingly, the contents of V, Cr, Mn and Se showed lower in HbA1c ≥ 7.0% group in contrast to HbA1c < 7.0% group. No correlation of HbA1c (or FBG) and trace elements was found in the healthy subjects. Trace element levels and metabolic abnormalities of blood glucose may be mutually affected. The extra supplement of trace elements needs to be cautious.

Adiponectin ameliorates placental injury in gestational diabetes mice by correcting fatty acid oxidation/peroxide imbalance-induced ferroptosis via restoration of CPT-1 activity

PURPOSE

In gestational diabetes (GDM), abnormalities occur not only in glucose metabolism, but also in lipid metabolism. Adiponectin (ADPN) plays an important role in the regulation of lipid metabolism. In this paper, the role and mechanism of ADPN in GDM are discussed.

METHODS

GDM model was formed in pregnant mice induced by high-fat diet and streptozotocin, and blood glucose level was detected after ADPN treatment. The levels of TG, TC, HDL-C, and LDL-C in blood lipid of mice were detected by biochemical apparatus. HE staining was used to detect the placenta damage in mice. The expression of oxidative stress-related indexes in placental tissues was also detected by ELISA. Placental iron deposition was detected by Prussian blue staining. Redox capacity of placental tissue was detected by ELISA. Western blot was used to detect the expression of ferroptosis-related proteins in placental tissues. The expression of ADPN in placenta and peripheral blood was detected by ELISA, and the expression of ADPNR, downstream CPT-1, and GLUT4 of placenta were detected by RT-qPCR and western blot. Subsequently, trophoblast cells were induced by palmitic acid and glucose, and the cell activity was detected by CCK-8. The results in animal experiments were verified in cell experiments by RT-qPCR, western blot, and fluorescence labeling of iron ions. Finally, ADPN and CPT-1 inhibitor PM were given to trophoblast cells to further explore the mechanism.

RESULTS

ADPN inhibited blood glucose and lipid levels in GDM mice. ADPN inhibited oxidation/peroxide imbalance-induced ferroptosis in placental tissues of GDM mice. ADPN inhibited the expression of CPT-1 and GLUT4 in placental tissues of GDM mice. This result was also confirmed in cell experiments, and this process may be achieved by regulating CPT-1.

CONCLUSIONS

ADPN ameliorated placental injury in GDM by correcting fatty acid oxidation/peroxide imbalance-induced ferroptosis via restoration of CPT-1 activity.

Maternal first trimester iron status and its association with obstetric and perinatal outcomes

PURPOSE

To assess the following in singleton pregnant women: (1) associations between first trimester iron deficiency and obstetric and perinatal outcomes, (2) overall first trimester iron status and (3) post-treatment iron status after intensified iron supplementation.

METHODS

A prospective cohort study was conducted with linkage of first trimester hemoglobin and plasma ferritin with obstetric and perinatal data from a hospital database. Blood sample data were obtained from a Danish University Hospital. The cohort was divided into groups according to ferritin and hemoglobin: (1) iron-deficient anemic (ferritin < 30 ng/mL and Hb < 110 g/L), (2) iron-deficient non-anemic (ferritin < 30 ng/mL and Hb ≥ 110 g/L), and (3) iron-replete non-anemic (ferritin 30-200 ng/mL and Hb ≥ 110 g/L). Obstetric and perinatal outcomes in each iron-deficient group were compared to the iron-replete non-anemic group using multivariable logistic regression. The effect of 4 weeks intensified iron supplementation on hemoglobin and ferritin was assessed by groupwise comparisons.

RESULTS

The cohort comprised 5763 singleton pregnant women, of which 14.2% had non-anemic iron deficiency, and 1.2% had iron-deficiency anemia. Compared to iron-replete non-anemic women, iron-deficient anemic women had a higher risk of gestational diabetes (aOR 3.8, 95% CI 1.4-9.0), and iron-deficient non-anemic women had a higher risk of stillbirth (aOR 4.0, 95% CI 1.0-14.3). In group 1 and 2, 81.5% and 67.7% remained iron-deficient after intensified iron supplementation.

CONCLUSION

Iron-deficiency anemia was associated with gestational diabetes, and non-anemic iron deficiency with stillbirth, although risk estimates were imprecise due to few events. Iron deficiency was present in 15.4% and often persisted despite 4 weeks intensified iron supplementation.

Association between per- and polyfluoroalkyl substances and risk of gestational diabetes mellitus

BACKGROUND

Existing evidence suggests that perfluoroalkyl and polyfluoroalkyl substances (PFASs) exposure might contribute to the incidence of gestational diabetes mellitus (GDM). This study aimed to perform a meta-analysis to identify the association between PFAS and the risk of GDM.

METHODS

We systematically searched PubMed, Ovid, Cochrane Library, and Web of Science databases for appropriate articles about the association between PFASs exposure and the risk of GDM before September 28, 2020. Odds ratios (OR) with 95% confidence intervals (CIs) were summarized by Stata 16.0 through fixed effect models according to heterogeneity. We also carried out subgroup analyses by geographic location, blood sampling time of subjects, method of chemical analysis, study design, sample size, and sampling year. In addition, a sensitivity analysis was conducted to explore the robustness of the results.

RESULTS

A total of eight studies involving 5654 pregnant women were included in the meta-analysis. Perfluorooctanoic acid (PFOA) exposure was positively and significantly associated with the risk of GDM (OR = 1.27, 95% CI: 1.02-1.59). Exposure to other types of PFASs such as perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA) was not statistically significantly associated with the risk of GDM with the pooled effect estimates of 0.97 (95% CI: 0.86-1.09), 1.03 (95% CI: 0.86-1.24), and 0.80 (95% CI: 0.55-1.16) respectively.

CONCLUSION

We conducted a meta-analysis to investigate the association between PFASs exposure and GDM and found that PFOA concentration was significantly associated with a higher risk of GDM, which is of great significance for the prevention and control of GDM in public health. Further studies are needed in order to establish causality and clarify the potential mechanism.

Relationship of Circulating Copper Level with Gestational Diabetes Mellitus: a Meta-Analysis and Systemic Review

BACKGROUND AND PURPOSE

Gestational diabetes mellitus (GDM) represents the frequently occurring medical disorder beginning in the process of pregnancy. No consensus has been reached about the relationship of circulating copper content with the risk of GDM. Therefore, the present work carried out a meta-analysis for summarizing epidemiological research regarding the copper level with the GDM risk. Furthermore, studies using categories of copper concentration as exposure were combined by dose-response meta-analysis.

METHODS

Related studies were retrieved against the PubMed, Web of Science, and Scopus databases from inception till August 2020. The overall effects were expressed as standard mean difference (SMD). A dose-response meta-analysis was conducted to assess whether the higher copper concentration was associated with higher risks of GDM. Stata 16.0 and Review Manager 5.3 were utilized for data analysis.

RESULTS

A total of fourteen articles involving were retrieved for meta-analysis; in the meantime, 2670 pregnant subjects including 910 GDM cases were enrolled for quantitative analysis. Based on the integrated findings, GDM cases showed increased circulating copper contents relative to those in normal pregnant subjects (SMD = 0.65, 95% CI 0.19 to 1.11; P = 0.005). There was no obvious evidence of publication bias among the studies enrolled. Subgroup analysis showed that such trend was consistent in the third trimester (SMD = 1.21, 95% CI 0.35 to 2.08; P = 0.006) but not second trimester. Meanwhile, circulating copper concentration was significantly higher in women with GDM than those without GDM within the Asian population but not within the Caucasian population (Asia: SMD = 0.73; 95% CI 0.12 to 1.34, P = 0.02; Europe: SMD = 0.49; 95% CI: - 0.23 to 1.20, P = 0.18). Further, serum copper analysis together with subgroup analysis was conducted, and the same result was obtained. For dose-response analysis, the linear associations between circulating copper and risks of GDM were revealed, that higher circulating copper concentration during pregnancy is closely associated with GDM.

CONCLUSION

According to existing evidence, the serum copper concentration increased among GDM cases compared with subjects with normality in glucose tolerance pregnant subject, in particular among the Asians and during the third trimester. The finding from dose-response analysis suggested that increased copper level is associated with an increased risk of GDM. Nonetheless, more specially designed prospective articles should be carried out for understanding the dynamic relationship of copper concentration with the GDM risk.

Iron Metabolism in Pancreatic Beta-Cell Function and Dysfunction

Iron is an essential element involved in a variety of physiological functions. In the pancreatic beta-cells, being part of Fe-S cluster proteins, it is necessary for the correct insulin synthesis and processing. In the mitochondria, as a component of the respiratory chain, it allows the production of ATP and reactive oxygen species (ROS) that trigger beta-cell depolarization and potentiate the calcium-dependent insulin release. Iron cellular content must be finely tuned to ensure the normal supply but also to prevent overloading. Indeed, due to the high reactivity with oxygen and the formation of free radicals, iron excess may cause oxidative damage of cells that are extremely vulnerable to this condition because the normal elevated ROS production and the paucity in antioxidant enzyme activities. The aim of the present review is to provide insights into the mechanisms responsible for iron homeostasis in beta-cells, describing how alteration of these processes has been related to beta-cell damage and failure. Defects in iron-storing or -chaperoning proteins have been detected in diabetic conditions; therefore, the control of iron metabolism in these cells deserves further investigation as a promising target for the development of new disease treatments.

Associations of TMPRSS6 Polymorphisms with Gestational Diabetes Mellitus in Chinese Han Pregnant Women: a Preliminary Cohort Study

Body iron status is likely to be associated with type 2 diabetes (T2DM) and gestational diabetes mellitus (GDM); transmembrane protease serine 6 (TMPRSS6) polymorphisms may be associated with T2DM risk through their effects on body iron status. However, it remains unknown whether the TMPRSS6 single nucleotide polymorphisms (SNPs) affect the risk of GDM development. We aimed to determine whether the TMPRSS6 SNPs rs855791 (V736A) and rs4820268 (D521D) are associated with the risk of GDM in pregnant women. The two SNPs in TMPRSS6 gene were genotyped and examined for their associations with body iron status and GDM risk in 398 unrelated Chinese Han pregnant women. The 2 TMPRSS6 SNPs rs855791 and rs4820268 were both significantly associated with serum iron and transferrin saturation (P < 0.01 for all) rather than ferritin. After adjustment for covariates, the C allele of rs4820268 was nominally and significantly associated with an increased risk of GDM (OR = 2.531; 95%CI = 1.044-6.136, P = 0.040); when concentrations of ferritin were further adjusted, the association was still significant (OR = 2.528; 95%CI = 1.043-6.126, P = 0.040). There was a significant trend (P = 0.065) in the association between the T allele of rs855791 and an increased GDM risk in this study population. The 2 TMPRSS6 SNPs rs855791 and rs4820268 were both significantly associated with serum iron and transferrin saturation, and TMPRSS6 variants might be associated with the risk of GDM. Furthermore, the effects of TMPRSS6 SNPs on the risk of GDM may not be completely explained by the mediation of body iron status. Further studies are warranted.

The relationship between iron metabolism, stress hormones, and insulin resistance in gestational diabetes mellitus

AIM

To analyze the relationship between iron metabolism index and stress hormones, insulin resistance, and oxidative stress in gestational diabetes mellitus (GDM).

METHODS

From January to November 2019, 75 patients with GDM were selected as GDM group, according to age of 1:1; 75 normal pregnant women were selected as Control group. Blood glucose, insulin, stress hormones such as cortisol, norepinephrine (NE), and epinephrine (E), and iron metabolism index such as serum iron, serum ferritin (SF), and transferrin saturation (TS) were measured. Insulin resistance was evaluated by homeostasis model insulin resistance index (HOMA-IR). Multiple linear regression was used to analyze the relationship between iron metabolism index and stress hormones, insulin resistance, and oxidative stress.

RESULTS

The levels of NE, E, serum iron, SF, and TS saturation in the GDM group were higher than Control group (t = 3.82, 2.75, 3.14, 6.12, and 3.90, P < 0.05, <0.05, <0.05, <0.01, <0.01); HOMA-IR was higher in the GDM group (t = 4.92, P < 0.01); malondialdehyde (MDA) was higher, while superoxide dismutase (SOD) was lower than Control group (t = 5.25, 4.98, both P < 0.01). Epinephrine, norepinephrine, cortisol, and serum ferritin were positively correlated (r = 0.21, 0.17, and 0.21); epinephrine, cortisol, and transferrin were positively correlated (r = 0.12, 0.31). There was a positive correlation between HOMA-IR and SF and TS (r = 0.34, 0.34). MDA was positively correlated with SF and TS (r = 0.24, 0.29); SOD was negatively related to SF and TS (r = -0.12, -0.17).

CONCLUSIONS

Iron metabolism index is related to insulin resistance in GDM women. The change in iron metabolism may be involved in the pathogenesis of gestational diabetes caused by stress- adaptive disorder.