Association between iron level, glucose impairment and increased DNA damage during pregnancy

Association of mid-pregnancy ferritin levels with postpartum glucose metabolism in women with gestational diabetes

BACKGROUND

Ferritin, a key indicator of body iron levels, has been reported to associate with type 2 diabetes (T2DM) and the onset of Gestational diabetes mellitus (GDM). However, limited research explores the association between mid-pregnancy ferritin levels and the risk of postpartum abnormal glucose metabolism (AGM) in patients with GDM.

METHODS

A retrospective cohort study was conducted in 1514 women with GDM recruited from January 2016 to January 2021, and 916 women were included. Demographic characteristics, medical history and family history, pregnancy complications were recorded. Multiple logistic regression models were performed to assess the association between mid-pregnancy ferritin levels and the risk of postpartum AGM.

RESULTS

Following the postpartum oral glucose tolerance test, 307 (33.5%) exhibited AGM. The AGM group had higher mid-pregnancy serum ferritin levels [AGM vs NGT: 23 (11.7, 69) µg/L vs 17.80 (9.85, 40.7) µg/L, P < 0.001] and had a larger proportion of women with ferritin levels ≥30 µg/L (AGM vs NGT: 43.6% vs 31.4%, P < 0.001). Logistic regression analysis demonstrated that women with ferritin levels≥ 30 µg/L had a 1.566 times higher risk of developing postpartum AGM.

CONCLUSIONS

These findings indicate that elevated mid-pregnancy ferritin levels are significantly and independently associated with increased postpartum AGM risk in women with previous GDM. Consequently, cautious consideration is necessary for prescribing iron supplements in prenatal care, particularly for non-anemic women with GDM at high risk of developing diabetes after delivery.

Vitamin C Alleviates the Risk of Gestational Diabetes Mellitus Associated With Exposure to Metals

Background: Exposure to heavy metals has been suggested to increase the risk of gestational diabetes mellitus (GDM) through the oxidative stress pathway. The study is aimed at examining whether vitamin C could modify the association between exposure to heavy metals and risk of GDM. Methods: We conducted a case-control study in Taiyuan, China, with 776 GDM cases and 776 controls. Data on vitamin C intake from diet and supplements were collected through questionnaires. Concentrations of metals in participants' blood were measured using inductively coupled plasma-mass spectrometry (ICP-MS). Unconditional logistic regression models were applied to estimate effect modification of vitamin C on the association between heavy metals and GDM. Results: Women with higher blood levels of mercury (Hg) (odds ratio (OR) = 2.36, 95% confidence interval (CI): 1.43, 3.92 and 2.04, 95% CI: 1.20, 3.46 for the second and third vs. the first tertile) and arsenic (As) (OR = 2.46, 95% CI: 1.37, 4.43 and 2.16, 95% CI: 1.12, 4.17 for the second and third vs. the first tertile) exposure were associated with increased risk of GDM among women without vitamin C supplement use and having dietary vitamin C intake < 85 mg/day. We found no significant association with metals among women who took vitamin C supplements and/or dietary vitamin C ≥ 85 mg/day. Significant interactions were observed between vitamin C and exposures to metals (i.e., Hg and As) on the risk of GDM (P interaction = 0.048 and 0.045, respectively). Conclusions: Our study, for the first time, suggests that vitamin C supplement use or higher dietary vitamin C intake during preconception and early pregnancy could alleviate the risk of GDM associated with exposure to As and Hg. The results warrant further investigation.

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.

The association of iron status, supplement iron in the first-trimester pregnancy with gestational diabetes mellitus: A nested case-control study

AIMS

The objective of this study was to examine whether the level of iron and iron supplements in the first-trimester pregnancy is associated with gestational diabetes mellitus (GDM).

METHODS

This was a nested case-control study using data from an established cohort in the Hunan Provincial Maternal and Child Health Hospital (HPMCHH) in South China. A total of 119 patients with GDM and 238 controls were enrolled in the study. Iron status indicators were tested in early pregnancy. Information on iron supplements use was collected by questionnaires. Binary logistic regression was used to obtain odds ratio (OR). The relative excess risk of interaction (RERI) was applied to evaluate the interaction.

RESULTS

We observed that pregnant women with normal ferritin levels (≥30 ng/ml) and iron supplements were associated with a 3.701-fold increased risk of GDM (OR: 3.701, 95% CI: 1.689-8.112) compared with the ferritin <30 ng/ml and without iron supplements group. Similarly, pregnant women with normal serum iron (SI) levels (≥9 μmol/L) and iron supplements were associated with a 5.447-fold increased risk of GDM (OR: 5.447, 95% CI: 2.246-13.209) compared with the SI < 9 μmol/L and without iron supplement group. We found an additive interaction between ferritin and iron supplements on the presence of GDM (RERI: 1.164, 95%CI: 0.333-1.994) and SI and iron supplements on the risk of GDM (RERI: 6.375, 95%CI: 4.494-8.256).

CONCLUSION

Pregnant women with normal ferritin or SI levels and iron supplements could significantly increase the risks for GDM.

Association between early oxidative DNA damage and iron status in women with gestational diabetes mellitus

This study aims to assess the relationship between oxidative DNA damage and iron status in women with gestational diabetes mellitus (GDM) compared to those with normal glucose tolerance in the first and the second trimesters of pregnancy. Maternal serum and urine samples were collected in the 11th-14th weeks and the 24th-28th weeks of gestation. In addition to oral glucose tolerance test in the second trimester, fasting blood glucose, HbA1c, ferritin and hemoglobin levels were measured in blood samples. Urinary levels of oxidative DNA damage products 8-hydroxy-2'-deoxyguanosine (8-OH-dG) and 8,5'-cyclo-2'-deoxyadenosines (S-cdA, R-cdA) were determined using liquid chromatography-tandem mass spectrometry with isotope-dilution. In the first trimester, urinary 8-OH-dG levels were found higher in the GDM group (n = 33) than in the control group (n = 84) (p = 0.006). R-cdA and S-cdA levels were not significantly different between the two groups (p = 0.794 and p = 0.792 respectively). When the cases were stratified according to their first trimester ferritin levels, women with ≥50th centile (≥130 ng/mL) demonstrated higher levels of 8-OH-dG and R-cdA than those under <50th centile (p = 0.034, p = 0.009). In the GDM group, there was a positive correlation between the second trimester 8-OH-dG and ferritin and 1st-hour glucose levels (p = 0.014, p = 0.020). This is the first study where oxidative DNA damage is evaluated in both early and late periods of pregnancy. Our findings reveal an association between GDM and iron status and oxidative DNA damage.

Multidimensional Approach to Assess Nutrition and Lifestyle in Breastfeeding Women during the First Month of Lactation

The first month of lactation is a vulnerable nutritional period for the mother. Our aims were (1) to evaluate the nutritional status of breastfeeding women in the first month of lactation, and (2) to explore different aspects of nutrition and lifestyle through a multidimensional approach. A total of 30 healthy breastfeeding women were enrolled in this study. Dietary pattern was assessed through a 72-hour dietary recall questionnaire (days 7 and 28 postpartum) and data were compared with Dietary Recommendation Values (DRV), and through the Adherence to Healthy Food Pyramid (HFP) questionnaire (day 28). Anthropometric parameters were evaluated by bioimpedance. Using factor analysis, nutritional dimensions were extracted, and linear regression models were used to analyze the association between anthropometric parameters and dimensions. Compared to the DRV, women showed insufficient energy, water, vitamin D, and potassium intake and excessive proteins, vitamins B1, B2, B3, B6, B12, and iron intake. We observed a moderate adherence to the HFP, with women being high in the fruits, vegetables, and oil categories, and low adherence to the physical activity, dairy products, and hydration categories. The nutritional dimension, including the HFP categories of physical activity, hydration, and animal protein intake together, was negatively associated with body weight (β = -3.7 ± 1.7; p-value = 0.047). In conclusion, during the first month postpartum, breastfeeding women exhibited several nutritional imbalances and poor physical activity negatively influencing anthropometric parameters. We propose a multidimensional approach to assess the nutritional status of breastfeeding women as a tool to detect specific deficiencies, allowing for personalized counseling.

Observations of the Effects of Maternal Fasting Plasma Glucose Changes in Early Pregnancy on Fetal Growth Profiles and Birth Outcomes

INTRODUCTION

Although the role of maternal hyperglycemia on birth outcomes is clear, literature regarding fetal growth is scarce. We examined the possible associations between maternal fasting plasma glucose (FPG) and fetal growth.

MATERIALS AND METHODS

A total of 35,981 singleton-pregnant women with FPG in the first trimester were included. Fetal growth parameters were measured during pregnancy by ultrasound at mid and late pregnancy. Information on birth characteristics was retrieved from medical records. We used multivariable linear and logistic regression to determine the associations between FPG and z-scores of fetal parameters and risks of birth outcomes and to assess effect modification by maternal characteristics.

RESULTS

A per-unit increase in FPG levels was negatively associated with fetal parameters in mid pregnancy but positively correlated with those in late pregnancy and with birth characteristics. The effect estimates in late pregnancy were attenuated by maternal pre-pregnancy body mass index (BMI). A significant relationship between FPG and abdominal circumference (AC), an indicator of fetal adiposity, was sustained in subgroups of women with advanced age, positive family history of diabetes, and multiparity in fully adjusted models. After stratification by BMI, high FPG was associated with accelerated AC only in normal controls (0.044 SD; 95% CI: 0.010, 0.079) and overweight/obese women (0.069 SD; 95% CI: -0.002, 0.140) but not in underweight women. High FPG was an independent risk factor for large-for-gestational age in the whole group and stratified subgroups.

CONCLUSIONS

Increased FPG in early pregnancy is closely related to fetal growth. Maternal characteristics may modify the associations between FPG and fetal adiposity in late pregnancy.

The association of elevated serum ferritin concentration in early pregnancy with gestational diabetes mellitus: a prospective observational study

BACKGROUND/OBJECTIVES

The results linking body iron stores to the risk of gestational diabetes mellitus (GDM) are conflicting. We aimed to measure the serum ferritin level of women in early pregnancy and evaluate the risk of GDM in a Chinese urban population.

SUBJECTS/METHODS

In total, 851 pregnant women between 10 and 20 weeks of gestation took part in the prospective, observational study conducted. The women were divided into four groups by quartiles of serum ferritin levels (Q1-4). Their blood samples were collected and assayed for several biochemical variables at the beginning of the study, and the women were followed up with a 75-g oral glucose tolerance test at 24-28 weeks of gestation.

RESULTS

The participants had an average serum ferritin concentration of 65.67 μg/L. GDM prevalence within each serum ferritin quartile was 9.4%, 14.6%, 18.8% and 19.3%, respectively, (P = 0.016). The odds ratio for GDM in the ferritin Q2-4 was 1.64 (CI: 0.90-2.99), 2.23 (CI: 1.26-3.96) and 2.31 (CI: 1.30-4.10), compared with Q1, respectively. This association persisted after adjusting for potential confounders factors. In addition, in Q4, pregnant women with a pre-pregnancy body mass index ≥24 kg/m², maternal age ≤35 years old or haemoglobin≥ 110 g/L did have an increased risk of developing GDM.

CONCLUSIONS

Elevated serum ferritin concentrations in early gestation are associated with an increased risk of GDM, especially in pregnant women who have a high baseline iron storage status with no anaemia or who are overweight/obese. Individual iron supplementation should be considered to minimize the risk of GDM.

Oxidative stress in healthy pregnancy and preeclampsia is linked to chronic inflammation, iron status and vascular function

Background

During normal pregnancy, placental oxidative stress (OS) is present during all three trimesters and is necessary to obtain normal cell function. However, if OS reaches a certain level, pregnancy complications might arise. In preeclampsia (PE), a dangerous pregnancy specific hypertensive disorder, OS induced in the ischemic placenta causes a systemic inflammatory response and activates maternal endothelial cells. In this study, we aimed to quantify superoxide concentrations (as a measure of systemic OS) using electron paramagnetic resonance (EPR) and correlate them to markers of systemic inflammation, iron status and vascular function.

Methods

Fifty-nine women with a healthy pregnancy (HP), 10 non-pregnant controls (NP) and 28 PE patients (32±3.3weeks) were included. During HP, blood samples for superoxide, neutrophil to lymphocyte ratio (NLR), mean platelet volume (MPV) and iron status were taken at 10, 25 and 39 weeks. Vascular measurements for arterial stiffness (carotid-femoral pulse wave velocity (CF-PWV), augmentation index (AIx), augmentation Pressure (AP)) and microvascular endothelial function (reactive hyperemia index (RHI)) were performed at 35 weeks. In PE, all measurements were performed at diagnosis. CMH (1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) was used as spin probe for EPR, since the formed CM radical corresponds to the amount of superoxide.

Results

Superoxide concentration remains stable during pregnancy (p = 0.92), but is significantly higher compared to the NP controls (p<0.0001). At 25 weeks, there is a significant positive correlation between superoxide and ferritin concentration. (p = 0.04) In PE, superoxide, systemic inflammation and iron status are much higher compared to HP (all p<0.001). During HP, superoxide concentrations correlate significantly with arterial stiffness (all p<0.04), while in PE superoxide is significantly correlated to microvascular endothelial function (p = 0.03).

Conclusions

During HP there is an increased but stable oxidative environment, which is correlated to ferritin concentration. If superoxide levels increase, there is an augmentation in arterial stiffness. In PE pregnancies, systemic inflammation and superoxide concentrations are higher and result in a deterioration of endothelial function. Together, these findings support the hypothesis that vascular function is directly linked to the amount of OS and that measurement of OS in combination with vascular function tests might be used in the prediction of PE.

No effects without causes: the Iron Dysregulation and Dormant Microbes hypothesis for chronic, inflammatory diseases

Since the successful conquest of many acute, communicable (infectious) diseases through the use of vaccines and antibiotics, the currently most prevalent diseases are chronic and progressive in nature, and are all accompanied by inflammation. These diseases include neurodegenerative (e.g. Alzheimer's, Parkinson's), vascular (e.g. atherosclerosis, pre-eclampsia, type 2 diabetes) and autoimmune (e.g. rheumatoid arthritis and multiple sclerosis) diseases that may appear to have little in common. In fact they all share significant features, in particular chronic inflammation and its attendant inflammatory cytokines. Such effects do not happen without underlying and initially 'external' causes, and it is of interest to seek these causes. Taking a systems approach, we argue that these causes include (i) stress-induced iron dysregulation, and (ii) its ability to awaken dormant, non-replicating microbes with which the host has become infected. Other external causes may be dietary. Such microbes are capable of shedding small, but functionally significant amounts of highly inflammagenic molecules such as lipopolysaccharide and lipoteichoic acid. Sequelae include significant coagulopathies, not least the recently discovered amyloidogenic clotting of blood, leading to cell death and the release of further inflammagens. The extensive evidence discussed here implies, as was found with ulcers, that almost all chronic, infectious diseases do in fact harbour a microbial component. What differs is simply the microbes and the anatomical location from and at which they exert damage. This analysis offers novel avenues for diagnosis and treatment.