Increased serum ferritin levels are independently associated with carotid atherosclerosis in women

Trace Metals and The Hemostatic System

In this narrative review we report the main relationships between trace metals and the hemostatic system since this aspect has seldom attracted the attention of the scientific community. A basic aspect to be considered is the importance of maintaining the fine control of all trace metals' levels since they have an important impact on the pathophysiology of the hemostatic system. It is worth noting that poor diet habits are responsible for most trace metal deficiencies, while pollution is responsible for dangerous exposure to them with a consequent negative impact on the general population. This appears of paramount importance in planning the implementation of food and nutrient support to ameliorate the hidden hunger and the quality of life of people especially in developing countries and limiting poisons both in the air and food. As it often happens, when damage to certain mechanisms takes a very long time to appear, no attention is paid to the importance of a systematic prevention to avoid late negative outcomes.

Maternal Iron Status in Early Pregnancy and Blood Pressure Throughout Pregnancy, Placental Hemodynamics, and the Risk of Gestational Hypertensive Disorders

BACKGROUND

In nonpregnant populations, higher serum ferritin, which reflects high iron stores, is associated with an increased risk of hypertension. We hypothesized that a dysregulated maternal iron status in early pregnancy may lead to impaired gestational hemodynamic adaptations, leading to an increased risk of gestational hypertensive disorders.

OBJECTIVES

We examined the associations of maternal iron status with maternal blood pressure, placental hemodynamic parameters, and the risks of gestational hypertensive disorders.

METHODS

In a population-based prospective cohort study among 5983 pregnant women, we measured maternal serum ferritin, transferrin saturation, serum iron, and transferrin concentrations at a median of 13.2 weeks gestation (95% range, 9.6-17.6). Maternal blood pressure was measured in early pregnancy, mid pregnancy, and late pregnancy, and placental hemodynamic parameters in mid pregnancy and late pregnancy were measured by ultrasound. Information on gestational hypertensive disorders was collected from medical records. We examined the associations of maternal early pregnancy iron status with maternal systolic and diastolic blood pressure, placental hemodynamic parameters, and the risks of gestational hypertensive disorders using linear and logistic regression models.

RESULTS

Higher maternal early pregnancy serum ferritin concentrations were associated with higher systolic and diastolic blood pressure throughout pregnancy in the basic models (P values < 0.05). After adjustment for maternal inflammation, sociodemographic and lifestyle factors, higher maternal early pregnancy serum ferritin concentrations were only associated with a higher early pregnancy diastolic blood pressure [0.27 (95% CI, 0.03-0.51) mmHg per SD score increase in serum ferritin] and with a higher mid pregnancy umbilical artery pulsatility index (P < 0.05). No associations with the risk of gestational hypertensive disorders were present.

CONCLUSIONS

No consistent associations were present of maternal iron status in early pregnancy with gestational hemodynamic adaptations or the risks of gestational hypertensive disorders. Further studies are needed to examine the potential role of iron metabolism in the development of gestational hypertensive disorders within higher-risk populations.

Increased plasma miR-146a levels are associated with subclinical atherosclerosis in newly diagnosed type 2 diabetes mellitus

AIMS

The association between circulating miR-146a and subclinical atherosclerosis in type 2 diabetes mellitus (T2DM) remains poorly understood. This study aimed to investigate the correlation between plasma miR-146a levels and subclinical atherosclerosis as measured by the carotid intima-media thickness (CIMT) and brachial-ankle pulse wave velocity (baPWV) in patients with newly diagnosed T2DM.

METHODS

We studied 100 patients with newly diagnosed T2DM. Subclinical atherosclerosis was defined as a thickened CIMT (≥1.0 mm) and high baPWV defined as a value greater than the 75th percentile. Plasma miR-146a levels and metabolic parameters were measured.

RESULTS

Patients with thickened CIMT had higher plasma miR-146a levels than those without thickened CIMT (3.36 ± 1.32 vs 1.38 ± 1.11, P < 0.001). Patients in the high baPWV group had higher plasma miR-146a levels than those in the normal baPWV group (3.43 ± 1.32 vs 1.98 ± 1.48, P < 0.001). Both CIMT (β = 0.569, P < 0.001) and baPWV (β = 0.274, P = 0.001) positively correlated with plasma miR-146a levels after adjustment for confounding factors by multiple stepwise regression. On binary logistic regression, plasma miR-146a level was an independent risk factor for thickened CIMT (OR = 3.890, 95% CI 1.415-7.698, P = 0.008) and high baPWV (OR = 1.954, 95% CI 1.256-3.040, P = 0.002) after adjustment for established cardiovascular risk factors. The area under the receiver operating characteristics curve (AUROC) of plasma miR-146a level for predicting thickened CIMT was 0.795 (95%CI 0.708-0.883, P < 0.001) and for predicting high baPWV was 0.773 (95%CI 0.679-0.867, P < 0.001).

CONCLUSION

Plasma miR-146a levels correlate with CIMT and baPWV and could act as a biomarker for early diagnosis and as a therapeutic target for atherosclerosis in T2DM.

Erythrocyte-rich thrombi related to serum iron contribute to single stent retrieval and favorable clinical outcomes in acute ischemic stroke by endovascular treatment

BACKGROUND

Erythrocyte-rich thrombi seem to be associated with favorable clinical outcomes of patients with AIS by endovascular treatment (EVT), as observed from previous studies. However, only few studies show whether erythrocyte-rich thrombi can be associated with favorable clinical outcomes by EVT and which factor can be related to erythrocyte-rich thrombi. This retrospective study aimed to evaluate the relationship between erythrocyte-rich thrombi and favorable clinical outcomes and further explored factors associated with erythrocyte-rich thrombi.

METHODS

This study was carried out retrospectively from March 2016 to April 2019 on patients who suffered acute ischemic stroke and were treated by EVT at this stroke center. The laboratory test and clinical data were assessed for the relationship between erythrocyte-rich thrombi and favorable clinical outcomes and factors associated with erythrocyte-rich thrombi. All thrombi were divided into erythrocyte-rich thrombi group and fibrin-rich thrombi group based on the proportion of area of the predominant composition which was more than 50% in retrieved thrombi.

RESULTS

This retrospective study enrolled 84 patients, including 32 patients in the erythrocyte-rich thrombi group and 52 patients in the fibrin-rich thrombi group. It showed single stent retrieval (p = 0.017, adjusted OR: 4.061, 95% CI: 1.281-12.872) and favorable clinical outcomes (p < 0.001, adjusted OR: 14.648, 95% CI: 4.637-46.270) were both significantly associated with erythrocyte-rich thrombi. A significant difference in the factor associated with erythrocyte-rich thrombi was serum iron, which correlated positively with erythrocyte fraction in thrombi (p < 0.001, r: 0.452).

CONCLUSIONS

Erythrocyte-rich thrombi could contribute to single stent retrieval and favorable clinical outcomes by EVT, and serum iron might be the factor associated with erythrocyte-rich thrombi.

Iron overload is related to elevated blood glucose levels in obese children and aggravates high glucose-induced endothelial cell dysfunction in vitro

INTRODUCTION

This study was performed to investigate the role of iron overload in the early stage of hyperglycemia-induced vascular functional impairment.

RESEARCH DESIGN AND METHODS

A total of 196 obese children were enrolled, and data regarding ferritin levels, blood glucose levels, intima-media thickness of carotid arteries, liver function and fibrosis index, hemoglobin, blood pressure, blood lipids, and inflammation indicators were collected. Ferritin levels were compared with a control group, which consisted of 148 healthy non-obese children who were age-matched and gender-matched. Endothelial cells were cultured in high glucose medium and supplemented with ferric citrate with or without iron remover (deferoxamine), a reducing agent (N-acetyl-cysteine), or a nuclear factor-κB (NF-κB) inhibitor (BAY 11-7082). Apoptosis, oxidative stress, nitric oxide levels, and endothelin content were evaluated. DNA microarray analysis was performed to analyze the expression of genes in the NF-κB signaling pathway.

RESULTS

Obese children have significantly higher ferritin levels compared with the control group. Ferritin level was positively correlated with hemoglobin and was related to metabolic disorders, including impaired glucose tolerance, higher blood pressure, dyslipidemia, and impaired hepatic function. Endothelial cells treated with ferric citrate showed a significantly higher rate of apoptosis, higher levels of oxidative stress, and impaired vasomotor function under high glucose conditions. The above effects were rescued by treatment with an iron remover, reducing agent, or NF-κB inhibitor. Further, detection of phosphorylated-p65 distribution in cells confirmed activation of the NF-κB pathway. DNA microarrays and subsequent gene oncology enrichment analyses revealed the main processes activated in cells.

CONCLUSION

Increased ferritin levels are related to impaired glucose tolerance and other metabolic disorders in obese children. At the cellular level, iron overload aggravated the endothelial cell dysfunction caused by high glucose.

Effects of Genetically Determined Iron Status on Risk of Venous Thromboembolism and Carotid Atherosclerotic Disease: A Mendelian Randomization Study

Background Systemic iron status has been implicated in atherosclerosis and thrombosis. The aim of this study was to investigate the effect of genetically determined iron status on carotid intima-media thickness, carotid plaque, and venous thromboembolism using Mendelian randomization. Methods and Results Genetic instrumental variables for iron status were selected from a genome-wide meta-analysis of 48 972 subjects. Genetic association estimates for carotid intima-media thickness and carotid plaque were obtained using data from 71 128 and 48 434 participants, respectively, and estimates for venous thromboembolism were obtained using data from a study incorporating 7507 cases and 52 632 controls. Conventional 2-sample summary data Mendelian randomization was performed for the main analysis. Higher genetically determined iron status was associated with increased risk of venous thromboembolism. Odds ratios per SD increase in biomarker levels were 1.37 (95% CI 1.14-1.66) for serum iron, 1.25 (1.09-1.43) for transferrin saturation, 1.92 (1.28-2.88) for ferritin, and 0.76 (0.63-0.92) for serum transferrin (with higher transferrin levels representing lower iron status). In contrast, higher iron status was associated with lower risk of carotid plaque. Corresponding odds ratios were 0.85 (0.73-0.99) for serum iron and 0.89 (0.80-1.00) for transferrin saturation, with concordant trends for serum transferrin and ferritin that did not reach statistical significance. There was no Mendelian randomization evidence of an effect of iron status on carotid intima-media thickness. Conclusions These findings support previous work to suggest that higher genetically determined iron status is protective against some forms of atherosclerotic disease but increases the risk of thrombosis related to stasis of blood.

Association of serum proprotein convertase subtilisin/kexin type 9 with early atherosclerosis in newly diagnosed type 2 diabetes mellitus

BACKGROUND AND AIM

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is rapidly gaining attention as a potential risk of developing atherosclerosis due to its crucial role in the regulation of low-density lipoprotein cholesterol (LDL-C) metabolism. The present study investigated the relationship between serum PCSK9 levels and early atherosclerosis as assessed by carotid intimal-medial thickness (CIMT) and brachial-ankle pulse wave velocity (ba-PWV) in newly diagnosed type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

A total of 100 newly diagnosed T2DM were enrolled and further divided into the thickened CIMT group (n = 41) and the non-thickened CIMT group (n = 59) according to the results of color Doppler ultrasonography. Serum PCSK9 levels, CIMT, ba-PWV, and metabolic parameters were measured. Patients in the thickened CIMT group had higher serum PCSK9 levels than patients in the non-thickened CIMT group (all P < 0.05). CIMT and ba-PWV were both positively correlated to serum PCSK9 levels, while serum PCSK9 levels were positively correlated to white blood cell count, neutrophil, lymphocyte, and high-sensitivity C-reactive protein (P < 0.05). Multiple linear regression indicated that serum PCSK9 level was an independent predictor of CIMT (β = 0.637, P < 0.001) and ba-PWV (β = 0.600, P < 0.001). Binary logistic regression analysis showed that serum PCSK9 levels were independent risk factors of thickened CIMT [OR = 1.120, 95%CI (1.041-1.204), P = 0.002].

CONCLUSION

Serum PCSK9 levels are significantly correlated with CIMT and ba-PWV, independent of CAD risk factors. Therefore, serum PCSK9 level may have the potential to serve as a prescriptive biomarker for early arteriosclerosis in newly diagnosed T2DM.

Relationship between high-sensitivity C-reactive protein and subclinical carotid atherosclerosis stratified by glucose metabolic status in Chinese adults

BACKGROUND

Atherosclerosis is an inflammatory disease. Many studies demonstrated that hyperglycemia is not only increased inflammatory response, but also is a cause of atherosclerosis, implying that glucose metabolic status may be an important stratification factor when analyzing the relationship between inflammatory levels and subclinical carotid atherosclerosis. The aim of the present study is to assess the relationship between inflammatory levels and subclinical carotid atherosclerosis, stratified by different glucose metabolic status in a general population.

METHODS

An assessment was performed in 7975 participants living in Tianjin, China. In the present study, we examined subclinical carotid atherosclerosis, as defined by increased carotid intima-media thickness [IMT] and plaques. Measurements were performed using a carotid artery B-mode ultrasound system. The glucose metabolic status was defined by the criteria of the American Diabetes Association, and high-sensitivity C-reactive protein (hs-CRP) as an inflammatory indicator, was measured by immunoturbidimetric assay. Multiple logistic models were used to assess a stratified relationship between hs-CRP levels and subclinical carotid atherosclerosis. Strata were defined according to glucose metabolic status.

RESULTS

The prevalence of increased IMT and plaques were 27.3% and 21.3%, respectively. The adjusted odds ratios (95% confidence interval) for IMT across hs-CRP quartiles were as follows: 1.00 (reference), 1.10(0.88-1.38), 1.08(0.86-1.35) and 1.32(1.06-1.66) in blood glucose-normal subjects; 1.00 (reference), 1.33(0.92-1.91), 1.33(0.93-1.91), and 1.59(1.10-2.30) in prediabetic subjects; 1.00 (reference), 0.94(0.54-1.62), 1.17(0.65-2.12) and 0.98(0.55-1.76) in diabetic subjects, respectively. Similar results were observed for plaques.

CONCLUSIONS

Our results suggest that inflammatory levels are differently related to subclinical carotid atherosclerosis by the different glucose metabolic status.