Abdominal aortic aneurysm or aortic occlusive disease: role of trace element imbalance

Cuproptosis and copper deficiency in ischemic vascular injury and repair

Ischemic vascular diseases are on the rise globally, including ischemic heart diseases, ischemic cerebrovascular diseases, and ischemic peripheral arterial diseases, posing a significant threat to life. Copper is an essential element in various biological processes, copper deficiency can reduce blood vessel elasticity and increase platelet aggregation, thereby increasing the risk of ischemic vascular disease; however, excess copper ions can lead to cytotoxicity, trigger cell death, and ultimately result in vascular injury through several signaling pathways. Herein, we review the role of cuproptosis and copper deficiency implicated in ischemic injury and repair including myocardial, cerebral, and limb ischemia. We conclude with a perspective on the therapeutic opportunities and future challenges of copper biology in understanding the pathogenesis of ischemic vascular disease states.

Top Five Stories of the Cellular Landscape and Therapies of Atherosclerosis: Current Knowledge and Future Perspectives

Atherosclerosis (AS) is characterized by impairment and apoptosis of endothelial cells, continuous systemic and focal inflammation and dysfunction of vascular smooth muscle cells, which is documented as the traditional cellular paradigm. However, the mechanisms appear much more complicated than we thought since a bulk of studies on efferocytosis, transdifferentiation and novel cell death forms such as ferroptosis, pyroptosis, and extracellular trap were reported. Discovery of novel pathological cellular landscapes provides a large number of therapeutic targets. On the other side, the unsatisfactory therapeutic effects of current treatment with lipid-lowering drugs as the cornerstone also restricts the efforts to reduce global AS burden. Stem cell- or nanoparticle-based strategies spurred a lot of attention due to the attractive therapeutic effects and minimized adverse effects. Given the complexity of pathological changes of AS, attempts to develop an almighty medicine based on single mechanisms could be theoretically challenging. In this review, the top stories in the cellular landscapes during the initiation and progression of AS and the therapies were summarized in an integrated perspective to facilitate efforts to develop a multi-targets strategy and fill the gap between mechanism research and clinical translation. The future challenges and improvements were also discussed.

The molecular mechanisms of cuproptosis and its relevance to cardiovascular disease

Recently, cuproptosis has been demonstrated to be a new non-apototic cell death mode that is characterized by copper dependence and the regulation of mitochondrial respiration. Cuproptosis is distinct from known cell death modes such as apoptosis, necrosis, pyroptosis, or ferroptosis. Excessive copper induces cuproptosis by promoting protein toxic stress reactions via copper-dependent anomalous oligomerization of lipoylation proteins in the tricarboxylic acid (TCA) cycle and reducing iron-sulfur cluster protein levels. Ferredoxin1 (FDX1) promotes dihydrolipoyl transacetylase (DLAT) lipoacylation and abates iron-sulfur cluster proteins by reducing Cu²⁺ to Cu⁺, inducing cell death. Copper homeostasis depends on the copper transporter, and disturbances to this homeostasis cause cuproptosis. Recent evidence has shown that cuproptosis plays a significant role in the occurrence and development of many cardiovascular diseases, such as myocardial ischemia/reperfusion (I/R) injury, heart failure, atherosclerosis, and arrhythmias. Copper chelators, such as ammonium tetrathiomolybdate(VI) and DL-Penicillamine, may ease the above cardiovascular diseases by inhibiting the cuproptosis pathway. Oxidative phosphorylation inhibitors may inhibit cuproptosis by inhibiting protein stress response. In conclusion, cuproptosis plays an essential role in cardiovascular disease pathogenesis. Inhibition of cardiovascular cuproptosis is expected to become a potential treatment. Here, we will thoroughly review the molecular mechanisms involved in cuproptosis and its significance in cardiovascular disease.

Copper homeostasis and copper-induced cell death in the pathogenesis of cardiovascular disease and therapeutic strategies

Copper is a vital mineral, and an optimal amount of copper is required to support normal physiologic processes in various systems, including the cardiovascular system. Over the past few decades, copper-induced cell death, named cuproptosis, has become increasingly recognized as an important process mediating the pathogenesis and progression of cardiovascular disease (CVD), including atherosclerosis, stroke, ischemia-reperfusion injury, and heart failure. Therefore, an in-depth understanding of the regulatory mechanisms of cuproptosis in CVD may be useful for improving CVD management. Here, we review the relationship between copper homeostasis and cuproptosis-related pathways in CVD, as well as therapeutic strategies addressing copper-induced cell death in CVD.

The Role of Copper Homeostasis in Brain Disease

In the human body, copper is an important trace element and is a cofactor for several important enzymes involved in energy production, iron metabolism, neuropeptide activation, connective tissue synthesis, and neurotransmitter synthesis. Copper is also necessary for cellular processes, such as the regulation of intracellular signal transduction, catecholamine balance, myelination of neurons, and efficient synaptic transmission in the central nervous system. Copper is naturally present in some foods and is available as a dietary supplement. Only small amounts of copper are typically stored in the body and a large amount of copper is excreted through bile and urine. Given the critical role of copper in a breadth of cellular processes, local concentrations of copper and the cellular distribution of copper transporter proteins in the brain are important to maintain the steady state of the internal environment. The dysfunction of copper metabolism or regulatory pathways results in an imbalance in copper homeostasis in the brain, which can lead to a myriad of acute and chronic pathological effects on neurological function. It suggests a unique mechanism linking copper homeostasis and neuronal activation within the central nervous system. This article explores the relationship between impaired copper homeostasis and neuropathophysiological progress in brain diseases.

Multiomics Data Integration Identifies New Molecular Signatures for Abdominal Aortic Aneurysm and Aortic Occlusive Disease: Implications for Early Diagnosis, Prognosis, and Therapeutic Targets

Cardiovascular disease (CVD) is the leading cause of death among adults in developed countries. Among CVDs, abdominal aortic aneurysm (AAA) and aortic occlusive disease (AOD) are of great public health importance because of the high mortality rate in the elderly population. Despite significant molecular insights into AAA and AOD, the molecular mechanisms of these diseases remain unclear, and the current lack of robust diagnostic and prognostic biomarkers requires novel approaches to biomarker discovery and molecular targeting. In this study, we performed a comparative analysis of genome-wide expression data from patients with large AAA (n = 29), small AAA (n = 20), AOD (n = 9), and controls (n = 10). Specifically, we identified the differentially expressed genes and associated molecular pathways and biological processes (BPs) in each disease. Using a systems science approach, these data were linked to comprehensive human biological networks (i.e., protein-protein interaction, transcriptional regulatory, and metabolic networks) to identify molecular signatures of the salient mechanisms of AAA and AOD. Significant alterations in lipid metabolism and valine, leucine, and isoleucine metabolism, as well as neurodegenerative diseases and sex differences in the pathogenesis of AAA and AOD were identified. In the presence of aneurysm, size-dependent changes in lipid metabolism were observed. In addition, molecules and signaling pathways related to immunity, inflammation, infectious disease, and oxidative phosphorylation were identified in common. The results of the comparative and integrative analyzes revealed important clues to disease mechanisms and reporter molecules at various levels that warrant future development as potential prognostic biomarkers and putative therapeutic targets.

T lymphocyte-derived extracellular vesicles aggravate abdominal aortic aneurysm by promoting macrophage lipid peroxidation and migration via pyruvate kinase muscle isozyme 2

T lymphocyte and macrophage infiltration in the aortic wall is critical for abdominal aortic aneurysm (AAA). However, how T lymphocytes interact with macrophages in the pathogenesis of AAA remains largely uncharacterized. In an elastase-induced murine AAA model, we first found that the expression of pyruvate kinase muscle isozyme 2 (PKM2), the last rate-limiting enzyme in glycolysis, was increased in infiltrated T lymphocytes of vascular lesions. T lymphocyte-specific PKM2 deficiency in mice (LckCrePKM2fl/fl) or intraperitoneal administration of the sphingomyelinase inhibitor GW4869 caused a significant attenuation of the elastase-increased aortic diameter, AAA incidence, elastic fiber disruption, matrix metalloproteinases (MMPs) expression, and macrophage infiltration in the vascular adventitia compared with those in PKM2fl/fl mice. Mechanistically, extracellular vesicles (EVs) derived from PKM2-activated T lymphocytes elevated macrophage iron accumulation, lipid peroxidation, and migration in vitro, while macrophages treated with EVs from PKM2-null T lymphocytes or pretreated with the lipid peroxidation inhibitors ferrostatin-1 (Fer-1), liproxstatin-1 (Lip-1), or the iron chelating agent deferoxamine mesylate (DFOM) reversed these effects. In vascular lesions of elastase-induced LckCrePKM2fl/fl mice with AAA, the oxidant system weakened, with downregulated 4-hydroxynonenal (4-HNE) levels and strengthened antioxidant defense systems with upregulated glutathione peroxidase 4 (GPX4) and cystine/glutamate antiporter solute carrier family 7 member 11 (Slc7a11) expressions in macrophages. High-throughput metabolomics showed that EVs derived from PKM2-activated T lymphocytes contained increased levels of polyunsaturated fatty acid (PUFA)-containing phospholipids, which may provide abundant substrates for lipid peroxidation in target macrophages. More importantly, upregulated T lymphocyte PKM2 expression was also found in clinical AAA subjects, and EVs isolated from AAA patient plasma enhanced macrophage iron accumulation, lipid peroxidation, and migration ex vivo. Therefore, from cell-cell crosstalk and metabolic perspectives, the present study shows that PKM2-activated T lymphocyte-derived EVs may drive AAA progression by promoting macrophage redox imbalance and migration, and targeting the T lymphocyte-EV-macrophage axis may be a potential strategy for early warning and treating AAA.

HDL cholesterol: A potential mediator of the association between serum levels of a mixture of metals and the risk of aortic dissection in a Chinese population

Aortic dissection (AD) is a severe cardiovascular disease with a high mortality rate. However, the associations between the serum levels of metals and the risk of AD remain unclear. One hundred twenty-seven patients with AD (type A and B) identified from 2017 to 2019 at the Second Affiliated Hospital of Nanjing Medical University were included; 183 controls that were also included. A logistic regression analysis was performed to determine the associations between serum levels of metals and the risk of AD. Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR) analyses were performed to explore the effects of mixtures of metals on the risk of AD. A linear regression analysis was performed to evaluate the relationships between the serum levels of metals and the white blood cells (WBCs) count and serum lipid levels and blood glucose. We conducted a mediation analysis to explore the contribution rates of WBC counts or serum lipid levels and blood glucose to the association between metal levels and the risk of AD. Exposure to serum levels of Cu (coefficient = 6.33; 95 % CI = 2.52, 10.14; p trend < 0.001) were significantly and positively associated with the risk of AD. In the WQS analysis, Cu (50.3 %), Ni (32.7 %) and Mo (17.1 %) contributed to the AD risk. In the BKMR analysis, Cu and Mo were shown to play important roles in the association with the AD risk. Moreover, serum concentrations of Cu were significantly and inversely associated with HDL-cholesterol levels. HDL-cholesterol levels mediated 7.42 % of the association between serum Cu levels and the prevalence of AD. Our study provided the first evidence that serum levels of mixtures of metals are associated with the AD risk in a Chinese population. Increased concentrations of metals, particularly Cu, may increase the risk of AD by reducing HDL-cholesterol levels.

Estimation of Selected Minerals in Aortic Aneurysms-Impaired Ratio of Zinc to Lead May Predispose?

The objective of this study was to estimate the content of copper, zinc, selenium, cadmium, and lead in the tissue of patients with aortic aneurysms. Molar ratio of Cu/Zn and antioxidant micronutrients to toxic elements was also calculated. A total of 108 patients: 47 with abdominal aortic aneurysm (AAA), 61 patients with thoracic aortic aneurysm (TAA), and a control group of 20 abdominal aortic (AA) and 20 thoracic aortic (TA) wall samples from the deceased were studied. The concentrations of mineral components in the tissue samples were determined by the AAS method. The average concentration of Cu in the aortic wall of patients with TAA was significantly lower than in the aortic wall samples of healthy people. The mean concentration of Zn in the aortic wall of patients with AAA and TAA was significantly lower than in the control group samples. Cu/Zn ratio was significantly higher in AAA patients than in control group which indicates a greater role of oxidative stress and inflammatory process in this type of aneurysm. The concentration of Se was significantly decreased in TAA patients compared with the control group; in turn, the concentration of Pb was increased in this group of patients. We observed significantly lower Cu/Pb ratio in TAA patients than in control group, whereas Zn/Pb ratio was significantly lower comparing with control samples in both types of aneurysms. In the examined aneurysms, we have shown the differences in concentrations of mineral components compared with the control tissues. The Zn concentration was decreased in both AAA and TAA samples. Impaired ratio of Zn to Pb may predispose to aortic aneurysms.

Association of Circulating and Aortic Zinc and Copper Levels with Clinical Abdominal Aortic Aneurysm: a Meta-analysis

It remains obscure whether circulating aortic zinc (Zn) and copper (Cu) levels are associated with the progress of human abdominal aortic aneurysms (AAA). Therefore, we conducted a meta-analysis to explore this relationship. A literature search on circulating and aortic zinc and copper levels and AAA patients was conducted using online databases including PubMed, Embase, and Cochrane up to March 20, 2019. To compare Zn and Cu concentrations in AAA patients with those in aortic occlusive disease (AOD) patients or healthy aorta donors or healthy blood donors, pooled weighted mean difference (WMD) and its 95% confidence interval (CI) were calculated. Subgroup analysis, sensitivity analysis, and meta-regression analysis were applied to explain the heterogeneity and evaluate the robustness of combined results. A total of 10 cross-sectional studies, including 252 cases and 304 controls, were used for meta-analysis. We found that circulating zinc and Zn/Cu ratio in AAA patients were significantly lower [WMD (95%CI): - 2.23 (- 4.10, - 0.36); - 0.18 (- 0.31, - 0.05), respectively] than those in non-AAA patients. Similarly, aneurysmal aorta had significantly lower zinc levels and Zn/Cu ratio [WMD (95%CI): - 9.22 (- 15.37, - 3.07); - 6.46 (- 10.14, - 2.77), respectively] than those in control group. No difference in circulating or aortic copper levels was noted between AAA patients and control group [WMD (95%CI): - 0.24 (- 2.09, 1.61); 0.30 (- 0.01, 0.61) , respectively]. Our meta-analysis suggests that zinc levels and Zn-Cu ratio, but not copper levels, may influence aneurysmal progress of AAA.

Iron deficiency promotes aortic medial degeneration via destructing cytoskeleton of vascular smooth muscle cells

BACKGROUND

Aortic dissection (AD) and aortic aneurysm (AA) are critical illnesses with an unclear pathogenetic mechanism that seriously threaten human life. Aortic medial degeneration (AMD) is the main pathological feature of AD and AA. Diseases of iron metabolism can cause a variety of physiological dysfunctions. In this study, we aimed to clarify the state of iron metabolism in patients with AD and AA, and to explore the effect of iron metabolism on AMD.

METHODS

A total of 200 patients with AD or AA, and 60 patients with hypertension were included in the study. Blood samples were drawn immediately when patients were admitted to the hospital. Aortic specimens from patients with Stanford type A AD were obtained at the time of surgery. The status of iron metabolism in the circulation and the aortic wall was analyzed. In addition, apolipoprotein E knockout mice were fed chow with a different iron content, and angiotensin II (Ang II) was used to induce AMD. Furthermore, transferrin receptor 1 knockout (TFR1-/-) mice were used to study the effects of iron deficiency (ID) on aortic development, to observe the effects of different iron metabolism status on the formation of AMD in mice, and to explore the cytoskeleton of vascular smooth muscle cells (VSMCs) under different iron metabolism.

RESULTS

Patients with AMD were iron deficient. ID is associated with the development of AMD in hypertensive patients. Iron-deficient feeding combined with Ang II pumping promoted the formation of AMD and significantly shortened the survival time of mice. ID significantly impaired the cytoskeleton of VSMCs.

CONCLUSIONS

Our results highlighted that ID was associated with the formation of AMD in patients with hypertension. In this study, we identified a novel mechanism behind VSMCs dysfunction that was induced by ID, thereby suggesting iron homeostasis as a future precaution in patients with hypertension based on its important role in the maintenance of VSMC function.

Sex-Specific Genetically Predicted Iron Status in relation to 12 Vascular Diseases: A Mendelian Randomization Study in the UK Biobank

Background

Iron overload has been implicated in the pathogenesis of varicose veins (VVs). However, the association of serum iron status with other vascular diseases (VDs) is not well understood, which might be a potential target for VD prevention. This study was aimed at investigating the causal associations between iron status and VDs using the Mendelian randomization (MR) method.

Methods

A two-sample MR was designed to investigate whether iron status was associated with VDs, based on iron data from a published genome-wide association study meta-analysis of 48,972 subjects of European descent and VD data obtained from the UK Biobank, including 361,194 British subjects (167,020 males and 194,174 females). We further explored whether there was sex difference in the associations between genetically predicted iron status and VDs.

Results

The results demonstrated that iron status had a significant causal effect on VVs of lower extremities (P < 0.001) and a potential effect on coronary atherosclerosis (P < 0.05 for serum iron, ferritin, and transferrin saturation, respectively), but not on other VDs. Furthermore, higher iron status exerted a detrimental effect on VVs of lower extremities in both genders (P < 0.05) and a protective effect on male patients with coronary atherosclerosis (P < 0.05 for serum iron, ferritin, and transferrin saturation, respectively).

Conclusions

This MR study provides robust evidence that higher iron status increases the risk of VVs of lower extremities, whereas it reduces the incidence of coronary atherosclerosis in the male population, which indicates that iron has divergent effects on vascular pathology.

Copper Transporter ATP7A (Copper-Transporting P-Type ATPase/Menkes ATPase) Limits Vascular Inflammation and Aortic Aneurysm Development: Role of MicroRNA-125b

OBJECTIVE

Copper (Cu) is essential micronutrient, and its dysregulation is implicated in aortic aneurysm (AA) development. The Cu exporter ATP7A (copper-transporting P-type ATPase/Menkes ATPase) delivers Cu via the Cu chaperone Atox1 (antioxidant 1) to secretory Cu enzymes, such as lysyl oxidase, and excludes excess Cu. Lysyl oxidase is shown to protect against AA formation. However, the role and mechanism of ATP7A in AA pathogenesis remain unknown. Approach and Results: Here, we show that Cu chelator markedly inhibited Ang II (angiotensin II)-induced abdominal AA (AAA) in which ATP7A expression was markedly downregulated. Transgenic ATP7A overexpression prevented Ang II-induced AAA formation. Conversely, Cu transport dysfunctional ATP7A^mut/+/ApoE^-/- mice exhibited robust AAA formation and dissection, excess aortic Cu accumulation as assessed by X-ray fluorescence microscopy, and reduced lysyl oxidase activity. In contrast, AAA formation was not observed in Atox1^-/-/ApoE^-/- mice, suggesting that decreased lysyl oxidase activity, which depends on both ATP7A and Atox1, was not sufficient to develop AAA. Bone marrow transplantation suggested importance of ATP7A in vascular cells, not bone marrow cells, in AAA development. MicroRNA (miR) array identified miR-125b as a highly upregulated miR in AAA from ATP7A^mut/+/ApoE^-/- mice. Furthermore, miR-125b target genes (histone methyltransferase Suv39h1 and the NF-κB negative regulator TNFAIP3 [tumor necrosis factor alpha induced protein 3]) were downregulated, which resulted in increased proinflammatory cytokine expression, aortic macrophage recruitment, MMP (matrix metalloproteinase)-2/9 activity, elastin fragmentation, and vascular smooth muscle cell loss in ATP7A^mut/+/ApoE^-/- mice and reversed by locked nucleic acid-anti-miR-125b infusion.

CONCLUSIONS

ATP7A downregulation/dysfunction promotes AAA formation via upregulating miR-125b, which augments proinflammatory signaling in a Cu-dependent manner. Thus, ATP7A is a potential therapeutic target for inflammatory vascular disease.

The comparison of zinc, copper and iron levels in serum, aorta and left internal mammarian artery tissues in coronary by-pass graft surgery patients

Trace elements are crucial for vital enzymatic reactions in all metabolic processes. Zinc (Zn) acts as a co-factor for many enzymes. Copper (Cu) and iron (Fe) have pro-atherogenic effects resulting in atherosclerosis. Aorta exposing high pulsatile pressure is sensitive for atherosclerosis because of its fast metabolism and poor nutrition by diffusion from vasa vasorum. We aimed to determine the relationship between serum Zn, Cu and Fe levels with aortic and left internal mammary artery (LIMA) tissues in 33 atherosclerotic individuals who inevitably underwent coronary artery by-pass graft (CBAG) surgery that is an end-point treatment for atherosclerosis. Trace elements in serum and tissues were measured using inductively coupled plasma-optical emission spectrophotometer. Pre-operative (Pre-op) serum Fe levels were statistically 46% higher than post-operative (Post-op) values (p = 0.009). Aortic Fe level was 49.8% higher than LIMA Fe (p = 0.0001). Our study points out the tendency of aortic tissue to atherosclerosis via pro- atherogenic effect of Fe. LIMA, being a potential graft for CBAG, is resistant to atherosclerosis with its intimal specialty of graft patency. In conclusion, serum Zn, Cu and Fe levels in atherosclerotic CBAG patients might be monitored to reveal minor alterations pre-operatively and post-operatively for ameliorating the treatment and life quality.

Copper transporters and copper chaperones: roles in cardiovascular physiology and disease

Copper (Cu) is an essential micronutrient but excess Cu is potentially toxic. Its important propensity to cycle between two oxidation states accounts for its frequent presence as a cofactor in many physiological processes through Cu-containing enzymes, including mitochondrial energy production (via cytochrome c-oxidase), protection against oxidative stress (via superoxide dismutase), and extracellular matrix stability (via lysyl oxidase). Since free Cu is potentially toxic, the bioavailability of intracellular Cu is tightly controlled by Cu transporters and Cu chaperones. Recent evidence reveals that these Cu transport systems play an essential role in the physiological responses of cardiovascular cells, including cell growth, migration, angiogenesis and wound repair. In response to growth factors, cytokines, and hypoxia, their expression, subcellular localization, and function are tightly regulated. Cu transport systems and their regulators have also been linked to various cardiovascular pathophysiologies such as hypertension, inflammation, atherosclerosis, diabetes, cardiac hypertrophy, and cardiomyopathy. A greater appreciation of the central importance of Cu transporters and Cu chaperones in cell signaling and gene expression in cardiovascular biology offers the possibility of identifying new therapeutic targets for cardiovascular disease.

Multidetector Computed Tomography Findings of Splenic Artery Aneurysms Associated With Liver Involvement in Wilson's Disease

PURPOSE

The purposed of this study was to examine the incidence and multidetector computed tomography (MDCT) findings of splenic artery aneurysms (SAAs) in patients with liver involvement related to Wilson's disease.

METHODS

Eighteen patients with clinically and/or pathologically proven Wilson's disease underwent triphasic MDCT. Arterial, portal, and equilibrium phase images were obtained. The analysis of the CT features included the presence and characteristics of the SAA, splenic artery (SA) diameter, the presence and size of the portosystemic collateral vessels, and spleen volume.

RESULTS

SAAs were detected in 11 patients (61.1%). Eight (72.7%) patients had multiple aneurysms. In 6 (54.5%) patients, the SAAs were located in the distal third of the SA and the intraparenchymal part of the SA. In 3 (27.3%) patients, the SAAs were located only in the distal third of the SA. In 1 (9.1%) patient, the aneurysms were located in the intermediate, distal third, and intraparenchymal part of the SA; in another (9.1%) patient, the aneurysms were located only in the intraparenchymal part of the SA. There were significant differences between the patients with SAA and those without SAA with respect to SA diameter, portosystemic collateral vessel diameter, and spleen volume (P = .007, P < .001, and P = .006, respectively).

CONCLUSIONS

The incidence of SAAs seems to be higher in patients with liver involvement related to Wilson's disease compared with patients with other causes of cirrhosis and portal hypertension. Large portosystemic collaterals, increased SA diameter, and spleen volume were significant factors for the presence of SAAs.

Association between diabetes and prevalence and growth rate of abdominal aortic aneurysms: A meta-analysis

BACKGROUND

Although the prevalence of abdominal aortic aneurysm (AAA) was lower in diabetes, the relationship between diabetes and AAA prevalence remains unclear. In this meta-analysis, we sought to clarify the effect of diabetes on prevalence and growth rate (GR) of AAA.

METHODS

We searched PubMed, Web of Science, Scopus and Cochrane databases. Articles reporting the AAA prevalence in diabetic patients and diabetic effects in GR of AAA were included.

RESULTS

Forty-nine studies on AAA prevalence in diabetics and thirteen studies on effect of diabetes in GR of AAA were included for meta-analysis. A strongly negative association was found between diabetes and AAA prevalence in population based screening (odds ratio [OR]adjusted: 0.66; 95% confidence interval [CI]: 0.58-0.75) and prospective studies (ORadjusted: 0.52; 95% CI: 0.43-0.63), but not in case-control studies (ORadjusted: 0.48; 95% CI: 0.20-1.15). Similar association was found in North American (ORadjusted: 0.62; 95% CI 0.54-0.71) and European (ORadjusted: 0.45; 95% CI 0.33-0.62) studies. The strongly negative association remained consistent after stratification by time of data collection (up to -1995 [ORadjusted: 0.65; 95% CI: 0.53-0.80], 1996-2005 [ORadjusted: 0.61; 95% CI: 0.47-0.78], 2006 and beyond- [ORadjusted: 0.67; 95% CI: 0.53-0.85], and data collection time >10years [ORadjusted: OR: 0.44; 95% CI 0.34-0.58]). The annual mean diabetic effect on AAA GR was -0.60mm/y (95% CI: -0.76 - -0.43).

CONCLUSION

Diabetes was strongly and negatively associated with AAA prevalence regardless of study type, geography and time of data collection, as well as negative impact of diabetes on GR of AAA.

Association of diabetes mellitus with presence, expansion, and rupture of abdominal aortic aneurysm: "Curiouser and curiouser!" cried ALICE

Both coronary artery and peripheral artery disease are representative atherosclerotic diseases that are positively associated with presence of abdominal aortic aneurysm (AAA). Diabetes mellitus, which is one of major risk factors of coronary artery and peripheral artery diseases, however, has been curiously suggested to be negatively associated with AAA, despite the positive associations of coronary artery and peripheral artery diseases with presence of AAA. In the present article, we overviewed epidemiologic evidence (meta-analyses) regarding the associations of diabetes mellitus with presence, expansion, and rupture of AAA through a systematic literature search. Our exhaustive search identified seven meta-analyses. Main results of almost all meta-analyses (except for the two earliest ones) apparently found that diabetes mellitus is negatively associated with presence, expansion, and rupture of AAA.

Systemic oxidant/antioxidant balance in human abdominal aortic aneurysm

The aim of this study was to evaluate the oxidant-antioxidant balance in patients with abdominal aortic aneurysms (AAA). Forty-two consecutive patients with AAA and 46 control subjects were included. Total oxidant status (TOS) and total antioxidant status (TAS) levels were measured and the oxidative stress index (OSI) value determined. Serum TOS and OSI values in patients with AAA were higher than those in the controls (p<0.001, p<0.001, respectively). There was a positive correlation between abdominal aortic diameters, serum TOS levels (r=0.592, p<0.001) and OSI values (r=0.598, p<0.001). A cut-off value of 17.68 µmol H2O2 equivalent/L for TOS was associated with 86% sensitivity and 83% specificity and a cut-off value of 1.77 for OSI was associated with 86% sensitivity and 81% specificity for predicting AAA. Systemic oxidative imbalance develops in patients with AAA, particularly as a result of an increase in TOS.

Diabetes and abdominal aortic aneurysms

Epidemiologic evidence suggests that patients with diabetes may have a lower incidence of abdominal aortic aneurysm (AAA); however, the link between diabetes and AAA development and expansion is unclear. The aim of this review is to analyze updated evidence to better understand the impact of diabetes on prevalence, incidence, clinical outcome, and expansion rate of AAA. A systematic review of literature published in the last 20 years using the PubMed and Cochrane databases was undertaken. Studies reporting appropriate data were identified and a meta-analysis performed using the generic inverse variance method. Sixty-four studies were identified. Methodological quality was "fair" in 16 and "good" in 44 studies according to a formal assessment checklist (Newcastle-Ottawa). In 17 large population prevalence studies there was a significant inverse association between diabetes and AAA: pooled odds ratio (OR) 0.80; 95% confidence intervals (CI) 0.70-0.90 (p = .0009). An inverse association was also confirmed by pooled analysis of data from smaller prevalence studies on selected populations (OR 0.59; 95% CI 0.35-0.99; p = .05), while no significant results were provided by case-control studies. A significant lower pooled incidence of new AAA in diabetics was found over six prospective studies: OR 0.54; 95% CI 0.31-0.91; p = .03. Diabetic patients showed increased operative (30-day/in-hospital) mortality after AAA repair: pooled OR 1.26; 95% CI 1.10-1.44; p = .0008. The increased operative risk was more evident in studies with 30-day assessment. In the long-term, diabetics showed lower survival rates at 2-5 years, while there was general evidence of lower growth rates of small AAA in patients with diabetes compared to non-diabetics. There is currently evidence to support an inverse relationship between diabetes and AAA development and enlargement, even though fair methodological quality or unclear risk of bias in many available studies decreases the strength of the finding. At the same time, operative and long-term survival is lower in diabetic patients, suggesting increased cardiovascular burden. The higher mortality in diabetics raises the question as to whether AAA repair should be individualized in selected diabetic populations at higher AAA rupture risk.

Intraluminal thrombus thickness is not related to lower concentrations of trace elements in the wall of infrarenal abdominal aortic aneurysms

BACKGROUND

Intraluminal thrombus (ILT) formation plays a significant role in the progression of infrarenal abdominal aortic aneurysms (AAA). Potentially, as ILT thickness increases the availability of trace elements in the aneurysm wall could decrease thereby leading to oxidative stress and intensifying pro-inflammatory cytokine generation.

AIM

To determine if thrombus thickness is related to the concentration of trace elements in the wall of infrarenal AAA.

PATIENTS AND METHODS

The concentrations of trace elements in the wall of the aneurysm sack and ILT obtained from 19 consecutive patients during surgery for infrarenal AAA were determined using emission spectrometry.

RESULTS

The concentrations of magnesium, zinc, manganese, and lead in the wall of AAA were significantly greater than in the ILT. Only the concentration of copper was lower in the AAA wall compared with the thrombus. The concentration of calcium, phosphorus, zinc, lead, copper, and magnesium increased with ILT thickness. The concentrations of no other trace elements in the wall of AAA were found to be related to the ILT thickness.

CONCLUSIONS

Intraluminal thrombus thickness is not associated with a lower concentration of trace elements in the wall of the infrarenal AAA. Thus, the intraluminal thrombus participates in the progression of AAA by mechanisms independent of trace element supply to the wall of the aneurysm sack.

Aortic aneurysm disease vs. aortic occlusive disease: differences in outcome and intensive care resource utilisation after elective surgery: an observational study

CONTEXT

Abdominal aortic surgery is a high-risk procedure, with aortic aneurysm and aortic occlusive diseases being the main indications. These groups are often regarded as having equal perioperative risk profiles. Previous reports suggest that the haemodynamic and inflammatory response to aortic clamping is more pronounced in patients with aortic aneurysm disease, which may affect outcome.

OBJECTIVES

The aim of this observational cohort study was to evaluate outcome after open elective abdominal aortic surgery, hypothesising a higher 30-day mortality, a higher incidence of postoperative organ dysfunction and a longer length of stay in patients with aortic aneurysm compared with aortic occlusive disease.

DESIGN

Cohort observational study based on prospective registrations from national databases.

SETTING

Eight Danish hospitals, including four university and four non-university centres, from 1 January 2007 to 1 March 2010.

PATIENTS

One thousand two hundred and ninety-three patients scheduled for primary open elective, aortoiliac bypass or aortofemoral bypass procedures or abdominal aortic aneurysm repair.

MAIN OUTCOME MEASURES

Mechanical ventilation, acute dialysis, use of vasopressors or inotropes, ICU stay more than 24 h, hospital length of stay and mortality.

RESULTS

Compared with aortic occlusive disease, more patients with aortic aneurysm disease had ICU stays more than 24 h (62 vs. 45%, P < 0.001) and more often needed acute dialysis or ventilatory support (17 vs. 11%, P = 0.04). No difference was found in hospital length of stay, 30-day mortality or overall risk of death. Mortality after 1 year was higher in patients with aortic aneurysm disease (8 vs. 4.7%, P = 0.04).

CONCLUSION

Patients with abdominal aortic aneurysms were at higher risk of developing postoperative organ dysfunction and required more ICU resources than patients with occlusive disease, despite no differences in hospital length of stay or 30-day mortality. Distinguishing between these two diseases may be useful in planning and distribution of ICU resources and for in future studies.

On the potential increase of the oxidative stress status in patients with abdominal aortic aneurysm

BACKGROUND

Abdominal aortic aneurysm (AAA) is a major cause of preventable deaths in older patients. Oxidative stress has been suggested to play a key role in the pathogenesis of AAA. However, only few studies have been conducted to evaluate the blood oxidative stress status of AAA patients.

METHODS AND RESULTS

Twenty seven AAA patients (mean age of 70 years) divided into two groups according to AAA size (≤ 50 or > 50 mm) were compared with an age-matched group of 18 healthy subjects. Antioxidants (vitamins C and E, β-carotene, glutathione, thiols, and ubiquinone), trace elements (selenium, copper, zinc, and copper/zinc ratio) and markers of oxidative damage to lipids (lipid peroxides, antibodies against oxidized patients, and isoprostanes) were measured in each subject. The comparison of the three groups by ordinal logistic regression showed a significant decrease of the plasma levels of vitamin C (P = 0.011), α-tocopherol (P = 0.016) but not when corrected for cholesterol values, β-carotene (P = 0.0096), ubiquinone (P = 0.014), zinc (P = 0.0035), and of selenium (P = 0.0038), as AAA size increased. By contrast, specific markers of lipid peroxidation such as the Cu/Zn ratio (P = 0.046) and to a lesser extent isoprostanes (P = 0.052) increased.

CONCLUSION

The present study emphasizes the potential role of the oxidative stress in AAA disease and suggests that an antioxidant therapy could be of interest to delay AAA progression.

The relationship between serum levels of Zn and Cu and severity of coronary atherosclerosis

The essential trace elements play important roles in the maintainance of the normal structure and physiology of cells. Several research groups have demonstrated that they also play important roles in states of cardiovascular diseases. Our aim is to investigate whether there is a relationship between trace elements (Zn and Cu) and the degree of atherosclerosis. The sample consisted of 67 patients with coronary artery disease and 26 clinically healthy individuals. Ninety-three subjects were separated into four groups according to their Gensini scores, the number of diseased vessels, the presence of acute coronary syndrome, and ejection fraction. Each group was divided into three subgroups, and serum zinc and copper levels were measured for each individual. The serum levels of zinc and copper were found to be significantly lower in patients with atherosclerosis than in the control group, but there were no significant differences in the serum levels of Cu and Zn between severe atherosclerosis and mild atherosclerosis. In Spearman's rank correlation, the zinc and copper levels were correlated with the Gensini score and the number of diseased vessels. The present study revealed a relationship between the serum levels of zinc and copper and atherosclerosis, but not between these levels and the severity of the disease.

Pathophysiology and epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are found in up to 8% of men aged >65 years, yet usually remain asymptomatic until they rupture. Rupture of an AAA and its associated catastrophic physiological insult carries overall mortality in excess of 80%, and 2% of all deaths are AAA-related. Pathologically, AAAs are associated with inflammation, smooth muscle cell apoptosis, and matrix degradation. Once thought to be a consequence of advanced atherosclerosis, accruing evidence indicates that AAAs are a focal representation of a systemic disease of the vasculature. Risk factors for AAAs include increasing age, male sex, smoking, and low HDL-cholesterol levels. Familial associations exist and although susceptibility genes have been described on the basis of candidate-gene studies, robust genetic studies have failed to discover causative gene mutations. The surgical management of AAAs has been revolutionized by minimally invasive endovascular repair. Ongoing randomized trials will establish whether endovascular repair confers a survival advantage over open surgery for patients with a ruptured AAA. In many countries, centralization of vascular surgical services has largely been driven by the improved outcomes of elective aneurysm surgery in specialized centers, the widespread adoption of endovascular techniques, and the introduction of screening programs.