The cardio-ankle vascular index and ankle-brachial index in young russians

Polymorphism of SERF2, the gene encoding a heat-resistant obscure (Hero) protein with chaperone activity, is a novel link in ischemic stroke

Background

Ischemic stroke (IS) is one of the most serious cardiovascular events associated with high risk of death or disability. The growing body of evidence highlights molecular chaperones as especially important players in the pathogenesis of the disease. Since six small proteins called "Hero" have been recently identified as a novel class of chaperones we aimed to evaluate whether SNP rs4644832 in SERF2 gene encoding the member of Hero-proteins, is associated with the risk of IS.

Methods

A total of 1929 unrelated Russians (861 patients with IS and 1068 healthy individuals) from Central Russia were recruited into the study. Genotyping was done using a probe-based PCR approach. Statistical analysis was carried out in the whole group and stratified by age, gender and smoking status.

Results

Analysis of the link between rs4644832 SERF2 and IS showed that G allele is the risk factor of IS only in females (OR=1.29, 95%CI 1.02-1.64, Padj=0.035). In addition, the analysis of associations of rs4644832 SERF2 and IS depending on the smoking status revealed that this genetic variant is associated with an increased risk of IS exclusively in non-smoking individuals (OR=1.26, 95%CI 1.01-1.56, P = 0.041).

Discussion

Sex- and smoking interactions between rs4644832 polymorphism and IS may be related to the impact of tobacco components metabolism and sex hormones on SERF2 expression.

Conclusion

The present study reveals the novel genetic association between rs4644832 polymorphism and the risk of IS suggesting that SERF2, the part of the protein quality control system, contributes to the pathogenesis of the disease.

Association between HSPA8 Gene Variants and Ischemic Stroke: A Pilot Study Providing Additional Evidence for the Role of Heat Shock Proteins in Disease Pathogenesis

HSPA8 is involved in many stroke-associated cellular processes, playing a pivotal role in the protein quality control system. Here we report the results of the pilot study aimed at determining whether HSPA8 SNPs are linked to the risk of ischemic stroke (IS). DNA samples from 2139 Russians (888 IS patients and 1251 healthy controls) were genotyped for tagSNPs (rs1461496, rs10892958, and rs1136141) in the HSPA8 gene using probe-based PCR. SNP rs10892958 of HSPA8 was associated with an increased risk (risk allele G) of IS in smokers (OR = 1.37; 95% CI = 1.07-1.77; p = 0.01) and patients with low fruit and vegetable consumption (OR = 1.36; 95% CI = 1.14-1.63; p = 0.002). SNP rs1136141 of HSPA8 was also associated with an increased risk of IS (risk allele A) exclusively in smokers (OR = 1.68; 95% CI = 1.23-2.28; p = 0.0007) and in patients with a low fruit and vegetable intake (OR = 1.29; 95% CI = 1.05-1.60; p = 0.04). Sex-stratified analysis revealed an association of rs10892958 HSPA8 with an increased risk of IS in males (risk allele G; OR = 1.30; 95% CI = 1.05-1.61; p = 0.01). Thus, SNPs rs10892958 and rs1136141 in the HSPA8 gene represent novel genetic markers of IS.

Assessment of Arterial Stiffness with Cardio-Ankle Vascular Index in Patients with Mitral Annular Calcification

Objective

Arterial stiffness is related to arteriolosclerotic diseases and is a marker of adverse cardiovascular events. Mitral annular calcification (MAC) is progressive calcium deposition on the posterior and inferior mitral annulus and is associated with atherosclerotic cardiovascular diseases. Cardio-ankle vascular index (CAVI) is a measurement technique used to estimate the degree of arterial stiffness without effect from blood pressure. The aim of this study is to research arterial stiffness using CAVI in patients with MAC.

Materials and Methods

The study was cross-sectional and observational and included 98 patients with MAC confirmed by echocardiography who referred to the cardiology clinics and met study inclusion criteria and 38 controls without MAC. CAVI measurements were obtained by using the Vascular Screening System VaSera VS-1000 (Fukuda Denshi, Tokyo, Japan) device.

Results

The two groups were similar in terms of demographic characteristics, including age, sex, hypertension, coronary artery disease, body surface area, and smoking (P > .05). Left atrial volume index was significantly higher in patients with MAC compared with the control group (P < .001). Right arm CAVI, left arm CAVI, and mean CAVI were significantly higher in the MAC group than the control group (P = .037, P = .005, and P = .014, respectively) and increased with MAC severity. There was a significant positive correlation between mean CAVI and MAC grade (r = 0.278, P = .001). Also, when ankle-brachial index (ABI) was measured with CAVI, left and right extremity ABI values were significantly lower in patients with MAC (P = .017 and P = .005, respectively).

Conclusion

CAVI increased in all patients with MAC and associated with increasing grade of calcification.

STUDY OF ANTIATHEROSCLEROTIC AND ENDOTHELIOPROTECTIVE ACTIVITY OF PEPTIDE AGONISTS OF EPOR/CD131 HETERORECEPTOR

Introduction. The drugs affecting a mitochondrial dysfunction, oxidative stresses, apoptosis and inflammation of the vascular wall, have a high potential for the prevention and treatment of atherosclerotic lesions. In this regard, the use of EPOR/CD131 heteroreceptor agonists which have a similar spectrum of pharmacological effects, is one of the promising strategies in the treatment of cardiovascular diseases.

Materials and Methods. The study was carried out on 68 C57Bl/6J male mice. Atherosclerosis was simulated in transgenic animals with an endotheliospecific knockdown of the Polg gene by simulating a balloon injury and keeping on a Western diet. Then, the studied drugs were injected once every 3 days at the dose of 20 μg/kg for 27 days. On the 28-th day, the animals were euthanized and the area of atherosclerotic plaques was assessed. The gene expression associated with the processes of inflammation, antioxidant protection, apoptosis, and angiogenesis was also determined in the aortic tissues. In addition, the endothelium protective effect of peptides on primary cultures of endothelial cells of wild and transgenic Polg-D257A mice was studied.

Results. No statistically significant effect of drugs on the area of lipid infiltration have been found. However, the studied peptides have significantly reduced the expression of proinflammatory genes (iNos, Icam1, Vcam1, Sele, Il6, Tnfa), the genes associated with angiogenesis (Vegfa, Kdr, and Hif1a), the expression of proapoptic factors; they decreased the Bax/Bcl-2 ratio by more than 1.5 times. In addition, when supplemented with H2 O2  in vitro, peptides dose-dependently increased endothelial cell survival.

Conclusion. The erythropoietin-based peptides can be used to improve the functional state of the vascular wall against the background of atherosclerotic lesions and have a depressing effect on pathobiological processes associated with a mitochondrial dysfunction. In addition, the studied peptides have a significant endothelial protective effect in the induction of oxidative stress in vitro.

[Possibilities of application of cardio-ankle vascular index in patients with cerebrovascular diseases]

This publication focuses on the feasibility of using the cardio-ankle vascular index (CAVI) in patients with cerebrovascular diseases. The authors consider the pathological conditions and risk factors of stroke associated with increased arterial stiffness, methods for its assessment, the advantages of using CAVI, the experience of using CAVI in patients with cardiovascular diseases, in particular, in neurological patients. The complexity of the application of CAVI in the Russian population, promising directions for determining the index in neurology as well as the importance of CAVI borderline indicators are shown. It is emphasized that stroke patients should be screened with a mandatory study of CAVI.

Arterial Stiffness Assessed by Cardio-Ankle Vascular Index

Arterial stiffness is an age-related disorder. In the medial layer of arteries, mechanical fracture due to fatigue failure for the pulsatile wall strain causes medial degeneration vascular remodeling. The alteration of extracellular matrix composition and arterial geometry result in structural arterial stiffness. Calcium deposition and other factors such as advanced glycation end product-mediated collagen cross-linking aggravate the structural arterial stiffness. On the other hand, endothelial dysfunction is a cause of arterial stiffness. The biological molecular mechanisms relating to aging are known to involve the progression of arterial stiffness. Arterial stiffness further applies stress on large arteries and also microcirculation. Therefore, it is closely related to adverse outcomes in cardiovascular and cerebrovascular system. Cardio-ankle vascular index (CAVI) is a promising diagnostic tool for evaluating arterial stiffness. The principle is based on stiffness parameter β, which is an index intended to assess the distensibility of carotid artery. Stiffness parameter β is a two-dimensional technique obtained from changes of arterial diameter by pulse in one section. CAVI applied the stiffness parameter β to all of the arterial segments between heart and ankle using pulse wave velocity. CAVI has been commercially available for a decade and the clinical data of its effectiveness has accumulated. The characteristics of CAVI differ from other physiological tests of arterial stiffness due to the independency from blood pressure at the time of examination. This review describes the pathophysiology of arterial stiffness and CAVI. Molecular mechanisms will also be covered.

Large artery stiffness according to different assessment methods in adult population of St.Petersburg

OBJECTIVE

The aim of the present study was to assess the prevalence of increased arterial stiffness by different diagnostic methods and its association with cardiovascular risk in Russian population-based cohort.

DESIGN AND METHODS

In terms of Russian epidemiological study ESSE-RF a random selection of 452 apparently healthy Saint-Petersburg inhabitants aged 25-65 years was performed. Fasting lipids, glucose and blood pressure measurements were performed. We used 3 diagnostic methods of arterial stiffness assessment: pulse wave velocity by applanation tonometry (SphygmoCor - PWV-S) and pulse wave velocity by volumetric sphygmography (VaSera - PWV-V), and cardio-ankle vascular index (CAVI) by VaSera.

RESULTS

341 (75,4%) had normal parameters of arterial stiffness assessed by all methods. Spearmen's coefficient of correlation and "kappa" coefficient for PWV-S and CAVI were 0,74 and 0,04, for PWV-S and PWV-V - 0,10 and 0,06, for CAVI and PWV-V - 0,28 and 0,03, respectively. There was a significant correlation between cardiovascular risk (defined by SCORE) and PWV-S (r = 0,38, p < 0,001) and a non-significant trend of increasing CAVI along with cardiovascular risk (r = 0,35, p = 0,14).

CONCLUSIONS

Different methods of arterial stiffness assessment showed a weak correlation with each other. Carotid-femoral pulse wave velocity detected by applanation tonometry is associated with high cardiovascular risk score and might be considered as better additional risk marker for cardiovascular risk stratification.

Association of matrix metalloproteinase 3 and γ-glutamyltransferase 1 gene polymorphisms with the cardio-ankle vascular index in young Russians

Specific gene polymorphisms are known to be associated with a different arterial physiology in the younger generation. The present study found that young Russians with the matrix metalloproteinase 3 6A/6A and γ-glutamyltransferase 1AA genotypes have lower levels of the cardio-ankle vascular index - a recent measure of arterial stiffness. This observation may serve as an additional tool for cardiovascular disease prevention in the young population.

Vascular Function in Alzheimer's Disease and Vascular Dementia

We investigated vascular functioning in patients with a clinical and radiological diagnosis of either Alzheimer's disease (AD) or vascular dementia (VaD) and examined a possible relationship between vascular function and cognitive status. Twenty-seven patients with AD, 23 patients with VaD, and 26 healthy control patients underwent measurements of flow-mediated dilation (FMD), ankle-brachial index (ABI), cardioankle vascular index (CAVI), and intima-media thickness (IMT). The FMD was significantly lower in patients with AD or VaD compared to controls. There were no significant differences in ABI, CAVI, or IMT among the 3 groups. A significant correlation was found between Mini-Mental State Examination (MMSE) scores and FMD. Furthermore, a multiple regression analysis revealed that FMD was significantly predicted by MMSE scores. These results suggest that endothelial involvement plays a role in AD pathogenesis, and FMD may be more sensitive than other surrogate methods (ABI, CAVI, and IMT) for detecting early-stage atherosclerosis and/or cognitive decline.

Antioxidant-related gene polymorphisms associated with the cardio-ankle vascular index in young Russians

The cardio-ankle vascular index is a measure of arterial stiffness, whereas oxidative stress underlies arterial pathology. This study aimed to investigate the association between the cardio-ankle vascular index and antioxidant-related gene polymorphisms in young Russians. A total of 89 patients (mean age, 21.6 years) were examined by the cardio-ankle vascular index and for 15 gene polymorphisms related to antioxidant enzymes including FMO3 (flavin-containing monooxygenase 3), GPX1 (glutathione peroxidase 1), and GPX4 (glutathione peroxidase 4). A higher cardio-ankle vascular index level was detected in carriers with the KK-genotype of FMO3 polymorphism rs2266782 than in those without (mean levels: 6.2 versus 5.6, respectively, p<0.05). Similarly, a higher cardio-ankle vascular index level was seen in carriers with the CC-genotype of GPX4 polymorphism rs713041 than in those without (6.0 versus 5.5, respectively, p<0.05). We did not observe significant associations between the cardio-ankle vascular index levels and the other gene polymorphisms. Although carriers with the LL-genotype of GPX1 polymorphism rs1050450 showed a higher diastolic blood pressure level than those without, the polymorphism did not affect the cardio-ankle vascular index level. This study showed a significant association between rs2266782 and rs713041 polymorphisms and arterial stiffness, as measured by the cardio-ankle vascular index, in young Russians. The pathways utilised by antioxidant enzymes may be responsible for early arterial stiffening in the Russian population.

Lipoprotein(a) and Arterial Stiffness Parameters

BACKGROUND

Circulating lipoprotein(a) [Lp(a)] and arterial stiffness are markers associated with the atherosclerotic processes. With regard to cardiovascular outcomes, the relationship between Lp(a) and arterial stiffness has not been sufficiently summarized. The present review focuses on the existing association between Lp(a) and arterial stiffness parameters.

SUMMARY

This review included human clinical studies that were published between 1980 and 2015. The metrics of arterial stiffness parameters, 'pulse wave velocity' (PWV) and 'cardio-ankle vascular index' (CAVI), were used for this search, which yielded only 4 cross-sectional studies on this topic. Of these 4 studies, 3 reports were based on the use of PWV, while 1 study was based on the use of CAVI. Three studies (including the study using CAVI) reported that high Lp(a) levels were positively associated with arterial stiffness.

CONCLUSION

The present review indicates a positive association between Lp(a) and arterial stiffness, as assessed by PWV and CAVI. To definitively establish these findings, there is a need for further prospective outcome studies that simultaneously measure Lp(a) and the oxidative form of Lp(a) (as a pathological marker) as well as PWV and CAVI.