Arterial stiffness predicts cardiovascular death independent of arterial thickness in a cohort of hemodialysis patients

Diabetes mellitus type 2 does not influence carotid stiffness in patients on maintenance hemodialysis

Patients on maintenance hemodialysis are a group with high cardiovascular risk, characterized by high arterial stiffness, which is considered a novel cardiovascular risk factor. Diabetes mellitus is both one of the leading causes of end-stage renal disease and a determinant of poor outcome in this group. The aim of the study was to examine carotid stiffness with high resolution echo-tracking in order to assess the influence of diabetes mellitus on arterial stiffness in this group.

Ninety patients (47 F; 43 M) with end-stage renal disease on maintenance hemodialysis were divided into two subgroups: diabetic and nondiabetic (37 and 53 patients respectively). They underwent clinical examination, laboratory tests, and ultrasonographic carotid stiffness assessment both before and after hemodialysis. Local arterial stiffness parameters β, Ep, AC, and PWVβ were calculated. Patient survival was assessed after a 58-month-long follow-up. During the 58-month period 25 of these diabetic patients died, as did 18 non-diabetic patients. Diabetes mellitus was a risk factor for overall mortality among the group of hemodialysed patients. Patients who died from non-cardiovascular causes significantly more often suffered from diabetes mellitus than survivors. There were no statistically significant differences in local arterial stiffness between the groups.

Local arterial stiffness in hemodialysed patients, assessed with high resolution echo-tracking, is not influenced by the presence of diabetes.

Klotho as a biomarker of subclinical atherosclerosis in patients with moderate to severe chronic kidney disease

Chronic kidney disease (CKD) has been associated with a higher risk of cardiovascular disease (CVD). CKD patients present a decrease in the levels of the protein Klotho that accompanies the decrease in kidney function. This protein has been related to protective effects against CVD. However, it is unclear whether circulating Klotho, and its expression in peripheral blood cells (PBCs) are also associated with subclinical atherosclerosis in CKD. The present study aimed to study the relationship between Klotho and subclinical atherosclerosis in a population of patients with moderate to severe CKD. We determined the serum levels and gene expression in PBCs levels of Klotho and three inflammatory cytokines in 103 patients with CKD and investigated their relationship with two surrogate markers of subclinical atherosclerotis: ankle-brachial index (ABI) and carotid intima-media thickness (CIMT). Patients with subclinical atherosclerosis presented lower serum and PBCs expression levels of Klotho. Both variables were associated with the presence of subclinical atherosclerosis, being directly related with ABI and inversely with CIMT (P < 0.0001 for both). Multiple regression analysis demonstrated that both variables were significant determinants for ABI (adjusted R² = 0.511, P < 0.0001) and CIMT (adjusted R² = 0.445, P < 0.0001), independently of traditional and emergent cardiovascular risk factors. Moreover, both constituted protective factors against subclinical atherosclerosis [OR: 0.993 (P = 0.002) and 0.231 (P = 0.025), respectively]. Receiver operating characteristic analysis pointed to the utility of serum Klotho (area under the curve [AUC]: 0.817, 95% CI: 0.736-0.898, P < 0.001) and its gene expression in PBCs (AUC: 0.742, 95% CI: 0.647-0.836, P < 0.001) to distinguish subclinical atherosclerosis. The reductions in serum and PBCs expression levels of Klotho in CKD patients are independently associated with the presence of for subclinical atherosclerosis. Further research exploring whether therapeutic approaches to maintain or elevate Klotho could reduce the impact of CVD in CKD patients is warranted.

Protocol for the WARM Hearts study: examining cardiovascular disease risk in middle-aged and older women - a prospective, observational cohort study

INTRODUCTION

Cardiovascular disease (CVD) is a leading cause of death in women. Novel approaches to detect early signs of elevated CVD risk in women are needed. Enhancement of traditional CVD risk assessment approaches through the addition of procedures to assess physical function or frailty as well as novel biomarkers of cardiovascular, gut and muscle health could improve early identification. The Women's Advanced Risk-assessment in Manitoba (WARM) Hearts study will examine the use of novel non-invasive assessments and biomarkers to identify women who are at elevated risk for adverse cardiovascular events.

METHODS AND ANALYSIS

One thousand women 55 years of age or older will be recruited and screened by the WARM Hearts observational, cohort study. The two screening appointments will include assessments of medical history, gender variables, body composition, cognition, frailty status, functional fitness, physical activity levels, nutritional status, quality of life questionnaires, sleep behaviour, resting blood pressure (BP), BP response to moderate-intensity exercise, a non-invasive measure of arterial stiffness and heart rate variability. Blood sample analysis will be used to assess lipid and novel biomarker profiles and stool samples will support the characterisation of gut microbiota. The incidence of the adverse cardiovascular outcomes will be assessed 5 years after screening to compare WARM Hearts approaches to the Framingham Risk Score, the current clinical standard of assessing CVD risk in Canada.

ETHICS AND DISSEMINATION

The University of Manitoba Health Research Ethics Board (7 October 2019) and the St Boniface Hospital Research Review Committee (7 October 2019) approved the trial (Ethics Number HS22576 (H2019:063)). Recruitment started 10 October 2020. Data gathered from the WARM Hearts study will be published in peer-reviewed journals and presented at national and international conferences. Knowledge translation strategies will be created to share our findings with stakeholders who are positioned to implement evidence-informed CVD risk assessment programming.

TRIAL REGISTRATION NUMBER

NCT03938155.

Is Stiffness Parameter β Useful for the Evaluation of Atherosclerosis?~ Its Clinical Implications, Limitations, and Future Perspectives ~

Atherosclerosis comprises two components, atherosis and sclerosis, characterized by morphological wall thickening and functional stiffening, respectively, of the arterial wall. In recent years, much interest has been directed to the role of functional changes in large arteries, i.e., increased stiffness or decreased elasticity, on the development of cardiovascular diseases. In fact, the clinical evaluation of arterial stiffness is increasingly performed in patients with cardiovascular risk factors. Local arterial stiffness is measured using an ultrasound technique implemented with an echo-tracking system at the common carotid and femoral arteries. Several indices of local arterial stiffness are obtained by ultrasound, among which stiffness parameter β is unique because it is the least affected by blood pressure at the time of measurement. Evidence from cross-sectional studies indicates that increased stiffness parameter β is associated with a number of cardiovascular risk factors, such as older age, smoking, insufficient physical activity, hypertension, obesity, metabolic syndrome, insulin resistance, type 2 diabetes, chronic kidney disease, and comorbid cardiovascular disease. Results from several prospective observational studies also suggest that carotid stiffness parameter β is a useful surrogate marker of cardiovascular events and/or mortality, although the results differ depending on the characteristics of the study subjects. Furthermore, several interventional studies have shown that carotid stiffness parameter β improved after lifestyle modification or drug treatment. In this review, we summarize the current evidence of stiffness parameter β of the carotid artery and discuss its clinical implications as a marker of vascular health or as a predictor of cardiovascular outcomes.

Platelet counts are associated with arterial stiffness in Chinese Han population: a longitudinal study

Background

Determining the risk factors for brachial-ankle pulse wave velocity (baPWV) may help to identify people susceptible to diabetic atherosclerosis and could prevent diabetic macrovascular complications in the early stages. We aim to comprehensively investigate risk factors contributing to arterial stiffness in patients with and without diabetes.

Methods

BaPWV was measured in 5651 individuals who attended health check-ups at baseline and follow-up. Lasso regression was used to screen for risk factors. Mixed models and multiple linear regressions were subsequently established to evaluate the effect size of the potential risk factors on baPWV and PWV change rates. All analyses were stratified by diabetes. Mediation analysis was also conducted to demonstrate the mechanisms of arterial stiffness in patients with diabetes.

Results

In lasso regression, postprandial 2-h glucose (P2hG), systolic blood pressure (SBP) and age were associated with baPWV regardless of diabetes. Platelet counts (PLT), mean corpuscular volume (MCV) and coronary heart disease (CHD) were associated with baPWV in patients with diabetes. In the mixed models, PLT were positively associated with baPWV in patients with diabetes (β_{platelet, perSD} = 25.80; 18.26–33.33). Elevated PLTs could also significantly increase the PWV change rate in patients with diabetes (β_{platelet, perSD} = 54.05; 10.00–107.10). In mediation analysis, diabetes had a significant average direct effect on baPWV. The average causal mediation effect (ACME) of PLTs was 1.76, with a range of 0.17 to 3.70.

Conclusions

Elevated PLT counts can increase baPWV in diabetes and are a potential mediator between diabetes and atherosclerosis.

Comparison of aortic pressures and aortic elastic properties between patients with end-stage renal disease and healthy controls

Background

Current evidence indicates that vascular calcification plays an essential role in the development of cardiovascular diseases in end-stage renal disease (ESRD) patients. Arterial stiffness is a marker of increased cardiovascular risk in various populations. The aim of this study is to evaluate the elastic properties of ascending aorta in patients with ESRD.

Methods

This single-center study enrolled 96 patients (45 females, age: 57.2 ± 12.8 years) with ESRD and 96 healthy controls (52 females, age: 55.3 ± 10.1 years). Aortic pressures and aortic elastic parameters including aortic strain, aortic distensibility, aortic stiffness index, and aortic compliance were calculated using accepted formulae.

Results

The hemodynamic parameters including aortic pulse pressure, aortic mean pressure, aortic fractional pulse pressure, and aortic pulsatility index were significantly higher in patients with ESRD. Systolic and diastolic aortic diameters were similar between the groups. However, pulsatile aortic diameter change, aortic strain, aortic distensibility, and aortic compliance were significantly lower, whereas aortic stiffness index was significantly higher in ESRD group.

Conclusions

The results demonstrated that a significant difference was present in terms of aortic blood pressures between patients with ESRD and controls. In addition, the elastic properties of ascending aorta were decreased in patients with ESRD.

The Role of Selenium in Oxidative Stress and in Nonthyroidal Illness Syndrome (NTIS): An Overview

Selenium is a trace element, nutritionally classified as an essential micronutrient, involved in maintaining the correct function of several enzymes incorporating the selenocysteine residue, namely the selenoproteins. The human selenoproteome including 25 proteins is extensively described here. The most relevant selenoproteins, including glutathione peroxidases, thioredoxin reductases and iodothyronine deiodinases are required for the proper cellular redox homeostasis as well as for the correct thyroid function, thus preventing oxidative stress and related diseases. This review summarizes the main advances on oxidative stress with a focus on selenium metabolism and transport. Moreover, thyroid-related disorders are discussed, considering that the thyroid gland contains the highest selenium amount per gram of tissue, also for future possible therapeutic implication.

Association between Sports Participation in Early Life and Arterial Intima-Media Thickness among Adults

Background: Early sports practice is associated with several health benefits during childhood and adolescence, moreover, recent evidence also suggests that sports during childhood and adolescence can produce some benefits during adulthood. However, the association between early sports practice and arterial thickness is not clear. Thus, our aim was analyze the association between sports participation in childhood and adolescence, carotid/femoral intima–media thickness, and blood flow index in adulthood. Material and Methods: Sample was composed of 107 adults (64 males) between 30 years and 50 years, which were recruited from different gyms and university staff from São Paulo State University. Participants were divided according to sports participation in early life (engaged in sports during childhood and adolescence (n = 52) and no engagement in sports during childhood and adolescence (n = 55)). Carotid and femoral intima–media thickness were measured through Doppler ultrasonography method. Carotid and femoral index were estimated from ultrasonography measures. As covariates, the following were adopted: chronological age, sex, body fat (through dual-energy x-ray absorptiometry), c-reactive protein, HOMA, alcohol consumption, tobacco smoking, mean arterial pressure and current physical activity (pedometer). General estimating equations were used, adopting p < 0.05. Results: In the adjusted analyses, early sports participation was associated with lower carotid intima–media index (early sports participation: 0.64 mm ± 0.14 mm vs. no early sports participation: 0.71 mm ± 0.21 mm; p = 0.011), but not associated with femoral intima–media thickness, carotid resistive index and femoral resistive index after the adjustment by potential confounders. Conclusions: Sports participation in childhood and adolescence was associated with a reduced carotid intima–media thickness, independently of relevant confounders.

Ambulatory arterial stiffness index and its role in assessing arterial stiffness in dialysis patients

OBJECTIVE

Ambulatory arterial stiffness index (AASI) is a parameter derived from ambulatory blood pressure (ABP) readings. It is calculated as 1 minus the linear slope of DBP on SBP. We tested its value in assessing arterial stiffness in dialysis patients.

METHODS

We performed a cross-sectional analysis of the baseline data from a cohort study. A total of 344 patients on maintenance hemodialysis from six tertiary hospitals were included. All patients underwent ABP monitoring and carotid-femoral pulse wave velocity (cfPWV) measurement. Clinical determinants of AASI were analyzed, and the ability of AASI for assessing arterial stiffness was compared with ambulatory pulse pressure (PP).

RESULTS

Multiple regression analysis revealed that ambulatory PP (β = 0.003), current smoker (β = -0.069), age (β = 0.003) and ambulatory SBP (β = 0.001) were independent determinants of AASI. Ambulatory PP correlates better with cfPWV than AASI (r = 0.28 for AASI and 0.59 for PP; P for difference: <0.001). When cfPWV was treated as a categorical variable, receiver operating characteristic curve analysis also showed a more potent predictive value of PP over AASI (area under the curve: 0.64 for AASI, 0.80 for PP; P for difference: <0.001). Net reclassification improvement and integrated discrimination improvement analysis demonstrated no added predictive value of AASI to PP (net reclassification improvement = -2.2%, P = 0.26; integrated discrimination improvement = 0.001, P = 0.51). Sensitivity analysis in patients with more ABP readings (≥49) yielded similar results.

CONCLUSION

For dialysis patients, AASI has very limited value in assessing arterial stiffness, whether used alone or added to PP. Our results suggest that this index should not be used as a surrogate marker of arterial stiffness for dialysis patients in future practice and studies.

Vascular Mechanobiology: Towards Control of In Situ Regeneration

The paradigm of regenerative medicine has recently shifted from in vitro to in situ tissue engineering: implanting a cell-free, biodegradable, off-the-shelf available scaffold and inducing the development of functional tissue by utilizing the regenerative potential of the body itself. This approach offers a prospect of not only alleviating the clinical demand for autologous vessels but also circumventing the current challenges with synthetic grafts. In order to move towards a hypothesis-driven engineering approach, we review three crucial aspects that need to be taken into account when regenerating vessels: (1) the structure-function relation for attaining mechanical homeostasis of vascular tissues, (2) the environmental cues governing cell function, and (3) the available experimental platforms to test instructive scaffolds for in situ tissue engineering. The understanding of cellular responses to environmental cues leads to the development of computational models to predict tissue formation and maturation, which are validated using experimental platforms recapitulating the (patho)physiological micro-environment. With the current advances, a progressive shift is anticipated towards a rational and effective approach of building instructive scaffolds for in situ vascular tissue regeneration.

Brachial-Ankle Pulse Wave Velocity and the Risk Prediction of Cardiovascular Disease: An Individual Participant Data Meta-Analysis

An individual participant data meta-analysis was conducted in the data of 14 673 Japanese participants without a history of cardiovascular disease (CVD) to examine the association of the brachial-ankle pulse wave velocity (baPWV) with the risk of development of CVD. During the average 6.4-year follow-up period, 687 participants died and 735 developed cardiovascular events. A higher baPWV was significantly associated with a higher risk of CVD, even after adjustments for conventional risk factors (P for trend <0.001). When the baPWV values were classified into quintiles, the multivariable-adjusted hazard ratio for CVD increased significantly as the baPWV quintile increased. The hazard ratio in the subjects with baPWV values in quintile 5 versus that in those with the values in quintile 1 was 3.50 (2.14-5.74; P<0.001). Every 1 SD increase of the baPWV was associated with a 1.19-fold (1.10-1.29; P<0.001) increase in the risk of CVD. Moreover, addition of baPWV to a model incorporating the Framingham risk score significantly increased the C statistics from 0.8026 to 0.8131 (P<0.001) and also improved the category-free net reclassification (0.247; P<0.001). The present meta-analysis clearly established baPWV as an independent predictor of the risk of development of CVD in Japanese subjects without preexisting CVD. Thus, measurement of the baPWV could enhance the efficacy of prediction of the risk of development of CVD over that of the Framingham risk score, which is based on the traditional cardiovascular risk factors.

Association of Beta-2 Microglobulin with Inflammation and Dislipidemia in High-Flux Membrane Hemodialysis Patients

BACKGROUND

Higher than expected cardiovascular mortality in hemodialysis patients, has been attributed to dyslipidemia as well as inflammation. Beta2-Microglobulin (β2M) is an independent predictor of outcome for hemodialysis patients and a representative substance of middle molecules.

RESULTS

In 40 patients in high-flux membrane hemodialysis, we found negative correlation of β2M with high density lipoprotein (r=-0.73, p<0.001) and albumin (r= -0.53, p<0.001) and positive correlation with triglycerides (r=0.69, p<0.001), parathyroid hormone (r=0.58, p < 0.05) and phosphorus (r= 0.53, p<0.001). There was no correlation of β2M with C- reactive protein (CRP) and interleukin-6 (IL-6). During the follow-up period of three years, 6 out of 40 patients have died from cardiovascular events.

CONCLUSION

In high-flux membrane hemodialysis patients, we observed a significant relationship of β2M with dyslipidemia and mineral bone disorders, but there was no correlation with inflammation.

Carotid atherosclerosis is associated with left ventricular diastolic function

BACKGROUND

It has been reported that carotid intima-media thickness (IMT) correlates with the risk of stroke or cardiovascular disease. The purpose of this study was to analyze the relationships between echocardiographic findings and carotid atherosclerosis.

METHODS

A total of 234 patients (62 ± 15 years) were referred for echocardiography to evaluate the left ventricular (LV) function. The LV ejection fraction, the ratio of the peak velocity of early rapid filling and the peak velocity of atrial filling (E/A), and the peak early diastolic mitral annular velocity (e') were obtained by echocardiography. The maximum IMT (Max-IMT) and plaque score (PS) were measured by carotid ultrasonography within 1 month of the echocardiographic examination.

RESULTS

The mean values of Max-IMT and carotid PS were 2.41 ± 1.23 mm and 8.5 ± 6.3, respectively. The decreased mean E/A (0.94 ± 0.39) and mitral e' (5.5 ± 1.9 cm/s) indicated LV diastolic dysfunction. A good correlation was observed between Max-IMT and PS (r = 0.83, p < 0.0001). It was shown that 2.8 mm of Max-IMT was equivalent to 10.1 of carotid PS, which indicated severe carotid atherosclerosis. In multiple logistic stepwise regression analysis, among the echocardiographic parameters, only e' was independently associated with severe carotid atherosclerosis (Max-IMT ≥ 2.8 mm or PS ≥ 10.1).

CONCLUSIONS

The present study demonstrated that decreased early diastolic mitral annular velocity relates to the parameter reflecting carotid atherosclerosis. Therefore, the presence of severe carotid atherosclerosis may affect LV diastolic dysfunction.

Reference values for local arterial stiffness. Part A: carotid artery

OBJECTIVE

Non-invasive measures of common carotid artery properties, such as diameter and distension, and pulse pressure, have been widely used to determine carotid artery distensibility coefficient - a measure of carotid stiffness (stiffness ∼1/distensibility coefficient). Carotid stiffness has been associated with incident cardiovascular disease (CVD) and may therefore be a useful intermediate marker for CVD. We aimed to establish age and sex-specific reference intervals of carotid stiffness.

METHODS

We combined data on 22 708 individuals (age range 15-99 years, 54% men) from 24 research centres worldwide. Individuals without CVD and established cardiovascular risk factors constituted a healthy sub-population (n = 3601, 48% men) and were used to establish sex-specific equations for percentiles of carotid distensibility coefficient across age.

RESULTS

In the sub-population without CVD and treatment (n = 12 906, 52% men), carotid distensibility coefficient Z-scores based on these percentile equations were independently and negatively associated, in men and women, respectively, with diabetes {-0.28 [95% confidence interval (CI) -0.41; -0.15] and -0.27 (-0.43; -0.12)}, mean arterial pressure [-0.26 (-0.29; -0.24) and -0.32 (-0.35; -0.29)], total-to-high-density lipoprotein cholesterol ratio [-0.05 (-0.09; -0.02) and -0.05 (-0.11; 0.01)] and BMI [-0.06 (-0.09; -0.04) and -0.05 (-0.08; -0.02)], whereas these were positively associated with smoking [0.30 (0.24; 0.36) and 0.24 (0.18; 0.31)].

CONCLUSIONS

We estimated age and sex-specific percentiles of carotid stiffness in a healthy population and assessed the association between cardiovascular risk factors and carotid distensibility coefficient Z-scores, which enables comparison of carotid stiffness values between (patient) groups with different cardiovascular risk profiles, helping interpretation of such measures.

Visceral Adiposity is Preferentially Associated with Vascular Stiffness Rather than Thickness in Men with Type 2 Diabetes

Aim: Visceral fat accumulation is known to underlie the clustering of cardiovascular risk factors. However, it is not completely understood how visceral fat accumulation influences the development of cardiovascular disease. In this study, we investigated the clinical impact of visceral adiposity on vascular stiffness and thickness in patients with type 2 diabetes (T2D).

Methods: One hundred and sixty-one patients with T2D, including 92 men and 69 women, were included in this cross-sectional study. Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured by dual bioelectrical impedance analysis. Stiffness parameter β and intima-media thickness (IMT) of the common carotid artery were measured by ultrasonography.

Results: The mean age and duration of diabetes in the study population were 61 years and 13.9 years, respectively. In men, VFA and waist circumference (WC) were positively correlated with stiffness parameter β, whereas body mass index (BMI), WC, and SFA were negatively correlated with IMT. In contrast, in women, none of the obesity-related indices were significantly correlated with stiffness parameter β or IMT. In multiple regression analyses, VFA as well as WC, BMI, and SFA were independently associated with stiffness parameter β after adjustment for age and other potential confounders in men but not in women. None of the obesity-related indices were independently associated with IMT for either sex.

Conclusion: In men with T2D, visceral adiposity is associated with carotid arterial stiffness but not thickness.

Measuring submicrometer displacement vectors using high-frame-rate ultrasound imaging

Measuring the magnitude and direction of tissue displacement provides the basis for the assessment of tissue motion or tissue stiffness. Using conventional displacement tracking by ultrasound delay estimation, only one direction of tissue displacement can be estimated reliably. In this paper, we describe a new technique for estimating the complete two-dimensional displacement vector using high-frame-rate ultrasound imaging. We compute the displacement vector using phase delays that can be measured between pairs of elements within an array. By combining multiple element-pair solutions, we find a new robust estimate for the displacement vector. In this paper, we provide experimental proof that this method permits measurement of the displacement vector for isolated scatterers and diffuse scatterers with high (submicrometer) precision, without the need for beam steering. We also show that we can measure the axial and lateral distension of a carotid artery in a transverse view.

Correlation between Echo-Tracking Parameters and In Vitro Measurements of Arterial Contraction and Relaxation in Rats Fed a High-Cholesterol Diet

BACKGROUND

Echo-tracking (ET) is a new technique that allows the assessment of arterial function and stiffness. This study aimed to ascertain the utility of the echo-tracking (ET) technique to assess vascular stiffness in rats with hypercholesterolemia and atherosclerosis.

MATERIAL AND METHODS

ET was used to measure the arterial stiffness of the aorta in cholesterol-fed Sprague-Dawley rats (group T1, n=10, for 4 weeks; group T2, n=10, for 12 weeks) and normal control rats (group C1, n=10; group C2, n=10). In vitro isometric tension experiments were used to measure the maximum contractile tension (MCT) and maximum relaxation percentage (MRR%) of aortic rings. Indicators of arterial stiffness and aortic MCT and MRR% were compared between groups using linear regression analysis. Light microscopic evaluation was used to demonstrate atherosclerotic changes in the aorta.

RESULTS

The rat models were successfully induced; pathological examination of the aortas showed significant atherosclerosis in group T2, but not in groups C1, C2, or T1. The arterial stiffness parameters obtained using ET and aortic rings in vitro showed significant impairments in T1 and T2 rats compared with C1 and C2 controls (all P<0.05 vs. controls). In addition, these impairments were greater in the T2 group than in the T1 group (all P<0.05). Finally, MRR% correlated with the distensibility coefficient (r=0.396, P=0.012), arterial compliance (r=0.317, P=0.047), stiffness parameter b (r=-0.406, P=0.009) and one-point pulse wave β (r=-0.434, P=0.005).

CONCLUSIONS

These results suggest that ET could be used to evaluate the changes in arterial wall elasticity associated with atherosclerosis and hypercholesterolemia.

A systematic literature review of the effect of carotid atherosclerosis on local vessel stiffness and elasticity

OBJECTIVE

This systematic literature review sought to determine the effects of carotid atherosclerotic plaque on local arterial stiffness.

METHODS

MedLine, EMBASE, and grey literature were searched with the following term: ("atherosclerosis" or "carotid atherosclerosis" or "carotid artery disease" or "carotid plaque") AND ("distensibility" or "elasticity" or "stiffness" or "compliance") NOT ("pulse wave velocity" or "PWV" or "carotid-ankle" or "ankle-brachial" or "augmentation index" or "cardio-ankle" or "CAVI" or "flow mediated dilation" or "FMD"). Results were restricted to English language articles reporting local arterial stiffness in human subjects with carotid atherosclerosis.

RESULTS

Of the 1466 search results, 1085 abstracts were screened and 191 full-text articles were reviewed for relevance. The results of the 50 studies that assessed some measure of carotid arterial elasticity or stiffness in patients with carotid plaque were synthesized and reviewed.

DISCUSSION

A number of different measures of carotid elasticity were found in the literature. Regardless of which metric was used, the majority of studies found increased carotid stiffness (or decreased distensibility) to be associated with carotid plaque presence, the degree of atherosclerosis, and incident stroke.

CONCLUSION

Carotid artery mechanics are influenced by the presence of atherosclerotic plaque. The clinical applicability of carotid elasticity measures may be limited by the lack of reference values and standardized techniques.

Observational multicenter study to evaluate the prevalence and prognosis of subclinical atheromatosis in a Spanish chronic kidney disease cohort: baseline data from the NEFRONA study

BACKGROUND

Cardiovascular events (CVE) are more prevalent in chronic kidney disease (CKD) than in general population, being the main cause of morbimortality. Specific risk factors related to CKD have been suggested, because traditional factors do not fully explain this increase in cardiovascular disease rates. However, the role of atheromatosis, its pathogenesis and evolution are still unclear. The potential use of diagnostic tests to detect subclinical atheromatosis has to be determined.

METHODS

NEFRONA is a prospective multicenter cohort study. 2445 CKD subjects were enrolled from 81 Spanish hospitals and dialysis clinics, from 2010 to 2012. Eligibility criteria included: 18 to 74 years old, CKD stage 3 or higher, and no previous CVE. 559 non-CKD controls were also recruited. Demographical, clinical and analytical data were collected. Carotid and femoral ultrasounds were performed by a single trained team to measure carotid intima-media thickness (cIMT) and detect atheromatous plaques. Ankle-brachial index (ABI) was measured.

RESULTS

Differences in age, sex and prevalence and control of cardiovascular risk factors were found between controls and CKD patients. These differences are similar to those described in epidemiological studies.No difference was found regarding cIMT between controls and CKD (when subjects with plaques in common carotid arteries were omitted); earlier CKD stages had higher values. CKD patients had a higher rate of atheromatous plaques, with no difference between stages in the unadjusted analysis. A group of patients had plaques in femoral arteries but were plaque-free in carotid arteries, and would have gone underdiagnosed without the femoral study. The percentage of pathologic ABI was higher in CKD, with higher prevalence in more advanced stages, and a higher rate of ABI >1.4 than <0.9, suggesting more vascular calcification.

CONCLUSIONS

NEFRONA is the first large study describing the actual prevalence of subclinical atheromatosis across different CKD stages. There is a very high rate of atheromatous plaques and pathologic ABI in CKD. Prospective data will add important information to the pathogenesis and evolution of atheromatosis in CKD, compared to non-CKD subjects.

High-definition imaging of carotid artery wall dynamics

The carotid artery (CA) is central to cardiovascular research, because of the clinical relevance of CA plaques as culprits of stroke and the accessibility of the CA for cardiovascular screening. The viscoelastic state of this artery, essential for clinical evaluation, can be assessed by observing arterial deformation in response to the pressure changes throughout the cardiac cycle. Ultrasound imaging has proven to be an excellent tool to monitor these dynamic deformation processes. We describe how a new technique called high-frame-rate ultrasound imaging captures the tissue deformation dynamics throughout the cardiac cycle in unprecedented detail. Local tissue motion exhibits distinct features of sub-micrometer displacements on a sub-millisecond time scale. We present a high-definition motion analysis technique based on plane wave ultrasound imaging able to capture these features. We validated this method by screening a group of healthy volunteers and compared the results with those for two patients known to have atherosclerosis to illustrate the potential utility of this technique.

Association between circulating endothelial cells and carotid atherosclerosis in patients receiving maintenance hemodialysis

Accelerated atherosclerosis is the major cause of mortality in maintenance hemodialysis (MHD) patients, and endothelial injury associated with MHD might contribute strongly to pathogenesis. The current study was designed to explore possible associations between circulating endothelial cells (CECs) and intima-media thickness of common carotid artery (CCA-IMT) as an indicator of carotid atherosclerosis. Sixty-two MHD patients and 26 age- and sex-matched healthy volunteers were recruited. The number of CECs was determined in peripheral blood using multiparametric flow cytometry. CCA-IMT and presence of plaques in the common carotid arteries were assessed with ultrasound. Laboratory tests results and the demographics were recorded. The finding indicated that numbers of CECs were higher in patients before hemodialysis (predialysis) compared with numbers in controls (P = 0.045). CCA-IMT was also significantly higher in patients than in controls (P < 0.01). A positive relationship was observed between predialysis CECs numbers and CCA-IMT (P < 0.01) in MHD patients. In multiple linear regression analysis, the relationship between the predialysis CECs level and CCA-IMT remained the same even if adjusting for confounding effects. Accordingly, the investigation indicates that the CECs level is positively associated with CCA-IMT in our hemodialysis patients. CECs might be an important marker to the severity of carotid atherosclerosis in MHD patients.

STUDY OF PLAQUE VULNERABILITY IN CORONARY ARTERY USING MOONEY–RIVLIN MODEL: A COMBINATION OF FINITE ELEMENT AND EXPERIMENTAL METHOD

Atherosclerosis is a disease in which plaque builds up inside arteries. It is also considered as one of the most serious and common forms of cardiovascular disease which can lead to heart attack and stroke. In the current research, finite element method is used to anticipate plaque vulnerability based on peak plaque stress using human samples. A total of 23 healthy and atherosclerotic human coronary arteries, including 14 healthy and 9 atherosclerotic are removed within 5 h postmortem. The samples are mounted on a uniaxial tensile test machine and the obtained mechanical properties are used in finite element models. The results, including the Mooney–Rivlin hyperelastic constants of the samples as well as peak plaque stresses, are computed. It is demonstrated that the atherosclerotic human coronary arteries have significantly (p < 0.05) higher stiffness compared to healthy ones. The hypocellular plaque, in addition, has the highest stress values compared to the cellular and calcified ones and, consequently, is so prone to rupture. The calcified plaque type, nevertheless, has the lowest stress values and, remains stable. The results of this study can be used in the plaque vulnerability prediction and could have clinical implications for interventions and surgeries, such as balloon angioplasty, bypass and stenting.

The thyroid and the kidney: a complex interplay in health and disease

Thyroid hormones may directly affect the kidney and altered kidney function may also contribute to thyroid disorders. The renal manifestations of thyroid disorders are based on hemodynamic alterations or/and to direct effects of thyroid hormones. The renin-angiotensin system plays a crucial role in the cross-talk between the thyroid and the kidney. Hypothyroidism may be accompanied by an increase of serum creatinine and reduction of glomerular filtration rate (GFR), whereas hyperthyroidism may increase GFR. Treatment of thyroid disorders may lead to normalization of GFR. Primary and subclinical hypothyroidism and low triiodothyronine (T3) syndrome are common features in patients with chronic kidney disease (CKD). In addition low levels of thyroid hormones may predict a higher risk of cardiovascular and overall mortality in patients with end-stage renal disease. The causal nature of this correlation remains uncertain. In this review, special emphasis is given to the thyroid pathophysiology, its impact on kidney function and CKD and the interpretation of laboratorial findings of thyroid dysfunction in CKD.

Association of the cardioankle vascular index and ankle-brachial index with carotid artery intima media thickness in hemodialysis patients

The objectives of the present study are (1) to compare the cardioankle vascular index (CAVI), ankle-brachial index (ABI), and carotid artery intima-media thickness (CA-IMT) between HD patients with and without type 2 diabetes (T2D) or prevalence of cardiovascular (CV) disease and (2) also to evaluate the relationship of these indices with CA-IMT in these patients according to ABI levels. This study consisted of 132 HD patients with T2D and the same number of patients without T2D. The patients with diabetes or prevalence of CV disease had significantly higher CA-IMT and lower ABI values than those without diabetes or prevalence of CV disease, respectively. Although diabetic patients had higher CAVI than those without diabetes, CAVI did not differ between patients with or without prevalence of CV disease. In univariate analysis, CA-IMT was more strongly correlated with ABI than CAVI. However, the opposite was true in patients with an ABI value of more than 0.95. Both indices were significantly correlated with CA-IMT although ABI was a powerful determinant than CAVI. It appears that both indices are associated with CA-IMT in HD patients, especially with an ABI value of more than 0.95.

A finite element investigation on plaque vulnerability in realistic healthy and atherosclerotic human coronary arteries

Atherosclerosis is the most common arterial disease. It has been shown that stresses that are induced during blood circulation can cause plaque rupture and, in turn, lead to thrombosis and stroke. In this study, finite element method is used to predict plaque vulnerability based on peak plaque stress using human samples. A total of 23 healthy and atherosclerotic human coronary arteries of 14 healthy and 9 atherosclerotic patients are excised within 5 h postmortem. The samples are mounted on an uniaxial tensile test machine, and the obtained mechanical properties are used in two-dimensional and three-dimensional finite element models. The results including the Neo-Hookean hyperelastic coefficients of the samples as well as peak plaque stresses are analyzed. The results indicate that the atherosclerotic human coronary arteries have significantly (p < 0.05) higher stiffness compared with the healthy ones. The hypocellular plaque also has the highest stress values and, as a result, is most likely (vulnerable) to rupture, while the calcified type has the lowest stress values and, consequently, is expected to remain stable. The results could be used in the plaque vulnerability anticipation and have clinical implications in interventions and surgeries, including balloon angioplasty, bypass, and stenting.

Association of serum phosphorus concentration with mortality in elderly and nonelderly hemodialysis patients

OBJECTIVE

Hypo- and hyperphosphatemia have each been associated with increased mortality in maintenance hemodialysis (MHD) patients. There has not been previous evaluation of a differential relationship between serum phosphorus level and death risk across varying age groups in MHD patients.

DESIGN AND SETTINGS

In a 6-year cohort of 107,817 MHD patients treated in a large dialysis organization, we examined the association between serum phosphorus levels with all-cause and cardiovascular mortality within 5 age categories (15 to <45, 45 to <65, 65 to <70, 70 to <75, and ≥75 years old) using Cox proportional hazards models adjusted for case-mix covariates and malnutrition inflammation complex syndrome (MICS) surrogates.

MAIN OUTCOME MEASURE

All-cause and cardiovascular mortality.

RESULTS

The overall mean age of the cohort was 60 ± 16 years, among whom there were 45% women, 35% Blacks, and 58% diabetics. The time-averaged serum phosphorus level (mean ± SD) within each age category was 6.26 ± 1.4, 5.65 ± 1.2, 5.26 ± 1.1, 5.11 ± 1.0, and 4.88 ± 1.0 mg/dL, respectively (P for trend <.001). Hyperphosphatemia (>5.5 mg/dL) was consistently associated with increased all-cause and cardiovascular mortality risks across all age categories, including after adjustment for case-mix and MICS-related covariates. In fully adjusted models, a low serum phosphorus level (<3.5 mg/dL) was associated with increased all-cause mortality only in elderly MHD patients ≥65 years old (hazard ratio [95% confidence interval]: 1.21 [1.07-1.37], 1.13 [1.02-1.25], and 1.28 [1.2-1.37] for patients 65 to <70, 70 to <75, and ≥75 years old, respectively), but not in younger patients (<65 years old). A similar differential cardiovascular mortality risk for low serum phosphorus levels between old and young age groups was observed.

CONCLUSIONS

The association between hyperphosphatemia and mortality is similar across all age groups of MHD patients, whereas hypophosphatemia is associated with increased mortality only in elderly MHD patients. Preventing very low serum phosphorus levels in elderly dialysis patients may be associated with better outcomes, which needs to be examined in future studies.

Usefulness of biventricular volume as a predictor of mortality in patients with diabetes mellitus (from the Diabetes Heart Study)

Patients with type 2 diabetes mellitus are at increased risk for cardiovascular disease (CVD) and mortality. Beyond traditional CVD risk factors, novel measures reflecting additional aspects of disease pathophysiology, such as biventricular volume (BiVV), may be useful for risk stratification. The aim of this study was to examine the relationship between BiVV and risk for mortality in European Americans with type 2 diabetes mellitus from the Diabetes Heart Study (DHS). BiVV was calculated from 771 noncontrast computed tomographic scans performed to image coronary artery calcified plaque. Relationships between BiVV and traditional CVD risk factors were examined. Cox proportional-hazards regression was performed to determine risk for mortality (all-cause and CVD mortality) associated with increasing BiVV. Area under the curve analysis was used to assess BiVV utility in risk prediction models. During 8.4 ± 2.4 years of follow-up, 23% of the patients died. In unadjusted analyses, BiVV was significantly associated with increasing body mass index, height, coronary artery calcified plaque, history of hypertension, and previous myocardial infarction (p <0.0001 to 0.012). BiVV was significantly associated with all-cause (hazard ratio 2.45, 95% confidence interval 1.06 to 5.67, p = 0.036) and CVD (hazard ratio 4.36, 95% confidence interval 1.36 to 14.03, p = 0.014) mortality in models adjusted for other known CVD risk factors. Area under the curve increased from 0.76 to 0.78 (p = 0.04) and from 0.74 to 0.77 (p = 0.02) for all-cause and CVD mortality with the inclusion of BiVV. In conclusion, in the absence of echocardiography or other noninvasive imaging modalities to assess ventricular volumes, or when such methods are contraindicated, BiVV from computed tomography may be considered a tool for the stratification of high-risk patients, such as those with type 2 diabetes mellitus.

Small artery elasticity predicts future cardiovascular events in chinese patients with angiographic coronary artery disease

Arterial elasticity has been shown to predict cardiovascular disease (CVD) in apparently healthy populations. The present study aimed to explore whether arterial elasticity could predict CVD events in Chinese patients with angiographic coronary artery disease (CAD). Arterial elasticity of 365 patients with angiographic CAD was measured. During follow-up (48 months; range 6-65), 140 CVD events occurred (including 34 deaths). Univariate Cox analysis demonstrated that both large arterial elasticity and small arterial elasticity were significant predictors of CVD events. Multivariate Cox analysis indicated that small arterial elasticity remained significant. Kaplan-Meier analysis showed that the probability of having a CVD event/CVD death increased with a decrease of small arterial elasticity (P < .001, respectively). Decreased small arterial elasticity independently predicts the risk of CVD events in Chinese patients with angiographic CAD.

Measurement of the uniaxial mechanical properties of healthy and atherosclerotic human coronary arteries

Atherosclerosis is a common arterial disease which alters the stiffness of arterial wall. Arterial stiffness is related to many cardiovascular diseases. In this investigation, maximum stress and strain as well as physiological and maximum elastic modulus of 22 human coronary arteries are measured. In addition, the force-displacement diagram of human coronary artery is obtained to discern the alterations between the healthy and atherosclerotic arterial wall stiffness. The age of each specimen and its effect on the elastic modulus of human coronary arteries is also considered. Twenty-two human coronary arteries, including eight atherosclerotic and fourteen healthy arteries are excised within 5 hours post-mortem. Samples are mounted on a tensile-testing machine and force is applied until breakage occurs. Elastic modulus coefficient of each specimen is calculated to compare the stiffness of healthy and atherosclerotic coronary arteries. The results show that the atherosclerotic arteries bear 44.55% more stress and 34.61% less strain compared to the healthy ones. The physiological and maximum elastic moduli of healthy arteries are 2.53 and 2.91 times higher than that of atherosclerotic arteries, respectively. The age of specimens show no correlation with the arterial wall stiffness. A combination of biomechanics and mathematics is used to characterize the mechanical properties of human coronary arteries. These results could be utilized to understand the extension and rupture mechanism of coronary arteries and has implications for interventions and surgeries, including balloon-angioplasty, bypass, and stenting.

Correlates of parathyroid hormone concentration in hemodialysis patients

BACKGROUND

The implications of chemical hyperparathyroidism on bone and mineral metabolism measures in maintenance hemodialysis (MHD) are not well known. We hypothesized that a higher serum intact parathyroid hormone (iPTH) level is associated with the higher likelihood of hyperphosphatemia, hyperphosphatasemia [high serum alkaline phosphatase (ALP) levels] and hypercalcemia.

METHODS

Over an 8-year period (July 2001-June 2009), we identified 106 760 MHD patients with iPTH and calcium (Ca), phosphorous (P) and ALP data from a large dialysis clinic. Logistic regression models were examined to assess the association between serum iPTH increments and the likelihood of hyperphosphatemia (P ≥5.5 mg/dL), hypercalcemia (Ca ≥10.2 mg/dL) and hyperphosphatasemia (ALP ≥120 U/L).

RESULTS

Patients were 61 ± 16 years old and included 45% women, 59% diabetics and 33% Blacks. Compared with an iPTH level of 100 to <200 pg/mL, patients with an iPTH level of 600-700, 700 to <800 and ≥800 pg/mL had 122% (OR: 2.22, 95% CI: 2.04-2.41), 153% (OR: 2.53, 95% CI: 2.29-2.80) and 243% (OR: 3.43, 95% CI: 3.22-3.66) higher risk of hyperphosphatemia, respectively, and had 109% (OR: 2.09, 95% CI: 1.93-2.26), 130% (OR: 2.30, 95% CI: 2.10-2.52) and 376% (OR: 4.76, 95% CI: 4.50-5.04) higher risk of hyperphosphatasemia, respectively. Compared with an iPTH level of 100 to <200 pg/mL, both the low iPTH (<100 pg/mL, OR: 2.45, 95% CI: 2.27-2.64) and the high iPTH (≥800 pg/mL: OR: 2.13, 95% CI: 1.95-2.33) levels were associated with hypercalcemia.

CONCLUSIONS

Higher levels of iPTH are incremental correlates of hyperphosphatemia and hyperphosphatasemia, whereas both very low and high PTH levels are linked to hypercalcemia. If these associations are causal, correction of hyperparathyroidism may have overarching implications on bone and mineral disorders in MHD patients.

The contribution of thyroid dysfunction on cardiovascular disease in patients with chronic kidney disease

Accelerated atherosclerosis and arterial stiffness are the two leading causes of increased cardiovascular disease in patients with chronic kidney disease. Dysfunctional thyroid hormone metabolism has been suggested to play a role in atherosclerosis and arterial stiffness. Changes in cardiac contractility and output, myocardial oxygen demand, systemic and peripheral vascular resistance, blood pressure and lipid profile, increased inflammatory burden and endothelial dysfunction may be responsible for thyroid hormone-related cardiovascular disease. This article focuses on the mechanistic insights of this association and provides a concise review of the current literature.

Association of pre-kidney transplant markers of mineral and bone disorder with post-transplant outcomes

BACKGROUND AND OBJECTIVES

Mineral and bone disorders (MBDs) are common in long-term dialysis patients and are risk factors for unfavorable outcomes. The associations between pretransplant levels of MBD surrogates and outcomes after kidney transplantation are not clear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the Scientific Registry of Transplant Recipients up to June 2007 were linked to the 5-year (July 2001-June 2006) cohort of a large dialysis organization in the United States. All dialysis patients who received a kidney transplant during this period were identified and divided into groups according to increments of pretransplant MBD markers. Unadjusted and multivariate adjusted predictors of transplant outcomes were examined.

RESULTS

The 11,776 patients were aged 47 ± 14 years and 39% were women. Compared with recipients with pretransplant time-averaged serum alkaline phosphatase of 80-120 U/L, recipients with pretransplant serum alkaline phosphatase of 120-160 and ≥160 U/L had 49% and 64% higher graft failure censored all-cause mortality in multivariable adjusted models. There was no significant association between time-averaged serum alkaline phosphatase categories and risk of death censored graft failure, delayed graft function (DGF), or acute rejection (AR). Compared with recipients with pretransplant time-averaged serum parathyroid hormone (PTH) levels of 150-300 pg/ml, there was no significant association with graft censored death among recipients with pretransplant serum PTH ≥800 pg/ml. In addition, the risk of graft failure, DGF, and AR did not show any association with time-averaged serum intact PTH level. There was no significant association between time-averaged serum calcium categories and risk of graft failure censored death, DGF, and AR.

CONCLUSIONS

In this cohort, hemodialysis patients with pretransplant serum alkaline phosphatase >120 U/L have unfavorable post-transplant mortality, whereas there was no association between serum PTH and serum calcium levels and post-transplant outcomes.

Inflammation, diabetes, and chronic kidney disease: role of aerobic capacity

The persistent inflammatory state is common in diabetes and chronic kidney disease (CKD). These patients present exercise intolerance and increased arterial stiffness. Long-term aerobic exercise has been associated with better arterial compliance, antidiabetic and antiinflammatory benefits. We assessed the hypothesis that in patients with diabetes and CKD, better aerobic capacity is associated with less inflammatory state and arterial stiffness. Thirty-nine CKD patients (17 in hemodialysis) were evaluated. According to CKD etiology two patient groups were obtained: group of diabetics (GD) was formed by 11 patients and nondiabetics (GND) formed by 28 patients. Central blood pressure and arterial stiffness were evaluated by Sphygmocor device. Carotida intima-media thickness (CA-IMT) was evaluated by ultrasonography. Aerobic capacity was measured by estimated VO₂max according to treadmill test by Bruce protocol. The GD showed a higher frequency of C-reactive protein above laboratory cutoff (P = 0.044), higher frequency of male gender, and a non significant higher value of VO₂max (P = 0.099). The CA-IMT was similar. Only better aerobic capacity was associated with lower frequency of high C-reactive protein when adjusted to diabetes and gender in a logistic regression model. In conclusion, aerobic capacity was associated with inflammatory state, in CKD patients, independently of diabetes presence.

Relationship between magnesium and clinical biomarkers on inhibition of vascular calcification

BACKGROUND

Arteriosclerosis and cardiovascular disease are strongly associated with vascular calcification. Hyperphosphatemia is an essential risk factor for increased vascular calcification. End-stage renal disease (ESRD) patients could serve as an in vivo model for accelerated calcification. This study focuses on the most likely protective effects of magnesium ion (Mg(2+)) on phosphate-induced vascular calcification ex vivo/in vitro. Furthermore, plasma Mg(2+) concentrations of ESRD and healthy controls were investigated for association with surrogate parameters of vascular calcification in vivo.

METHODS

Aortic segments of male Wistar-Kyoto rats were incubated and the phosphate concentration of the medium was elevated. The aortic segments were incubated in the absence and presence of MgCl(2); tissue calcification was quantified by different methods. Serum Mg(2+) concentrations of patients with chronic kidney disease (CKD stage 5; ESRD) and patients without CKD (controls) were associated with carotid intima media thickness (IMT) and aortic pulse wave velocity (PWV) as surrogate parameter for arteriosclerosis and arterial stiffening.

RESULTS

Incubation of aortic segments in the presence of β-glycerophosphate and NaH(2)PO(4) caused an increased tissue Ca(2+) deposition compared to control conditions. This increased amount of Ca(2+) in the aortic rings was significantly decreased in the presence of Mg(2+). In CKD patients, but not in controls, magnesium serum concentration was associated with the IMT of the carotid arteries. In addition, CKD patients with higher magnesium serum concentration had a significantly lower PWV.

DISCUSSION AND CONCLUSION

Elevated phosphate concentrations in the culture media induce ex vivo/in vitro medial calcification in intact rat aortic rings in the presence of alkaline phosphatase. Mg(2+) ions reduced ex vivo/in vitro vascular calcification despite increased phosphate concentration. This hypothesis is additionally based on the fact that CKD patients with high Mg(2) serum levels had significantly lower IMT and PWV values, which may result in a lower risk for cardiovascular events and mortality in these patients. Therefore, Mg(2+) supplementation may be an option for treatment and prevention of vascular calcification resulting in a reduction of cardiovascular events in CKD patients.

Mineral and bone disorders and survival in hemodialysis patients with and without polycystic kidney disease

BACKGROUND

Maintenance hemodialysis (MHD) patients with polycystic kidney disease (PKD) have better survival than non-PKD patients. Mineral and bone disorders (MBD) are associated with accelerated atherosclerosis and cardiovascular death in MHD patients. It is unknown whether the different MBD mortality association between MHD populations with and without PKD can explain the survival differential.

METHODS

Survival models were examined to assess the association between different laboratory markers of MBD [such as serum phosphorous, parathyroid hormone (PTH), calcium and alkaline phosphatase] and mortality in a 6-year cohort of 60,089 non-PKD and 1501 PKD MHD patients.

RESULTS

PKD and non-PKD patients were 57±13 and 62±15 years old and included 46 and 45% women and 14 and 32% Blacks, respectively. Whereas PKD individuals with PTH 150 to <300 pg/mL (reference) had the lowest risk for mortality, the death risk was higher in patients with PTH<150 [hazard ratio (HR): 2.16 (95% confidence interval 1.53-3.06)], 300 to <600 [HR: 1.30 (0.97-1.74)] and ≥600 pg/mL [HR: 1.46 (1.02-2.08)], respectively. Similar patterns were found in non-PKD patients. Fully adjusted death HRs of time-averaged serum phosphorous increments<3.5, 5.5 to <7.5 and ≥7.5 mg/dL (reference: 3.5 to <5.5 mg/dL) for PKD patients were 2.82 (1.50-5.29), 1.40 (1.12-1.75) and 2.25 (1.57-3.22). The associations of alkaline phosphatase and calcium with mortality were similar in PKD and non-PKD patients.

CONCLUSION

Bone-mineral disorder markers exhibit similar mortality trends between PKD and non-PKD MHD patients, although some differences are observed in particular in low PTH and phosphorus ranges.

High serum level of lutein may be protective against early atherosclerosis: the Beijing atherosclerosis study

OBJECTIVE

We investigated whether early atherosclerosis before calcified plaque appeared as assessed by carotid intima-media thickness (IMT) was associated with levels of the major carotenoids, and assessed the associations among these serum carotenoids, carotid IMT, and arterial stiffness.

METHODS

The case-control study comprised 125 subjects with early atherosclerosis and 107 controls aged 45-68 years. We simultaneously measured common carotid IMT and arterial stiffness by carotid ultrasonography, and serum carotenoids were determined by high-pressure liquid chromatograph (HPLC).

RESULTS

In cases of early atherosclerosis, serum level of lutein was significantly lower than that in controls. Serum lutein was inversely associated with carotid IMT. Zeaxanthin and β-carotene were both negatively correlated with right common carotid artery stiffness β, elastic modulus (E(p)), and pulse wave velocity (PWV). After adjusting for age and gender, the associations remain significantly (P<0.05). However, there is no significant difference for zeaxanthin and β-carotene between the cases and controls.

CONCLUSION

These findings suggest that lutein may play a protective role in the prevention of early atherosclerosis, and the associations between serum carotenoids and arterial stiffness remained to be investigated.

Incremental Value of Arterial Stiffness Over Traditional Risk Factors in Predicting Subclinical Cardiovascular Remodeling in Patients With Moderate Chronic Renal Failure

Cardiovascular remodeling in chronic kidney disease (CKD) is responsible for the high mortality found in this condition. A total of 89 consecutive outpatients with stage III CKD and 52 patients with stage II CKD with similar degree of traditional atherosclerotic risk factors underwent routine echocardiographic and carotid Doppler examination, evaluating vascular and cardiac remodeling (intima—media thickness [IMT] and left ventricular mass index [LVMi]), and its relation with arterial stiffness, determined in the same examination, using an echo-tracking technique. Also the absolute values of LVMi and IMT were statistically similar between the 2 groups, their determinants were completely different, only in stage III the markers of renal impairment and arterial stiffness being independent predictors of cardiac and vascular modifications. We concluded that macroanatomical measurements do not fully describe cardiovascular remodeling in this setting. Arterial stiffness echo-tracking derived could add valuable information, being an easy-to-perform parameter during a routine examination.

Head-to-head comparison of the cardio-ankle vascular index between patients with acute coronary syndrome and stable angina pectoris

We aimed to evaluate whether there was a difference in the arterial stiffness assessed by the cardio-ankle vascular index (CAVI) between patients with acute coronary syndrome (ACS) and those with stable angina pectoris (SAP). A total of 199 consecutive patients, 79 with ACS and 120 with SAP, who underwent emergency or elective coronary revascularization were enrolled. The CAVI was measured within 2 days after the procedures, and was compared between the ACS and SAP patients. As parameters related to arteriosclerosis, carotid intima-media thickness (IMT) and number of stenotic coronary vessels were also evaluated. Although IMT was significantly greater in SAP patients (2.1±1.1 vs. 2.4±0.9; P=0.022), CAVI was significantly higher in ACS patients (10.0±1.7 vs. 9.3±1.3; P=0.0012). After an adjustment for the clinical parameters with a significant difference between the two patient groups, CAVI remained significantly higher in ACS patients than in SAP patients (odds ratio 1.92, 95% confidence interval 1.30-3.02; P=0.0023). A multiple linear regression analysis revealed that age (β=0.44; P<0.0001) and ACS (β=0.3; P<0.0001) were the independent determinants of CAVI. A significant decrease in CAVI was observed at 6 months of follow-up as compared with the acute phase in 18 patients with ACS (10.9±1.6 vs. 10.0±1.5; P=0.019). In conclusion, CAVI was significantly and independently higher in patients with ACS than in those with SAP, which might result from a transient increase in the CAVI caused by acute myocardial ischemia.