Brachial artery diameter and vasodilator response to nitroglycerine, but not flow-mediated dilatation, are associated with the presence and quantity of coronary artery calcium in asymptomatic adults

Sirtuin 1 and Vascular Function in Healthy Women and Men: A Randomized Clinical Trial Comparing the Effects of Energy Restriction and Resveratrol

Background: Sirtuin 1 (SIRT1) has been associated with longevity and protection against cardiometabolic diseases, but little is known about how it influences human vascular function. Therefore, this study evaluated the effects of SIRT1 activation by resveratrol and energy restriction on vascular reactivity in adults. Methods: A randomized trial allocated 48 healthy adults (24 women and 24 men), aged 55 to 65 years, to resveratrol supplementation or energy restriction for 30 days. Blood lipids, glucose, insulin, C-reactive protein, noradrenaline, SIRT1 (circulating and gene expression), and flow-mediated vasodilation (FMD) and nitrate-mediated vasodilation (NMD) were measured. Results: Both interventions increased circulating SIRT1 (p < 0.001). Pre- and post-tests changes of plasma noradrenaline were significant for both groups (resveratrol: p = 0.037; energy restriction: p = 0.008). Baseline circulating SIRT1 was inversely correlated with noradrenaline (r = -0.508; p < 0.01), and post-treatment circulating SIRT1 was correlated with NMD (r = 0.433; p < 0.01). Circulating SIRT1 was a predictor of FMD in men (p = 0.045), but not in women. SIRT1 was an independent predictor of NMD (p = 0.026) only in the energy restriction group. Conclusions: Energy restriction and resveratrol increased circulating SIRT1 and reduced sympathetic activity similarly in healthy adults. SIRT1 was independently associated with NMD only in the energy restriction group.

Assessment of vascular function in complete glycaemic spectrum

Purpose: The present study was conceived to delineate the point of vascular dysfunction along the glycemic spectrum (normoglycemic individuals with no family history of diabetes, normoglycemic individuals with family history of diabetes, prediabetic individuals, and diabetic individuals).Materials and Methods: In this cross-sectional comparative study, we enrolled 252 participants of both gender in the age group of 30-50 years. They were classified based on their family history of diabetes and glycemic status into four groups along the glycemic spectrum as mentioned above. We measured flow-mediated dilation (FMD) from brachial artery and vascular function biomarkers such as enthothelin-1 (ET-1), von Willbrand Factor (vWF), Vascular Endothelial Growth Factor (VEGF) to assess the vascular function. The comparison of data between groups were done using One Way ANOVA/Kruskal-Wallis followed by post-hoc analysis using LSD/Mann-Whitney U Test depending on the normality of the data. Spearman correlation was done between vascular function and plasma glucose levels to identify its relationship. Linear regression was carried out to identify the factors influencing the FMD across the glycemic spectrum.Results: We observed that vascular function negatively correlated with blood glucose levels. However, endothelin-1 and vWF derangement was there even in normoglycemic first degree relatives of diabetes (FDRD) and the derangement increased in prediabetes and diabetes. Physiological dysfunction in terms of decreased flow-mediated dilation starts from prediabetes only. VEGF derangement is found only in diabetic individuals.Conclusion: Vascular dysfunction is found even in normoglycemic FDRD and the derangement increased and compounded with the advancement of disease.

Endothelial function and dysfunction: Impact of sodium-glucose cotransporter 2 inhibitors

Diabetes mellitus is associated with endothelial dysfunction that leads to cardiovascular complications. Sodium-glucose cotransporter 2 (SGLT2) inhibitors demonstrated efficacy in glycemic control in type 2 diabetes patients with positive cardiovascular outcome. Recent research revealed a link between SGLT2 inhibition and improved macro- and microvascular endothelial functions. Mechanisms underlying this phenomenon could be due to the role of SLGT2 in the regulation of endothelial physiology. In this review, current knowledge and hypothesis on the link between SGLT2 and endothelial function were critically appraised and the impact of SGLT2 inhibitors on endothelial dysfunction in pre-clinical and clinical studies was discussed.

Sleep disorders and vascular responsiveness in patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is the most common systemic autoimmune disease characterized by chronic systemic inflammation. Half of the deaths of patients with RA are due to cardiovascular diseases (CVD), considered to be 1.5 to -2.0-fold that in the general population. Patients with RA also experience poor sleep, which by itself is associated with endothelial dysfunction, CVD events and sudden death. Our aim was to study the mechanistic pathways and the correlations between sleep efficiency and vascular reactivity of patients with RA.

METHODS AND RESULTS

A prospective study that evaluated quality of sleep using ACTi Graphs, vascular inflammation and endothelial function of 18 patients with RA. Inflammation was studied by levels of E-selectin, intercellular adhesion molecule 1 (ICAM-1) and NO in serum. Endothelial function was studied using the brachial artery plethysmography method. Eighteen RA patients (aged 57.56 ± 13.55 years; 16 women) with a long-standing active RA: Eight patients had impaired sleep efficiency and 10 had a good sleep efficiency. Those who had an impaired sleep had larger baseline diameters of the brachial artery (0.39 ± 0.08 cm vs. 0.32 ± 0.04 cm; P = 0.02). Negative correlations were found between baseline brachial artery diameter and sleep efficiency (P = 0.01), and with NO level (P = 0.04). Stepwise regression found that brachial artery diameter at baseline and NO level could predict sleep efficiency (r²  = 0.543, P = 0.01).

CONCLUSION

Vascular reactivity could predict quality of sleep in patients with RA. Quality of sleep may serve as an independent CVD risk factor in patients with RA.

Effects of Dapagliflozin on Endothelial Dysfunction in Type 2 Diabetes With Established Ischemic Heart Disease (EDIFIED)

Objectives

To evaluate the effect of the sodium-glucose cotransporter 2 inhibitor (SGLT2-I) dapagliflozin on endothelial function in patients with high-risk type 2 diabetes mellitus (T2DM).

Methods

This was a prospective, double-blind, randomized, placebo-controlled, clinical trial of patients with T2DM with underlying ischemic heart disease who were receiving metformin and insulin therapy (n = 81). After 12-weeks of additional therapy with either dapagliflozin (n = 40) or placebo (n = 41), systemic endothelial function was evaluated by change in flow-mediated dilation (ΔFMD), change in nitroglycerin-mediated dilation (ΔNMD) and surrogate markers including intercellular adhesion molecule 1 (ICAM-1), endothelial nitric oxide synthase (eNOS), high-sensitivity C-reactive protein (hs-CRP), and lipoprotein(a) (Lp[a]). Glycemic and lipid profiles were also measured.

Results

The dapagliflozin group demonstrated significant reductions of hemoglobin A1c (HbA1c) and fasting blood glucose (FBG) compared to the placebo group (ΔHbA1c –0.83 ± 1.47% vs –0.16 ± 1.25%, P = 0.042 and ΔFBG vs –0.73 ± 4.55 mmol/L vs –1.90 ± 4.40 mmol/L, P = 0.015, respectively). The placebo group showed worsening of ΔFMD while the dapagliflozin group maintained similar measurements pre- and posttherapy (P = not significant). There was a reduction in ICAM-1 levels in the dapagliflozin group (–83.9 ± 205.9 ng/mL, P < 0.02), which remained unchanged in the placebo group (–11.0 ± 169.1 ng/mL, P = 0.699). Univariate correlation analysis revealed a significant negative correlation between HbA1c and ΔFMD within the active group.

Conclusion

A 12-week therapy with dapagliflozin, in addition to insulin and metformin therapies, in high-risk patients resulted in significant reductions in HbA1c, FBG, and surrogate markers of the endothelial function. Although the dapagliflozin group demonstrated a significant association between reduction in HbA1c and improvement in FMD, there was no significant difference in FMD between the 2 groups.

Hemodynamic and autonomic effects of low-dose glyceryl trinitrate used to test endothelium-independent vasodilation of the brachial artery

Smooth muscle function is explored by sublingual glyceryl trinitrate (GTN) administration to compare with endothelium-dependent vasodilation of the brachial artery by flow-mediated-dilation (FMD). This study compared the hemodynamic and autonomic effects of the two most often used GTN dosages. In 80 essential hypertensive patients (HT) and 60 normotensive subjects (NT), FMD of the brachial artery and endothelium-independent response to sublingual GTN (25 μg and 400 μg) were evaluated by high-resolution ultrasound and automated image analysis. In 10 HT, muscle sympathetic nerve activity (MSNA) was also assessed by microneurography. HT showed significantly (p < .01) lower FMD (5.5 ± 3.3%) compared to NT (6.9 ± 2.2%). The response to GTN 25 μg tended to be lower (HT:7.2 ± 3.3%; NT:7.9 ± 2.9%; p = .06), whereas response to GTN 400 μg was similar (HT:14.3 ± 4.8%, NT:14.5 ± 4.7%, p = ns). Blood pressure (BP) reduction induced by GTN 400 μg (systolic-BP:-3.2 ± 7.7 mm Hg, diastolic-BP:-4.7 ± 5.0 mm Hg) was greater (p < .001) compared to GTN 25 μg (systolic-BP:-0.7 ± 5.8 mm Hg, diastolic-BP:-0.7 ± 4.4 mm Hg). Changes in heart rate were also greater (+5.6 ± 6.4 bpm versus -0.2 ± 5.4 bpm, p < .001). This behaviour was similar in either NT or HT. MSNA was significantly increased by GTN 400 μg (31 ± 7bursts/min to 41 ± 6bursts/min, p < .001) but not by 25 μg (33 ± 9bursts/min to 37 ± 11bursts/min, p = .19). In conclusion, the administration of low-dose GTN allows exploring endothelium-independent vasodilation in FMD protocols, inducing only modest hemodynamic and sympathetic responses.

Assessment of endothelium-independent vasodilation: from methodology to clinical perspectives

: Vascular response to exogenously administered nitroglycerine, an index of endothelium-independent vasodilation, has been used as a control test for the assessment of endothelium-dependent vasodilation (endothelial function) in humans. However, evidence has been accumulating that not only endothelium-dependent vasodilation but also endothelium-independent vasodilation per se is impaired in individuals with cardiovascular risk factors and cardiovascular disease. Impaired endothelium-independent vasodilation is associated with structural vascular alterations and alterations in vascular smooth muscle cells. Several methods, including assessment of vascular responses to vasoactive agents using angiography in a coronary artery and vascular responses to vasoactive agents using venous occlusion plethysmography and ultrasonography in a peripheral artery, are used to assess endothelium-independent vasodilation in humans. Measurement of endothelium-independent vasodilation is also useful for assessment of atherosclerosis and may be a predictor of future cardiovascular events. In this review, we focus on assessment of endothelium-independent vasodilation from methodology aspects to clinical perspectives.

Expert consensus and evidence-based recommendations for the assessment of flow-mediated dilation in humans

Endothelial dysfunction is involved in the development of atherosclerosis, which precedes asymptomatic structural vascular alterations as well as clinical manifestations of cardiovascular disease (CVD). Endothelial function can be assessed non-invasively using the flow-mediated dilation (FMD) technique. Flow-mediated dilation represents an endothelium-dependent, largely nitric oxide (NO)-mediated dilatation of conduit arteries in response to an imposed increase in blood flow and shear stress. Flow-mediated dilation is affected by cardiovascular (CV) risk factors, relates to coronary artery endothelial function, and independently predicts CVD outcome. Accordingly, FMD is a tool for examining the pathophysiology of CVD and possibly identifying subjects at increased risk for future CV events. Moreover, it has merit in examining the acute and long-term impact of physiological and pharmacological interventions in humans. Despite concerns about its reproducibility, the available evidence shows that highly reliable FMD measurements can be achieved when specialized laboratories follow standardized protocols. For this purpose, updated expert consensus guidelines for the performance of FMD are presented, which are based on critical appraisal of novel technical approaches, development of analysis software, and studies exploring the physiological principles underlying the technique. Uniformity in FMD performance will (i) improve comparability between studies, (ii) contribute to construction of reference values, and (iii) offer an easy accessible and early marker of atherosclerosis that could complement clinical symptoms of structural arterial disease and facilitate early diagnosis and prediction of CVD outcomes.

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Insulin resistance is associated with subclinical vascular disease in humans

Insulin resistance is associated with subclinical vascular disease that is not justified by conventional cardiovascular risk factors, such as smoking or hypercholesterolemia. Vascular injury associated to insulin resistance involves functional and structural damage to the arterial wall that includes impaired vasodilation in response to chemical mediators, reduced distensibility of the arterial wall (arterial stiffness), vascular calcification, and increased thickness of the arterial wall. Vascular dysfunction associated to insulin resistance is present in asymptomatic subjects and predisposes to cardiovascular diseases, such as heart failure, ischemic heart disease, stroke, and peripheral vascular disease. Structural and functional vascular disease associated to insulin resistance is highly predictive of cardiovascular morbidity and mortality. Its pathogenic mechanisms remain undefined. Prospective studies have demonstrated that animal protein consumption increases the risk of developing cardiovascular disease and predisposes to type 2 diabetes (T2D) whereas vegetable protein intake has the opposite effect. Vascular disease linked to insulin resistance begins to occur early in life. Children and adolescents with insulin resistance show an injured arterial system compared with youth free of insulin resistance, suggesting that insulin resistance plays a crucial role in the development of initial vascular damage. Prevention of the vascular dysfunction related to insulin resistance should begin early in life. Before the clinical onset of T2D, asymptomatic subjects endure a long period of time characterized by insulin resistance. Latent vascular dysfunction begins to develop during this phase, so that patients with T2D are at increased cardiovascular risk long before the diagnosis of the disease.

Metformin, lipids and atherosclerosis prevention

PURPOSE OF REVIEW

We provide an overview of recent publications that extend clinically relevant knowledge relating to metformin's effects on lipids and atherosclerotic vascular disease and/or provide insights into the drug's mechanisms of action on the heart and vasculature.

RECENT FINDINGS

We focus on original research in humans or in human tissues. Several recently completed randomized clinical trials have reported effects of metformin on surrogate measures of atherosclerotic vascular disease, including carotid-intima media thickness, vascular reactivity and calcification in people with Type 1 (T1D) and Type 2 (T2D) diabetes as well as nondiabetic dysglycaemia. In addition, observational studies have provided novel insights into the mechanisms of metformin's effects on carotid plaque, monocytes/macrophages, vascular smooth muscle and endothelial cells, including via 5'-adenosine monophosphate-activated protein kinase (AMPK) activation.

SUMMARY

Recent trials based on surrogate outcome measures have provided further data suggesting protective effects of metformin against vascular disease in youth and adults with Type 1 diabetes, as well as in adults with prediabetes and Type 2 diabetes. In parallel, human tissue and cell studies have provided new insights into pleiotropic effects of metformin and suggest novel drug targets. As metformin is an inexpensive agent with an established safety profile, larger scale clinical trials based on hard clinical outcomes [cardiovascular disease (CVD) events] are now indicated.

Programmed cell death 5 suppresses AKT-mediated cytoprotection of endothelium

Programmed cell death 5 (PDCD5) has been associated with human cancers as a regulator of cell death; however, the role of PDCD5 in the endothelium has not been revealed. Thus, we investigated whether PDCD5 regulates protein kinase B (PKB/AKT)-endothelial nitric oxide synthase (eNOS)-dependent signal transduction in the endothelium and affects atherosclerosis. Endothelial-specific PDCD5 knockout mice showed significantly reduced vascular remodeling compared with wild-type (WT) mice after partial carotid ligation. WT PDCD5 competitively inhibited interaction between histone deacetylase 3 (HDAC3) and AKT, but PDCD5^L6R, an HDAC3-binding-deficient mutant, did not. Knockdown of PDCD5 accelerated HDAC3-AKT interaction, AKT and eNOS phosphorylation, and nitric oxide (NO) production in human umbilical vein endothelial cells. Moreover, we found that serum PDCD5 levels reflect endothelial NO production and are correlated with diabetes mellitus, high-density lipoprotein cholesterol, and coronary calcium in human samples obtained from the cardiovascular high-risk cohort. Therefore, we conclude that PDCD5 is associated with endothelial dysfunction and may be a novel therapeutic target in atherosclerosis.

Effects of combined high-intensity aerobic interval training program and Mediterranean diet recommendations after myocardial infarction (INTERFARCT Project): study protocol for a randomized controlled trial

BACKGROUND

Exercise therapy has long been used for rehabilitation purposes after myocardial infarction (MI) and the benefit of regular physical exercise is also well-established. High-intensity interval training (HIIT) has been proposed to be more effective than continuous exercise for improving exercise capacity and health-related adaptations to low-volume (LV) and HIIT are also known. Furthermore, the Mediterranean diet (Mediet) has been widely reported to be a model of healthy eating for its contribution to a favorable health status and a better quality of life, reducing overall mortality. This study will investigate the effects of different HIIT programs (high-volume [HV] vs LV) and Mediet recommendations in clinical condition, cardiorespiratory fitness, biomarkers, ventricular function, and perception of quality of life after MI, and compared to an attention control group that is recommended to Mediet and physical activity without supervision sessions.

METHODS/DESIGN

In this randomized controlled trial, cardiorespiratory fitness, anthropometry, central and peripheral cardiovascular variables, biochemical and nutritional condition, and quality of life will be assessed before and after 16 weeks of intervention in 177 participants diagnosed with MI type 1. All participants will be randomly (1:1:1) assigned to the attention control group or two exercise groups (Mediet recommendations plus supervised aerobic exercise two days/week: (1) HV (40 min) HIIT group and (2) LV (20 min) HIIT group.

DISCUSSION

This study will be the first clinical trial comparing the effects of two different volumes of HIIT programs with Mediet recommendations for people after MI. The results of this study will provide good evidence for physical rehabilitation in this population.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02876952 . Registered on 24 August 2016.

Effect of Metformin on Vascular Function in Children With Type 1 Diabetes: A 12-Month Randomized Controlled Trial

CONTEXT

Children with type 1 diabetes have vascular dysfunction preceding atherosclerosis. Early interventions are needed to reduce cardiovascular disease.

OBJECTIVE

To evaluate the effect of metformin on vascular function in children with type 1 diabetes.

DESIGN

Twelve-month double-blind, randomized, placebo-controlled trial.

SETTING

Tertiary pediatric diabetes clinic.

PARTICIPANTS

Ninety children (8 to 18 years of age), >50th percentile body mass index (BMI), with type 1 diabetes.

INTERVENTION

Metformin (up to 1 g twice a day) or placebo.

MAIN OUTCOME MEASURE

Vascular function measured by brachial artery ultrasound [flow-mediated dilatation/glyceryl trinitrate-mediated dilatation (GTN)].

RESULTS

Ninety participants were enrolled [41 boys, 13.6 (2.5) years of age, 45 per group], 10 discontinued intervention, and 1 was lost to follow-up. On metformin, GTN improved, independent of glycosylated hemoglobin (HbA1c), by 3.3 percentage units [95% confidence interval (CI) 0.3, 6.3, P = 0.03] and insulin dose reduced by 0.2 U/kg/d (95% CI 0.1, 0.3, P = 0.001) during 12 months, with effects from 3 months. Metformin had a beneficial effect on HbA1c at 3 months (P = 0.001) and difference in adjusted HbA1c between groups during 12 months was 1.0%; 95% CI 0.4, 1.5 (10.9 mmol/mol; 95% CI 4.4, 16.4), P = 0.001. There were no effects on carotid/aortic intima media thickness, BMI, lipids, blood pressure, or other cardiovascular risk factors. Median (95% CI) adherence, evaluated by electronic monitoring, was 75.5% (65.7, 81.5), without group differences. More gastrointestinal side effects were reported on metformin (incidence rate ratio 1.65, 95% CI 1.08, 2.52, P = 0.02), with no difference in hypoglycemia or diabetic ketoacidosis.

CONCLUSIONS

Metformin improved vascular smooth muscle function and HbA1c, and lowered insulin dose in type 1 diabetes children. These benefits and good safety profile warrant further consideration of its use.

Impact of flow-mediated dilatation and coronary calcification in providing complementary information on the severity of coronary artery disease

BACKGROUND AND AIMS

Endothelial dysfunction and coronary artery calcification (CAC) may represent two distinct and separate processes in the development of coronary atherosclerosis. However, the interaction between these factors in determining the development of coronary artery disease (CAD) is uncertain.

METHODS

Brachial artery flow-mediated dilatation (FMD) was measured by high-resolution ultrasound before coronary angiography, in 156 patients undergoing coronary CT angiography on suspicion of CAD (M/F 100/56, age 67 ± 11yrs). CAC score was measured with the Agatston method.

RESULTS

The discriminative performance of FMD and CAC score in predicting the presence of type C lesion, multivessel disease, and high SYNTAX score (>22) was determined by ROC curve analysis. The optimal cutoff values for type C lesion were FMD ≤3.70% (AUC 0.663, p = 0.037) and log(CACscore+1)≥ 6.452 (AUC 0.735, p = 0.006). The combination of these cutoff values identified the lesion with the highest predictive accuracy of 82%. In addition, the optimal cutoff values for multivessel disease were FMD ≤5.40% (AUC 0.689, p = 0.001) and log(CACscore+1)≥ 5.914 (AUC 0.731, p = 0.001), while those for high SYNTAX score were FMD ≤4.10% (AUC 0.664, p = 0.020) and log(CACscore+1) ≥6.693 (AUC 0.817, p = 0.001). The combined measurement of each cutoff value identified multivessel disease and high SYNTAX score with predictive accuracy of 77% and 83%, respectively, which were significantly higher than each parameter alone, with the exception of the predictive accuracy of log(CACscore+1) for high SYNTAX score (p = 0.083).

CONCLUSIONS

Endothelial dysfunction and CAC may provide complementary information in predicting the extent and severity of coronary artery disease.

Cardiovascular risk assessment in patients with rheumatoid arthritis: a correlative study of noninvasive arterial health testing

This study aimed to determine the relationship between noninvasive measures of arterial health and both estimated 10-year cardiovascular risk and measures of disease activity over time in established rheumatoid arthritis. Fifty rheumatoid arthritis patients underwent noninvasive arterial health testing (brachial artery reactivity, aortic augmentation index [AIx], pulse wave velocity, carotid artery intima-media thickness, and carotid artery plaque presence) and assessment of clinical disease activity (tender or swollen joint counts, Clinical Disease Activity Index [CDAI], and Health Assessment Questionnaire II [HAQ-II]). Clinical measures during 3 years before the study visit were averaged. Arterial health testing was compared with the American Heart Association/American College of Cardiology (AHA/ACC) Pooled Cohort Equation. Spearman methods identified correlations between disease activity measures, cardiac biomarkers, and arterial health parameters. Among the patients (mean age, 57.5 years), disease activity was moderate (mean [SD] CDAI, 16.9 [15.3]). At the study visit, corrected aortic augmentation index correlated with CDAI (r = 0.37, P = .009) and HAQ-II (r = 0.33, P = .02). AIx correlated with time-averaged tender joint count (r = 0.37, P = .008), CDAI (r = 0.36, P = .01), HAQ-II (r = 0.36, P = .01), swollen joint count (r = 0.36, P = .10), patient global assessment (r = 0.33, P = .02), physician global assessment (r = 0.35, P = .01), and pain score (r = 0.38, P = .007). The AHA/ACC low-risk group (<5% 10-year risk) had highest prevalence of carotid plaques. Arterial health testing may identify increased risk of cardiovascular disease compared with risk obtained through AHA/ACC Pooled Cohort Equation. Measures of arterial stiffness correlate with the burden of disease activity over time.

Effect of vitamin D3 treatment on endothelial function in obese adolescents

BACKGROUND

Obesity in children is associated with vitamin D deficiency and endothelial dysfunction. It is not known if treatment with vitamin D improves endothelial function in obese adolescents.

OBJECTIVE

This study aimed to determine whether treatment with vitamin D3 improves endothelial function in obese adolescents.

METHODS

Nineteen obese adolescents, 13-18 years of age, with 25-hydroxy vitamin D (25[OH]D) levels <75 nmol L(-1) were treated with 100 000 IU vitamin D3 orally once a month for 3 months in an open-label, single-centre prospective trial. Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery at study entry and 1 month after the third dose of vitamin D3 . Biochemical parameters, including calcium, fasting lipids, glucose, insulin and high-sensitivity C-reactive protein, were also obtained.

RESULTS

Mean 25(OH)D levels increased from 55.9 ± 12.2 to 86.9 ± 16.7 nmol L(-1) (P < 0.01). There was no correlation between 25(OH)D levels and brachial artery FMD. The brachial artery FMD (%) did not change significantly following vitamin D3 treatment (9.5 ± 3.53 vs. 10.3 ± 3.83, P = 0.83). Serum parathyroid hormone declined from 3.8 ± 1.5 to 3.1 ± 1 pmol L(-1) (P = 0.01). The remainder of biochemical measurements did not show a significant change.

CONCLUSIONS

Treatment with vitamin D3 , 100 000 IU once a month for 3 months was effective in increasing 25(OH)D levels in obese adolescents but did not impact endothelial function.

Varying patterns of brachial artery flow-mediated dilatation in women with polycystic ovary syndrome and controls: An application of the group-based trajectory modeling

PURPOSE

To identify changing patterns of absolute change in brachial artery lumen diameter (LD) after reactive hyperemia in women with polycystic ovary syndrome (PCOS) and controls and to quantify the association of PCOS status and participants' factors with these patterns.

METHODS

Brachial flow-mediated dilation was measured in 128 women with PCOS and 148 controls aged 30-60 years. Group-based trajectory modeling was used to investigate absolute change in LD every 30 seconds for 2 minutes after occluding cuff deflation. Multinomial logistic regression was used to identify factors associated with trajectories.

RESULTS

Three patterns emerged, namely nondilators (42.2%), dilators (44.6%), and enhanced dilators (13.0%). The proportion of women with PCOS did not differ across groups. Independently of age and PCOS status, larger baseline LD (odds ratio; 95% confidence interval: 2.51; 1.29, 4.89) and lower insulin levels (0.70; 0.52, 0.93) were associated with nondilators rather than with dilators. Higher total cholesterol was associated with dilators in women with PCOS but with nondilators in controls.

CONCLUSIONS

Trajectory modeling identified distinct patterns of change in LD and factors associated with the endothelial response. This method may be a useful tool to understand the brachial flow-mediated vasodilator response.

Volume elastic modulus of the brachial artery and coronary artery stenosis in patients with suspected stable coronary artery disease

This study aimed to examine the association between the non-invasive measurement of the brachial artery volume elastic modulus (V E), an index of arterial stiffness, and the presence of coronary artery stenosis in patients with suspected stable coronary artery disease (CAD). A total of 135 patients with suspected stable CAD (87 men, mean age, 64 ± 12 years) underwent oscillometric measurement of the brachial artery to obtain V E. Coronary angiography was thereafter carried out to diagnose CAD, defined as having ≥75 % stenosis in the epicardial coronary arteries. V E was significantly higher in patients with CAD (1.94 ± 0.34 mmHg/%) than in those without CAD (1.71 ± 0.35 mmHg/%, P < 0.001). In multiple logistic regression analysis, V E was an independent predictor for the presence of CAD (odds ratio 1.19 per 0.1 mmHg/% increase, 95 % CI 1.04-1.51) even after adjusting for multiple potential confounders including the Framingham risk score (FRS). The area under the curve of the receiver operating characteristic curve analysis for discriminating CAD increased significantly after the addition of V E to the FRS (from 0.75 to 0.81, P = 0.034). The category-free net reclassification improvement and the integrated discrimination improvement by adding V E to the FRS were 0.476 (95 % CI 0.146-0.806) and 0.086 (95 % CI 0.041-0.132), respectively. In conclusion, the brachial V E was significantly associated with the presence of coronary artery stenosis. The additional measurement of V E to the FRS improved the ability to identify patients with coronary artery stenosis among those with suspected stable CAD.

The association of brachial artery diameter with noncalcified coronary plaque burden in apparently healthy individuals

OBJECTIVE

Coronary atherosclerosis has been associated with systemic arterial remodeling even in nonatherosclerotic vessels. However, it is not known whether systemic remodeling is differentially associated with the cumulative atherosclerotic process, reflected by putatively quiescent calcified plaque (CP), or with active atherosclerosis, consisting of noncalcified plaque (NCP). We thus examined the association of brachial artery diameter (BAD), an artery that does not suffer clinical atherosclerosis, with the presence and the extent of coronary CP and NCP.

METHODS

We studied 688 apparently healthy, asymptomatic participants from 350 families with a history of early-onset coronary artery disease (<60 years of age) by measuring coronary artery disease risk factors and coronary plaque using dual-source computed tomographic angiography. Plaque volumes were quantified using a validated automated method. BAD was measured during diastole using B-mode ultrasound. The association of resting BAD with any detectable plaque, and log-transformed CP and NCP volumes if detectable, was tested using generalized estimating equations adjusted for age, sex, race, current smoking, diabetes, hypertension, BMI, and non-HDL and HDL cholesterol.

RESULTS

Higher quintiles of BAD were associated with greater age and male sex (both P<0.001). In the fully adjusted analysis, CP volume was not associated with BAD (P=0.65) but a 1 ml greater NCP volume was associated with a 0.65 mm larger BAD (P=0.027).

CONCLUSION

Our results suggest that systemic arterial remodeling of nonatherosclerotic arteries is a dynamic process that is correlated with the extent of putatively active atherosclerotic processes in distant beds but not with inactive accumulated plaque burden.

Effects of exercise training on arterial function in type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Controversy exists among trials assessing whether exercise can improve arterial function in type 2 diabetes mellitus (T2DM) subjects. Therefore the aim of this study was to systematically review and quantify the effects of exercise on arterial function in T2DM subjects.

METHODS

MEDLINE, Cochrane, Scopus and Web of Science were searched up until January 2013 for randomized controlled trials evaluating the effects of exercise interventions lasting 4 weeks or more on arterial function in T2DM subjects. Flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the brachial conduit artery were considered for assessment of arterial endothelial function and smooth muscle function, respectively.

RESULTS

Five randomized trials comparing exercise and control groups (overall n = 217) met the inclusion criteria. The mean exercise characteristics were as follows: 3.6 sessions per week, 67.5 min per session, intensity at 74.4 % of the maximum heart rate (HR(max)), for 14 weeks. The post-intervention mean difference in FMD favoured the exercise groups over the control groups (2.23 %; P < 0.0001). No significant post-intervention mean difference in NMD (1.22 %; P = 0.29) was found between the groups. Neither heterogeneity nor publication bias was detected among the trials.

CONCLUSION

Exercise training alone improved FMD, showing its capacity to restore arterial endothelial function in T2DM subjects. However, further research is needed to determine whether longer and/or more intense exercise interventions could enhance arterial smooth muscle function in this population.

Value of coronary artery calcium score to predict severity or complexity of coronary artery disease

BACKGROUND

Prediction of severity or complexity of coronary artery disease (CAD) is valuable owing to increased risk for cardiovascular events. Although the association between total coronary artery calcium (CAC) score and severity of CAD, Gensini score was not used, it has been previously demonstrated. There is no information about the association between total CAC score and complexity of CAD.

OBJECTIVES

To investigate the association between severity or complexity of coronary artery disease (CAD) assessed by Gensini score and SYNTAX score (SS), respectively, and coronary artery calcium (CAC) score, which is a noninvasive method for CAD evaluation in symptomatic patients with accompanying significant CAD.

METHODS

Two-hundred-fourteen patients were enrolled. Total CAC score was obtained before angiography. Severity and complexity of CAD was assessed by Gensini score and SS, respectively. Associations between clinical and angiographic parameters and total CAC score were analyzed.

RESULTS

Median total CAC score was 192 (23.0-729.8), and this was positively correlated with both Gensini score (r: 0.299, p<0.001) and SS (r: 0.577, p<0.001). At multivariate analysis, it was independently associated with age (ß: 0.154, p: 0.027), male gender (ß: 0.126, p: 0.035) and SS (ß: 0.481, p<0.001). Receiver-operating characteristic (ROC) curve analysis revealed a cut-off value>809 for SS>32 (high SS tertile).

CONCLUSION

In symptomatic patients with accompanying significant CAD, total CAC score was independently associated with SS and patients with SS>32 may be detected through high Agatston score.

The peroxisome proliferator activated receptor-γ pioglitazone improves vascular function and decreases disease activity in patients with rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is associated with heightened mortality due to atherosclerotic cardiovascular disease (CVD). Inflammatory pathways in RA negatively affect vascular physiology and promote metabolic disturbances that contribute to CVD. We hypothesized that the peroxisome proliferator activated receptor‐γ (PPAR‐γ) pioglitazone could promote potent vasculoprotective and anti‐inflammatory effects in RA.

Methods and Results

One hundred forty‐three non‐diabetic adult RA patients (76.2% female, age 55.2±12.1 [mean±SD]) on stable RA standard of care treatment were enrolled in a randomized, double‐blind placebo controlled crossover trial of 45 mg daily pioglitazone versus placebo, with a 3‐month duration/arm and a 2‐month washout period. Pulse wave velocity of the aorta (PWV), brachial artery flow mediated dilatation (FMD), nitroglycerin mediated dilatation (NMD), microvascular endothelial function (reactive hyperemia index [RHI]), and circulating biomarkers of inflammation, insulin resistance, and atherosclerosis risk all were quantified. RA disease activity was assessed with the 28‐Joint Count Disease Activity Score (DAS‐28) C‐reactive protein (CRP) and the Short Form (36) Health Survey quality of life questionnaire. When added to standard of care RA treatment, pioglitazone significantly decreased pulse wave velocity (ie, aortic stiffness) (P=0.01), while FMD and RHI remained unchanged when compared to treatment with placebo. Further, pioglitazone significantly reduced RA disease activity (P=0.02) and CRP levels (P=0.001), while improving lipid profiles. The drug was well tolerated.

Conclusions

Addition of pioglitazone to RA standard of care significantly improves aortic elasticity and decreases inflammation and disease activity with minimal safety issues. The clinical implications of these findings remain to be established.

Clinical Trial Registration

URL: ClinicalTrials.gov Unique Identifier: NCT00554853.

Vascular smooth muscle function in type 2 diabetes mellitus: a systematic review and meta-analysis

AIMS/HYPOTHESIS

In type 2 diabetes, in contrast to the well-documented endothelial dysfunction, studies assessing vascular smooth muscle (VSM) function have yielded discrepant results over the last two decades. We therefore sought to determine whether or not VSM function is impaired in individuals with type 2 diabetes.

METHODS

We conducted a systematic search of MEDLINE, Cochrane, Scopus and Web of Science databases, from their respective inceptions until December 2012, for articles evaluating VSM function in individuals with type 2 diabetes. A meta-analysis was performed to compare the standardised mean difference (SMD) in VSM function between individuals with type 2 diabetes and age-matched controls. Subgroup analyses and meta-regression were used to identify sources of heterogeneity.

RESULTS

Twenty-seven articles (1,042 individuals with type 2 diabetes and 601 control subjects) were included in this analysis. VSM function was significantly impaired in diabetic compared with control subjects (SMD -0.68, 95% CI -0.84, -0.52; p < 0.001). Although moderate heterogeneity among studies was found (I (2) = 52%), no significant publication bias was detected. Subgroup analyses showed a further decline in VSM function assessed in the microcirculation compared with the macrocirculation of individuals with type 2 diabetes (p = 0.009). In meta-regression, VSM function in the microcirculation was inversely associated with BMI and triacylglycerols and was positively associated with HDL-cholesterol.

CONCLUSIONS/INTERPRETATION

In addition to the endothelium, the VSM is a source of vascular dysfunction in type 2 diabetes. An exacerbation of VSM function in the microcirculation may be a distinctive feature in type 2 diabetes.

Concomitant carotid plaque development and brachial artery diameter enlargement: a retrospective, recall-based study in postmenopausal women

BACKGROUND AND AIM

To verify if the carotid plaque development is concomitant to brachial artery diameter enlargement, in healthy postmenopausal women.

METHODS AND RESULTS

This is a retrospective, recall study. We enrolled 40 postmenopausal women, selected from a database for the period 2000-2008, not affected by subclinical carotid atherosclerosis and without risk factors for cardiovascular disease. At the recall visit, carotid and brachial duplex scan was again obtained. The incidence of plaque was 30% after a mean follow-up period of 60 months. There were no differences in baseline characteristics between subjects developing carotid atherosclerosis and subjects who did not, except for the brachial diameter change, follow-up and heart rate. The logistic-regression analysis confirmed that only brachial diameter change resulted to be correlated with the development of carotid atherosclerosis.

CONCLUSION

Brachial artery diameter increase is concomitant to carotid plaque development. Vascular enlargement could not be a focal change but a systemic process associated with atherosclerotic plaque development. Brachial diameter could be a tool with a predictive significance.

Oscillometric measurement of brachial artery cross-sectional area and its relationship with cardiovascular risk factors and arterial stiffness in a middle-aged male population

An enlarged arterial diameter is associated with an increased risk for cardiovascular disease. This study examined the relationship of noninvasively measured brachial artery cross-sectional area with cardiovascular risk factors and arterial stiffness in a middle-aged male population. Absolute volumetric changes of the brachial artery were measured with a newly developed oscillometric method during a general health examination in 387 men (mean age: 38±9 years) without known cardiovascular disease. Based on the measurement, the estimated area (eA) of the brachial artery at end-diastole was obtained. Brachial artery volume elastic modulus (VE) and brachial-ankle pulse wave velocity (baPWV) were simultaneously measured as indices of arterial stiffness by the same device. The relationships of eA with cardiovascular risk factors, including age, obesity, hypertension, dyslipidemia, impaired fasting glucose/diabetes mellitus (IFG/DM), hyperuricemia, smoking and their associated continuous variables, as well as VE and baPWV, were examined. Overall, the mean eA was 12.9 ± 2.9 mm². The eA was significantly higher in subjects with obesity, hypertension or IFG/DM than in those without each of these risk factors. In a multiple linear regression analysis, body mass index (β=0.31, P<0.001), age (β=0.25, P<0.001), systolic blood pressure (β=0.16, P=0.004) and pulse rate (β=-0.13, P=0.005) were independent determinants of eA. In contrast, neither VE nor baPWV were selected as independent determinants of eA. In conclusion, enlarged brachial artery cross-sectional area was significantly associated with cardiovascular risk factors such as age, body mass index and systolic blood pressure, but it was not associated with increased arterial stiffness.

Brachial artery diameter and the right ventricle: the Multi-Ethnic Study of Atherosclerosis-right ventricle study

BACKGROUND

Endothelial dysfunction is associated with left ventricular morphology and long-term cardiovascular outcomes. The purpose of this study was to assess the relationship between both baseline brachial artery diameter and peripheral endothelial function (assessed by brachial artery ultrasonography) and right ventricular (RV) mass, RV end-diastolic volume (RVEDV), and RV ejection fraction (RVEF).

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac MRI and brachial artery ultrasonography on participants without clinical cardiovascular disease. Baseline brachial artery diameter and flow-mediated dilation were assessed.

RESULTS

The mean age was 60.9 years, and 49.4% of subjects were men (n = 2,425). In adjusted models, larger brachial artery diameter was strongly associated with greater RV mass (β = 0.55 g, P &lt; .001), larger RVEDV (β = 3.99 mL, P &lt; .001), and decreased RVEF (β = -0.46%, P = .03). These relationships persisted after further adjustment for the respective left ventricular parameters. Flow-mediated dilation was not associated with RV mass or RVEF and was only weakly associated with RVEDV.

CONCLUSIONS

Brachial artery diameter is associated with greater RV mass and RVEDV, as well as lower RVEF. Changes in the systemic arterial circulation may have pathophysiologic links to pulmonary vascular dysfunction or abnormalities in RV perfusion.

The association between coronary flow reserve and development of coronary calcifications: a follow-up study for 11 years in healthy young men

AIMS

We studied whether a reduced coronary flow reserve (CFR) in healthy young men independently predicts the presence of coronary artery disease as assessed by coronary artery calcification after 11 years of follow-up.

METHODS AND RESULTS

Coronary microvascular dysfunction in early stages of coronary artery disease can be detected as a reduced CFR by positron emission tomography (PET). Seventy-seven healthy, lean, normotensive, non-smoking and non-diabetic men underwent 15-Oxygen ((15)O) water myocardial perfusion PET at rest and during vasodilator stress at the age of 35 ± 4 years at baseline. The subjects were followed-up for 11 ± 1 years and the coronary artery calcium score (CCS) was measured with computed tomography at the end of the follow-up. At the end of the follow-up, 30 (39%) individuals had CCS >0 (average 65 ± 93), but none had clinical symptoms or evidence of ischaemia in stress echocardiography. At baseline, the average CFR was comparable in individuals with CCS >0 and CCS = 0 (4.2 ± 1.4 vs. 4.0 ± 1.2, P = 0.4). Logistic regression analysis showed no associations between CFR, serum glucose, cholesterol levels, systolic blood pressure or body mass index at baseline and CCS at the end of the follow-up (P always >0.05). The presence of CCS (CCS >0) was associated with higher systolic and diastolic blood pressures at the end of the follow-up (137 ± 18 vs. 128 ± 11 mmHg, P = 0.04 and 86 ± 12 vs. 78 ± 11 mmHg, P = 0.01).

CONCLUSIONS

Coronary reactivity to vasodilator-induced hyperaemia as assessed by perfusion PET was not predictive of the presence of coronary calcification after 11 years of follow-up in asymptomatic men with very low likelihood of coronary artery disease.

Determinants of vascular function in patients with type 2 diabetes

Background

Type 2 diabetes mellitus (T2DM) is independently associated with an increased risk for cardiovascular diseases that is primarily due to the early development of advanced atherosclerotic vascular changes. The aim of our study was to investigate the predictors of vascular dysfunction in T2DM patients.

Methods

We studied 165 T2DM patients without known macrovascular or microvascular disease. Standard demographic (age, gender, cardiovascular risk factors, medications), clinical (body mass index, blood pressure) and laboratory (glucose, glycated hemoglobin, lipids, renal function) parameters were included in analyses. Brachial artery flow-mediated dilation (FMD), nitrate mediated dilation (NMD) and Carotid-Femoral Pulse Wave Velocity (PWV) were measured.

Results

Median age was 66 years and duration since T2DM diagnosis was 10 years, 70% were females and 79% hypertensives, while only 10% had a glycated hemoglobin <7%. FMD was positively associated with NMD (r 0.391, P < 0.001), while PWV was inversely associated with FMD (r -0.218, P = 0.014) and NMD (r -0.309, P < 0.001). Time since diagnosis of diabetes was the single independent predictor of FMD (β -0.40, P = 0.003). Increased age and fasting glucose and the presence of hypertension were independent predictors of decreased NMD (P < 0.001). Increased age and systolic blood pressure were independently associated with increased PWV (P < 0.001).

Conclusions

In T2DM patients, impairment of endothelium-dependent vasodilation was independently associated only with longer diabetes duration while no association with other established risk factors was found. Vascular smooth muscle dysfunction and increased arterial stiffness were more prominent in older T2DM patients with hypertension. Worse glycemic control was associated with impaired vascular smooth muscle function.

Grape polyphenols reduce blood pressure and increase flow-mediated vasodilation in men with metabolic syndrome

We evaluated the effects of grape polyphenols in individuals classified with metabolic syndrome (MetS). Men (n = 24) aged 30-70 y were randomly assigned to consume either a freeze-dried grape polyphenol powder (GRAPE) or a placebo for 30 d in a double-blind, crossover design, separated by a 3-wk washout period. Participants were asked to maintain their usual diet and physical activity during the study and abstain from consuming polyphenol-rich foods. MetS criteria including blood pressure (BP) and markers of vascular endothelial function including brachial artery flow-mediated vasodilation (FMD), plasma total nitrite + nitrate (NOx) to estimate NO production, plasma soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured at the end of each dietary period. Systolic BP (P < 0.0025) and plasma sICAM-1 concentrations (P < 0.025) were lower, whereas the FMD response was higher (P < 0.0001), during the GRAPE compared with the placebo period. In addition, changes in sVCAM-1 concentrations between periods were positively correlated with changes in systolic BP (r = 0.45; P < 0.05). Although NOx concentrations did not differ between periods, changes in systolic BP were negatively correlated with changes in NOx concentrations (r = -0.44; P < 0.05), indicating the vasodilating properties of NO. Other MetS variables did not differ between the GRAPE and placebo periods. These results suggest that GRAPE polyphenols may potentiate vasorelaxation and reduce BP and circulating cell adhesion molecules, resulting in improvements in vascular function.

Normal vascular function as a prerequisite for the absence of coronary calcification in patients free of cardiovascular disease and diabetes

BACKGROUND

The absence of coronary artery calcium (CAC) is a marker of very low cardiovascular risk. Endothelial cells may have an effect on the initiation and propagation of arterial calcification. We aimed to identify the relationship between the absence of CAC and endothelial function in individuals without cardiovascular disease and diabetes.

METHODS AND RESULTS

CAC was assessed using electron-beam computed tomography and the calcium score was then computed. Endothelial function was measured by assessing reactive hyperemia-induced vasodilation and expressed by the reactive hyperemia index (RHI). Of 82 patients, 39 had non-detectable calcium (CAC score=0) and 43 had a CAC score >0. In the CAC score=0 group, the prevalence of normal endothelial function was 84.6%, compared to 48.8% in the CAC score >0 group, P=0.001. The absence of CAC was highly correlated with normal endothelial function (γ=0.704, P<0.001). On average, endothelial function was significantly better in the CAC score=0 group than in the CAC score >0 group (RHI 2.2±0.6 vs. 1.8±0.5, P=0.002). In a multivariate logistic regression model, only normal endothelial function (odds ratio [OR] 5.03, 95% confidence interval [CI] 1.55-16.27, P=0.007) and age (years) (OR 0.91, 95% CI 0.86-0.96, P=0.002) were independently associated with the absence of CAC.

CONCLUSIONS

Normal functional status of the vasculature may be important for the prevention of coronary calcification and may partly account for the low cardiovascular risk of absent CAC.

Association between bilirubin and cardiovascular disease risk factors: using Mendelian randomization to assess causal inference

BACKGROUND

Elevated serum bilirubin has been associated with reduced risk of cardiovascular disease (CVD). However, serum bilirubin is also related with several potential confounders related to CVD, such as obesity. Mendelian randomization has been proposed as a method to address challenges to validity from confounding and reverse causality. It utilizes genotype to estimate causal relationships between a gene product and physiological outcomes. In this report, we demonstrate its use in assessing direct causal relations between serum bilirubin levels and CVD risk factors, including obesity, cholesterol, measures of vascular function and blood pressure.

METHODS

Study subjects included 868 asymptomatic individuals. Study subjects were genotyped at the UGT1A1*28 locus, which is strongly associated with bilirubin levels.

RESULTS

Serum bilirubin levels were inversely associated with levels of several cardiovascular disease risk factors, including body mass index (p=0.003), LDL (p=0.0005) and total cholesterol (p=0.0002). In contrast, UGT1A1*28 genotype, a known cause of elevated bilirubin levels, was not significantly associated with any of these traditional CVD risk factors. We did observe an association between genotype and brachial artery diameter (p=0.003) and cold pressor reactivity (p=0.01).

CONCLUSIONS

Our findings imply that the observed association of serum bilirubin levels with body mass index and cholesterol are likely due to confounding and suggest that previously established CVD benefits of increased bilirubin may in part be mediated by the early regulation of vascular structure and reactivity.

Prevalence and predictors of abnormal arterial function in statin-treated type 2 diabetes mellitus patients

Arterial dysfunction (AD) in type 2 diabetes mellitus (T2DM) predicts cardiovascular events. The objective was to investigate the prevalence and predictors of AD in statin-treated T2DM patients. We measured flow-mediated (FMD) and nitrate-mediated (NMD) brachial artery dilatation in 86 statin-treated T2DM patients. Patients were classified into 2 groups: normal arterial function (FMD ≥3.7% with NMD ≥11.9%) or AD (FMD <3.7% with or without NMD <11.9%). Endothelial dysfunction without smooth muscle cell dysfunction (ED) was defined as FMD less than 3.7% with NMD of at least 11.9%, and endothelial dysfunction with smooth muscle cell dysfunction (ED/SMD) was defined as FMD less than 3.7% with NMD less than 11.9%. Predictors of arterial function were investigated using linear and logistic regression methods. The prevalence of AD was 33.7% (23.2% with ED and 10.5% with ED/SMD). In multivariate linear regression, history of hypertension (P < .01), statin dose (P < .05), and estimated glomerular filtration rate (eGFR) (P = .02) were significant predictors of FMD. Sex (P < .01) and creatinine (P = .03) or eGFR (P = .02) predicted NMD. In multivariate logistic regression, the independent predictors of AD were history of hypertension (odds ratio [OR], 8.79; 95% confidence interval, 2.14-36.12; P < .01), age (OR, 1.08; 1.01-1.17; P = .03), and statin dose (OR, 0.33; 0.12-0.87; P = .02). A history of hypertension (OR, 8.99; 1.87-43.26; P < .01) was the sole independent predictor of ED; eGFR (OR, 0.01; 0.00-0.26; P < .01) independently predicted ED/SMD. Our data suggest that one third of statin-treated diabetic patients have residual AD, mainly due to ED alone. Earlier identification and treatment of hypertension and renal impairment may improve AD and further decrease cardiovascular risk in such patients.

Brachial artery diameter measurement: a tool to simplify non-invasive vascular assessment

AIM

The mechanisms of vascular remodeling have attracted great interest since it is a phenomenon related to cardiovascular diseases. We would like to examine studies that contributed to clarify the remodeling mechanisms, to explore the different faces of atherosclerosis process.

DATA SYNTHESIS

A number of invasive and non-invasive vascular assessment methods were developed, to detect the early sign of atherosclerosis. It became clear that the invasive tests were not applicable to large-scale studies. Consequently, a non-invasive test was developed. Studies showed that the endothelial function evaluation is a predictor of future cardiac events in individuals at cardiovascular risk and in those with established disease. However, analyzing several works, an interesting concept emerged, i.e., the inverse relation between endothelium-dependent dilation and vessel size, since large vessel tend not to dilate significantly. This notion emphasized the role of basal diameter on vascular response. In particular, as brachial artery diameter is the measure on which FMD is based, it could add more information in clinical evaluation, simplifying the assessment. Several studies showed that morphological change of brachial artery is a better indicator of the extent of coronary disease rather than FMD. Other studies showed that brachial diameter has predictive significance in the stratification of cardiovascular risk.

CONCLUSION

Brachial diameter is a useful and simple tool. It should be incorporated into the overall assessment of cardiovascular risk but further studies are warranted to determine the final place of brachial diameter assessment in routine clinical setting.

Inflammatory effects of blood leukocytes: association with vascular function in neuropeptide Y proline 7-genotyped type 2 diabetes patients

OBJECTIVE

We investigated the associations of inflammatory blood cell activation with vascular parameters in patients with type 2 diabetes to elucidate the possible mechanisms of accelerated atherosclerosis observed in subjects with the Leucine 7 to Proline 7 polymorphism (Leu7Pro) in the neuropeptide Y (NPY).

METHODS

Our study included 31 Caucasian patients with type 2 diabetes; 12 of them had the Leu7Pro7 (heterozygous), and 19 had the Leu7Leu7 (wild type) genotype. Vascular parameters were determined by ultrasound methods. Leukocyte analyses were performed from blood samples using flow cytometry. NPY concentrations were determined in plasma.

RESULTS

The amount of platelet-granulocyte complexes was positively correlated with NPY concentration (p=0.008) and carotid intima-media thickness (p=0.035) in the Leu7Pro7 group. Interferon gamma (IFN-γ) expression in monocytes correlated negatively with brachial artery flow-mediated dilatation also in the Leu7Pro7 group (p=0.037). The expression of tissue factor on monocytes correlated negatively with brachial artery diameter in the Leu7Pro7 patients as well (p=0.019).

CONCLUSION

The results indicate significant associations between inflammatory cell activation in blood and vascular atherosclerosis in genetically prone subjects, and provide possible mechanistic information about the role of NPY and the Leu7Pro polymorphism in the development of atherosclerosis.

Noninvasive vascular function measurement in the community: cross-sectional relations and comparison of methods

BACKGROUND

Several methods of noninvasive vascular function testing have been suggested for cardiovascular risk screening in the community. A direct comparison of the different methods and their relation to classical cardiovascular risk factors in a large cohort is missing.

METHODS AND RESULTS

In 5000 individuals (mean age, 55.5 ± 10.9 years; age range, 35 to 74 years; women, 49.2%) of the population-based Gutenberg Heart Study, we performed simultaneous measurement of flow-mediated dilation (FMD) and peripheral arterial volume pulse determined by infrared photo (reflection index) and pneumatic plethysmography (PAT) and explored their associations. All function measures were recorded at baseline and after reactive hyperemia induced by 5-minute brachial artery occlusion. Correlations between different measures of vascular function were statistically significant but moderate. The strongest association for hyperemic response variables was observed for PAT ratio and FMD (Spearman r = 0.17; age- and sex-adjusted partial correlation, 0.068). Classical risk factors explained between 15.8% (baseline reflection index) and 58.4% (brachial artery diameter) of the baseline values but only accounted for 3.2% (reflection index), 15.4% (FMD), and 13.9% (PAT ratio) of the variability of reflective hyperemic response. Regression models varied in their relations to classical risk factors for the individual vascular function measures. Consistently associated with different vascular function methods were age, sex, body mass index, and indicators of hypertension. Peripheral tonometry also showed a relation to fasting glucose concentrations.

CONCLUSIONS

Noninvasive measures of conduit artery and peripheral arterial function are modestly correlated, differ in their relation to classical cardiovascular risk factors, and may thus reflect different pathologies.

Nitroglycerin-mediated vasodilatation of the brachial artery may predict long-term cardiovascular events irrespective of the presence of atherosclerotic disease

AIM

Nitroglycerin-mediated vasodilatation (NMD) provides insight into the NTG-induced bioactivity of smooth muscle. It is plausible that in dysfunctional smooth muscle cells, the response to nitroglycerin may become blunted. The relationship between impaired brachial artery NMD and subsequent cardiovascular events is not well established.

METHODS

We examined brachial artery flow-mediated dilatation (FMD) and NMD using ultrasound in 93 subjects (71±7 years, including 26 with peripheral artery disease (PAD), 37 with aortic aneurysms, 10 with PAD complicated with aneurysms, and 20 without evident arterial disease). Brachial artery responses to hyperemia and nitroglycerin were measured every minute after cuff deflation and nitroglycerin administration. Time courses of vasodilatation were assessed and maximal FMD and NMD were measured.

RESULTS

The time courses in response to NTG were sigmoidal and maximal diameter reached 7.2±1.6 minutes after NTG was administered sublingually. The mean FMD was 2.3±2.0% and the mean NMD was 17.6±7.1%. Subjects were prospectively followed for an average of 47±13 months. Eighteen subjects had an event during follow-up; events included myocardial infarction (five), unstable angina pectoris (four), stroke (two), aortic dissection (one), ruptured aortic aneurysm (three), symptomatic abdominal aortic aneurysm (two), and lower limb ischemia requiring revascularization (one). NMD and FMD were significantly lower in subjects with events than in those without an event. In a Cox proportional-hazards model, lower FMD as well as lower NMD independently predicted future cardiovascular events.

CONCLUSION

Brachial artery nitroglycerin-mediated vasodilatation may add information to conventional risk stratification.

Assessing individual cardiac risk using extra-cardiac arterial imaging

Cardiovascular disease is the leading cause of death globally. Cardiovascular risk factors predict the risk of cardiovascular events in populations but have limitations in predicting individual risk. Emerging technologies that non-invasively measure carotid intima media thickness, aortic pressure and brachial artery reactivity may be useful in identifying the vulnerable patient who may benefit from more aggressive preventive therapy. These tests vary between each other in their reproducibility, cost, required operator skill, availability and patient preparation. However, all require further validation for clinical use as screening tests for cardiovascular disease.

Relationship between coronary endothelial function and coronary calcification in early atherosclerosis

BACKGROUND

The relationship between coronary endothelial function and coronary calcification is not well established.

METHODS

Forty-six patients 17 men [37%]; age, 47.4+/-11.4 years prospectively underwent testing for coronary endothelial function and measurement of coronary artery calcification (CAC).

RESULTS

Log CAC scores were not significantly different between patients with normal (n=31) and abnormal (n=15) response of epicardial coronary artery diameter to acetylcholine (%CAD(Ach)) (median (25, 75 percentile) 1.1 (0.0, 3.7) vs. 0.3 (0.0, 2.4), P=.32) and with normal (n=28) and abnormal (n=18) response of coronary blood flow to acetylcholine (%CBF(Ach)) (0.5 (0.0, 3.6) vs. 0.5 (0.0, 3.2), P=.76). Log CAC scores did not correlate with %CAD(Ach) (r=0.08, P=.59), %CBF(Ach) (r=0.14, P=.35).

CONCLUSIONS

In patients without significant coronary artery disease, coronary endothelial dysfunction showed no apparent association with coronary calcification. Our findings suggest that these 2 markers may represent separate, independent processes in the progression of coronary atherosclerosis.

Forearm vascular reactivity and arterial stiffness in asymptomatic adults from the community

Vascular reactivity may affect the stiffness characteristics of the arterial wall. We investigated the association between forearm microcirculatory and conduit artery function and measures of arterial stiffness in 527 asymptomatic non-Hispanic white adults without known cardiovascular disease. High-resolution ultrasonography of the brachial artery (ba) was performed to assess forearm microcirculatory function (ba blood flow velocity, local shear stress, and forearm vascular resistance at rest and during reactive hyperemia) and conduit artery function (ba flow-mediated dilatation [baFMD] and ba nitroglycerin-mediated dilatation [baNMD]). Arterial stiffness was assessed by cuff-derived brachial pulse pressure and aortic pulse wave velocity (aPWV) measured by applanation tonometry. In regression analyses that adjusted for heart rate, mean arterial pressure, height, cardiovascular risk factors, and hypertension medication and statin use, higher baseline ba systolic velocity and systolic shear stress were associated with greater pulse pressure (P=0.0002 and P=0.006, respectively) and higher aPWV (each P<0.0001). During hyperemia, lower ba mean velocity and lower mean shear stress were associated with higher pulse pressure (P=0.045 and P=0.036, respectively), whereas both systolic and mean velocity (P<0.0001 and P=0.002, respectively) and systolic and mean shear stress (P<0.0001 and P=0.003, respectively) were inversely associated with aPWV. baFMD was not associated with pulse pressure but was inversely associated with aPWV (P=0.011). baNMD was inversely associated with pulse pressure (P=0.0002) and aPWV (P=0.008). Our findings demonstrate that impaired forearm microvascular function (in the form of elevated resting blood flow velocity and impaired flow reserve) and impaired brachial artery reactivity are associated with increased arterial stiffness.

Efficacy of low-density lipoprotein apheresis in patients with peripheral arterial occlusive disease undergoing hemodialysis treatment

BACKGROUND

Low-density lipoprotein (LDL) apheresis is effective in the treatment of peripheral arterial occlusive disease (PAOD). In the present study, we attempted to determine whether LDL apheresis is effective even for PAOD patients undergoing hemodialysis, who tend to be refractory to any treatment, and if so, to determine the mechanism of its efficacy.

METHODS

Serum levels of lipids and vascular growth factors, leg symptom, and endothelium-dependent vasodilation were investigated before and after 10 sessions of LDL apheresis in 11 PAOD patients undergoing hemodialysis.

RESULTS

Serum levels of total cholesterol, LDL cholesterol, and triglyceride exhibited drastic reduction, which completely disappeared 4 weeks after the final apheresis. Resting leg pain was improved in 6 cases even 4 weeks after final apheresis. Endothelium-dependent vasodilation was significantly increased 4 weeks after final apheresis (1.6 +/- 0.6 to 4.7 +/- 1.0%, p < 0.05). Levels of vascular growth factors, hepatocyte growth factor and vascular endothelial growth factor were not changed during treatment.

CONCLUSIONS

These findings suggested that LDL apheresis is effective even in PAOD patients undergoing hemodialysis. Our findings suggest that its mechanisms of efficacy include improvement of vascular endothelial dysfunction, in addition to drastic but acute reduction of lipid levels. Since PAOD patients undergoing hemodialysis tend to be resistant to any treatment and are at high risk for lower-extremity amputation, LDL apheresis could be a useful strategy for treatment of them.

Serum uric acid is associated with microvascular function in hypertensive individuals

We investigated the relationship of serum uric acid (UA) with resting forearm blood flow (FBF), reactive hyperaemia (RH) and flow-mediated dilation (FMD) of the brachial artery in hypertensive adults (n=506, mean age 62 years, 59% women). UA was measured by a colorimetric method. FBF, RH and FMD were measured by brachial artery ultrasound. Regression analyses were used to assess whether UA was associated with FBF, RH and FMD before and after adjustment for age, sex, systolic BP, diabetes, total and high-density lipoprotein cholesterol, smoking, body mass index (BMI), C-reactive protein (CRP), serum creatinine, alcohol intake, statin and diuretic use and brachial artery diameter (BAD). UA was significantly associated with FBF (P<0.0001) and RH (P=0.0001) but not with FMD (P=0.43). After adjustment for the covariates listed above, higher UA level remained independently associated with a higher FBF (P=0.012) and lower RH (P=0.004). The independent predictors were as follows: (a) higher FBF: lower age, higher BMI, history of smoking, statin use, higher CRP, higher BAD and higher UA levels; (b) lower RH: higher BMI, diabetes and higher UA levels; (c) lower FMD: greater age, male sex, higher BMI, history of smoking, statin use and higher BAD. We conclude that in hypertensive individuals, higher UA levels are associated with higher resting FBF and lower RH, markers of microvascular function, but not with brachial artery FMD.