Another modifiable risk factor for cardiovascular disease? Some evidence points to arterial stiffness

Ideal Life’s Simple 7 Score Relates to Macrovascular Structure and Function in the Healthy Population

Background: Cardiovascular health scores, such as Life’s Simple 7 from the American Heart Association, and the assessment of arterial properties are independently used to determine cardiovascular risk. However, evidence of their association remains scarce, especially in healthy, middle-aged to older populations. Methods: A healthy sample of the Swiss population aged 50–91 years as part of the COmPLETE cohort study was included. Carotid intima–media thickness (cIMT), carotid lumen diameter (cLD), carotid distensibility coefficient (DC), flow-mediated dilation (FMD), and brachial–ankle pulse wave velocity (baPWV) were used to determine arterial properties. The Life’s Simple 7 cardiovascular health score was calculated using seven categories (body-mass index, cholesterol, systolic blood pressure, hemoglobin A1c, smoking status, physical activity, and diet). In accordance with the American Heart Association, for each category, two points were given for an ideal health metric level, intermediate scores one point, and poor scores zero points. Intermediate and ideal health scores corresponded to a total of 5–9 and 10–14 points, respectively. Results: A total of 280 participants (50.7% male) were included. After adjusting for age and sex, an ideal health score was associated with lower cIMT (−0.038 mm, 95% CI: −0.069 mm–−0.007 mm, p = 0.017), lower cLD (−0.28 mm, 95% CI: −0.46 mm–−0.11 mm, p = 0.002), and lower baPWV (−0.05 m/s, 95% CI: −0.08 m/s–−0.02 m/s, p = 0.003). No differences were found for FMD and DC. Conclusions: Even in a healthy sample of middle-aged and older adults, individuals with an ideal cardiovascular health score showed more favorable biomarkers of vascular aging than those with an intermediate score. This stresses the relevance of promoting an optimal lifestyle, even among the healthy population.

Evaluation of augmentation index and pulse wave velocity measurements in central retinal vein occlusion patients with and without hypertension

PURPOSE

To evaluate arterial stiffness using the pulse wave velocity (PWV) and augmentation index (AI) in central retinal vein occlusion (CRVO) patients.

METHODS

Forty-two CRVO patients (i.e., CRVO group) and 54 healthy controls (i.e., control group) were included in this comparative and cross-sectional study. The PWV, AI and augmentation pressure were measured with a noninvasive, oscillometric method.

RESULTS

The mean PWV, AI and augmentation pressure values were significantly higher in CRVO patients than in controls (p = 0.024, p < 0.001 and p = 0.001, respectively). The mean augmentation pressure, AI and PWV measurements were not statistically significant between CRVO patients with and without hypertension (p = 0.856 and p < 0.526, p = 0.432, respectively). Age, presence of hypertension, AI and PWV were found to be as independent risk factors of CRVO development (OR = 2.21, 95% CI [1.44, 3.38] and OR = 2.40, 95% CI [1.50, 3.86], OR = 3.2, 95% CI [1.70, 5.60] and OR = 5.70, 95% CI [2.00, 18.50], respectively).

CONCLUSION

The AI and PWV values were significantly higher in CRVO patients than in controls. These results indicate that similar abnormalities in the arterial wall structure may play an important role in the pathogenesis of the CRVO and cardiovascular diseases. In addition, our findings show that each patient with RVO should be examined in terms of systemic vascular pathologies.

Equol-producing status affects exercise training-induced improvement in arterial compliance in postmenopausal women

Central arterial compliance decreases drastically after menopause. Regular intake of soy isoflavone and aerobic exercise increase arterial compliance. The equol is a metabolite of isoflavone daidzein by gut microbiome. We determined whether the equol-producing status affects aerobic exercise-induced improvement in carotid arterial compliance. Forty-three postmenopausal women were assigned to two intervention groups: 1) exercise and isoflavone (Ex+Iso, n = 27 females) or 2) isoflavone interventions (Iso; n = 16 females). Participants of the Ex+Iso intervention group completed an 8-wk aerobic exercise training, and all participants were administered with oral isoflavone supplements during the interventions. The equol-producing status (equol producers or nonproducers) was determined from urine equol concentrations after a soy challenge. In the Ex+Iso intervention group, carotid arterial compliance increased in the equol producers (0.084 ± 0.030→0.117 ± 0.035 mm²/mmHg), but not in the nonproducers (0.089 ± 0.028→0.097 ± 0.026 mm²/mmHg) after the intervention (interaction effect; P < 0.05). The magnitude of increases in carotid arterial compliance was significantly greater in the equol producers than in the non-equol producers (P < 0.05). In the isoflavone intervention group, there were no changes in any parameters after the intervention irrespective of the equol status. These results suggest that equol-producing status is obligatory to aerobic exercise training-induced improvements in central arterial compliance in postmenopausal women.NEW & NOTEWORTHY Isoflavone intake and aerobic exercise increase central artery compliance. Equol, a metabolite of isoflavone daidzein by gut microbiome, has beneficial effects on vascular function. We demonstrated for the first time that the interaction of aerobic exercise and equol production status plays an essential role in improvements in central artery compliance in postmenopausal women. More specifically, the equol-producing status was obligatory to exercise training-induced improvements in central arterial compliance in postmenopausal women.

Greater Adherence to Life's Simple 7 Is Associated With Less Arterial Stiffness: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Greater arterial stiffness is associated independently with increased cardiovascular disease risk. The American Heart Association (AHA) has recommended following "Life's Simple 7 (LS7)" to optimize cardiovascular health; we tested whether better LS7 in middle age is associated with less arterial stiffness in later life.

METHODS

We studied 4,232 black and white participants aged 45-64 years at the baseline (1987-89) visit of the Atherosclerosis Risk in Communities Study cohort who also had arterial stiffness measured in 2011-13 (mean ± SD interval: 23.6 ± 1.0 years). We calculated a 14-point summary score for baseline LS7 and classified participants as having "poor" (0-4), "average" (5-9), or "ideal" (10-14) cardiovascular health. We used logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (95% CI) for arterial stiffening: a high carotid-femoral pulse wave velocity (cfPWV, ≥13.23 m/s) or a high central pulse pressure (central PP, ≥ 82.35 mm Hg).

RESULTS

The age, race, sex, and heart rate-adjusted ORs (95% CI) for high cfPWV in the "ideal," "average," and "poor" LS7 summary categories were 1 (Reference), 1.30 (1.11, 1.53), and 1.68 (1.10,2.56), respectively (P-trend = 0.0003). Similarly, the adjusted ORs (95% CI) for high central PP across LS7 summary categories were 1 (Reference), 1.48 (1.27, 1.74), and 1.63 (1.04, 2.56), respectively (P-trend <0.0001).

CONCLUSION

Greater LS7 score in middle age is associated with less arterial stiffness 2-3 decades later. These findings further support the AHA recommendation to follow LS7 for cardiovascular disease prevention.

Antioxidant Rich Potato Improves Arterial Stiffness in Healthy Adults

Arterial stiffness is an emerging risk factor for cardiovascular disease and dietary anthocyanins may be important in mediating vascular tone. The present study investigated the effect of consumption of an anthocyanin-rich potato, Purple Majesty on arterial stiffness measured as pulse wave velocity in 14 healthy male and female adults. Participants consumed 200 g/day of cooked purple potato containing 288 mg anthocyanins, or a white potato containing negligible anthocyanins for 14 days, separated by a 7-day washout period. Non-invasive assessment of vascular tone by pulse wave velocity was determined in addition to systolic and diastolic blood pressure, high-density lipoproteins, low-density lipoproteins, triglycerides, glucose, insulin and C-reactive protein. Pulse wave velocity was significantly reduced (p = 0.001) following Purple Majesty consumption for 14-days. There were no significant changes with any other clinical parameter measured, and no changes following white potato consumption. The findings from this short-term study indicate a potential effect of Purple Majesty consumption on arterial stiffness.

Arterial stiffness in fertile women with metabolic syndrome

INTRODUCTION

Although metabolic syndrome (MetS) is evidently associated with the risk of cardiovascular disease (CVD), recently its use has been questioned. We studied the utility of MetS diagnosis when estimating individual CVD risk.

METHODS

We compared 27 fertile women with MetS and 27 counterparts without the syndrome, matched pairwise according to well-known risk factors of CVD. Pulse wave velocity (PWV) and central blood pressure (cBP) were determined noninvasively via a SphygmoCor device. Arterial compliance was measured noninvasively with an HDI/PulseWave^TMCR-2000 arterial tonometer.

RESULTS

PWV (7.1 ± 2.5 versus 6.5 ± 1.1 m/s, p = .037), and both systolic (120.9 ± 12.2 versus 111.5 ± 16.0 mmHg, p = .031) and diastolic cBP (81.3 ± 8.5 versus 74.1 ± 11.2 mmHg, p = .035) were higher in the MetS group. Systemic arterial compliance values were lower in both large (15.1 ± 8.0 versus 16.1 ± 4.4 mL/mmHg × 10, p = .034) and small arteries (7.1 ± 2.5 versus 9.3 ± 3.2 mL/mmHg ×100, p = .010) in women with MetS.

CONCLUSIONS

Fertile women with MetS had increased arterial stiffness, as measured by three different methods. Our results highlight the utility of MetS when revealing increased individual CVD risks in fertile-aged women. Key messages Women with MetS have increased arterial stiffness when measured by different methods. MetS is a useful clinical tool to assess increased cardiovascular risk, particularly among fertile-aged women.

Cervical Rotatory Manipulation Decreases Uniaxial Tensile Properties of Rabbit Atherosclerotic Internal Carotid Artery

Objective. To investigate the effects of one of the Chinese massage therapies, cervical rotatory manipulation (CRM), on uniaxial tensile properties of rabbit atherosclerotic internal carotid artery (ICA). Methods. 40 male purebred New Zealand white rabbits were randomly divided into CRM-Model group, Non-CRM-Model group, CRM-Normal group, and Non-CRM-Normal group. After modeling (atherosclerotic model) and intervention (CRM or Non-CRM), uniaxial tensile tests were performed on the ICAs to assess the differences in tensile mechanical properties between the four groups. Results. Both CRM and modeling were the main effects affecting physiological elastic modulus (PEM) of ICA. PEM in CRM-Model group was 1.81 times as much as Non-CRM-Model group, while the value in CRM-Model group was 1.34 times as much as CRM-Normal group. Maximum elastic modulus in CRM-Model group was 1.80 times as much as CRM-Normal group. Max strains in CRM-Model group and Non-CRM-Model group were 30.98% and 28.71% lower than CRM-Normal group and Non-CRM-Normal group, respectively. However, whether treated with CRM or not, the uniaxial tensile properties of healthy ICAs were not statistically different. Conclusion. CRM may decrease the uniaxial tensile properties of rabbit arteriosclerotic ICA, but with no effect on normal group. The study will aid in the meaningful explanation of the controversy about the harmfulness of CRM and the suitable population of CRM.

Acute Effect of High-Intensity Eccentric Exercise on Vascular Endothelial Function in Young Men

Choi, Y, Akazawa, N, Zempo-Miyaki, A, Ra, S-G, Shiraki, H, Ajisaka, R, and Maeda, S. Acute effect of high-intensity eccentric exercise on vascular endothelial function in young men. J Strength Cond Res 30(8): 2279-2285, 2016-Increased central arterial stiffness is as an independent risk factor for cardiovascular disease. Evidence regarding the effects of high-intensity resistance exercise on vascular endothelial function and central arterial stiffness is conflicting. The purpose of this study was to examine the effects of acute high-intensity eccentric exercise on vascular endothelial function and central arterial stiffness. We evaluated the acute changes in endothelium-dependent flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and arterial stiffness after high-intensity eccentric exercise. Seven healthy, sedentary men (age, 24 ± 1 year) performed maximal eccentric elbow flexor exercise using their nondominant arm. Before and 45 minutes after eccentric exercise, carotid arterial compliance and brachial artery FMD and L-FMC in the nonexercised arm were measured. Carotid arterial compliance was significantly decreased, and β-stiffness index significantly increased after eccentric exercise. Brachial FMD was significantly reduced after eccentric exercise, whereas there was no significant difference in brachial L-FMC before and after eccentric exercise. A positive correlation was detected between change in arterial compliance and change in FMD (r = 0.779; p ≤ 0.05), and a negative correlation was detected between change in β-stiffness index and change in FMD (r = -0.891; p < 0.01) with eccentric exercise. In this study, acute high-intensity eccentric exercise increased central arterial stiffness; this increase was accompanied by a decrease in endothelial function caused by reduced endothelium-dependent vasodilation but not by a change in endothelium-dependent vasoconstriction.

Arterial Stiffness in Patients Taking Second-generation Antipsychotics

Objective

That treatment with second-generation antipsychotics (SGAs) causes metabolic side effects and atherosclerosis in patients with schizophrenia and bipolar disorder (BD) is well-known. Increased arterial stiffness is an important marker of arteriosclerosis and has been identified as an independent risk factor for cardiovascular diseases. We measured pulse wave velocity (PWV) as a marker of arteriosclerosis in patients with schizophrenia and BD who use SGAs.

Methods

Patients and controls were collected from our psychiatry outpatient clinics or family medicine. Mental illness was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Mean age, gender, systolic and diastolic blood pressure, body mass index, Framingham risk score (FRS), etc. were determined. Simultaneous electrocardiography and pulse wave were recorded with an electromyography device. The photo-plethysmographic method was used to record the pulse wave. Inclusion criteria included use of SGAs for at least the last six months. Patients with diseases that are known to cause stiffness and the use of typical antipsychotics were excluded.

Results

Ninety-six subject (56 patients, 40 controls) were included in our study. There were 49 females, 47 males. Patients had schizophrenia (n=17) and BD (n=39). Their treatments were quetiapine (n=15), risperidone (n=13), olanzapine (n=15), and aripiprazole (n=13). Although differences in mean age, gender, and FRS in the patient and control groups were not statistically significant (p=1), PWV was greater in patients in the antipsychotic group (p=0.048).

Conclusion

This study supported the liability to stiffness in patients with schizophrenia and BD. Using SGAs may contribute to arterial stiffness in these patients.

Abnormal mechanical properties of larger arteries in postmenopausal women with systemic lupus erythematosus

There is limited knowledge of potential defects in arterial wall properties in female systemic lupus erythematosus (SLE) patients without manifest cardiovascular disease (CVD) and significant atherosclerotic lesions. The aim of the present study was to investigate the mechanical properties of larger vessels in these patients and to compare them with healthy controls. B-mode ultrasound was used to assess vessel wall structure and to exclude presence of plaque. The ankle/brachial pressure index was measured to exclude occlusive arterial disease. An ultrasound echo-tracking system was used to determine stiffness of the abdominal aorta, common carotid artery (CCA) and popliteal artery (PA) in 39 female patientswith SLE and 55 female, healthy controls. SLE had an independent effect on stiffening of the CCA ( P = 0.01) and PA ( P = 0.005). In addition, larger vessel diameters were observed in the CCA (P = 0.002) after adjustments for the effects of mean arterial pressure and age. Thus, this investigation demonstrated an increased arterial stiffness and signs of premature vascular ageing in the SLE patients without manifest cardiovascular disease and without significant atherosclerotic lesions. The results of this study indicate that other mechanisms besides atherosclerosis might be involved in the pathogenesis of arterial stiffening in SLE patients.

Myocardial performance is impaired in patients with branch retinal vein occlusion

OBJECTIVE

To investigate whether the Tei index, which is an indicator of global myocardial function and an independent predictor of cardiac death, is increased in patients with branch retinal vein occlusion (BRVO).

METHODS

The Tei index was used to evaluate myocardial performance, in addition to conventional echocardiographic evaluation of myocardial structural and functional changes, in patients with BRVO, patients with hypertension and healthy controls.

RESULTS

Out of 36 patients with BRVO (18 female, 18 male; 17 hypertensive, 19 normotensive), 29 patients with hypertension (15 female, 14 male) and 28 healthy controls (15 female, 13 male), there were no significant between-group differences in age and sex. The mitral A wave was higher and mitral E/A ratio, mitral E wave and ejection time were lower, in patients with BRVO than in healthy controls. Mean Tei index was significantly higher in the BRVO group than in patients with hypertension or healthy controls. Compared with healthy controls, the Tei index was significantly higher in hypertensive and normotensive patients with BRVO.

CONCLUSION

Myocardial performance is decreased in patients with BRVO, independent of whether or not they have hypertension.

Decreased peripheral arterial volume distensibility in patients with branch retinal vein occlusion in comparison with normal subjects

This study aimed to quantify arterial volume distensibility in patients with branch retinal vein occlusion (BRVO) in comparison with normal subjects and to investigate factors associated with their differences. 40 normal subjects and 30 BRVO patients were studied. Brachial-ankle pulse wave velocity (baPWV) was measured to determine arterial volume distensibility. In comparison with the normal subjects, after adjusting for pulse pressure, baPWV in the BRVO patients was significantly higher by 2.3 m/s (P < 0.01) and arterial distensibility was significantly lower by 0.015% per mmHg (P < 0.01). No subject in the normal group had an arterial distensibility lower than 0.04% per mmHg, in comparison with 67% (20/30) in the BRVO group. Arterial distensibility was significantly related to systolic and diastolic blood pressures (SBP and DBP) and ageing for both groups (all P < 0.05), but in the BRVO group, blood pressures and ageing had more prominent effect on arterial volume distensibility. Peripheral arterial distensibility has been shown to be significantly lower in BRVO patients in comparison with normal subjects. The more prominent effect of SBP, DBP and ageing on arterial distensibility indicates the potential underlying mechanisms of the interaction between higher blood pressures, ageing and BRVO disease.

Radial arterial compliance measurement by fiber Bragg grating pulse recorder

In the present work, we report a novel, in vivo, noninvasive technique to determine radial arterial compliance using the radial arterial pressure pulse waveform (RAPPW) acquired by fiber Bragg grating pulse recorder (FBGPR). The radial arterial compliance of the subject can be measured during sphygmomanometric examination by the unique signatures of arterial diametrical variations and the beat-to-beat pulse pressure acquired simultaneously from the RAPPW recorded using FBGPR. This proposed technique has been validated against the radial arterial diametrical measurements obtained from the color Doppler ultrasound. Two distinct trials have been illustrated in this work and the results from both techniques have been found to be in good agreement with each other.

Aerobic exercise training decreases plasma asymmetric dimethylarginine concentrations with increase in arterial compliance in postmenopausal women

BACKGROUND

Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, increase with advancing age and menopausal status. ADMA plays a role in endothelial dysfunction and increasing arterial stiffness. Regular aerobic exercise has a positive effect on arterial function (i.e., arterial compliance). This study investigated the effects of aerobic exercise training on plasma ADMA concentrations and arterial compliance in postmenopausal women.

METHODS

Thirty postmenopausal women were divided into 2 groups: an exercise group (n = 20) and a control group (n = 10). Subjects in the exercise group completed 12 weeks of aerobic exercise training (65%-80% of maximal heart rate, 40-60 min/day, 3-6 days/week). Before and after each intervention, plasma ADMA concentrations and carotid arterial compliance were measured in all participants.

RESULTS

The baseline plasma ADMA concentrations, carotid arterial compliance, and most other key dependent variables did not differ between the 2 groups. In the exercise group, carotid arterial compliance significantly increased after exercise intervention (P < 0.01), and plasma ADMA concentrations significantly decreased (P < 0.05). In addition, changes in carotid arterial compliance after the exercise intervention were inversely correlated with changes in plasma ADMA concentrations (r = -0.367; P < 0.05).

CONCLUSIONS

We demonstrated that aerobic exercise training significantly decreased plasma ADMA concentrations with increase in carotid arterial compliance in postmenopausal women. These results suggest that reduction in ADMA may play an important role in the aerobic exercise training-induced increase in arterial compliance.

The influence of gender on carotid artery compliance and distensibility in children and adults

PURPOSE

Given the role of arterial wall elasticity in the development of cardiovascular disease, carotid artery compliance and distensibility have been used commonly over the last decade as predictors of cardiovascular risk, although their gender differences remain unknown. The purpose of our study was to evaluate the impact of gender on carotid arterial elasticity in a large sample of children and adults.

METHODS

Carotid artery compliance and distensibility were measured with ultrasonography in 294 children (157 boys, 137 girls; ages 6-18 years) and 604 adults (291 men, 311 women; ages 18-49 years) previously recruited for a study investigating cardiovascular risk factors. An independent sample t test was used to compare demographic and carotid artery elasticity values by age and gender.

RESULTS

No significant gender difference in carotid arterial compliance and distensibility was observed in children. Women had significantly greater cross-sectional compliance than men (0.004 ± 0.000 versus 0.003 ± 0.000 1/mmHg, p = 0.041).

CONCLUSIONS

We found significant gender difference in carotid compliance in adults, but not in children, suggesting that gender differences in arterial stiffness are not present early in life but emerge later in adulthood.

Blood flow restricted exercise and vascular function

It is established that regular aerobic training improves vascular function, for example, endothelium-dependent vasodilatation and arterial stiffness or compliance and thereby constitutes a preventative measure against cardiovascular disease. In contrast, high-intensity resistance training impairs vascular function, while the influence of moderate-intensity resistance training on vascular function is still controversial. However, aerobic training is insufficient to inhibit loss in muscular strength with advancing age; thus, resistance training is recommended to prevent sarcopenia. Recently, several lines of study have provided compelling data showing that exercise and training with blood flow restriction (BFR) leads to muscle hypertrophy and strength increase. As such, BFR training might be a novel means of overcoming the contradiction between aerobic and high-intensity resistance training. Although it is not enough evidence to obtain consensus about impact of BFR training on vascular function, available evidences suggested that BFR training did not change coagulation factors and arterial compliance though with inconsistence results in endothelial function. This paper is a review of the literature on the impact of BFR exercise and training on vascular function, such as endothelial function, arterial compliance, or other potential factors in comparison with those of aerobic and resistance training.

The effect of tumor necrosis factor-α antagonists on arterial stiffness in rheumatoid arthritis: a literature review

BACKGROUND

There is evidence that patients with rheumatoid arthritis (RA) have a higher arterial stiffness than their age-matched healthy counterparts and thus have a higher cardiovascular risk. Under National Institute for Clinical Excellence guidelines, tumor necrosis factor-α (TNF-α) antagonists are indicated clinically in patients with severe active rheumatoid disease. TNF-α antagonists have been found to reduce inflammatory markers in RA; however, it is debatable if they have favorable effects on the cardiovascular system. This review evaluates the effect of TNF-α antagonists on arterial stiffness, a predictor of cardiovascular disease, in RA patients.

SEARCH STRATEGY

A search of Ovid MEDLINE and ISI Web of Knowledge databases was conducted to identify studies into the effect of TNF-α antagonists on arterial stiffness in RA patients. Eight studies matching the search criteria were included for analysis.

FINDINGS

Two methods were used to assess arterial stiffness: pulse wave velocity and augmentation index. Despite inconsistencies in augmentation index values, aortic pulse wave velocity in all but one study was significantly reduced following TNF-α antagonist treatment. Most studies had methodological limitations, including inadequate sample size, nonblinding of those involved in the measurements, and inadequate inclusion/exclusion criteria. Variation in results could be due to the use of different TNF-α antagonists, different outcome measures being used, and differences in follow-up.

CONCLUSIONS

The balance of evidence suggests that TNF-α antagonists may have a beneficial effect on arterial stiffness and therefore cardiovascular risk. However, larger more robust longer term studies are warranted to confirm recent findings.

Association of N-terminal pro brain natriuretic peptide and impaired aortic elastic property in hypertensive patients

BACKGROUND

N-terminal pro brain natriuretic peptide (NT-proBNP) is closely related to risk stratification in many cardiovascular diseases. The objective of this study was to evaluate the association of NT-proBNP and impaired aortic elastic property in hypertensive patients.

METHODS

One hundred fifty-five hypertensive patients without obvious cardiac dysfunction were included and divided in tertiles based on their NT-proBNP concentration. Eighty-six normotensive healthy volunteers were also enrolled as controls. All subjects underwent Doppler echocardiography to assess cardiac parameters and aortic distensibility index. Plasma NT-proBNP was measured by electrochemiluminescence.

RESULTS

The parameters of aortic elastic property were decreased and NT-proBNP was significantly increased in hypertensive patients compared with controls (all P<0.05). Among hypertensive patients, higher NT-proBNP tertiles were associated with larger systolic and diastolic aortic diameters, longer deceleration time of the E wave velocity (DT) and isovolumic relaxation time; decreased E/A ratio and more percent of diastolic dysfunction. The parameters of aortic elastic property showed stepwise decreases from the first tertiles to the third tertiles (P<0.05). Multiple linear regression analysis showed that concentrations of NT-proBNP were significantly correlated with age and impaired aortic distensibility.

CONCLUSIONS

NT-proBNP is a marker for impaired aortic elastic property in hypertensive patients. Measurement of NT-proBNP could be indicated in hypertensive patients for further risk stratification.

The relationship of gamma-glutamyltransferase to aortic elastic properties in young patients with prehypertension

Some cross-sectional studies have demonstrated a positive association between serum gamma-glutamyltransferase (GGT) levels and blood pressure. Accordingly, we aimed to analyze serum GGT levels in patients with prehypertension and examine the relationship with aortic elasticity parameters. The study population consisted of 25 newly diagnosed prehypertensive individuals and 25 healthy control subjects. Aortic strain, distensibility index, and stiffness index beta were calculated from aortic diameters measured by echocardiography and blood pressures simultaneously measured by sphygmomanometry. Prehypertensive patients were detected to have significantly lower aortic distensibility and strain indexes compared to control subjects aortic distensibility. However, aortic stiffness index beta of the prehypertensive group was significantly higher compared to that of the control group (3.73 ± 1.41 vs. 2.97 ± 0.82, p = 0.02). The mean GGT levels were found to be higher in patients with prehypertension compared to those of controls (47.9 ± 15.9 U/L vs. 36.1 ± 9.4 U/L, p = 0.003). When multiple linear regression analysis was done to clarify the contributions of GGT to aortic elasticity adjusting for age, body mass index, uric acid, serum glucose, heart rate, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol, and triglyceride, we observed that only serum GGT levels were significantly associated with aortic elasticity parameters (for aortic strain beta = -0.247, p < 0.001; for aortic distensibility beta = -0.108, p < 0.001; for stiffness index beta = 0.063, p < 0.001). Whatever the mechanism is, young patients with prehypertension have higher serum GGT levels compared to healthy control subjects. More importantly, increased GGT levels are independently associated with impaired aortic elasticity in patients with prehypertension.

The ageing cardiovascular system

The increase in the ageing population has generated much interest and research into what constitutes normal ageing. By identifying normal ageing processes it is hoped it will be possible to distinguish risk factors for the development of abnormal or premature ageing.

This review discusses biological, structural and mechanical changes in the cardiovascular system with ageing that are thought to increase the risk of cardiovascular disease with ageing. Contributory factors are thought to be genetic and lifestyle related. Measurements of biological as opposed to chronological ageing such as vascular stiffness are explored as a possible useful predictor of cardiovascular morbidity and mortality, indicating its possible utilization as a non-invasive screening tool in older people.

The identification of those at risk of cardiovascular disease and modification of risk factors may minimize interactions of the ageing process and therefore reduce the incidence of cardiovascular disease within the UK population.

Aortic distensibility associates with increased ascending thoracic aorta diameter and left ventricular diastolic dysfunction in patients with coronary artery ectasia

Coronary artery ectasia is usually linked to coronary atherosclerosis. Its primary defect is a destruction of vascular media, which leads to coronary dilatation. The aim of the present study is to evaluate whether ascending aorta present anatomical and functional wall changes in patients with coronary ectasia compared with patients without ectasia. Forty patients with known coronary ectasia (group A) underwent echocardiography in order to study aortic lumen diameter and wall properties (distensibility and stiffness index). Twenty-five patients with coronary artery disease (group B) and 40 individuals with normal coronary arteries (group C) served as control groups. Both ascending aorta diameter and ascending aorta index were significantly increased in group A compared with groups B and C (P < 0.05 and P < 0.001, respectively). Furthermore, in patients with ectatic coronary arteries ascending aorta index, systolic blood pressure and diastolic dysfunction independently associate with aortic distensibility. In patients with coronary artery ectasia, ascending aortic diameter could be enlarged while aortic stiffness is related to diastolic dysfunction. We suggest that coronary ectasia is not an isolated lesion but a reflection of a generalized vascular media defect, and should not be recognized as a benign entity.

Impaired aortic stiffness and pulse wave velocity in patients with branch retinal vein occlusion

BACKGROUND

Aortic distensibility (AD) and pulse wave velocity (PWV) reflect arterial stiffness, which is linked to increased cardiovascular morbidity and mortality in different diseases such as atherosclerosis, hypertension, and diabetes mellitus, all of which are also common risk factors in patients with branch retinal vein occlusion (BRVO). In the present study, we aimed to determine whether arterial stiffness in different segments of the arterial tree is increased in patients with BRVO.

METHODS

The study group consisted of 35 patients with BRVO (20 female, 15 male, mean age: 55.9+/-6.8) and the age-matched control groups consisted of 19 patients with hypertension (9 female, 10 male, mean age: 55.2+/7.6) and 17 healthy subjects (9 female, 8 male, mean age: 53.4+/-9.6). Radial artery PWV was measured using a Pulse Wave Sensor HDI system, which measures non-invasively the radial pulse-wave recording with computer analysis of the diastolic decay, and provides separate assessment of the large arterial elasticity index (LAEI) and small artery elasticity index (SAEI). Aortic strain and AD was determined echocardiographically based on the relationship between changes in aortic diameter and pressure with each cardiac pulse. Patients with diabetes mellitus or inflammatory BRVO, and control patients with any occlusive vascular eye disease, were excluded. The results of the three groups were compared.

RESULTS

Compared to the subjects of the healthy control group, those with BRVO had lower LAEI (p<0.05). Both AD and aortic strain were significantly lower in the BRVO group than in both control groups (p<0.05 for both) and in the hypertensive control group than the healthy controls (p<0.05). The AD, LAEI and SAEI were positively correlated (p=0.021, r=0.307 and p=0.041, r=0.269 respectively).

CONCLUSIONS

The results of this study show that the arterial stiffness indices (large arterial elasticity index and aortic distensibility) are abnormal in patients with BRVO compared to the healthy and hypertensive controls. Arterial stiffness may play a role in the onset or progression of BRVO. Further studies are needed to determine the exact role of AS in the pathogenesis of BRVO, and to reveal its value in predicting systemic morbidity and mortality in patients with BRVO.

Effects of continuous vs. interval exercise training on blood pressure and arterial stiffness in treated hypertension

Exercise is an effective intervention for treating hypertension and arterial stiffness, but little is known about which exercise modality is the most effective in reducing arterial stiffness and blood pressure in hypertensive subjects. Our purpose was to evaluate the effect of continuous vs. interval exercise training on arterial stiffness and blood pressure in hypertensive patients. Sixty-five patients with hypertension were randomized to 16 weeks of continuous exercise training (n=26), interval training (n=26) or a sedentary routine (n=13). The training was conducted in two 40-min sessions a week. Assessment of arterial stiffness by carotid-femoral pulse wave velocity (PWV) measurement and 24-h ambulatory blood pressure monitoring (ABPM) were performed before and after the 16 weeks of training. At the end of the study, ABPM blood pressure had declined significantly only in the subjects with higher basal values and was independent of training modality. PWV had declined significantly only after interval training from 9.44+/-0.91 to 8.90+/-0.96 m s(-1), P=0.009 (continuous from 10.15+/-1.66 to 9.98+/-1.81 m s(-1), P=ns; control from 10.23+/-1.82 to 10.53+/-1.97 m s(-1), P=ns). Continuous and interval exercise training were beneficial for blood pressure control, but only interval training reduced arterial stiffness in treated hypertensive subjects.

Aortic elasticity is impaired in patients with endemic fluorosis

Sixty-three patients with endemic fluorosis (36 males/27 females; mean age 33.9 +/- 8.6 years) and 45 age-, sex-, and body mass index-matched healthy controls (30 males/15 females; mean age 32.7 +/- 8.8 years) were included in this study. Aortic stiffness indices, aortic strain (AS), aortic distensibility (AD), and aortic strain index (ASI) were calculated from the aortic diameters measured by echocardiography and blood pressure obtained by sphygmomanometry. The urine fluoride levels of fluorosis patients were significantly higher than control subjects as expected (1.9 +/- 0.1 mg/l vs. 0.4 +/- 0.1 mg/l, respectively; P < 0.001). AS and AD were significantly lower in fluorosis patients than in the controls (for AS 5.3 +/- 3.6 vs. 8.0 +/- 3.4%; P < 0.001 and for AD 0.2 +/- 0.1 vs. 0.3 +/- 0.1 cm(2) dyn(-1) 10(-3); P < 0.001, respectively). In contrast, significantly higher ASI was observed in fluorosis patients than in the controls (3.4 +/- 0.6 vs. 3.0 +/- 0.4; P < 0.001, respectively). The results of our study demonstrate that elastic properties of ascending aorta are impaired in patients with endemic fluorosis.

Comparison between carotid-femoral and brachial-ankle pulse wave velocity as measures of arterial stiffness

BACKGROUND

Arterial stiffness is an important risk factor for cardiovascular disease. Carotid-femoral pulse wave velocity (cfPWV) is the most recognized and established index of arterial stiffness. An emerging automatic measure of PWV primarily used in the Asian countries is brachial-ankle PWV (baPWV).

METHOD

To systematically compare these two methodologies, we conducted a multicenter study involving a total of 2287 patients.

RESULTS

There was a significant positive relation between baPWV and cfPWV (r = 0.73). Average baPWV was approximately 20% higher than cfPWV. Both cfPWV and baPWV were significantly and positively associated with age (r = 0.56 and 0.64), systolic blood pressure (r = 0.49 and 0.61), and the Framingham risk score (r = 0.48 and 0.63). The areas under the receiver operating curves (ROCs) of PWV to predict the presence of both stroke and coronary artery disease were comparable between cfPWV and baPWV.

CONCLUSION

Collectively, these results indicate that cfPWV and baPWV are indices of arterial stiffness that exhibit similar extent of associations with cardiovascular disease risk factors and clinical events.

Additive beneficial effects of lactotripeptides and aerobic exercise on arterial compliance in postmenopausal women

Central arterial compliance plays an important role in the functional abilities of the vasculature. Two active tripeptides, valine-proline-proline and isoleucine-proline-proline, were isolated from sour milk and were referred to as lactotripeptides (LTP). Because LTP appears to act as an angiotensin-converting enzyme inhibitor, it is plausible to hypothesize that LTP improves arterial compliance. We determined the effects of LTP ingestion alone or in combination with regular aerobic exercise on arterial compliance. A total of 55 postmenopausal women (50-65 yr old) were randomly divided into four groups: placebo, LTP, exercise and placebo (Ex + placebo), or exercise and LTP (Ex + LTP). LTP or placebo was administered orally for 8 wk. The exercise groups completed an 8-wk moderate aerobic exercise intervention. There were no differences in baseline arterial compliance and most other key dependent variables among the groups. Carotid arterial compliance increased significantly in the LTP (0.93 + or - 0.07 vs. 0.99 + or - 0.08 mm(2)/mmHg x 10(-1)), Ex + placebo (0.92 + or - 0.04 vs. 1.00 + or - 0.05 mm(2)/mmHg x 10(-1)), and Ex + LTP groups (0.86 + or - 0.06 vs. 1.00 + or - 0.06 mm(2)/mmHg x 10(-1)), whereas no such changes were observed in the placebo control group (0.86 + or - 0.06 vs. 0.85 + or - 0.07 mm(2)/mmHg x 10(-1)). The magnitude of increases in carotid arterial compliance was significantly greater in the Ex + LTP group (19 + or - 4%) than in other groups. The improvements in arterial compliance with LTP were associated with the corresponding reductions in arterial blood pressure and plasma angiotensin II concentrations. We concluded that LTP ingestion improves carotid arterial compliance and that the combination of LTP ingestion and regular exercise is additive and synergistic in improving arterial compliance in postmenopausal women.

Effect of habitual aerobic exercise on body weight and arterial function in overweight and obese men

The effect of habitual exercise on vascular function, including central arterial distensibility and endothelial function, in obese subjects has not yet been clarified. We investigated whether aerobic exercise training affects central arterial distensibility and endothelial function in middle-age overweight and obese men. A total of 21 overweight and obese men (age 50 +/- 2 years, body mass index 30 +/- 1 kg/m(2)) completed a 12-week aerobic exercise intervention. Aerobic exercise training significantly reduced their body weight and resulted in a significant decrease in body mass index. After the weight-reduction exercise program, carotid arterial compliance (determined by simultaneous B-mode ultrasonography and arterial applanation tonometry on the common carotid artery) significantly increased; and the beta-stiffness index, an index of arterial compliance adjusted for distending pressure, significantly decreased. The concentrations of plasma endothelin-1, a potent vasoconstrictor peptide produced by vascular endothelial cells, significantly decreased and plasma nitric oxide (measured as the stable end product [nitrite/nitrate]), a potent vasodilator produced by vascular endothelial cells, significantly increased after the weight-reduction exercise program. In conclusion, weight reduction by aerobic exercise training in overweight and obese men increased the central arterial distensibility. This increase might contribute to the improvement in endothelial function, as assessed by a decrease in endothelin-1 and an increase in nitric oxide, after exercise training-induced weight loss.

Association between arterial compliance and age in participants 9 to 77 years old

We characterized the age-related change in large and small artery compliance in 137 healthy participants between 9 and 77 years of age. Large artery compliance, measured by diastolic pulse contour analysis, had a sharp positive linear trend (0.89 mL x mm Hg( -1) x year(-1)) highly correlated with age in participants younger than 30 years (r = .76, p <.0001), had a slight negative trend (-0.10 mL x mm Hg(-1) x year(-1)) not significantly associated with age (r = -.11, p = .532) in middle-aged participants, and had a sharper negative trend (-0.19 mL x mm Hg(-1) x year(-1)) significantly associated with age (r = -.30, p =.023) in participants beyond 50 years. Similar results were found for small artery compliance. Large and small artery compliance increase in children, adolescents, and young adults, reach plateaus near age 30, and then decline beyond 30 years of age in those free of cardiovascular disease and risk factors.

Visceral adiposity and arterial stiffness: echocardiographic epicardial fat thickness reflects, better than waist circumference, carotid arterial stiffness in a large population of hypertensives

AIMS

Relationship between obesity and cardiovascular (CV) disease depends not only on the amount of body fat, but also on its distribution. For example, individuals with increased fat accumulation in the abdominal region have atherogenic lipid profiles and are at increased CV risk. The loss of elasticity in medium and large arteries is an early manifestation of atherosclerosis. The aim of this study was to evaluate whether echocardiographic epicardial adipose tissue, an index of cardiac adiposity, is related to carotid stiffness and carotid intima-media thickness (IMT), indexes of subclinical atherosclerosis, better than waist circumference in hypertensive patients.

METHODS AND RESULTS

We studied 459 patients with Grade I and II essential hypertension who were referred to our outpatient clinic over a period from May 2007 to March 2008. The population was first sorted by waist circumference and then by epicardial fat < or = 7 or >7 mm. We measured epicardial fat thickness, waist circumference, carotid artery stiffness, and carotid IMT in all patients. Patients divided according to waist circumference showed no statistical differences in carotid artery stiffness between the two groups. Subjects with epicardial fat >7 mm were older, had higher systolic, diastolic, and pulse pressure, increased left ventricular mass index, carotid IMT, diastolic parameters, and stiffness parameters compared with those with epicardial fat < or = 7 mm (P < 0.001). A positive correlation was found between epicardial fat and age, pulse pressure, stiffness parameters, carotid IMT, systolic blood pressure, and duration of hypertension, and a negative correlation was found with diastolic parameters. Age, carotid IMT, and stiffness parameters were independently related to epicardial fat.

CONCLUSION

Our findings indicate that epicardial fat reflects carotid artery stiffness in hypertension-induced organ damage.

The Vascular and Biochemical Effects of Cilostazol in Diabetic Patients With Peripheral Arterial Disease

Objectives: Cilostazol improves walking in patients with peripheral arterial disease (PAD). We hypothesized that cilostazol reduces diabetic complications in PAD patients.

Methods: Diabetic PAD patients were prospectively recruited to a randomized double-blinded, placebo-controlled trial, using cilostazol 100mg twice a day. Clinical assessment included ankle-brachial index, arterial compliance, peripheral transcutaneous oxygenation, treadmill walking distance and validated quality of life (QoL) questionnaires. Biochemical analyses included glucose and lipid profiles. All tests were at baseline, 6, and 24 weeks.

Results: 26 diabetic PAD patients (20 men) were recruited. Cilostazol improved absolute walking distance at 6 and 24 weeks (86.4% vs. 14.1%, P = .049; 143% vs. 23.2%, P = .086). Arterial compliance and lipid profiles improved as did some QoL indices for cilostazol at 6 and 24 weeks. Blood indices were similar at baseline and at follow-up points for both treatment groups.

Conclusions: Cilostazol is a well-tolerated and efficacious treatment, which improves claudication distances in diabetic PAD patients with further benefits in arterial compliance, lipid profiles, and QoL.

Right coronary artery becomes stiffer with increase in elastin and collagen in right ventricular hypertrophy

Changes in blood flow influence the structure, function, mechanical properties, and remodeling of arteries. The objective of the present study was to investigate the role of increased blood flow on the biaxial incremental elastic moduli of the porcine right coronary artery (RCA) and to determine the microstructural basis for the changes in moduli. We hypothesized that an increase in RCA flow will lead to increased stiffness in conjunction with remodeling of elastin and collagen in the vessel wall. The control and experimental groups consisted of five RCA vessels each. The RCA of the experimental group was exposed to 4 wk of flow-overload in right ventricular hypertrophy induced by pulmonary artery banding. Stress-strain relationships were determined and the incremental elastic moduli were derived in the circumferential, axial, and cross directions. The results show a significant increase in the elastic moduli in the circumferential (262.7 +/- 15.7 vs. 120.2 +/- 12.4 kPa; P < 0.001), axial (177.8 +/- 25.5 vs. 100.3 +/- 11.9 kPa; P = 0.025), and cross directions (104.8 +/- 8.2 vs. 68.2 +/- 8.6 kPa; P = 0.016) of the experimental RCA compared with controls. Multiphoton microscopy was used to assess the changes in elastin and collagen content in the media and adventitia of the vessel wall. We found a significant increase in elastin and collagen area fraction particularly in the adventitial layer. These data suggest stiffening of the vessel wall as a result of increased elastin and more predominantly collagen.

Effect of Weight Reduction with Dietary Intervention on Arterial Distensibility and Endothelial Function in Obese Men

Obesity and reduction in central arterial distensibility, respectively, have been identified as powerful and independent risk factors for cardiovascular disease. However, the effect of weight reduction on central arterial function in obese subjects has not yet been clarified. We investigated whether low-calorie diet-induced weight reduction affects central arterial distensibility and endothelial function in middle-aged obese men. Twelve obese men (age: 45 ± 2 yrs, BMI: 30±1 kg/m2) completed a 12-week dietary intervention. Caloric restriction induced significantly weight loss and decrease in BMI. After the program, carotid arterial compliance significantly increased and β-stiffness index and aortic pulse-wave velocity remarkably decreased. Concentrations of plasma endothelin-1 (ET-1) significantly decreased and plasma nitric oxide (NO) markedly increased after the program. Weight reduction by low-calorie diet in obese men increases central arterial distensibility, which may contribute to the improvement in endothelial function, as noted by a decrease in ET-1 and an increase in NO.

The comparative effects of metoprolol and perindopril on aortic elasticity in young patients with prehypertension

OBJECTIVES

It has been recently demonstrated that aortic elasticity is impaired in young patients with prehypertension compared with healthy controls. Accordingly, the purpose of the current study was to analyze the comparative effects of metoprolol and perindopril on aortic elasticity in young patients with prehypertension after 6 months of therapy.

MATERIAL AND METHODS

Fifty newly diagnosed patients with hypertension, who were in the prehypertension category according to the Joint National Committee seventh report, were enrolled in this blind, randomized, prospective study. After baseline clinical assessment, patients were randomly assigned to 4 mg daily dose of perindopril (group I, n=27, 18 male, median age=35 years) or 100 mg daily dose of metoprolol succinate (group II, n=28, 16 male, median age=33 years) for 6 months. Aortic strain, distensibility, and stiffness indexes were calculated from aortic diameters measured by echocardiography and blood pressures simultaneously measured by sphygmomanometry before and after treatment.

RESULTS

When the median aortic distensibility and strain indexes after 6 months of therapy were analyzed, aortic distensibility and strain indexes of both treatment arms were found to be significantly higher than those of the pretreatment period. In contrast, the posttreatment aortic stiffness indexes of both groups were significantly lower compared with those of pretreatment period. No statistical difference was found between pretreatment and posttreatment aortic elasticity parameters of both groups. Importantly, no statistically significant difference was found between the percentage change from baseline of metoprolol and perindopril groups regarding aortic elasticity parameters (aortic distensibility: 38.1 vs. 37.9%, respectively, P=0.86; aortic strain: 37.7 vs. 37.9%, respectively, P=0.44; stiffness index: -20.0 vs. -23.9%).

CONCLUSION

The current study revealed that early pharmacological intervention had strong beneficial effects on aortic elasticity in patients with prehypertension despite the fact that neither metoprolol nor perindopril was superior to the other.

Elastic Properties of the Ascending Aorta in Patients with ?-Thalassemia Major

BACKGROUND

Beta-thalassemia major (beta-TM) is a congenital hemolytic disorder characterized by impaired left ventricular and endothelial function. However, elastic properties of the aorta have not been sufficiently investigated in patients with beta-TM. We investigated whether beta-TM is related to impaired ascending aortic elastic properties.

METHODS

We studied 36 patients with beta-TM (age: 15.8 +/- 2.6 years) and 30 age- and sex-matched control subjects by echocardiography. Aortic elastic indexes, aortic strain (%), distensibility (cm(2) dyn(-1) 10(-3)), and stiffness index were calculated from the echocardiographically derived thoracic aortic diameters (mm/m(2)), and the measurement of pulse pressure obtained by cuff sphygmomanometry.

RESULTS

Patients versus control subjects had increased aortic diameters (P < 0.001), lower mean aortic strain (9 +/- 3.6 vs. 14.9 +/- 3.2, P < 0.001) and distensibility (0.6 +/- 0.36 vs. 0.8 +/- 0.2, P < 0.012), and higher mean stiffness index (5.3 +/- 2.4 vs. 2.8 +/- 0.6, P < 0.001). Aortic elastic indexes were significantly associated with ferritin level, while stiffness index was significantly related to platelet count.

CONCLUSION

Elastic properties of ascending aorta are impaired in patients with beta-TM. Impaired functions of aorta may lead to deterioration of left ventricular function.

Reduced flow velocity in the internal carotid artery independently of cardiac hemodynamics in patients with cerebral ischemia

PURPOSE

To retrospectively investigate the relationships between carotid flow velocities, clinical features and cardiac hemodynamics to assess the meaning and significance of reduced carotid flow velocities in patients with cerebral ischemic symptoms.

METHODS

We selected the files from patients who had undergone duplex Doppler sonographic examination of extracranial carotid arteries, echocardiography, and MR angiography, and in whom the following parameters were available: peak systolic (PSV) and end diastolic (EDV) flow velocity, pulsatility index (PI), and diameter of the left and right common (CCA) and internal (ICA) carotid arteries, intima-media thickness (IMT) of the left and right CCA, left ventricle (LV) mass, peak flow velocity on LV outflow tract, and fractional shortening (FS). Patients with stenosis of the carotid artery or its main intracranial branches were excluded, as were patients with major cerebral infarction, severe intracranial abnormality, or heart function disorder. The remaining 59 patients were subdivided according to the presence or absence of cerebral ischemic symptoms, diabetes mellitus, arterial hypertension, and hyperlipidemia for multivariate analyses and stepwise regressions.

RESULTS

Women had smaller diameters and lower PI in the left and right CCA, and smaller LV mass than men. Age, CCA diameter, and IMT showed an inverse correlation with carotid flow velocities in several arterial segments. There was a positive correlation between PSV in the left CCA and ICA and FS, and between PSV in the left CCA and peak velocity on LV outflow tract. Flow velocities in the left and right ICA were significantly slower in patients with than in patients without cerebral ischemic symptoms.

CONCLUSIONS

Cardiac hemodynamics and carotid flow velocities are significantly related, only on the left side, probably due to larger hemodynamic stress. Increased intracerebral circulatory resistance is probably involved in the decrease in carotid flow velocity and increase in PI in patients with cerebral ischemic symptoms.

Vascular adaptations to 8-week cycling training in older men

AIM

Because age-related changes in the large conduit arteries (increased wall thickness, and attenuated arterial compliance and endothelial function) are associated with cardiovascular pathology, prevention is of paramount importance. The effects of endurance training (i.e. walking or cycling) in older humans are assessed in cross-sectional studies, examining the brachial and carotid arteries (supplying non-trained areas). The purpose of this study was to assess the effects of 8-week endurance training in older men on conduit artery characteristics in the trained and non-trained vascular beds.

METHODS

In eight healthy sedentary older men (70 +/- 3 years), characteristics of the large conduit arteries [common femoral (CFA), superficial femoral (SFA), carotid (CA), and brachial artery (BA)] were measured before and after 8-week cycling training. Functional [arterial compliance and flow-mediated dilation (FMD)] and structural (diameter and intima-media thickness) conduit artery properties were measured using echo-Doppler. Peak blood flow, representing structural peripheral adaptations, was measured using venous occlusion plethysmography.

RESULTS

After training, peak leg blood flow was increased (P < 0.01) and baseline diameter and flow were increased in the CFA (P < 0.05). Cycling training enhanced arterial compliance of the SFA (P = 0.03), but did not affect the FMD (P = 0.32) or the intima-media thickness of the SFA. Exercise training did not alter characteristics of the BA or CA.

CONCLUSION

Eight weeks of endurance training in older men altered functional and structural characteristics of the lower extremity vasculature, whereas no changes are reported for the conduit arteries in the non-trained areas (BA or in the CA).

Aortic elastic properties in patients with coronary artery ectasia

BACKGROUND

The purpose of the present study was to investigate the elastic characteristics of the aorta in patients with coronary ectasia (CE) and the relationship between these characteristics and echocardiographic left ventricular (LV) diastolic functions.

METHODS AND RESULTS

In the first group there were 35 patients with CE, the second group consisted of 35 patients with coronary artery disease (CAD) and the third group consisted of 35 patients with normal coronary arteries. Echocardiographic investigation was carried out for the assessment of the LV diastolic functions. Aortic strain, beta index and aortic distensibility were used as aortic elasticity parameters. LV diastolic functions were impaired in both the ectasia group and the CAD group as compared with patients with normal coronary arteries. Beta index and aortic distensibility measurements were similar between the CAD and CE groups. The values obtained for aortic strain, beta index and aortic distensibility were lower in the CAD and ectasia groups when compared with the values of the normal group. On performing the stepwise linear multivariable analyses, aortic elastic parameters have been determined to possess the strongest diagnostic power for LV diastolic functions.

CONCLUSIONS

The results of the current study show that stiffness parameters of aorta are impaired in the patients with CE as in the patients with CAD. The increase in aortic stiffness might be responsible for LV diastolic dysfunction.

Biomechanics of the cardiovascular system: the aorta as an illustratory example

Biomechanics relates the function of a physiological system to its structure. The objective of biomechanics is to deduce the function of a system from its geometry, material properties and boundary conditions based on the balance laws of mechanics (e.g. conservation of mass, momentum and energy). In the present review, we shall outline the general approach of biomechanics. As this is an enormously broad field, we shall consider a detailed biomechanical analysis of the aorta as an illustration. Specifically, we will consider the geometry and material properties of the aorta in conjunction with appropriate boundary conditions to formulate and solve several well-posed boundary value problems. Among other issues, we shall consider the effect of longitudinal pre-stretch and surrounding tissue on the mechanical status of the vessel wall. The solutions of the boundary value problems predict the presence of mechanical homeostasis in the vessel wall. The implications of mechanical homeostasis on growth, remodelling and postnatal development of the aorta are considered.

Ageing and vascular ageing

There is an age related decline in various physiological processes. Vascular ageing is associated with changes in the mechanical and the structural properties of the vascular wall, which leads to the loss of arterial elasticity and reduced arterial compliance. Arterial compliance can be measured by different parameters like pulse wave velocity, augmentation index, and systemic arterial compliance. There is evidence that arterial compliance is reduced in disease states such as hypertension, diabetes, and end stage renal failure. Changes in arterial compliance can be present before the clinical manifestation of cardiovascular disease. Pharmacological and non-pharmacological measures have been shown to improve arterial compliance. Arterial compliance may constitute an early cardiovascular risk marker and may be useful in assessing the effects of drugs on the cardiovascular system. Pharmacogenetics and genetics of arterial compliance in the future will improve our knowledge and understanding about vascular ageing.