Arterial stiffness: a new cardiovascular risk factor?

Vascular adaptations to hypobaric hypoxic training in postmenopausal women

The objective of this study was to examine the effects of exercise training in hypoxia on arterial stiffness and flow-mediated vasodilation (FMD) in postmenopausal women. Sixteen postmenopausal women (56±1 years) were assigned to a normoxic exercise group (Normoxic group, n=8) or a hypoxic exercise group (Hypoxic group, n=8). The Hypoxic group performed exercise under hypobaric hypoxic conditions corresponding to 2000 m above sea level, and was exposed to these conditions for 2 h per session. Aquatic exercise was performed at an intensity of around 50% peak oxygen uptake for 30min, 4days per week, for 8 weeks. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV), and FMD was evaluated by peak diameter of the popliteal artery during reactive hyperemia. After the 8 weeks of training, the Normoxic group showed no significant changes. In contrast, baPWV (P < 0.05) was significantly reduced and peak diameter (P<0.05) and %FMD (P<0.01) were significantly increased in the Hypoxic group after training. These results suggest that exercise training under mild intermittent hypoxic conditions could more effectively reduce arterial stiffness in postmenopausal women, compared with exercise training performed at the same relative intensity under normoxic conditions. Our data also indicate that hypoxic exercise training may induce vascular functional adaptation, for example an increase in FMD response. These findings therefore could have important implications for the development of a new effective exercise prescription program.

Ethnicity and arterial stiffness in Brazil

BACKGROUND

The impact of increased central arterial stiffness as a predictor of morbidity and mortality, independently of other cardiovascular (CV) risk factors, has been established. The main aim of the present work was to investigate the association of ethnicity on arterial stiffness in different ethnic groups from the Brazilian population.

METHODS

A total of 1,427 individuals from the general population were randomly selected from the Vitoria City metropolitan area and 588 Amerindians from a native community in Brazil. The ethnicity of the general population was classified by a standard questionnaire as Caucasian descent, African descent, or Mulattos (considered racially mixed subjects). Pulse wave velocity (PWV) was measured with a noninvasive automatic device (Complior, Colson; Garges les Gonesses, France).

RESULTS

Hemodynamic data of PWV, systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) was higher in African descent individuals than in the other groups (P < 0.001). These results were still observed after adjustment for age and mean arterial pressure (P < 0.001). In addition, studying only normotensive individuals, PWV adjusted levels were higher in African descent individuals, and lower in Amerindians when compared with other ethnic groups (P < 0.01), showing, without the possible confounder effects of time and severity of hypertension or medication use, that PWV is associated with ethnicity in our population.

CONCLUSION

The study of different ethnic groups from a highly admixtured population was able to demonstrate an association between ethnicity and arterial stiffness.

Aortic elastic properties in patients with venous thromboembolism

OBJECTIVES

The relationship between venous thrombosis (VT) and atherosclerosis is controversial in recent studies. Aortic elastic properties have a predictive value in detecting early stages of atherosclerosis. The aim of this study is to evaluate the relationship between aortic elastic properties and VT.

METHODS

Elastic properties of aorta in patients with spontaneous VT, without history of known cardiovascular disease and cardiovascular risk factors (n: 31), and in healthy subjects without cardiovascular risk factors (n: 30) were compared. Elastic properties of the aorta were assessed with transthoracic echocardiography.

RESULTS

A significant increase in aortic stiffness index (6.5 ± 1.0 versus 6 ± 0.7, P = 0.03) and a significant decrease in aortic strain and aortic distensibility were found in patients with VT compared with healthy subjects (8.4 ± 7 versus 13 ± 8, P = 0.01, 4.9 ± 4.8 versus 6.5 ± 4.4, P = 0.03, respectively).

CONCLUSIONS

Elastic properties of aorta in patients with spontaneous VT were impaired. These results may support the role of endothelial dysfunction in the pathogenesis of VT.

Regional in vivo transit time measurements of aortic pulse wave velocity in mice with high-field CMR at 17.6 Tesla

BACKGROUND

Transgenic mouse models are increasingly used to study the pathophysiology of human cardiovascular diseases. The aortic pulse wave velocity (PWV) is an indirect measure for vascular stiffness and a marker for cardiovascular risk.

RESULTS

This study presents a cardiovascular magnetic resonance (CMR) transit time (TT) method that allows the determination of the PWV in the descending murine aorta by analyzing blood flow waveforms. Systolic flow pulses were recorded with a temporal resolution of 1 ms applying phase velocity encoding. In a first step, the CMR method was validated by pressure waveform measurements on a pulsatile elastic vessel phantom. In a second step, the CMR method was applied to measure PWVs in a group of five eight-month-old apolipoprotein E deficient (ApoE(-/-)) mice and an age matched group of four C57Bl/6J mice. The ApoE(-/-) group had a higher mean PWV (PWV = 3.0 ± 0.6 m/s) than the C57Bl/6J group (PWV = 2.4 ± 0.4 m/s). The difference was statistically significant (p = 0.014).

CONCLUSIONS

The findings of this study demonstrate that high field CMR is applicable to non-invasively determine and distinguish PWVs in the arterial system of healthy and diseased groups of mice.

Partial contributions of developmental hypoxia and undernutrition to prenatal alterations in somatic growth and cardiovascular structure and function

OBJECTIVE

The objective of the study was to compare and contrast the effects of developmental hypoxia vs undernutrition on fetal growth, cardiovascular morphology, and function.

STUDY DESIGN

On day 15 of gestation, Wistar dams were divided into control, hypoxic (10% O(2)), or undernourished (35% reduction in food intake) pregnancy. On day 20, fetal thoraces were fixed, and the fetal heart and aorta underwent quantitative histological analysis. In a separate group, fetal aortic vascular reactivity was determined via wire myography.

RESULTS

Both hypoxic and undernourished pregnancy was associated with asymmetric fetal growth restriction. Pregnancy complicated by hypoxia promoted fetal aortic thickening without changes in cardiac volumes when expressed as a percentage of total heart volume. In contrast, maternal undernutrition affected fetal cardiac morphology without changes in aortic structure. Fetal aortic vascular reactivity was also differentially affected by hypoxia or undernutrition.

CONCLUSION

Developmental hypoxia or undernutrition in late gestation has differential effects on fetal cardiovascular morphology and function.

Aortic elastic properties in nonalcoholic fatty liver disease

BACKGROUND

Recent studies have shown that patients with nonalcoholic fatty liver disease (NAFLD) have an increased risk of developing cardiovascular disease. Aortic stiffness, an early marker of arteriosclerosis, is associated with cardiovascular mortality. In this study, the aortic elastic properties of nondiabetic, normotensive NAFLD patients were evaluated.

METHODS

Thirty-five patients with NAFLD and 30 age-matched and sex-matched healthy controls were enrolled. Aortic distensibility, aortic strain, aortic stiffness index (ASI), left ventricular mass index (LVMI), homeostasis model assessment of insulin resistance (HOMA-IR) and fasting lipid parameters were assessed in both the groups.

RESULTS

ASI was higher in NAFLD patients (7.1+/-2.0) than in the control group (3.8+/-1.0) (P<0.01). Aortic distensibility and aortic strain were also significantly decreased in NAFLD patients as compared with the control group (2.9+/-0.7 cm/dyn vs. 6.3+/-2.4 cm/dyn, P<0.0001 and 7.1+/-1.7 vs. 14.5+/-4.0, P<0.0001, respectively). Although ASI was significantly correlated with age, HOMA-IR, waist circumference, body mass index and LVMI, a stepwise multiple linear regression analysis showed that HOMA-IR and LVMI were the only variables associated with ASI index [(standardized beta coefficient= 0.41, P=0.004, overall R=0.17) and (standardized beta coefficient=0.31, P=0.02, overall R=0.10), respectively].

CONCLUSION

Our data suggest that aortic elasticity is significantly impaired and is also associated with insulin resistance and LVMI in NAFLD patients, which may contribute to the relationship between NAFLD and the increased risk of cardiovascular disease among these patients.

Sex differences in the combined effect of chronic stress with impaired vascular endothelium functioning and the development of early atherosclerosis: the Cardiovascular Risk in Young Finns study

Background

The syndrome of vital exhaustion (VE), characterized by fatigue and irritability, may contribute to an increased risk of atherosclerosis. The aim of the study was to explore sex differences in the interactions of VE with endothelial dysfunction and VE with reduced carotid elasticity, the important contributors to the development of early atherosclerosis, on preclinical atherosclerosis.

Methods

The participants were 1002 women and 719 men aged 24-39 examined in the Cardiovascular Risk in Young Finns study. Vital exhaustion was measured using the Maastricht Questionnaire. Preclinical atherosclerosis was assessed by carotid intima-media thickness (IMT), endothelial function was measured by brachial flow-mediated dilatation (FMD), and arterial elasticity by carotid artery compliance (CAC) using ultrasound techniques.

Results

We found a significant CAC x VE interaction for IMT only for the men. Our results imply that high VE level significantly related to high IMT levels among the men with low CAC, but not among the women with low CAC or among the women or men with high CAC. No significant FMD x VE interactions for IMT for the women or men were found.

Conclusions

High VE may exert an effect on IMT for men with impaired arterial elasticity. The results suggest that high vitally exhausted men with reduced arterial elasticity are at increased risk of atherosclerosis in early life and imply men's decreased stress coping in relation to stressful psychological coronary risk factors.

Biomechanical and microstructural properties of common carotid arteries from fibulin-5 null mice

Alteration in the mechanical properties of arteries occurs with aging and disease, and arterial stiffening is a key risk factor for subsequent cardiovascular events. Arterial stiffening is associated with the loss of functional elastic fibers and increased collagen content in the wall of large arteries. Arterial mechanical properties are controlled largely by the turnover and reorganization of key structural proteins and cells, a process termed growth and remodeling. Fibulin-5 (fbln5) is a microfibrillar protein that binds tropoelastin, interacts with integrins, and localizes to elastin fibers; tropoelastin and microfibrillar proteins constitute functional elastic fibers. We performed biaxial mechanical testing and confocal imaging of common carotid arteries (CCAs) from fibulin-5 null mice (fbln5 ⁻(/)⁻) and littermate controls (fbln5 (+/+)) to characterize the mechanical behavior and microstructural content of these arteries; mechanical testing data were fit to a four-fiber family constitutive model. We found that CCAs from fbln5 ⁻(/)⁻ mice exhibited lower in vivo axial stretch and lower in vivo stresses while maintaining a similar compliance over physiological pressures compared to littermate controls. Specifically, for fbln5 ⁻(/)⁻ the axial stretch λ = 1.41 ± 0.07, the circumferential stress σ(θ) = 101 ± 32 kPa, and the axial stress σ ( z ) = 74 ± 28 kPa; for fbln5 (+/+) λ = 1.64 ± 0.03, σ(θ) = 194 ± 38 kPa, and σ(z) = 159 ± 29 kPa. Structurally, CCAs from fbln5 ⁻(/)⁻ mice lack distinct functional elastic fibers defined by the lamellar structure of alternating layers of smooth muscle cells and elastin sheets. These data suggest that structural differences in fbln5 ⁻(/)⁻ arteries correlate with significant differences in mechanical properties. Despite these significant differences fbln5 ⁻(/)⁻ CCAs exhibited nearly normal levels of cyclic strain over the cardiac cycle.

Feasibility of dual Doppler velocity measurements to estimate volume pulsations of an arterial segment

If volume flow was measured at each end of an arterial segment with no branches, any instantaneous differences would indicate that volume was increasing or decreasing transiently within the segment. This concept could provide an alternative method to assess the mechanical properties or distensibility of an artery noninvasively using ultrasound. The goal of this study was to determine the feasibility of using Doppler measurements of pulsatile velocity (opposed to flow) at two sites to estimate the volume pulsations of the intervening arterial segment. To test the concept over a wide range of dimensions, we made simultaneous measurements of velocity in a short 5 mm segment of a mouse common carotid artery and in a longer 20 cm segment of a human brachial-radial artery using a two-channel 20 MHz pulsed Doppler and calculated the waveforms and magnitudes of the volume pulsations during the cardiac cycle. We also estimated pulse wave velocity from the velocity upstroke arrival times and measured artery wall motion using tissue Doppler methods for comparison of magnitudes and waveforms. Volume pulsations estimated from Doppler velocity measurements were 16% for the mouse carotid artery and 4% for the human brachial artery. These values are consistent with the measured pulse wave velocities of 4.2 m/s and 10 m/s, respectively, and with the mouse carotid diameter pulsation. In addition, the segmental volume waveforms resemble diameter and pressure waveforms as expected. We conclude that with proper application and further validation, dual Doppler velocity measurements can be used to estimate the magnitude and waveform of volume pulsations of an arterial segment and to provide an alternative noninvasive index of arterial mechanical properties.

Intra-operative ultrasound hand-held strain imaging for the visualization of ablations produced in the liver with a toroidal HIFU transducer: first in vivo results

The use of hand-held ultrasound strain imaging for the intra-operative real-time visualization of HIFU (high-intensity focused ultrasound) ablations produced in the liver by a toroidal transducer was investigated. A linear 12 MHz ultrasound imaging probe was used to obtain radiofrequency signals. Using a fast cross-correlation algorithm, strain images were calculated and displayed at 60 frames s(-1), allowing the use of hand-held strain imaging intra-operatively. Fourteen HIFU lesions were produced in four pigs. Intra-operative strain imaging of HIFU ablations in the liver was feasible owing to the high frame rate. The correlation between dimensions measured on gross pathology and dimensions measured on B-mode images and on strain images were R = 0.72 and R = 0.94 respectively. The contrast between ablated and non-ablated tissue was significantly higher (p < 0.05) in the strain images (22 dB) than in the B-mode images (9 dB). Strain images allowed equivalent or improved definition of ablated regions when compared with B-mode images. Real-time intra-operative hand-held strain imaging seems to be a promising complement to conventional B-mode imaging for the guidance of HIFU ablations produced in the liver during an open procedure. These results support that hand-held strain imaging outperforms conventional B-mode ultrasound and could potentially be used for the assessment of thermal therapies.

Reduced arterial compliance associated with metabolic syndrome in Chinese children and adolescents

OBJECTIVE

To explore the metabolic syndrome and its association with arterial compliance in Chinese children and adolescents.

METHODS

337 participants aged 6 to 18 years with males accounted for 55.8% were grouped according to their traits of metablic syndrome. Anthropometry, blood pressure, fasting plasma glucose, insulin and serum lipid profile were measured. Homeostasis model was assessed and insulin resistance (HOMA-IR) index was measured and calculated for estimating individual insulin resistance. Arterial compliance was also measured using digital pulse wave analyzing method (Micro medical, London), and stiffness index was calculated.

RESULTS

The stiffness index in participants with metablic syndrome was significant higher than that in participants with no riskof metablic syndrome [(7.69 +/- 1.63) vs (6.25 +/- 0.86) m/s, P < 0.01] and stiffness index and HOMA-IR were progressively increased with the increase of traits of metablic syndrom (P for linear trend < 0.001). After gender, age, and pubertal development were adjusted, both traits of metablic syndrome and HOMA-IR were correlated positively with stiffness index (both P < 0.05).

CONCLUSION

The clustering of metablic syndrome was closely associated with risk at increased arterial stiffness in Chinese children and adolescents. It was suggested that arterial compliance assessment of children and adolescents might be an important measure for prevention of cardiovascular diseases.

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.

Insight into the dicrotic notch in photoplethysmographic pulses from the finger tip of young adults

This study aims to investigate arterial stiffness in selected young adults by non-invasively determining the characteristics of the photoplethysmographic dicrotic notch. A total of 15 volunteers participated in this study, divided into four groups by age and gender. Contour analysis was applied to analyse the photoplethysmographic dicrotic notch, including time-related and height-related parameters. The height of reflected wave, mirrored by the notch relative amplitude (NRA), was found to be significantly larger in the older group compared to the younger group (p = 0.016). The timing of the reflected wave, measured by three parameters, i.e. notch index (NI), notch latency (NL) and peak-to-notch latency (PTNL), significantly increased in the female group compared to the male group (all p < 0.02). The results confirm that arterial stiffness occurs in young adults, and demonstrate that a difference of arterial stiffness exists between young male and female. This study indicates that examining the characteristic notch of the PPG pulse could help in identifying differences of vascular activities.

Chronic stress and the development of early atherosclerosis: moderating effect of endothelial dysfunction and impaired arterial elasticity

This study aims to explore the interactive effect of vital exhaustion (VE) and endothelial dysfunction on preclinical atherosclerosis, assessed by carotid intima-media thickness (IMT). Furthermore, interaction between VE and carotid elasticity is examined. Participants were 1,596 young healthy adults from the Cardiovascular Risk in Young Finns study. Endothelial dysfunction was measured by brachial flow-mediated dilatation (FMD), and carotid elasticity by carotid artery compliance (CAC). Significant interactions between FMD and VE, and between CAC and VE, for IMT were found in participants with the very lowest FMD and CAC. Thus, VE may be harmful if the endothelium is not working properly.

Low-fat versus low-carbohydrate weight reduction diets: effects on weight loss, insulin resistance, and cardiovascular risk: a randomized control trial

OBJECTIVE

Low-fat hypocaloric diets reduce insulin resistance and prevent type 2 diabetes in those at risk. Low-carbohydrate, high-fat diets are advocated as an alternative, but reciprocal increases in dietary fat may have detrimental effects on insulin resistance and offset the benefits of weight reduction.

RESEARCH DESIGN AND METHODS

We investigated a low-fat (20% fat, 60% carbohydrate) versus a low-carbohydrate (60% fat, 20% carbohydrate) weight reduction diet in 24 overweight/obese subjects ([mean +/- SD] BMI 33.6 +/- 3.7 kg/m(2), aged 39 +/- 10 years) in an 8-week randomized controlled trial. All food was weighed and distributed, and intake was calculated to produce a 500 kcal/day energy deficit. Insulin action was assessed by the euglycemic clamp and insulin secretion by meal tolerance test. Body composition, adipokine levels, and vascular compliance by pulse-wave analysis were also measured.

RESULTS

Significant weight loss occurred in both groups (P < 0.01), with no difference between groups (P = 0.40). Peripheral glucose uptake increased, but there was no difference between groups (P = 0.28), and suppression of endogenous glucose production was also similar between groups. Meal tolerance-related insulin secretion decreased with weight loss with no difference between groups (P = 0.71). The change in overall systemic arterial stiffness was, however, significantly different between diets (P = 0.04); this reflected a significant decrease in augmentation index following the low-fat diet, compared with a nonsignificant increase within the low-carbohydrate group.

CONCLUSIONS

This study demonstrates comparable effects on insulin resistance of low-fat and low-carbohydrate diets independent of macronutrient content. The difference in augmentation index may imply a negative effect of low-carbohydrate diets on vascular risk.

Multichannel pulsed Doppler signal processing for vascular measurements in mice

The small size, high heart rate and small tissue displacement of a mouse require small sensors that are capable of high spatial and temporal tissue displacement resolutions and multichannel data acquisition systems with high sampling rates for simultaneous measurement of high fidelity signals. We developed and evaluated an ultrasound-based mouse vascular research system (MVRS) that can be used to characterize vascular physiology in normal, transgenic, surgically altered and disease models of mice. The system consists of multiple 10/20MHz ultrasound transducers, analog electronics for Doppler displacement and velocity measurement, signal acquisition and processing electronics and personal computer based software for real-time and off-line analysis. In vitro testing of the system showed that it is capable of measuring tissue displacement as low as 0.1mum and tissue velocity (mum/s) starting from 0. The system can measure blood velocities up to 9m/s (with 10MHz Doppler at a PRF of 125kHz) and has a temporal resolution of 0.1 milliseconds. Ex vivo tracking of an excised mouse carotid artery wall using our Doppler technique and a video pixel tracking technique showed high correlation (R(2)=0.99). The system can be used to measure diameter changes, augmentation index, impedance spectra, pulse wave velocity, characteristic impedance, forward and backward waves, reflection coefficients, coronary flow reserve and cardiac motion in murine models. The system will facilitate the study of mouse vascular mechanics and arterial abnormalities resulting in significant impact on the evaluation and screening of vascular disease in mice.

Effect of upper body aerobic exercise on arterial stiffness in older adults

The authors evaluated the effects of acute arm-cycling exercise on arterial stiffness of the brachial artery (BA: working limb) and posterior tibial artery (PTA: nonworking limb) in healthy older participants. Eleven participants were tested to evaluate BA and PTA stiffness. Blood pressure (BP), heart rate (HR), and arterial stiffness indices of the BA and PTA measured by Doppler ultrasound were determined before and 10 min after graded arm-cycling exercise to volitional fatigue on 2 separate days. After the exercise, although BA diameter, brachial systolic BP, pulse pressure, and HR increased significantly (all p < .05), arterial stiffness indices of the BA remained unchanged. Similarly, arterial stiffness indices of the PTA remained unchanged after the exercise, whereas HR increased significantly (p < .05). These results show that acute arm-cycling exercise failed to modify arterial stiffness of the BA and PTA, suggesting that it has no systemic effect on arterial stiffness in healthy older adults.

Vascular health in children and adolescents: effects of obesity and diabetes

The foundations for cardiovascular disease in adults are laid in childhood and accelerated by the presence of comorbid conditions, such as obesity, diabetes, hypertension, and dyslipidemia. Early detection of vascular dysfunction is an important clinical objective to identify those at risk for subsequent cardiovascular morbidity and events, and to initiate behavioral and medical interventions to reduce risk. Typically, cardiovascular screening is recommended for young adults, especially in people with a family history of cardiovascular conditions. Children and adolescents were once considered to be at low risk, but with the growing health concerns related to sedentary lifestyle, poor diet and obesity, cardiovascular screening may be needed earlier so that interventions to improve cardiovascular health can be initiated. This review describes comorbid conditions that increase cardiovascular risk in youth, namely obesity and diabetes, and describes noninvasive methods to objectively detect vascular disease and quantify vascular function and structure through measurements of endothelial function, arterial compliance, and intima-media thickness. Additionally, current strategies directed toward prevention of vascular disease in these populations, including exercise, dietary interventions and pharmacological therapy are described.

The effects of short-duration exercise on arterial stiffness in patients with stable coronary artery disease

Arterial stiffness is an important contributor to the development of cardiovascular disease. We investigated the effect of short duration exercise using the treadmill test on arterial stiffness in the presence of coronary artery disease. We enrolled patients with and without coronary artery diseases (CAD and control group, 50 patients each) referred for treadmill testing. Brachial-ankle pulse wave velocity (baPWV) were measured before and after treadmill testing. Values of baPWV were significantly reduced at 10 min after exercise in both groups, more in the CAD group than in the control group (baseline baPWV and post-exercise change [cm/sec]: 1,527+/-245 and -132+/-155 in the CAD group, 1,439+/-202 and -77+/-93 in the control group, respectively, P for change in each group <0.001, P for difference in changes between the two groups <0.001). These findings persisted after adjusting for age, body mass index, systolic blood pressure, mean arterial pressure (MAP), MAP decreases, and baseline baPWV. Significant post-exercise baPWV reductions were observed in both groups, and more prominently in the CAD group. This finding suggests that short-duration exercise may effectively improve arterial stiffness even in patients with stable coronary artery disease.

Arterial wall dysfunction in systemic lupus erythematosus

Carotid-radial pulse wave velocity (PWV), aortic augmentation index (AIx) and endothelium-dependent flow-mediated dilatation (FMD) have been repeatedly showed to be related to premature atherosclerosis and cardiovascular diseases in different settings of population. The increased arterial stiffness and endothelium dysfunction may add to premature aging of the arteries in systemic lupus erythematosus (SLE) patients. Still data about arterial stiffness and endothelium function in inflammatory rheumatic diseases are not well described. The aim of this study was to determine the PWV, its derivate marker AIx and FMD and factors possibly influencing them in young SLE women without significant organ damage. Thirty women between 23 and 55 years with an established SLE diagnosis and 66 healthy women were consequently included in the study and both groups were comparable according to age, body mass index (BMI), serum lipid profile and creatinine. PWV was determined by measuring carotid-radial pulse wave transit time with the help of applanation tonometry and AIx, its derivate marker, was calculated as a difference between two waveform peaks expressed as a percentage of the pulse pressure. The FMD was performed by obtaining the repeated scans of the brachial artery at rest and during reactive hyperemia. In SLE women, PWV and AIx were significantly higher and FMD was not different from controls. In linear multiple stepwise regression analysis if patients and controls were both considered, PWV was weakly related to mean blood pressure (MBP), AIx was mostly predicted by age and MBP and FMD was predicted by the diameter of blood vessel, BMI, high density lipoproteins. If the sole SLE setting was analyzed, PWV was not related to any of the pending parameters, AIx turned out to be related to organ damage measured by Systemic Lupus International collaborative Clinics (SLICC) index and age, and FMD obtained strong and significant relation with vessel diameter, and BMI, and disease duration. Regardless of the small number of study group patients, we can state that controlling for MBP and taking measures towards organ damage prevention can partially slow down the process of early atherosclerosis in SLE patients.

Arterial destiffening with atorvastatin in overweight and obese middle-aged and older adults

We hypothesized that atorvastatin (ATOR) treatment would reduce arterial stiffness in overweight and obese middle-aged and older adults. Twenty-six (11 men and 15 women) overweight or obese (body mass index: 31.6+/-0.7 kg/m(2)) middle-aged and older adults (age: 54+/-2 years) were randomly assigned to receive either ATOR (80 mg/d) or placebo for 12 weeks. Arterial stiffness (beta-stiffness and pulse wave velocity) was measured before and after the intervention. At baseline, the ATOR (n=16) and placebo (n=10) groups did not differ with respect to age, body mass index, blood pressure, serum lipid and lipoprotein concentrations, high-sensitivity C-reactive protein, indices of arterial stiffness, or compliance (all P>0.05). After the 12-week treatment period, the ATOR group experienced a 47% reduction in low-density lipoprotein cholesterol (149+/-6 to 80+/-8 mg/dL) and a 42% reduction in high-sensitivity C-reactive protein (3.6+/-0.8 to 2.1+/-0.5 mg/L; both P<0.05). In addition, beta-stiffness (9.4+/-0.6 to 7.6+/-0.5 U) and aortic pulse wave velocity (1096+/-36 to 932+/-32 cm/s), but not brachial pulse wave velocity, decreased (both P<0.05) with ATOR. In contrast, there were no significant changes in beta-stiffness (9.1+/-0.8 to 9.1+/-0.7 U) or aortic pulse wave velocity (1238+/-89 to 1191+/-90 cm/s; both P>0.05) in the placebo group. There were no relations between the reductions in arterial stiffness indices and any of the baseline cardiometabolic risk factors (all P>0.05). However, the reductions in arterial stiffness were correlated with the reduction in low-density lipoprotein cholesterol but not high-sensitivity C-reactive protein or any other cardiometabolic variables (all P<0.05). Taken together, these findings suggest that ATOR reduces arterial stiffness in overweight and obese middle-aged and older adults, and these favorable changes occur irrespective of baseline cardiometabolic risk factors.

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.

Vascular disease in rheumatoid arthritis: from subclinical lesions to cardiovascular risk

Rheumatoid arthritis (RA) is one of the most prevalent and complex inflammatory diseases affecting primarily the joints, but also associating several extra-articular features. The vascular disease in RA encompasses a large spectrum of lesions, from rheumatoid vasculitis to atherosclerotic lesions. During the last years the importance of the vascular disease related to atherosclerosis in terms of cardiovascular morbidity and global mortality became evident in RA. The inflammatory hypothesis of atherosclerosis in RA implies that mediators originating from the inflamed synovial tissue or from the liver may have systemic vascular consequences, leading to endothelial dysfunction and structural abnormalities of the vessels. Hence, the global management of patients with RA must include the improvement of cardiovascular risk in parallel with the management of joint disease.

Arterial Compliance in Multiple Sclerosis: A Pilot Study

A reduction in arterial compliance in patients with autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus has been previously reported. It is caused by the effect that systemic inflammation has on the cardiovascular system. Multiple sclerosis (MS), an immune-mediated disease that exclusively affects the central nervous system (CNS), has a significant inflammatory component that is limited to that compartment. The potential effects of its inflammatory mediators in the cardiovascular system are largely unknown. Purpose: To examine large (C1) and small arterial compliance (C2) in patients with MS and compare them with healthy age-matched controls. To also determine whether any differences in C1 and C2 indices between participants diagnosed with relapsing remitting MS (RR-MS), secondary progressive MS (SP-MS), and controls exist. Methods: A total of 26 men and women between the ages of 18 and 64 diagnosed with MS and 25 healthy controls volunteered for this study. Arterial compliance was measured by using pulse contour analysis (PCA), which records and analyzes the blood pressure waveform data from the Arterial Pulse Wave Sensors. Results: Significant differences in C1 and C2 were found between young RR-MS and healthy young controls (P < .05), with the MS group showing lower arterial C1 and C2 compliance. No significant differences (P > .05) were seen for C1 or C2 values between older RR-MS, SP-MS, and healthy controls. Conclusion: Arterial compliance is significantly compromised in young individuals with MS, compared with age-matched controls, but not for older individuals, suggesting a systemic effect of an inflammatory process that predominantly affects the CNS.

Arterial stiffness, carotid artery intima-media thickness and plasma myeloperoxidase level in children with type 1 diabetes

OBJECTIVE

The present study investigated the functional-structural changes of the arteries along with a new biochemical marker of atherosclerosis, plasma myeloperoxidase level, in children with type 1 diabetes (T1DM).

METHODS

We studied 30 children with T1DM, aged 4.7-18.6 years (mean T1DM duration 5.4+/-3.4 years, mean HbA(1c) 9.8%) and 30 healthy subjects, matched by sex, age and body mass index. Fasting blood samples were obtained for myeloperoxidase (MPO). Ultrasonography and pulse wave analysis were used to measure carotid intima-media thickness (IMT), augmentation index corrected to a heart rate of 75 (AIx@75) and pulse wave velocity (PWV).

RESULTS

Children with diabetes had significantly higher plasma MPO levels (p=0.006), increased AIx@75 (p=0.02), IMT (p=0.005) and IMT standard deviation scores (IMT SDS) (p=0.02), compared to the control group. IMT SDS correlated positively with HbA(1c) (r=0.39, p=0.05). PWV, adjusted for age and mean arterial blood pressure, correlated with diabetes duration (r=0.49, p=0.02).

CONCLUSIONS

Children with T1DM have substantially elevated plasma levels of myeloperoxidase as well as atherosclerosis-related structural and functional changes of the arterial wall.

Associations between augmentation index and severity of atheroma or aortic stiffness of the descending thoracic aorta by transesophageal echocardiography

BACKGROUND

Although the aortic augmentation index (AI) is an attractive tool as an index of the vascular system, the association between radial AI or brachial-ankle pulse wave velocity (PWV) and severity of atheroma or arterial stiffness of the morphological central artery is unclear.

METHODS AND RESULTS

Severity of atheroma and aortic stiffness of the descending thoracic aorta (DTA) by transesophageal echography in 96 patients with paroxysmal atrial fibrillation was assessed. The relationship between radial AI or brachial-ankle PWV and atherosclerotic lesions was also investigated. The DTA was divided into 3 equal longitudinal portions, and the atheromatous lesions of each portion of the DTA were scored according to their character and extension. Instantaneous dimensional changes in the DTA was measured, and the aortic stiffness index beta was calculated. Radial AI was significantly correlated with age, plasma low-density lipoprotein-cholesterol concentrations, systolic blood pressure, pulse pressure, the mean atheromatous score and the mean aortic stiffness index. However, brachial-ankle PWV was not associated with central arterial stiffness. Multivariate logistic regression analysis showed that radial AI was most closely correlated with the mean atheromatous score.

CONCLUSIONS

Radial AI might be a novel tool for determining the severity of central aortic atheromatous lesions.

Relation of plasma homocysteine to arterial stiffness in black and white young adults (from the Bogalusa Heart Study)

The aim of this study was to determine the association between homocysteine and arterial wall stiffness in a biracial (black and white) community-based cohort of asymptomatic young adults. That increased plasma homocysteine was adversely associated with atherothrombosis was well recognized. However, findings about the association of homocysteine and arterial wall stiffness, an indicator of vascular damage, were conflicting. Plasma homocysteine and other cardiovascular disease risk-factor variables were measured in 735 white and 294 black subjects aged 24 to 44 years enrolled in the Bogalusa Heart Study. Large-artery stiffness was assessed in terms of aorta-femoral pulse wave velocity (af-PWV) using echocardiography Doppler. Men versus women had higher fasting homocysteine (8.85 vs 7.32 micromol/L; p <0.01), and blacks versus whites had higher af-PWV (5.47 vs 5.24 m/s; p <0.01). In bivariate analyses, log-transformed homocysteine significantly correlated with af-PWV (p = 0.0004). In multivariate stepwise regression analyses, systolic blood pressure, age, heart rate, log-homocysteine, log-Homeostasis Model Assessment of Insulin Resistance, and smoking, in that order, were independently and positively associated with af-PWV. In conclusion, plasma homocysteine was an independent correlate of arterial stiffness in asymptomatic black and white young adults and may be a potential marker for cardiovascular disease risk in this age group.

Resistance Training Effects on Arterial Compliance in Premenopausal Women

Endurance training has been shown to increase arterial compliance; however, the effect of resistance training is unclear. Purpose: The purpose of this study was to examine the effect lower body resistance training on arterial compliance in healthy premenopausal women. Methods: Thirty-two women were assigned to a resistance training group (n = 21) or a control group (n = 11). Large (C1) and small (C2) arterial compliance (Pulse Contour Analysis) were measured at baseline and after twelve weeks of training. Results: Two-way (group × time) repeated measured ANOVA did not detect significant group, time effects or group × time interactions for small arterial compliance (P > 0.05). There was a significant time effect for large arterial compliance (P < 0.05), which increased in both groups. Conclusions: In contrast to previous studies in men, which found decrease in arterial compliance with resistance training, no decrease in arterial compliance was observed.

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.

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.

Estimation of carotid diameter with heartbeat on longitudinal B-mode ultrasonic images

Arteriosclerosis, i.e. degrading arterial elasticity, causes cerebral infarction and myocardial infarction. Premonition of arteriosclerosis is important because arteriosclerosis is never cured completely. We therefore propose a method to track the carotid diameter to evaluate the initial carotid elasticity accompanied with a person's heartbeat using the longitudinal B-mode ultrasonic images. If the diameter of carotid artery can be accurately estimated, it is possible to implies for initial inference of the presence of arteriosclerosis. In future studies, it has to be assessed with comparisons to anaother established method.

Racial and socioeconomic disparities in arterial stiffness and intima media thickness among adolescents

Racial and socioeconomic status (SES) disparities in cardiovascular disease (CVD) risk are well established among adults. However, little is known about disparities in CVD risk among adolescents, particularly considering indices of subclinical CVD. Our aim was to examine socioeconomic and racial disparities in subclinical CVD indices among adolescents. We hypothesized that African American and lower SES adolescents would show greater arterial stiffness and intima media thickness compared to Caucasian and higher SES adolescents, respectively. Participants were 81 African American and 78 Caucasian adolescents (mean age=17.8) from two schools in Pittsburgh, PA, USA. Measures of subclinical CVD were pulse wave velocity and intima media thickness, as assessed by Doppler and B-mode ultrasound, respectively. SES indices included parental education, family income, family assets, subjective social status, and census-derived neighborhood SES. Hypotheses were evaluated in multiple linear regression models with the covariates age, gender, body mass index, and systolic blood pressure. Results indicated that African American adolescents were more often in low SES positions than Caucasians. When considered individually, racial and SES disparities in pulse wave velocity, and to a lesser extent, intima media thickness, were evident. When race and SES were considered together, high school education, low or medium income, and low neighborhood SES were associated with higher pulse wave velocity. Fewer assets were associated with higher intima media thickness. In conclusion, racial and SES disparities in indices of subclinical CVD were observed, with findings most pronounced for SES disparities in pulse wave velocity. This study extends previous findings in adults to adolescents, indicating that disparities in arterial stiffness and intima media thickness occur as early as adolescence. Efforts to reduce socioeconomic and racial disparities in CVD should target disparities early in life.

Relationship between birthweight and arterial elasticity in childhood

There is a considerable debate about the potential influence of ‘fetal programming’ on cardiovascular diseases in adulthood. In the present prospective epidemiological cohort study, the relationship between birthweight and arterial elasticity in 472 children between 5 and 8 years of age was assessed. LAEI (large artery elasticity index), SAEI (small artery elasticity index) and BP (blood pressure) were assessed using the HDI/PulseWave™ CR-2000 CardioVascular Profiling System. Blood concentrations of glucose, total cholesterol and its fractions [LDL (low-density lipoprotein)-cholesterol and HDL (high-density lipoprotein)-cholesterol] and triacylglycerols (triglycerides) were determined by automated enzymatic methods. Insulin was assessed by a chemiluminescent method, insulin resistance by HOMA (homoeostasis model assessment) and CRP (C-reactive protein) by immunonephelometry. Two linear regression models were applied to investigate the relationship between the outcomes, LAEI and SAEI, and the following variables: birthweight, gestational age, glucose, LDL-cholesterol, HDL-cholesterol, triacylglycerols, insulin, CRP, HOMA, age, gender, waist circumference, per capita income, SBP (systolic BP) and DBP (diastolic BP). LAEI was positively associated with birthweight (P=0.036), waist circumference (P<0.001) and age (P<0.001), and negatively associated with CRP (P=0.024) and SBP (P<0.001). SAEI was positively associated with birthweight (P=0.04), waist circumference (P=0.001) and age (P<0.001), and negatively associated with DBP (P<0.001). Arterial elasticity was decreased in apparently healthy children who had lower birthweights, indicating an earlier atherogenetic susceptibility to cardiovascular diseases in adolescence and adult life. Possible explanations for the results include changes in angiogenesis during critical phases of intrauterine life caused by periods of fetal growth inhibition and local haemodynamic anomalies as a way of adaptation to abnormal pressure and flow.

Cardiovascular aspects of primary hyperparathyroidism

Data concerning the cardiovascular manifestations of primary hyperparathyroidism (PHPT) are inconsistent, which is due, in part, to the decrease in disease severity over the last several decades. In areas where patients tend to be more symptomatic, data support the presence of cardiovascular findings including myocardial and vascular calcification as well as increased cardiovascular mortality. Data from the cohorts in whom the disease is characterized by mild hypercalcemia, suggest that clinically overt cardiovascular manifestations are unusual in PHPT. Recent data, however, support the presence of subtle cardiovascular manifestations in mild disease, such as changes in endothelial function as well as increased vascular stiffness and perhaps diastolic dysfunction. Left ventricular hypertrophy is a more consistent finding across a spectrum of disease severity, though this finding may be related to hypertension, which has long been associated with PHPT.

Association of left ventricular diastolic function abnormalities with aortic elastic properties in asymptomatic patients with type 2 diabetes mellitus. A tissue doppler echocardiographic study

BACKGROUND

The aim of this study was to investigate the association between the aortic elastic properties and the left ventricular diastolic function measured by tissue Doppler echocardiography (TDE) in asymptomatic type 2 diabetes mellitus.

METHODS

Fifty-seven asymptomatic patients with type 2 diabetes (33 women, mean age: 49 +/- 6 years) and 25 healthy control subjects (19 women, mean age: 46 +/- 7 years) were included in the present study. Diastolic filling indices were measured by conventional (CE) and tissue Doppler echocardiography. The aortic elastic properties [Aortic stiffness index (ASI), aortic distensibility and strain] were measured as previous definition.

RESULTS

Compared with control subjects, the ratio of LV diastolic abnormalities measured by CE and TDE were found higher in patients with type 2 diabetes (36% and 73.6%, p = 0.001, respectively, and 52% and 89.4%, p < 0.001, for septal annulus; 48% and 89.4%, p < 0.001 for septal basal respectively). The ASI was significantly higher (p < 0.001), aortic distensibility and aortic strain were also significantly lower in patients with type 2 diabetes than control subjects (p < 0.001 and p < 0.001 respectively). In the regression analysis, Ao distensibility was correlated to age (beta = -0.299, p = 0.004), septal basal Em/Am ratio (beta =0.543, p < 0.001) and HDL-cholesterol (beta = 0.192, p = 0.039). ASI was also correlated only to age (beta = 0.255, p = 0.044), the presence of diabetes mellitus (beta = 0.304, p = 0.009), mitral A wave (beta = 0.322, p = 0.013) and mitral annulus Em wave (beta = -0.505, p < 0.001).

CONCLUSION

The aortic elastic function is impaired in asymptomatic patients with type 2 diabetes. Increased ASI and decreased Ao distensibility are closely associated with diastolic filling indices measured by CE and TDE.

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.

Effect of integration of supplemental nutrition with public health programmes in pregnancy and early childhood on cardiovascular risk in rural Indian adolescents: long term follow-up of Hyderabad nutrition trial

OBJECTIVE

To determine whether integration of nutritional supplementation with other public health programmes in early life reduces the risk of cardiovascular disease in undernourished populations.

DESIGN

Approximately 15 years' follow-up of participants born within an earlier controlled, community trial of nutritional supplementation integrated with other public health programmes.

SETTING

29 villages (15 intervention, 14 control) near Hyderabad city, south India.

PARTICIPANTS

1165 adolescents aged 13-18 years.

INTERVENTION

Balanced protein-calorie supplementation (2.51 MJ, 20 g protein) offered daily to pregnant women and preschool children aged under 6 years, coupled with integrated delivery of vertical public health programmes.

MAIN OUTCOME MEASURES

Height, adiposity, blood pressures, lipids, insulin resistance (homoeostasis model assessment (HOMA) score), and arterial stiffness (augmentation index).

RESULTS

The participants from the intervention villages were 14 mm (95% confidence interval 4 to 23; P=0.007) taller than controls but had similar body composition. The participants from the intervention villages had more favourable measures of insulin resistance and arterial stiffness: 20% (3% to 39%; P=0.02) lower HOMA score and 3.3% (1% to 5.7%; P=0.008) lower augmentation index. No strong evidence existed for differences in blood pressures and serum lipids.

CONCLUSIONS

In this undernourished population, integrated delivery of supplemental nutrition with other public health programmes in pregnancy and early childhood was associated with a more favourable profile of cardiovascular disease risk factors in adolescence. This pragmatic study provides the most robust evidence to date on this important hypothesis for which classic trials are unlikely. Improved maternal and child nutrition may have a role in reducing the burden of cardiovascular disease in low income and middle income countries.

Association of serum bilirubin with pulsatile arterial function in asymptomatic young adults: the Bogalusa Heart Study

The inverse association between serum bilirubin, a potent antioxidant, and oxidative stress-mediated diseases like cardiovascular disease is known. However, information is scant regarding the influence of bilirubin in relation to traditional cardiovascular risk factors on pulsatile arterial function in asymptomatic younger adults. The present study examines this aspect in 777 black and white subjects (71% white, 42% male) aged 18 to 44 years. Pulsatile arterial function was assessed in terms of large-artery (capacitive) and small-artery (oscillatory) compliances by radial artery pressure pulse contour analysis. In bivariate analysis adjusted for race and sex, bilirubin related significantly and positively to large- and small-artery compliances and high-density lipoprotein cholesterol, and inversely to age, body mass index, blood pressure variables, non-high-density lipoprotein cholesterol, triglycerides, and insulin resistance index. In multivariable analysis including race, sex, body surface area, and risk factor variables mentioned above, bilirubin did not relate to large-artery compliance, without or with smoking status in the model, whereas bilirubin associated beneficially with small-artery compliance (P=.01) in a model that excluded smoking status. When smoking status was included in the model, this association became less strong (P=.04); and smoking entered the model as an adverse predictor (P=.003). The observed beneficial association of serum bilirubin on pulsatile arterial function, albeit the attenuating effect of smoking on this relationship, in asymptomatic younger adults supports the antioxidant function of bilirubin in providing protection against oxidative stress-mediated vascular dysfunction.

Acute and chronic impact of dynamic exercise on arterial stiffness in older hypertensives

Arterial stiffness increases with ageing and hypertension. Regular physical activity has been recommended as an important management component of hypertension. The purpose of this study was to examine the acute impact of maximal dynamic exercise and the effect of 20 weeks of aerobic exercise on arterial stiffness of the carotid and brachial arteries in older hypertensives. Nine previously sedentary and treated older hypertensives (2 men and 7 women, age 68.2 ± 5.4 yrs) performed maximal treadmill exercise to volitional fatigue while arterial stiffness indices (arterial distensibility and β stiffness index) were measured prior to, immediately (about 10 min) following, and 24 h following maximal exercise. These measurements were repeated following 20 weeks of moderate intensity aerobic exercise training. Maximal exercise had no impact on arterial stiffness indices immediately and 24 h following exercise intervention. Following 20 weeks of training, arterial stiffness indices remained unchanged at rest and following maximal exercise. These data show that, in older hypertensives, 1) acute maximal dynamic exercise had no impact on arterial stiffness of the carotid and brachial arteries, and 2) 20 weeks of moderate intensity aerobic exercise training failed to modify arterial stiffness.

Arterial haemodynamics on ventricular hypertrophy in rats with simulated aortic stiffness

Aortic stiffness (AS) exerts significant impact on the cardiovascular risks. We developed a new model to produce AS. The purposes were to evaluate the haemodynamic consequence and to correlate the haemodynamic parameters with the extent of ventricular hypertrophy (VH). We applied silicon gel for embedding of the abdominal and/or thoracic aorta. After 1-4 weeks of AS, the left ventricular weight (LVW), LVW to body weight (BW) ratio (LVW/BW), and the morphological changes in cardiomyotes were quantified for VH. We determined the aortic pressure (AP), stroke volume, cardiac output, total peripheral resistance (TPR), characteristic impedance (Zc), pulse wave reflection (P(b)) and pulse wave velocity (PWV). Aortic embedding (AE) increased LVW, LVW/BW, systolic and pulse pressure (PP), Zc, P(b) and PWV accompanied by decreases in diastolic pressure and arterial compliance. The magnitude of these haemodynamic and cardiac changes were in an order of combined, thoracic and abdominal AE. Correlation analysis revealed that the VH was well correlated with pulsatile haemodynamics such as Zc, PP, P(b) and PWV, while less with steady components (Mean AP and TPR). Our results indicate that pulsatile haemodynamic parameters are significantly elevated after AS. The alterations in pulsatile haemodynamics are the major causes leading to VH.