Relations of cardiovascular risk factors to aortic pulse wave velocity in asymptomatic middle-aged women

Non-invasive measurement of brachial-ankle pulse wave velocity is associated with serum C-reactive protein but not with alpha-tocopherol in Japanese middle-aged male workers

Pulse wave velocity (PWV) is an indicator of arterial stiffness, especially in the aorta, and a marker for vascular damage. We examined the association of brachial-ankle PWV (baPWV) with serum alpha-tocopherol and C-reactive protein (CRP) levels in addition to the traditional risk factors. Study subjects were 178 Japanese male workers aged 50-59 without past histories of cardiovascular diseases. The relation of baPWV with serum alpha-tocopherol and CRP levels was cross-sectionally analyzed after adjusting for other cardiovascular risk factors. The arithmetic mean of serum alpha-tocopherol was 38.9 micromol/l, and the geometric mean of serum CRP was 0.47 mg/l. Multiple linear regression analysis indicated that serum CRP levels were associated with an elevation of baPWV, in addition to age, systolic blood pressure and heart rate. However, serum alpha-tocopherol, serum lipids (triglyceride, low and high density lipoprotein cholesterol), fasting plasma glucose, body mass index, smoking and alcohol drinking did not significantly correlate to baPWV. Multivariate-adjusted means of baPWV according to serum CRP quartile were 1,431, 1,436, 1,507 and 1,508 cm/s (p = 0.033). The serum CRP level might be an important marker for arterial stiffness in Japanese middle-aged males. However, no relation was observed between alpha-tocopherol and baPWV.

Post-challenge hyperglycaemia is an independent risk factor for arterial stiffness in Japanese men

AIMS

Arterial stiffness is an independent predictor of cardiovascular disease, but the impact of post-challenge hyperglycaemia on arterial stiffness is unknown. To investigate the association between arterial stiffness and post-challenge hyperglycaemia, we measured the second derivative of photoplethysmogram as an indicator of arterial stiffness.

METHODS

This study was done in 159 asymptomatic Japanese men aged 50.7 +/- 13.0 years. All subjects underwent a 75-g oral glucose tolerance test and measurement of the second derivative of photoplethysmogram.

RESULTS

According to the World Health Organization criteria (1998), 110 subjects had normal glucose tolerance, 10 had impaired fasting glucose, 30 had impaired glucose tolerance, and nine had diabetes. The b/a ratio (an index of arterial stiffness) showed a significant relationship with age (r = 0.58, P < 0.0001), height (r = -0.33, P < 0.0001), 2-h post-challenge glucose (r = 0.32, P < 0.0001), systolic blood pressure (r = 0.22, P = 0.006), and diastolic blood pressure (r = 0.21, P = 0.009). After adjustment for age and height, there were significant correlations between the b/a ratio and diastolic blood pressure (r = 0.18, P = 0.02), fasting glucose (r = 0.16, P = 0.049), and 2-h post-challenge glucose (r = 0.21, P = 0.009). Stepwise multiple regression analysis showed that only age (beta= 0.006, SE = 0.0007, P < 0.001) and 2-h post-challenge glucose (beta = 0.0005, SE = 0.0002, P < 0.05) contributed significantly to the b/a ratio (adjusted R(2) = 0.38).

CONCLUSIONS

These results indicate that post-challenge hyperglycaemia is an independent risk factor for arterial stiffness.

Higher carotid-radial pulse wave velocity in healthy offspring of patients with Type 2 diabetes

AIMS

To determine whether carotid-radial pulse wave velocity (crPWV), a simple non-invasive measurement of muscular artery structure and function, is increased in offspring of patients with Type 2 diabetes compared with well-matched controls with no family history of diabetes. Serum levels of intercellular adhesion molecule-1 (sICAM-1) were also examined.

METHODS

Offspring (n = 19, M = 8) were recruited via contact with patients attending clinics. Controls (n = 19, M = 8) were recruited by advertisement. crPWV was measured using COMPLIOR. Blood pressure and heart rate were determined and fasting blood taken for measurement of metabolic and endothelial parameters.

RESULTS

Offspring and controls were well matched [mean (sd)] for age [33.1 (9.6) vs. 32.8 (9.5) years], body mass index [24.8 (4.9) vs. 24.3 (3.4) kg/m2], waist circumference [78.3 (2.3) vs. 76.3 (2.5) cm], and systolic blood pressure [120 (9.3) vs. 119 (14.2) mmHg]. crPWV was 10% higher in the offspring [9.94 (1.3) m/s] compared with controls [9.01 (1.2) m/s, P = 0.02] despite similar pulse pressure [52 (10.5) vs. 53.5 (9.3) mmHg] and resting heart rate [71 (8.7) vs. 69 (14.0) beats/min]. They also showed a trend toward higher sICAM-1 [217 (55) vs. 188 (40) ng/ml, P = 0.07] concentrations which were also strongly correlated to crPWV in offspring (r = 0.63, P = 0.004).

CONCLUSIONS

Vascular dysfunction in the form of increased muscular artery stiffness is present from an early stage in subjects at higher risk of developing diabetes. This may be secondary to impaired activation of endothelial signalling pathways in the context of inherited insulin resistance.

Alcohol consumption and arterial stiffness in men

OBJECTIVE

Moderate alcohol consumption has been proposed to be anti-atherogenic and protect against coronary heart disease. Arterial stiffness provides a summary measure of atherosclerotic arterial damage and cardiovascular risk. A vascular protective effect of moderate alcohol consumption would be reflected in an inverse association between alcohol intake and aortic stiffness.

DESIGN

A cross-sectional study.

SETTING

The male population of Utrecht.

PARTICIPANTS

Of 370 men, aged 40-80 years, alcohol intake was calculated from a standardized questionnaire and aortic stiffness was non-invasively assessed by pulse-wave velocity (PWV) measurement of the aorta.

RESULTS

There were no non-drinkers; therefore the group consuming 0-3 glasses of alcoholic beverage per week was chosen as the reference group in the analyses. Those drinking 4-10, 11-21 and 22-58 glasses of alcoholic beverage per week had a -0.77 m/s (95% confidence interval, -1.26 to -0.28), -0.57 m/s (95% confidence interval, -1.07 to -0.08) and -0.14 m/s (95% confidence interval, -0.65 to 0.36) difference in mean PWV compared with those drinking 0-3 glasses per week. Adjustment for factors that correlated with PWV or alcohol consumption did not change the strength of the association.

CONCLUSION

Among men aged 40-80 years there is a J-shaped association between alcohol consumption and PWV. This further supports a decreased risk of cardiovascular disease with moderate alcohol consumption.

Comparison of risk factors for vascular disease in the carotid artery and aorta in women with systemic lupus erythematosus

OBJECTIVE

To examine and compare risk factors for various stages of subclinical vascular disease in different vascular beds (carotid and aorta) in women with systemic lupus erythematosus (SLE) who have not yet developed clinical cardiovascular disease.

METHODS

This cross-sectional study was conducted in 214 women without clinical cardiovascular disease who were enrolled in the Pittsburgh Lupus Registry. B-mode ultrasound was used to measure carotid plaque and intima-media wall thickness (IMT). Doppler probes were used to collect pulse-wave velocity waveforms from the right carotid and femoral arteries as a measure of aortic stiffness. All risk factor data were collected on the day of the ultrasound examinations.

RESULTS

The mean +/- SD age of the women was 45.2 +/- 10.5 years and the median SLE disease duration was approximately 9 years. Sixty-eight (32%) of the women had at least 1 focal plaque. The mean +/- SD IMT was 0.71 +/- 0.1 mm, and the mean +/- SD pulse-wave velocity was 5.96 +/- 1.6 meters/second. Using logistic regression, we found that determinants of plaque included older age, higher systolic blood pressure, lower levels of high-density lipoprotein 3, and antidepressant use. Determinants of plaque severity were older age, higher systolic blood pressure, lower levels of albumin, and smoking. Independent determinants of the highest quartile of IMT were older age, higher pulse pressure, lower levels of albumin, elevated C-reactive protein levels, high cholesterol, and higher levels of glucose. Higher aortic stiffness was associated with older age, higher systolic blood pressure, higher C3 levels, lower white blood cell count, higher insulin levels, and renal disease.

CONCLUSION

In women with SLE, the risk factors associated with carotid plaque and IMT are those typically associated with cardiovascular disease in the general population, whereas the risk factors associated with vascular stiffness include SLE-specific variables related to immune dysregulation and complement metabolism. The high prevalence of cardiovascular disease among lupus patients may result from both early adverse effects on vascular stiffening as well as later promotion of wall thickening and plaque through inflammatory-mediated processes. These observations provide clues for future mechanistic studies.

Alcohol consumption in relation to aortic stiffness and aortic wave reflections: a cross-sectional study in healthy postmenopausal women

OBJECTIVE

Moderate alcohol consumption has been postulated to be cardioprotective. Such an effect might be reflected in large-artery properties, such as arterial stiffness and wave reflections.

METHODS AND RESULTS

Three hundred seventy-one healthy postmenopausal women aged 50 to 74 years were sampled from a population-based study. Alcohol intake was calculated from a standardized questionnaire. Applanation tonometry was applied to assess the augmentation index and aortic pulse-wave velocity. Those drinking 1 to 3, 4 to 9, 10 to 14, and 15 to 35 glasses of alcoholic beverages per week had a 0.044 (95% CI -0.47 to 0.56), -0.085 (95% CI -0.59 to 0.43), -0.869 (95% CI -1.44 to -0.29), and -0.225 (95% CI -0.98 to 0.53) m/s difference in mean pulse-wave velocity compared with nondrinkers, respectively, which indicates a J-shaped relationship. Adjustment for potential confounders of pulse-wave velocity or alcohol intake did not materially change the strength of the association. Adjustment for HDL further attenuated the relationship. The augmentation index was not related to alcohol consumption when adjustments were made for physiological determinants such as age, height, and ejection duration.

CONCLUSIONS

Among postmenopausal women, alcohol consumption is inversely associated with pulse-wave velocity. This supports the presence of a decreased risk of cardiovascular disease with moderate alcohol consumption, which may be mediated in part by HDL cholesterol.

The Atherosclerosis Risk in Young Adults (ARYA) study: rationale and design

INTRODUCTION

Despite recent advances in treatment, cardiovascular disease (CVD) is still health problem number one in western societies. Aiming at specific prevention strategies for high-risk individuals and shifting the available prevention programs towards younger age groups might increase the success of primary prevention. However, before addressing age-specific prevention programs, more insight in the determinants of early vascular damage and increased cardiovascular risk is warranted as well as insight in determinants increased cardiovascular risk, including vascular damage, at an early age. The Atherosclerosis Risk in Young Adults (ARYA) study was specifically designed to address this issue.

OBJECTIVES

The ARYA study started off with studies evaluating (1) whether it is possible to predict cardiovascular risk at young adulthood by routinely measured adolescent data, and (2) evaluating the role of birth characteristics and adolescent characteristics to the development of vascular damage at young adulthood.

METHODS

The ARYA study comprises of two cohorts of young adults. The Utrecht cohort includes 750 young adults, aged 27-30 years. The Hague-cohort includes 261 young adults born between 1963 and 1968. Data on birth characteristics, growth in early infancy as well as adolescent anthropometry, blood pressure, lipids, body mass index were obtained from the original medical records of the Municipal Health Service. In 1999/2001, the extent of subclinical vascular damage was measured using carotid wall thickness and aortic stiffness. Also, data on adult cardiovascular risk profile, bone density and central blood pressure were assessed, fasting blood was drawn and timed overnight urine samples were collected.

CONCLUSION

The ARYA study is aimed to provide data on early determinants of cardiovascular risk, including vascular damage, at an early age. This knowledge enhances the understanding of atherosclerosis development and CVD risk and is needed to improve the available primary prevention programs.

Clustered features of the metabolic syndrome and the risk for increased aortic pulse wave velocity in middle-aged Japanese men

The association between different features of the metabolic syndrome (MS) (obesity, hypertension, hypercholesterolemia, low high-density lipoprotein cholesterol level, hypertriglyceridemia, high fasting plasma glucose level, and hyperuricemia) and the risk for increased aortic pulse wave velocity (PWV) of > or = 8.0 m/sec was examined in 2431 Japanese men aged 35 to 54 years who were not taking antihypertensive medication. After controlling for age, cigarette smoking, and alcohol intake, the odds ratios for increased aortic PWV in subjects with 1, 2, 3, and > or = 4 features of the MS, compared with those without features of the MS, were 1.35 (95% CI, 0.86 to 2.11), 1.90 (95% CI, 1.18 to 3.06), 1.57 (95% CI, 0.89 to 2.76), and 2.38 (95% CI, 1.26 to 4.49), respectively (p for trend = 0.003). A 9-year longitudinal study was also performed to prospectively examine the association between clustered features of the MS and the development of increased aortic PWV in 2073 men without aortic stiffness with a PWV < 8.0 m/sec and without antihypertensive medication during the follow-up period. The multivariate-adjusted hazard ratios for the incidence of increased aortic PWV in subjects with 1, 2, 3, and > or = 4 features of the MS, compared with those without features of the MS, were 1.39 (95% CI, 1.10 to 1.77), 1.46 (95% CI, 1.1 1 to 1.92), 1.75 (95% CI, 1.27 to 2.40), and 2.22 (95% CI, 1.52 to 3.25), respectively (p for trend < 0.001). These results suggest that clustered features of the MS are closely associated with the risk for increased aortic PWV in middle-aged Japanese men.

Measures of obesity are associated with vascular stiffness in young and older adults

Obesity has reached epidemic levels and carries a risk for cardiovascular disease. Obesity's effects on the vascular systems of young adults and African Americans have not been well characterized. The aim of this study was to assess the association between measures of obesity and aortic stiffness in 186 young adults (20 to 40 years, 50% African American) and 177 older adults (41 to 70 years, 33% African American). Aortic stiffness was measured by aortic pulse-wave velocity. The median pulse-wave velocity value was 468 cm/s for young adults and 627 cm/s for older adults (P<0.001). Higher body weight, body mass index, waist and hip circumferences, and waist-hip ratio were strongly correlated with higher pulse-wave velocity, independent of age, systolic blood pressure, race, and sex overall and among both age groups (P<0.01 for all). Even among the 20- to 30-year-olds, obese individuals (body mass index>30) had a mean pulse-wave velocity value 47 cm/s higher than did nonobese individuals (P<0.001). Obesity measures were among the strongest independent predictors of pulse-wave velocity overall and for both age groups. Results were consistent by race. In conclusion, excess body weight is associated with higher aortic stiffness in whites and African Americans as young as 20 to 30 years. The strength of the association, the early age at which it appears, and the prevalence of obesity among the young warn of substantially increased cardiovascular disease incidence as this cohort ages.

An association between aortic pulse wave velocity, blood pressure and chronic inflammation in ESRD patients on peritoneal dialysis

Increased aortic pulse wave velocity (AoPWV) has been identified as a risk factor for cardiovascular morbidity in the general population and in patients on dialysis. Most of the studies in ESRD patients refer to subjects on hemodialysis. Influence of the inflammatory process on aortic stiffening remains largely unknown. The aim of the present study was to evaluate potential relationships between AoPWV and blood pressure, basic anthropometric parameters, selected growth factors and markers of the inflammatory process in ESRD patients treated with peritoneal dialysis. The study population consisted of 43 patients (19 F, 24 M) with a mean age of 50.6 +/- 13.4 years on PD for a mean period of 21.9 +/- 20.7 months. AoPWV was measured using two pressure transducers placed on the carotid and femoral arteries and connected to an automatic processor (Complion Colson AS, Paris, France). Serum levels of Tumor Necrosis Factor alpha (TNFalpha), interleukin 6 (IL-6) and plasma basic Fibroblast Growth Factor (bFGF) were measured with ELISA; C-reactive protein and fibrinogen with nephelometry. Serum lipid profile was also assessed. Blood pressure was measured in an outpatient department under standardized conditions. Mean aortic pulse wave velocity in the study population was 10.7 +/- 2.1 m/s. No difference in AoPWV was found between men and women. AoPWV correlated significantly with age (R = 0.41; p < 0.01) but not with time on dialysis. Positive relationship between AoPWV and body weight and BMI was shown (R = 0.31; p < 0.05 and R = 0.35; p < 0.05, respectively). AoPWV correlated significantly with systolic blood pressure (SBP), mean arterial pressure (MAP) and pulse pressure (PP) (R = 0.46, p < 0.005, R = 0.46, p < 0.005 and R = 0.43, p < 0.01, respectively). AoPWV correlated with serum IL-6 and plasma bFGF (R = 0.32, p < 0.05 and R = 0.4, p < 0.01; respectively). The correlation with serum CRP was borderline significant (p < 0.53). In multiple regression analysis age (beta 0.38; p < 0.005), plasma bFGF level (beta 0.3; p < 0.05), and systolic blood pressure (beta 0.29; p < 0.05) were independently associated with pulse wave velocity. Our results suggest that AoPWV values in patients on PD are associated with factors similar to those encountered in the general population. We suggest that increased aortic stiffening may also be related to the chronic inflammatory process in PD patients.

Adolescent blood pressure does not predict aortic stiffness in healthy young adults. The Atherosclerosis Risk in Young Adults (ARYA) study

BACKGROUND

Increased arterial stiffness has been shown to be a good predictor of cardiovascular morbidity and mortality and to be associated with an adverse cardiovascular risk profile.

OBJECTIVE

To evaluate the relationship between adolescent blood pressure and aortic stiffness in 524 healthy young adults aged 27-30 years, as a means of investigating early determinants of arterial stiffness.

SETTING

General community.

PARTICIPANTS

We studied 524 healthy young adults, aged 27-30 years, who attended secondary school in Utrecht, The Netherlands.

MEASUREMENTS

Data on adolescent weight, height, blood pressure and stage of puberty were available from the original school health records of the Municipal Health Service. At young adulthood, a questionnaire on cardiovascular risk factors was completed and a fasting blood sample was drawn.

MAIN OUTCOME MEASURE

Arterial stiffness, assessed by carotid-femoral pulse wave velocity (PWV).

RESULTS

Adolescent blood pressure did not predict aortic PWV at young adulthood (linear regression coefficient 0.03 m/s per 10 mmHg increase in systolic blood pressure; 95% confidence interval 0.09 to 0.14). Repeated analysis in a subgroup (n = 199) for whom two adolescent blood pressure measurements were averaged showed stronger (2-19x) associations with adult PWV, although these were not significant.

CONCLUSION

Adolescent blood pressure did not predict arterial stiffness in healthy young adults. Measurement error in the baseline blood readings (regression to the mean phenomenon) may partly explain the lack of association in our study. Further studies should confirm our results in order to enable better understanding of the role of adolescent blood pressure in the aetiology of vascular damage.

Cardiovascular risk factors associated with pulse pressure in a screened cohort in Okinawa, Japan

We evaluated the association between pulse pressure (PP) and cardiovascular risk factors in a screened cohort. Individuals who were receiving medications for hypertension or heart disease, who had no ECG record, or who had a record of arrhythmia were excluded. In total, 8,508 subjects (5,299 men and 3,209 women; age range, 18 to 89 years) were studied. Subjects were divided into four PP classes: PP.1 (PP < or = 40 mmHg, n=2,127), PP.2 (40 < or = PP < or = 44 mmHg, n=2,127), PP.3 (44 < or = PP < or = 50 mmHg, n=2,127) and PP.4 (50 mmHg < or = PP, n=2,127). Multiple regression analysis was used for evaluating the association between PP and cardiovascular risk factor or lifestyle. In men, the regression coefficient was 0.27 for age, 2.50 for diabetes mellitus, 0.33 for uric acid, 0.20 for body mass index, 0.07 for heart rate, -0.83 for current smoking habit and 1.23 for habitual drinking. In women, the regression coefficient was 0.37 for age, 4.09 for diabetes mellitus, 0.42 for body mass index, 0.14 for heart rate, and 0.84 for habitual exercise. In both men and women, PP was significantly increased in association with an increase in the number of risk factors (diabetes mellitus, obesity, current drinking status, heart rate, and hyperuricemia). In conclusion, higher PP was associated with cardiovascular risk factors. These associations were similar in both men and women.

Arterial stiffness in postmenopausal women: determinants of pulse wave velocity

OBJECTIVE To investigate the degree and potential cardiovascular determinants of arterial stiffness, assessed by aortic pulse wave velocity (PWV) measurements, and to relate arterial stiffness to absolute 10-12-year risks of stroke, coronary heart disease and death, as estimated by available risk functions, in postmenopausal women. METHOD We performed a cross-sectional study among 385 postmenopausal women, aged 50-74 years, sampled from the general population. Arterial stiffness was assessed non-invasively by measurement of aortic PWV using applanation tonometry. Information on health was obtained by medical history, registration of current medication, and physical examination. Height, weight, waist and hip circumferences, fasting glucose, total and high-density lipoprotein (HDL) cholesterol, triglycerides, resting blood pressure, and heart rate were measured. Three risk scores were used to estimate, for each individual, the absolute risk of stroke, coronary heart disease, and death within 10-12 years as a function of their cardiovascular risk factor profile. The relationship between PWV and these risk scores was subsequently determined. RESULTS Significant positive relationships with PWV were found for body mass index, fasting glucose, diabetes mellitus, and triglycerides in analyses adjusted for age, mean arterial blood pressure, and heart rate. Height and HDL cholesterol were inversely related to PWV. The risks of stroke, coronary heart disease, and death increased with increasing PWV in a linear graded manner. CONCLUSIONS This cross-sectional study among postmenopausal women provides evidence that most of the established cardiovascular risk factors are determinants of aortic PWV. Increased PWV marks an increased risk of stroke, coronary heart disease, and death within 10-12 years.

Heart rate: an important confounder of pulse wave velocity assessment

Arterial stiffness is a strong determinant of cardiovascular risk. Pulse wave velocity (PWV) is an index of arterial stiffness, and its prognostic value has been repeatedly emphasized. The purpose of the present study was to assess the effect of heart rate (HR) on PWV. Twenty-two subjects with a mean age of 77.8+/-8.4 (SD) years and permanent cardiac pacing were studied. In each subject, PWV was measured at 5 different pacing frequencies in the same session (60, 70, 80, 90, 100 bpm), the order of the various frequencies being randomly determined. Furthermore, to test the reproducibility, a repeat measurement of PWV was obtained in one randomly selected frequency. Blood pressure (BP) was measured by conventional means at each pacing frequency. PWV appeared fairly reproducible because no significant difference was disclosed between the 2 measurements obtained at the same HR level (P=0.5) and both measurements were strongly correlated (r=0.87, P<0.001). No significant BP variation was observed during pacing. There was a highly significant effect of HR on PWV estimated by a one-way, within-subjects analysis of variance (P=0.01). This study demonstrates that HR is an important factor in the intraindividual variation of PWV in elderly subjects. This raises methodological concern about the measurement of this parameter. Standardizing PWV for HR level seems mandatory if one wants to interpret PWV changes in clinical trials or in the follow-up of patients.

Hormone replacement therapy with estradiol valerate and cyproterone acetate: effects on endothelium-dependent vasodilatation and arterial wall compliance

OBJECTIVE

to evaluate changes in vasomotor endothelium function and elastic properties of the brachial artery in postmenopausal women beginning hormone replacement therapy (HRT) with Climen(R), a 28-day sequential therapy combining estradiol valerate (E2V) 2 mg/day D1-D21 with cyproterone acetate (CPA) 1 mg/day D12-D22, followed by a 7-day treatment-free interval.

METHODS

Thirty-one women with natural or surgical menopause were included in an open multicenter study. Before treatment, at the end of the estrogen-only phase of cycle 1, and after the combined phase in cycles 1 and 3, endothelium-dependent vasodilatation (EDVD%) in the brachial artery was measured by the post-ischemia increase of the inner diameter, and pulse wave velocity (PWV) was measured in the same artery by simultaneous continuous wave Doppler and photo-plethysmography.

RESULTS

compared to pre-treatment values, the median increase in EDVD was 14.3% after cycle 1 (P=0.0001) and 27.9% after cycle 3 (P=0.0001). CPA did not alter the effect of E2V on EDVD in cycle 1. Median arterial systolic pressure was unchanged, but median diastolic pressure fell from 70 to 67.5 mmHg (P=0.04) after cycle 3. Median PWV was reduced by 0.76 m/s after cycle 3 (relative reduction -9.3%) (P=0.035). There was a significant correlation between PWV and EDVD changes from pre-treatment values at the end of the 3rd cycle.

CONCLUSION

treatment of postmenopausal women with E2V/CPA led to an immediate and significant improvement in endothelium-dependent vasodilatation. The estrogen-related vasomotor effect was not suppressed by the progestogen CPA. The WV changes are consistent with slower improvement of arterial compliance in some women. The non-invasive measurement of EDVD and PWV is a convenient method for the evaluation of both mechanical and functional effects of combination HRT on the arterial wall.

Spontaneous baroreflex sensitivity: toward an ideal index of cardiovascular risk in hypertension?

OBJECTIVE

Estimating the risk entailed by classical risk factors like blood pressure (BP) or serum cholesterol may be difficult because of their variability and the often unknown duration of exposure. Having variables integrating the impact of those classical risk factors on the cardiovascular system would probably aid the prediction of cardiovascular events. The present study aimed at determining whether cardiac baroreflex sensitivity (BRS), correlates with several risk factors and thus is a good candidate for being such an integrative variable. As a comparison, left ventricular mass (LVM), pulse wave velocity (PWV), and creatinine were also tested for association with risk factors.

DESIGN

A total of 302 subjects referred for hypertension, were considered. They had a 24-h BP recording and a determination of BRS by two different methods (sequence and alpha coefficient), in two different positions (lying and standing). They were also tested for the presence of left ventricular hypertrophy (LVH) (by echocardiography and electrocardiogram) and had a PWV measurement. Biological testing included serum lipids, blood glucose, creatinine, proteinuria and urinary excretion of microalbumin.

RESULTS

There was a strong correlation between the two methods of BRS measurement in each position (P < 0.001). BRS determined by the sequence method in the lying position was correlated significantly and independently with age, 24-h systolic BP, heart rate, and serum cholesterol with P values < 0.001, < 0.001, < 0.01, and < 0.05, respectively. In an univariate analysis, BRS was also correlated with echocardiographic LVM index (r = -0.21, P < 0.05) and PWV (r = -0.27, P < 0.001), which possibly reflects its dependence on both vascular and cardiac damages.

CONCLUSION

The present study supports the hypothesis that BRS could encompass the impact over time of several risk factors on the cardiovascular system. Thus, it may constitute a valuable parameter in assessing more precisely the risk of cardiovascular events.

Association of left ventricular hypertrophy with metabolic risk factors: the HyperGEN study

OBJECTIVE

To determine whether combinations of metabolic risk factors (obesity, diabetes and hypercholesterolemia) influence the magnitude of left ventricular (LV) mass and prevalence of LV hypertrophy.

DESIGN

Cross-sectional, relational.

METHODS

A total of 1627 hypertensive (85.9% treated, 1036 women, 1041 African Americans) and 342 normotensive (180 women, 183 African Americans) participants in the Hypertension Genetic Epidemiology Network (HyperGEN) Study, without prevalent cardiovascular disease, were studied. Echocardiographic LV mass, normalized by height(2.7) or fat-free mass or body surface area (BSA) and the ratio of stroke volume to pulse pressure as a percentage of predicted (as a crude estimate of arterial compliance) were analyzed in relation to obesity [by body mass index (BMI)], central fat distribution (by waist circumference), diabetes (by ADA criteria) and hypercholesterolemia.

RESULTS

Obesity, hypercholesterolemia, and diabetes were more frequent among hypertensives than normotensives (all P < 0.001). After controlling for age, sex, race and type and combination of antihypertensive medication, LV mass/height(2.7), but not LV mass/fat-free mass and LV mass/BSA, increased with the number of metabolic risk factors, both in normotensive and hypertensive participants, also after further adjustment for blood pressure (all P < 0.001). Stroke volume/pulse pressure also decreased in hypertensive, but much less in normotensive subjects, with increasing number of metabolic risk factors, independently of relevant confounders (P < 0.0001). Prevalence of LV hypertrophy was predicted by older age, hypertension, central fat distribution, black race and independently increased with the number of associated metabolic risk factors (P < 0.0001).

CONCLUSIONS

The progressive addition of metabolic risk factors including central obesity, diabetes and hypercholesterolemia is associated with higher LV mass normalized by height(2.7), independently of hypertension and other important biological covariates. Obesity played a major role in this association. This finding indicates that LV mass is a potentially useful bioassay of strategies of global cardiovascular prevention.

Correlates of aortic stiffness in elderly individuals: a subgroup of the Cardiovascular Health Study

BACKGROUND

Arterial stiffness has been associated with aging, hypertension, and diabetes; however, little data has been published examining risk factors associated with arterial stiffness in elderly individuals.

METHODS

Longitudinal associations were made between aortic stiffness and risk factors measured approximately 4 years earlier. Aortic pulse wave velocity (PWV), an established index of arterial stiffness, was measured in 356 participants (53.4% women, 25.3% African American), aged 70 to 96 years, from the Pittsburgh site of the Cardiovascular Health Study during 1996 to 1998.

RESULTS

Mean aortic pulse wave velocity (850 cm/sec, range 365 to 1863) did not differ by ethnicity or sex. Increased aortic stiffness was positively associated with higher systolic blood pressure (SBP), age, fasting and 2-h postload glucose, fasting and 2-h insulin, triglycerides, waist circumference, body mass index, truncal fat, decreased physical activity, heart rate, and common carotid artery wall thickness (P < .05). After controlling for age and SBP, the strongest predictors of aortic stiffness in men were heart rate (P = .001) and 2-h glucose (P = .063). In women, PWV was positively associated with heart rate (P = .018), use of antihypertensive medication (P = .035), waist circumference (P = .030), and triglycerides (P = .081), and was negatively associated with physical activity (P = .111). Results were similar when the analysis was repeated in nondiabetic individuals and in those free of clinical or subclinical cardiovascular disease in 1992 to 1993.

CONCLUSIONS

In these elderly participants, aortic stiffness was positively associated with risk factors associated with the insulin resistance syndrome, increased common carotid intima-media thickness, heart rate, and decreased physical activity measured several years earlier.

Reduced pulmonary function is associated with central arterial stiffness in men

The association of impaired pulmonary function with cardiovascular morbidity and mortality has been reported in several prospective studies. The nature of this association and the mechanisms underlying it are unknown. Both atherosclerosis and central arterial stiffness might be involved. We recently reported, in a 4-yr longitudinal study, that reduced lung function predicts the development of carotid atherosclerotic plaques. In the present study, we report the associations of aortic stiffness with lung function measurements. One hundred and ninety-four men, aged 30 to 70 yr and free of coronary heart disease, who volunteered for a standard health examination were included. FEV(1) and FVC were used to assess lung function. Aortic stiffness was estimated from the carotid-femoral pulse-wave velocity (PWV), which increases proportionally with an increase in aortic stiffness. PWV was significantly and negatively associated with FEV(1) and FVC (partial correlation coefficients adjusted for age and height: -0.27 [p < 0.001] and -0.24 [p < 0.001], respectively). For every 1 SD increase in PWV (2.5 m/s), FEV(1) decreased by 195.2 +/- 50.1 ml (p < 0.001) in an age- and height-adjusted analysis. The corresponding decrease in FVC was 190.4 +/- 55.0 ml (p < 0.001). Further adjustment for cardiovascular risk factors (weight, smoking habits, hypercholesterolemia, diabetes, and hypertension) did not markedly alter these results. In addition, negative associations of PWV with lung function measurements were observed within each category of cardiovascular risk factors. This study suggests that reduced pulmonary function is independently associated with aortic stiffness in men. The interrelations between pulmonary and vascular alterations should be thoroughly investigated.

Clinical usefulness of measuring pulse wave velocity in predicting cerebrovascular disease: evaluation from a cross-Sectional and longitudinal follow-up study

The present study was designed both as a cross-sectional and longitudinal follow-up study to evaluate the association between pulse wave velocity (PWV) and cardiovascular disease. The subjects in this study included a total 260 patients (134 men and 126 women) ranging from 25 to 91 years (mean, 67.6+/-11.0 years). Carotid to femoral PWV was measured in all patients. The subsequent development of a cerebrovascular or coronary event was defined as a cardiovascular event. The longitudinal follow-up study was conducted with the occurrence of a cardiovascular event as the endpoint. The patients were classified into two groups: an L group with a PWV of less than 10 m/sec and an H group with a PWV of 10 m/sec or higher. Cross-sectional study at baseline: The H group patients were significantly older than the L group patients. The prevalence of hypertension, cardiovascular disease, ischemic heart disease, and cerebrovascular disease were significantly higher in the H group. Systolic blood pressure and serum uric acid were significantly higher in the H group than in the L group. However, there were no significant differences between the two groups with respect to other risk factors. Multivariate analysis using the prevalence of cardiovascular disease as the dependent variable showed "age" and "H group" to be independent variables. When the prevalence of ischemic heart disease or cerebrovascular disease was used as dependent variable, only "age" was an independent variable. Longitudinal follow-up study: The prevalence of cardiovascular event and cerebrovascular event were significantly higher in the H group than in the L group. The prevalence of coronary event in the H group tended to be higher than in the L group, but the difference was not statistically significant. Multivariate analysis using the cardiovascular event rate or coronary event rate as the dependent variable showed only "age" to be an independent variable. When the cerebrovascular event rate was used as the dependent variable, "uric acid" and "H group" were independent variables. The results of this study suggest a higher rate of cerebrovascular disease in patients with high PWV.

Endothelium-derived nitric oxide regulates arterial elasticity in human arteries in vivo

Arterial elasticity is determined by structural characteristics of the artery wall and by vascular smooth muscle tone. The identity of endogenous vasoactive substances that regulate elasticity has not been defined in humans. We hypothesized that NO, a vasodilator released constitutively by the endothelium, augments arterial elasticity. Seven healthy young men were studied. A 20-MHz intravascular ultrasound catheter was introduced through an arterial sheath to measure brachial artery cross-sectional area, wall thickness, and intra-arterial pressure. After control was established, indices of elasticity (pressure-area relationship, instantaneous compliance, and stress-strain, pressure-incremental elastic modulus (E(inc)), and pressure-pulse wave velocity relationships) were examined over 0 to 100 mm Hg transmural pressure obtained by inflation of an external cuff. Thereafter, the basal production of endothelium-derived NO was inhibited by N(G)-monomethyl-L-arginine (L-NMMA) (4 and 8 mg/min). Finally, nitroglycerin (2.5 and 12.5 microgram/min), an exogenous donor of NO, was given to relax the vascular smooth muscle. Elasticity was measured under all of these conditions. L-NMMA (8 mg/min) decreased brachial artery area (P=0.016) and compliance (P<0.0001) and increased E(inc) (P<0.01) and pulse wave velocity (P<0.0001). Nitroglycerin (12.5 microgram/min) increased brachial artery area (P<0.001) and compliance (P<0.001) and decreased pulse wave velocity (P=0.02). NO, an endothelium-derived vasodilator, augments arterial elasticity in the human brachial artery. Loss of constitutively released NO associated with cardiovascular risk factors may adversely affect arterial elasticity in humans.

Aortic stiffness is associated with visceral adiposity in older adults enrolled in the study of health, aging, and body composition

The central arteries stiffen with age, causing hemodynamic alterations that have been associated with cardiovascular events. Changes in body fat with age may be related to aortic stiffening. The association between vascular stiffness and body fat was evaluated in 2488 older adults (mean age, 74 years; 52% female; 40% black) enrolled in the Study of Health, Aging, and Body Composition (Health ABC), a prospective study of changes in weight and body composition. Clinical sites were located in Pittsburgh, Pa, and Memphis, Tenn. Aortic pulse wave velocity was used as an indirect measure of aortic stiffness. A faster pulse wave velocity indicates a stiffer aorta. Body fat measures were evaluated with dual energy x-ray absorptiometry and computed tomography. Independent of age and blood pressure, pulse wave velocity was positively associated with weight, abdominal circumference, abdominal subcutaneous fat, abdominal visceral fat, thigh fat area, and total fat (P<0.001 for all). The strongest association was with abdominal visceral fat. Elevated pulse wave velocity was also positively associated with history of diabetes and higher levels of glucose, insulin, and hemoglobin A1c (P<0.001 for all). In multivariate analysis, independent positive associations with pulse wave velocity were found for age, systolic blood pressure, heart rate, abdominal visceral fat, smoking, hemoglobin A1c, and history of hypertension. The association between pulse wave velocity and abdominal visceral fat was consistent across tertiles of body weight. Among older adults, higher levels of visceral fat are associated with greater aortic stiffness as measured by pulse wave velocity.

Vascular stiffness in women with systemic lupus erythematosus

Large-vessel manifestations of systemic lupus erythematosus (SLE), a multisystem disease characterized by disturbances in the immune system, include higher than expected rates of hypertension and cardiovascular disease. Reductions in the elasticity of central arteries may act as a marker of early changes that predispose to the development of major vascular disease. This study evaluated risk factors associated with aortic stiffness measured by pulse wave velocity (PWV) in women with SLE. We expected SLE-specific factors, especially variables indicative of inflammation and active disease, to be associated with increasing PWV. The study population included 220 women currently enrolled in the Pittsburgh Lupus

REGISTRY

All risk factor data were collected on the day of the ultrasound examinations. PWV waveforms were collected from the right carotid and femoral arteries by Doppler probes. The mean age of the women was 45.5+/-10.8 years, the median SLE disease duration approximated 9 years, and the mean PWV was 6.1+/-1.7 m/s. Multiple regression models were stratified by menopausal status. Among postmenopausal women, PWV risk factors were primarily traditional factors and included age, systolic blood pressure, family history of vascular disease, carotid plaque, creatinine, obesity, glucose, white cell count, and cumulative SLE organ damage. Among premenopausal women, PWV risk factors consisted of a mix of SLE-related and traditional variables and included higher C3 levels, presence of ds-DNA antibodies, nonuse of hydroxychloroquine, lower leukocyte count, higher mean arterial pressure, and carotid plaque. SLE-specific variables appeared to be associated with increases in aortic PWV, indicating central artery stiffening. This was seen most clearly among premenopausal women. This finding may partially explain the higher rates of cardiovascular disease and hypertension observed in young women with SLE.

Cardiovascular risk in women with polycystic ovary syndrome

Compared with normal cycling women of similar age, women with polycystic ovary syndrome (PCOS) have an adverse lipid profile and an increased prevalence of Type II diabetes and hypertension. These woman also appear to have greater subclinical atherosclerotic disease, as demonstrated by greater carotid intimamedia wall thickness and higher levels of coronary calcification. Given the high prevalence of PCOS in the female population, this condition may potentially account for a significant proportion of the atherosclerotic heart disease observed in younger women. This article reviews the issues and uncertainties surrounding the PCOS-CHD association.

The effect of hormone replacement therapy on arterial distensibility and compliance in perimenopausal women: a 2-year randomised trial

A single centre randomised placebo-controlled trial was performed to assess the 2-year effects of hormone replacement therapy compared to placebo on mechanical arterial properties in 99 perimenopausal women recruited from the general population. The trial was double-blind with respect to a sequential combined regimen of oral 17beta-oestradiol and desogestrel (17betaE(2)-D) and the placebo group and open with respect to combination of conjugated equine oestrogens and norgestrel (CEE-N). At baseline, distensibility and compliance of the common carotid artery were measured non-invasively with B-mode ultrasound and a vessel wall movement detector system, and the distensibility coefficient (DC) and compliance coefficient (CC) were calculated. Measurements were repeated after 6 and 24 months. Change in DC and CC in treatment groups was compared to placebo. After 24 months, changes for 17betaE(2)-D compared to placebo were -1.4x10(-3)/kPa (95% CI -4.4; 1.7, P=0.39) for DC and 0. 26 mm(2)/kPa (95% CI -0.01; 0.53, P=0.07) for CC. Changes for CEE-N compared to placebo were 0.4x10(-3)/kPa (95% CI -1.0; 1.9, P=0.79) and 0.11 mm(2)/kPa (95% CI -0.14; 0.37, P=0.40). For systolic blood pressure (SBP), diastolic blood pressure (DBP) and arterial lumen diameter no changes were found. In this study no significant differences in changes in distensibility and compliance were found between perimenopausal women using 17betaE(2)-D or CEE-N and women using placebo after 6 and 24 months.

Vascular imaging: changing the face of cardiovascular research

Patients with systemic lupus erythematosus (SLE) are at significant risk for premature cardiovascular disease, now a leading cause of death in this population. Most previous studies have used an overt clinical event to identify cardiovascular disease, likely underestimating the actual prevalence in these patients. Although the rates of myocardial infarction in SLE are high, the actual number of coronary events is low, precluding large clinical trials using a coronary event as the sole outcome. The ability to measure atherosclerosis, a known determinant of coronary heart disease, provides investigators with a desirable surrogate for the clinical cardiac event. With the advent of sensitive imaging techniques to identify subclinical atherosclerosis, we are now better equipped to determine the true prevalence and mechanisms of vascular disease in SLE. In this review, we will discuss several vascular imaging techniques and the current trend away from measuring flow-limiting vessel stenosis toward measuring earlier structural and functional aspects of the vascular system.

[Factors associated with arterial distensibility in hypertension]

OBJECTIVE

To find out what variables affect changes in arterial compliance in subjects with hypertension by measuring their pulse wave velocity (PWV).

DESIGN

Cross-sectional, descriptive study.

SETTING

Rural health centre.

PATIENTS

156 hypertense patients under 76, chosen by simple random sampling from those on the hypertension register.

MEASUREMENTS AND INTERVENTIONS

We determined the degree of hypertension, years of evolution, systolic pressure (SBP), diastolic pressure (DBP), body mass index (BMI), glucaemia, whether lipaemia existed, diabetes or glucose intolerance, tobacco habit, age, sex and PWV (measured automatically by computer). We performed multivariate analysis by means of multiple linear regression, with PWV as the dependent variable, and age, SBP, DBP, BMI, years of evolution of hypertension, cholesterol, triglycerides and glucaemia as independent variables.

RESULTS

Mean age 62.5 (SD 8.8). 28.2% male. Mean SBP 153 (SD 18.9). Mean DBP 87 (SD 10.3). Mean years of evolution 10.4 (SD 7.4). Mean BMI 31.2 (SD 4.9). Hyperglucaemia 24.4%. Mean glucaemia 111.3 (SD 29). Mean PWV 11.82 (SD 2.37). PWV was above the theoretically normal figures in 69.2% of cases. Multiple linear regression showed that the variables which affected PWV significantly were age, SBP and hyperglucaemia.

CONCLUSIONS

Arterial compliance can be improved by controlling SBP, given that the other related factors cannot be changed.

Stroke volume/pulse pressure ratio and cardiovascular risk in arterial hypertension

Ratio of stroke volume (SV, M-mode echocardiography) to pulse pressure (PP) has been proposed as an estimate of total arterial compliance and has been shown to be related to body size, age, and heart rate in normal adults. SV/PP was estimated in 294 hypertensive patients (98 women) as a raw value by use of SV/body surface area (SVi) and by the ratio of SV/PP to the value predicted by a previously developed equation (%SV/PP). At baseline, the 50 patients who had cardiovascular events over the following 10 years exhibited higher PP and lower SV/PP, SVi/PP, and %SV/PP (all P<0.008) than patients without events. Crude risk of follow-up total and fatal cardiovascular events increased with increasing level of PP and decreasing SV/PP, SVi/PP, and %SV/PP (all P<0.002). In multivariate logistic regression models with continuous covariates, the risk of total cardiovascular events was independently related to increasing age (P<0.0001) and left ventricular (LV) mass index (P<0.003) and decreasing values of %SV/PP (P<0.006) but not to increasing systolic, pulse, or mean blood pressure or gender. Similar although less strong results were obtained with the use of SVi/PP (P<0.02), whereas SV/PP did not enter the model as an independent predictor. Risk of cardiovascular death was only predicted by age and LV mass index. The %SV/PP was also an independent predictor of total cardiovascular events in Cox proportional hazards analysis (exp[b]: 2.49, P<0.001) independent of age (exp[b]: 1.05, P<0.003) and LV mass index (exp[b]: 1.02, P<0.0003), whereas no effect was detected for height. Thus, in patients with arterial hypertension, a reduced ratio of M-mode echocardiographic SV/PP as a percentage of the value predicted by demographic variables is a predictor of cardiovascular morbid events independent of age and LV mass index.

Menopausal status and distensibility of the common carotid artery

Although several studies have shown that exogenous estrogens have beneficial effects on arterial characteristics, the effect of endogenous estrogen on the vascular system is still unknown. In this study, distensibility, an indicator of arterial elasticity, of the common carotid artery was compared in pre- and postmenopausal women. The study comprised 93 premenopausal and 93 postmenopausal women of similar age (range, 43 to 55 years). Women were selected from respondents to a mailed questionnaire about the menopause, which was sent to all women aged 40 to 60 years in the Dutch town of Zoetermeer (n=12 675). Postmenopausal women who were at least 3 years past natural menopause or whose menses had stopped naturally before age 48, were age-matched with premenopausal women with regular menses and without menopausal complaints. The selection aimed at maximizing the contrast in estrogen status between pre- and postmenopausal women of the same age. Distensibility of the carotid artery was measured noninvasively with B-mode ultrasound and a vessel wall movement detector system. Arterial distensibility is expressed as the change in arterial diameter (distension, DeltaD) with the cardiac cycle, adjusted for lumen diameter, pulse pressure, and mean arterial blood pressure. Compared with premenopausal women, postmenopausal women had significantly lower arterial distension (DeltaD 370.5 microm [SE 9.5] versus 397.3 microm [SE 9.6]). These results suggest that the distensibility of the common carotid artery is negatively affected by natural menopause in presumed healthy women.

Risk factors for the incidence of aortic stiffness by serial aortic pulse wave velocity measurement in middle-aged Japanese men

To examine the risk factors related to the incidence of aortic stiffness, 1,045 Japanese men aged 40 to 54 years with aortic pulse wave velocity (PWV) of less than 8.0 m/sec were followed up for seven years with annual examinations, with an average period of observation of 6.3 years with standard deviation of 1.56 years. Subjects who showed 8.0 m/sec and over of PWV during follow-up surveys were defined as incidental cases of aortic stiffness. Kaplan-Meier analysis showed that die incidence of aortic stiffness increased significantly with increases in age, body mass index, and total cholesterol and low-density lipoprotein (LDL) cholesterol levels. The incidence of aortic stiffness was significantly higher among those who had or currently smoked than among those who never smoked. From multivariate analysis using Cox proportional hazards model, the incidence of aortic stiffness showed a significant dose-response relationship for age, PWV, total cholesterol and LDL cholesterol levels and smoking habits. These results indicate that increased levels of total cholesterol and LDL cholesterol and smoking habits may constitute contributing factors for the development of aortic stiffness in middle-aged Japanese men.

Reproducibility of arterial compliance and carotid wall thickness measurements in normal subjects

1. Non-invasive techniques to measure indices of arterial function and wall thickness are frequently used as surrogate markers of cardiovascular disease. Reproducibility of measurements of arterial compliance has been infrequently reported and little is known about the interrelationships of the various indices in vivo. 2. The present study was designed to assess reproducibility and interrelationships of indices of systemic arterial compliance, pulse wave velocity, carotid compliance and intima-media thickness (IMT). 3. Fifty healthy volunteers (20 male and 30 female: aged 20-70 years, mean 46.5 years), participated in the present study. Each subject was studied on two occasions by the same investigators, using an identical protocol at an interval of 1-5 weeks (mean 2.5 weeks) without lifestyle change. 4. There were no significant differences between visits for any recorded general data, except resting blood pressure, which was lower on the second occasion. There were no systematic differences within each pair over the range of measurements for any of the variables. Bland-Altman plots of repeatability of changes in indices showed that the mean values between visits were not significantly different. All indices of central arterial compliance were significantly related to age and IMT. 5. Thus, under controlled experimental conditions, there was satisfactory repeatability of measurements of indices of both intrinsic and functional arterial mechanical properties (central and carotid arterial compliance and IMT). This type of information will permit the construction of sample size tables for clinical trials using these indices. 6. Central arterial compliance may be an important determinant of IMT.

Protective effect of chronic garlic intake on elastic properties of aorta in the elderly

BACKGROUND

Epidemiological studies have suggested that garlic may have protective effects against cardiovascular diseases. We undertook this cross-sectional observational study to test the hypothesis that regular garlic intake would delay the stiffening of the aorta relating to aging.

METHODS AND RESULTS

We studied healthy adults (n=101; age, 50 to 80 years) who were taking > or = 300 mg/d of standardized garlic powder for > or = 2 years and 101 age- and sex-matched control subjects. Pulse wave velocity (PWV) and pressure-standardized elastic vascular resistance (EVR) were used to measure the elastic properties of the aorta. Blood pressures, heart rate, and plasma lipid levels were similar in the two groups. PWV (8.3+/-1.46 versus 9.8+/-2.45 m/s; P<.0001) and EVR (0.63+/-0.21 versus 0.9+/-0.44 m2 x s(-2) x mm Hg(-1); P<.0001) were lower in the garlic group than in the control group. PWV showed significant positive correlation with age (garlic group, r=.44; control group, r=.52) and systolic blood pressure (SBP) (garlic group, r=.48; control group, r=.54). With any degree of increase in age or SBP, PWV increased less in the garlic group than in the control group (P<.0001). ANCOVA and multiple regression analyses demonstrated that age and SBP were the most important determinants of PWV and that the effect of garlic on PWV was independent of confounding factors.

CONCLUSIONS

Chronic garlic powder intake attenuated age-related increases in aortic stiffness. These data strongly support the hypothesis that garlic intake had a protective effect on the elastic properties of the aorta related to aging in humans.

Role of molecular regulation in vascular calcification

Calcium deposits account for most of the dry weight of atherosclerotic lesions. Previously considered uncommon, vascular calcification is now known to be present in 80% of significant lesions and in at least 90% of patients with coronary artery disease. Previously considered a passive process, it is increasingly recognized as an active, regulated process. Previously considered benign, it is now becoming recognized as a major risk factor for cardiovascular events, and a major contributor to systolic hypertension, heart failure, plaque rupture and stenosis. To confirm the similarity of vascular calcification with embryonic osteogenesis, we demonstrated the expression of bone morphogenetic protein in calcified human lesions, and we developed an in vitro model of vascular calcification that provides a useful experimental system for elucidating the molecular regulation of this process, which we have shown to include alkaline phosphatase induction and expression of bone matrix proteins and differentiation factors. Understanding the regulatory mechanisms of vascular calcification will allow future therapeutic approaches to prevent and possibly reverse this disease and its clinical consequences.