Determination of aortic pulse wave velocity from waveform decomposition of the central aortic pressure pulse

Aortic pulse wave velocity (PWV), calculated from pulse transit time (PTT) using 2 separate pulse recordings over a known distance, is a significant biomarker of cardiovascular risk. This study evaluates a novel method of determining PTT from waveform decomposition of central aortic pressure using a single pulse measurement. Aortic pressure was estimated from a transformed radial pulse and decomposed into forward and backward waves using a triangular flow wave. Pulse transit time was determined from cross-correlation of forward and backward waves. Pulse transit time, representing twice the PTT between 2 specific sites, was compared with independent measurements of carotid-femoral PTT in a cohort of 46 subjects (23 females; age 57+/-14 years). Linear regression between measured PTT (y; milliseconds) and calculated PTT (x; milliseconds) was y=1.05x-2.1 (r=0.67; P<0.001). This model was tested in a separate group of 44 subjects (21 females; age 55+/-14 years) by comparing measured carotid-femoral PWV (y; meters per second) and PWV calculated using the estimated value of PTT (eTR/2) and carotid femoral distance (x; meters per second; y=1.21x-2.5; r=0.82; P<0.001). Findings indicate that the time lag between the forward and backward waves obtained from the decomposition of aortic pressure wave can be used to determine PWV along the aortic trunk and shows good agreement with carotid-femoral PWV. This technique can be used as a noninvasive and nonintrusive method for measurement of aortic PWV using a single pressure recording.     

Aortic stiffness is an independent predictor of all-cause and cardiovascular mortality in hypertensive patients

Although various studies reported that pulse pressure, an indirect index of arterial stiffening, was an independent risk factor for mortality, a direct relationship between arterial stiffness and all-cause and cardiovascular mortality remained to be established in patients with essential hypertension. A cohort of 1980 essential hypertensive patients who attended the outpatient hypertension clinic of Broussais Hospital between 1980 and 1996 and who had a measurement of arterial stiffness was studied. At entry, aortic stiffness was assessed from the measurement of carotid-femoral pulse-wave velocity (PWV). A logistic regression model was used to estimate the relative risk of all-cause and cardiovascular deaths. Selection of classic risk factors for adjustment of PWV was based on their influence on mortality in this cohort in univariate analysis. Mean age at entry was 50+/-13 years (mean+/-SD). During an average follow-up of 112+/-53 months, 107 fatal events occurred. Among them, 46 were of cardiovascular origin. PWV was significantly associated with all-cause and cardiovascular mortality in a univariate model of logistic regression analysis (odds ratio for 5 m/s PWV was 2.14 [95% confidence interval, 1.71 to 2.67, P<0.0001] and 2.35 [95% confidence interval, 1.76 to 3.14, P<0.0001], respectively). In multivariate models of logistic regression analysis, PWV was significantly associated with all-cause and cardiovascular mortality, independent of previous cardiovascular diseases, age, and diabetes. By contrast, pulse pressure was not significantly and independently associated to mortality. This study provides the first direct evidence that aortic stiffness is an independent predictor of all-cause and cardiovascular mortality in patients with essential hypertension.     

Gender influence on metabolic syndrome's effects on arterial stiffness and pressure wave reflections in treated hypertensive subjects

BACKGROUND: In hypertensive subjects, aortic stiffness, an independent predictor of cardiovascular (CV) risk, measured from pulse wave velocity (PWV), contributes to enhance augmentation index (AI), a marker of the timing and amplitude of wave reflections. Whether PWV and AI are correlated and reflect CV risk in hypertensive men and women with metabolic syndrome (MS) remains unknown. METHODS: In a cohort of 613 (364 males) treated hypertensive subjects with and without MS (41% MS) pulse wave analysis was used to determine aortic PWV and carotid AI. CV risk was estimated from standard Framingham equations. RESULTS: In females, but not in males, aortic PWV was higher in subjects with MS, when compared with those without MS (12.7+/-0.3m/s versus 11.1+/-0.4m/s, p<0.001). This result was independent of age and blood pressure. Only in females AI was independently related to the presence of MS; AI did not differ between subjects with or without MS, both males and females. AI did not correlate with PWV, except in males without MS. The overall CV risk was strongly associated to PWV independently of MS and gender, but AI was associated to CV risk only in males. CONCLUSION: In treated hypertensive subjects, the effect of MS on PWV and AI is modulated by gender. The dissociation between PWV and AI observed in women with MS was due to "blunted" wave reflections. This finding is associated with the fact that PWV, but not AI, was a constant marker of CV risk in subjects with MS, whether men and women.     

Stiffness of capacitive and conduit arteries: prognostic significance for end-stage renal disease patients

The aorta is the principal capacitive element of the arterial tree and its increased stiffness, determined by measurement of aortic pulse wave velocity (PWV), is a strong independent predictor of cardiovascular mortality in the general population and end-stage renal disease (ESRD) patients. Whether stiffness of ESRD patients' peripheral arteries has the same prognostic value has never been investigated. A cohort of 305 ESRD patients was followed for 70+/-49 months (mean+/-SD). Ninety-six deaths of cardiovascular origin occurred. At entry into the study, together with standard clinical and biochemical analyses, patients' aortic, brachial artery, and femorotibial PWV were determined. Based on Kaplan-Meier survival curve analyses and Cox proportional hazards analyses, adjusted for age, pulse pressure, and clinical data, aortic PWV was a significant and independent predictor of outcome. Neither brachial artery nor femotibial artery stiffness was able to predict cardiovascular outcome. Receiver operating characteristic curve analysis of aortic PWV indicated the cutoff value of 10.75 m/s, with 84% sensitivity, 73% specificity, 87% negative predictive value, and 72% positive predictive value. These results provide evidence that, in ESRD, increased stiffness of capacitive arteries, like the aorta, is an independent strong predictor of cardiovascular mortality, whereas stiffness of peripheral conduit arteries had no prognostic value.     

Aortic stiffness for the detection of preclinical left ventricular diastolic dysfunction: pulse wave velocity versus pulse pressure

OBJECTIVE: An age-dependent relationship between aortic and left ventricular (LV) stiffening has been observed in community-based adults. Our aim was to compare the performances of wave reflection-dependent (pulse pressure) and independent [carotid-femoral pulse wave velocity (PWV)] indexes of aortic stiffness to detect preclinical LV diastolic dysfunction. METHODS: In this case-control study, a stratified subsample of participants of a population-based echocardiographic survey with LV ejection fraction higher than 45% and without overt heart failure was randomly selected to undergo assessment of brachial blood pressure, LV diastolic function by Doppler echocardiography, and estimation of central aortic pressures and PWV by applanation tonometry. RESULTS: Of the 233 subjects (mean age 73 +/- 6 years, 54% men), 84 had normal diastolic function, 99 had mild diastolic dysfunction, and 50 had moderate or severe diastolic dysfunction. Brachial pulse pressure, central pulse pressure, and PWV progressively increased according to the severity of diastolic dysfunction, independent of age and sex. The overall performance of PWV was superior to brachial pulse pressure [area under receiver operating characteristic curve (AUC): 0.70 versus 0.59, respectively; P = 0.005] and central pulse pressure (AUC: 0.70 versus 0.56, respectively; P = 0.001) for the detection of any diastolic dysfunction. CONCLUSION: PWV appeared to be superior to central and brachial pulse pressure for the detection of diastolic dysfunction in older adults with 'preserved' LV ejection fraction.     

Relation between insulin and aortic stiffness: a population-based study

Recent studies have suggested that a high pulse wave velocity (PWV), a measure of aortic stiffness, may be a stronger risk factor for cardiovascular disease (CVD) than a high blood pressure (BP). The relation between insulin, believed to play an important role in the development and clinical course of high BP, and PWV is not yet clear. Therefore, we decided to examine the relationship between insulin and PWV in a large population-based study. The study population consisted of a random sample of 1213 women and 1207 men (age range, 41-72 years) without a history of myocardial infarction or stroke. Fasting insulin was determined together with conventional risk factors for CVD. PWV was recorded transcutaneously by a mechanical electrical principle with one transducer positioned over the left common carotid artery, and another over the left femoral artery. In univariate analysis, insulin was highly significantly related to PWV (standardized regression coefficient: 0.0669+/-0.0051; P<0.001). In multivariate analysis, controlling for all well-established predictors of PWV, such as age, systolic BP or mean BP and pulse pressure, sex, and heart rate, as well as controlling for conventional risk factors for CVD and use of BP-lowering drugs, the level of insulin remained a significant predictor of PWV (standardized regression coefficient: 0.0122+/-0.0048; P=0.012). In conclusion, the present study found that a higher insulin level was related to a higher PWV. This indicates that hyperinsulinaemia may affect BP and risk of CVD by increasing aortic stiffness.     

Central pulse pressure and mortality in end-stage renal disease

Damage of large arteries is a major factor in the high cardiovascular morbidity and mortality of patients with end-stage renal disease (ESRD). Increased aortic pulse wave velocity (PWV) and brachial pulse pressure (PP) are the principal arterial markers of cardiovascular mortality described in these patients. Whether central (carotid) PP and brachial-carotid PP amplification may predict all-cause (including cardiovascular) mortality has never been investigated. A cohort of 180 patients with ESRD who were undergoing hemodialysis was studied between January 1990 and March 2000. The mean duration of follow-up was 52+/-36 months (mean+/-SD). Mean age at entry was 51.5+/-16.3 years. Seventy deaths occurred, including both cardiovascular and noncardiovascular fatal events. At entry, patients underwent carotid PP measurements (pulse wave analysis), echocardiography, and aortic PWV (Doppler ultrasonography), together with standard clinical and biochemical analyses. On the basis of Cox analyses, after adjustment of age, time on dialysis before inclusion, and previous cardiovascular events, 3 factors emerged as predictors of all-cause mortality: carotid PP, brachial/carotid PP, and aortic PWV. Adjusted hazard ratios for 1-SD increments were 1.4 (1.1 to 1.8) for carotid PP, 0.5 (0.3 to 0.8) for brachial/carotid PP, and 1.3 (1.0 to 1.7) for PWV. Brachial blood pressure, including PP, had no predictive value for mortality after adjustment. These results provide the first direct evidence that in patients with ESRD, the carotid PP level and, mostly, the disappearance of PP amplification are strong independent predictors of all-cause (including cardiovascular) mortality.     

Genetic variation in fibrillin-1 gene is not associated with arterial stiffness in apparently healthy individuals

OBJECTIVE: Arterial stiffness is an independent determinant of cardiovascular risk, and there is evidence that it has a strong genetic component. Fibrillin-1 (FBN-1) is the disease gene for Marfan's syndrome and an FBN-1 polymorphism has been associated with large artery stiffening and elevated pulse pressure (PP) in patients with cardiovascular disease. The aim of this study was to investigate the possible influence of the common FBN-1 genotypes on arterial stiffness in a large cohort of healthy individuals. SUBJECTS AND METHODS: A total of 742 individuals free from cardiovascular disease or risk factors were studied. Aortic pulse wave velocity (PWV) and augmentation index (AIx), blood pressure, lipids and glucose were assessed. Genomic DNA was extracted, and genotyping for the FBN-1 variable nucleotide tandem repeat (VNTR) was performed using a CEQ 8000 sequencer. RESULTS: The mean age (+/- SEM) of the cohort was 49 +/- 1 years. The three common VNTR genotypes accounted for 87.1% of the population frequency. Their frequencies were: 52.3%, 2-2; 16.3%, 2-3; 18.5% 2-4. There were no significant differences in the blood pressure, AIx, PWV, lipids or body mass index among the common genotypes. Moreover, the FBN-1 genotype was not associated with either aortic PWV or other measures of stiffness after correction for other confounding factors. CONCLUSION: These data do not support the hypothesis that aortic PWV or PP are influenced by the FBN-1 VNTR genotype. Although we cannot exclude small effects, this negative finding also suggests that there is not a major allele for stiffness or blood pressure in apparently healthy individuals linked to this VNTR.     

Relation between renal function within the normal range and central and peripheral arterial stiffness in hypertension

Chronic kidney disease is accompanied by increased large-artery stiffness, but the relation between glomerular filtration rate within the reference range and central or peripheral arterial stiffness has been understudied. The link between renal function and arterial stiffness was assessed in 305 patients with never-treated essential hypertension (men: 58%; age: 48+/-11 years, blood pressure: 151/95+/-20/11 mm Hg), free from overt cardiovascular disease and with serum creatinine values <1.4 mg/dL (men) and <1.2 mg/dL (women), who underwent noninvasive aortic and upper-limb pulse wave velocity (PWV) determination. Aortic PWV was strongly related to age (r=0.55; P<0.001), whereas upper-limb PWV had a weaker nonlinear relation with age (beta=1.392; P<0.001 for age; beta=-1.312; P<0.001 for age squared) and a weak relation with aortic PWV (r=0.22; P<0.001). Glomerular filtration rate (GFR), estimated according to the Mayo clinic equation for healthy subjects, was inversely correlated with large-artery stiffness, as assessed by aortic PWV (r=-0.34; P<0.001), and with peripheral artery stiffness, as assessed by upper-limb PWV (r=-0.25; P<0.001). In a multivariate linear regression, aortic PWV was independently predicted by age (beta=0.48; P<0.001), mean arterial pressure (beta=0.14; P=0.013), and GFR (beta=-0.13, P=0.029). Upper-limb PWV was predicted by GFR (beta=-0.24; P<0.001) and mean arterial pressure (beta=0.20; P<0.001). We conclude that, in hypertensive patients with normal renal function, an inverse relationship exists between GFR and stiffness of both central elastic and peripheral muscular arteries. These relations are in part independent from the effect of several confounders, including age, sex, and blood pressure values.     

The relationship between pulse wave velocity and pulse pressure in Chinese patients with essential hypertension.

Aortic pulse wave velocity (PWV) is a significant and independent predictor of cardiovascular disease in hypertensive subjects and in patients with end-stage renal disease, but there have been few studies on PWV in Chinese patients with essential hypertension. In this cross-sectional study, we investigated 3,156 consecutive patients (mean age: 53.7 +/- 11.58 years) of the Hypertension Division of Ruijin Hospital in Shanghai. Together with sphygmomanometric blood pressure measurements, aortic PWV was measured using a validated automatic device. PWV in patients with pulse pressure (PP) > or = 60 mmHg was significantly greater than that in patients with PP < 60 mmHg (p < 0.01). PP and PWV were positively related to age (PP: r = 0.396, p = 0.001; PWV: r = 0.531, p = 0.001). After adjustment by age and heart rate, PWV was still closely related to PP (r = 0.249, p = 0.001). At any given systolic blood pressure (SBP), PWV significantly decreased with the increase of diastolic blood pressure (DBP), whereas at any given DBP there was a significant increase of PWV with the increase of SBP. In conclusion, PWV was the major determinant of PP, and was highest in Chinese patients with isolated systolic hypertension, followed by those with systolic and diastolic hypertension, isolated diastolic hypertension, and normal blood pressure.     

Normal vascular aging: differential effects on wave reflection and aortic pulse wave velocity: the Anglo-Cardiff Collaborative Trial (ACCT).

OBJECTIVES: The aim of the current investigation was to test the hypothesis that age-related changes in augmentation index (AIx) are more prominent in younger individuals (<50 years), whereas changes in aortic stiffness per se are more marked in older individuals (>50 years). BACKGROUND: Aging exerts a number of deleterious changes in the cardiovascular system, and, in particular, on the large arteries. Previous studies have suggested that AIx and pulse wave velocity (PWV) increase linearly with age, yet epidemiological data concerning pulse pressure suggest that large artery stiffening predominantly occurs later in life. METHODS: Peripheral and central blood pressure, augmentation pressure (AP), and AIx were determined in 4,001 healthy, normotensive individuals, aged 18 to 90 years. Aortic and brachial PWV were also determined in a subset of 998 subjects. RESULTS: Peripheral and central pulse pressure, AP, AIx, and aortic and brachial PWV all increased significantly with age; however, the age-related changes in AIx and aortic PWV were non-linear, with AIx increasing more in younger individuals, whereas the changes in PWV were more prominent in older individuals. CONCLUSIONS: These data suggest that AIx might be a more sensitive marker of arterial stiffening and risk in younger individuals but aortic PWV is likely to be a better measure in older individuals.     

Arterial stiffness and osteoporosis in chronic obstructive pulmonary disease

RATIONALE: Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of cardiovascular events and osteoporosis. Increased arterial stiffness is an independent predictor of cardiovascular disease. OBJECTIVES: We tested the hypothesis that patients with COPD would have increased arterial stiffness, which would be associated with osteoporosis and systemic inflammation. METHODS: We studied 75 clinically stable patients with a range of severity of airway obstruction and 42 healthy smoker or ex-smoker control subjects, free of cardiovascular disease. All subjects underwent spirometry, measurement of aortic pulse wave velocity (PWV) and augmentation index, dual-energy X-ray absorptiometry, and blood sampling for inflammatory mediators. MEASUREMENTS AND MAIN RESULTS: Mean (SD) aortic PWV was greater in patients, 11.4 (2.7) m/s, than in control subjects, 8.95 (1.7) m/s, p < 0.0001. Inflammatory mediators and augmentation index were also greater in patients. Patients with osteoporosis at the hip had a greater aortic PWV, 13.1 (1.8) m/s, than those without, 11.2 (2.7) m/s, p < 0.05. In patients, aortic PWV was related to age (r = 0.63, p < 0.0001) and log(10) IL-6 (r = 0.31, p < 0.01), and inversely to FEV(1) (r = -0.34, p < 0.01). The strongest predictors of aortic PWV in all subjects were age (p < 0.0001), percent predicted FEV(1) (p < 0.05), mean arterial pressure (p < 0.05), and log(10) IL-6 (p < 0.05). CONCLUSIONS: Increased arterial stiffness was related to the severity of airflow obstruction and may be a factor in the excess risk for cardiovascular disease in COPD. The increased aortic PWV in patients with osteoporosis and the association with systemic inflammation suggest that age-related bone and vascular changes occur prematurely in COPD.     

Aortic stiffness in untreated adult patients with human immunodeficiency virus infection

HIV infection is associated with chronic immune activation, subclinical inflammation, and an atherogenic metabolic profile. It remains controversial whether HIV infection is a risk factor for accelerated arteriosclerosis independent from the effects of antiretroviral drugs. We investigated whether aortic stiffness, an early marker of arteriosclerosis, is increased in HIV patients who were not under antiretroviral treatment. In 39 untreated HIV-infected patients and 78 individually matched age-, sex-, and blood pressure-matched HIV-uninfected control subjects, we determined aortic pulse wave velocity (PWV), a direct noninvasive measure of aortic stiffness, by tonometric method. Subjects with overt cardiovascular disease or major cardiovascular risk factors were excluded from the study. Prevalence of the metabolic syndrome was higher in HIV patients (18% versus 5%; P=0.025). HIV patients had a higher aortic PWV (7.5+/-1.4 versus 6.7+/-1.1 m.s(-1); P=0.001) than control subjects. Age, mean arterial pressure as a measure of distending pressure, and HIV infection (all P<0.05) independently predicted aortic PWV when a consistent number of cardiovascular risk factors was simultaneously controlled for. Among HIV-infected subjects, serum gamma-glutamyl transpeptidase concentration (beta=0.46; P=0.003) and mean arterial pressure (beta=0.32; P=0.03) were independent determinants of aortic PWV. In conclusion, aortic stiffness is increased in HIV-infected individuals who have never received antiretroviral therapy. PWV increases with increasing serum gamma-glutamyl transpeptidase concentration. Our data support the hypothesis that HIV infection is a risk factor for arteriosclerosis.     

Prognostic application of arterial stiffness: task forces

Epidemiologic and clinical studies have shown that increased pulse pressure is an independent cardiovascular risk factor in general population. Pulse pressure is determined by combined effects of cardiac factors (stroke volume) and the arterial stiffness. Arterial stiffness can be more directly evaluated by several measurements including the measure of pulse wave velocity (PWV). Aortic PWV, a marker of aortic stiffness, has been shown to be a strong independent predictor of cardiovascular and all cause mortality in patients with end-stage renal disease (ESRD) on hemodialysis as well as in patients with essential hypertension and older subjects over 80 years. Local arterial stiffness assessment, namely carotid distensibility was also shown to predict cardiovascular risk, both in ESRD patients and in renal transplant recipients. Furthermore, it has been shown in a therapeutic trial that the lack of aortic PWV attenuation despite significant drug-induced reduction in mean blood pressure was a significant predictor of cardiovascular death in subjects with ESRD. These results support the hypothesis that measurement of aortic PWV could then help, not only in risk assessment strategies, but also in risk reduction strategies by monitoring arterial stiffness under different pharmacologic regimens. The drug-related reduction of aortic PWV could then give prognostic information, additionally to blood pressure reduction. Aortic stiffness measurements could serve as an important tool in identifying ESRD patients at higher risk of cardiovascular disease. The ability to identify these patients would lead to better risk stratification and earlier and more cost-effective preventive therapy.     

Arterial stiffness and cardiovascular risk factors in a population-based study

OBJECTIVE: To determine the relationships between pulse wave velocity (PWV), an estimate of arterial distensibility and cardiovascular risk factors. DESIGN: This cross-sectional population-based study was carried out from 1995 to 1997 to investigate these relationships. POPULATION AND METHODS: Some 993 subjects, aged 35-64 years (52.7% men), living in the south-west of France, were randomly selected from electoral rolls and participated in a cross-sectional study. Medical examinations were performed by specially trained medical staff. Carotid-femoral PWV was measured using a semiautomatic device (Complior, Garges les Gonesse, France). The relationships between PWV and risk factors were assessed, first in subjects not treated with hypolipidaemic, antidiabetic and antihypertensive drugs and then in treated subjects. In subjects not treated for cardiovascular risk factors, age, gender, systolic blood pressure (SBP) and heart rate (P< 0.001) were the variables significantly associated with PWV. In treated patients, age (P < 0.01), SBP (P < 0.001), heart rate (P < 0.001), apolipoprotein B (P< 0.05) and the number of treated cardiovascular risk factors (P< 0.05) were positively correlated with PWV. CONCLUSION: This study shows that, in a sample of subjects at high risk, the cumulative influence of risk factors, even treated, is an independent determinant of arterial stiffness. These results suggest that PWV may be used as a relevant tool to assess the influence of cardiovascular risk factors on aortic stiffness in high-risk patients.     

Carotid plaques, but not common carotid intima-media thickness, are independently associated with aortic stiffness.

OBJECTIVE: It has been suggested that non-invasive aortic stiffness measurements can be used as an indicator of atherosclerosis. The relationships of arterial stiffness with arterial wall hypertrophy and atherosclerosis however, have rarely been investigated in large-scale studies. The present study reports the associations of carotid arterial structure assessed by B-mode ultrasound with carotid-femoral pulse-wave velocity in hypertensive and non-hypertensive subjects. DESIGN AND METHODS: Free health examinations were performed on 564 subjects (age 58.2 +/- 10.8 years, 31.9% of women, 53.2% of all were hypertensive). Carotid-femoral pulse-wave velocity (PWV) was used to assess aortic stiffness. Carotid ultrasound examination included measurements (at sites free of plaques) of intima-media thickness (IMT) at the common carotid arteries (CCA), CCA-lumen diameter, and assessment of atherosclerotic plaques in the extracranial carotid arteries. RESULTS: Subjects with carotid plaques had significantly higher mean sex-adjusted values of PWV than those without carotid plaques (12.7 +/- 0.2 versus 11.1 +/- 0.1 m/s, P < 0.001). Multivariate analyses showed that this association was independent of sex, age, height, body mass index, mean blood pressure, pulse pressure, diabetes, hypercholesterolaemia and smoking habits (P < 0.009). PWV was positively associated with CCA-IMT and CCA-lumen diameter in sex-adjusted analysis (partial correlation coefficients (r ) were respectively 0.39 and 0.42, P < 0.001 for each). However, the association of PWV with CCA-IMT, but not that with CCA-lumen diameter, disappeared after further adjustment for age and blood pressure measurements (mean blood pressure and/or pulse pressure). CONCLUSION: This study shows that there is a differential association of PWV with CCA-IMT and carotid plaques. The nature of the independent positive association between atherosclerosis and arterial stiffness should be thoroughly investigated.     

Arterial stiffness and central hemodynamics in treated hypertensive subjects according to brachial blood pressure classification

BACKGROUND: International recommendations have classified brachial blood pressure (BP) in subgroups enabling better cardiovascular risk stratification. Central BP is an independent predictor of cardiovascular risk, differing from brachial BP through the predominant influence of arterial stiffness and wave reflections. Central BP has never been studied in relation to international guidelines for brachial BP classification. METHODS: In 580 chronically treated hypertensive subjects we measured: carotid-femoral pulse wave velocity (PWV), carotid artery augmentation index (AI) and carotid blood pressures, using applanation tonometry and pulse wave analysis, and using brachial BP for carotid pressure wave calibration. RESULTS: For each given brachial value, carotid systolic blood pressure (SBP) and PP were significantly lower than the corresponding brachial SBP and PP. This pressure amplification was significantly lower in the 'optimal' and 'normal' BP ranges (6.8-7.4 mmHg) than in the higher BP ranges (10.1-11.3 mmHg), mainly depending on heart rate (HR) and PWV levels. PWV gradually increased as a function of brachial BP classification and was a significant predictor of this classification independently of age, drug treatment, atherosclerotic lesions and even mean BP. Finally, PWV was a highly sensitive marker of the effective BP control throughout all decades of age. CONCLUSION: Under chronic antihypertensive therapy, central BP does not strictly parallel the corresponding brachial BP classification, depending on differences in aortic stiffness and HR. Whether aortic PWV might predict the brachial BP classification and/or the presence of effective BP control, as suggested in this study, needs further confirmation.     

Overweight women with polycystic ovary syndrome have evidence of subclinical cardiovascular disease

CONTEXT: Polycystic ovary syndrome (PCOS) is associated with insulin resistance (IR) and the metabolic syndrome. There are no adequate data demonstrating significantly increased cardiovascular disease (CVD) mortality. In the absence of clinical outcome studies, surrogate markers of early CVD can provide insight into early CVD. OBJECTIVE: The aim of this study was to clarify whether overweight women with PCOS have an increased prevalence of cardiovascular risk factors and early CVD, compared with age- and body mass index-matched controls, to determine the contribution of PCOS per se to CVD status. DESIGN AND PATIENTS: This was a case control study of 100 overweight women with PCOS and 20 subjects of similar body mass index and age. MAIN OUTCOME MEASURES: Noninvasive markers of early CVD [carotid intimal media thickness, pulse wave velocity (PWV), and brachial arterial flow-mediated vasodilation] were measured. Metabolic parameters studied included insulin, glucose, C-reactive protein, lipids, and androgens. RESULTS: Subjects with PCOS had elevated testosterone (2.5 +/- 0.2 vs. 1.3 +/- 0.1 nmol/liter), dehydroepiandrosterone sulfate (4.9 +/- 0.3 vs. 3.6 +/- 0.4 mmol/liter), fasting insulin (19.6 +/- 1.4 vs. 6.8 +/- 0.8 microU/ml), and homeostasis model assessment of IR (4.1 +/- 0.3 vs. 1.3 +/- 0.2), compared with controls. In addition, those with PCOS had elevated cholesterol (5.1 +/- 0.1 vs. 4.6 +/- 0.2 mmol/liter) and triglycerides (1.4 +/- 0.1 vs. 0.9 +/- 0.1 mmol/liter), whereas there were no differences in either C-reactive protein or 24-h ambulatory blood pressure parameters. Subjects with PCOS also had increased arterial stiffness (PWV, 7.4 +/- 0.1 vs. 6.6 +/- 0.2 m/sec) and endothelial dysfunction (flow-mediated vasodilation, 9.8 +/- 0.4 vs. 13.3 +/- 0.9), compared with controls. There was no difference in mean intimal media thickness between the groups. Stepwise regression in PCOS subjects showed that IR and lipids were independent predictors of PWV. CONCLUSION: Overweight women with PCOS have increased cardiovascular risk factors and evidence of early CVD, compared with weight-matched controls, potentially related to IR.     

Metabolic syndrome and age-related progression of aortic stiffness.

Aortic stiffness measured from pulse wave velocity (PWV) was studied during a six-year period in a population of subjects with zero to three and more cardiovascular (CV) factors involving hypertension, body mass index, dyslipidemia, hypertriglyceridemia, and hyperglycemia. During the follow-up, the increase in PWV was significantly higher in subjects with three and more CV risk factors (i.e., in subjects with metabolic syndrome) than in subjects with zero, one, or two factors, even after adjustments for confounding factors. Metabolic syndrome involves an increased progression of arterial stiffness with age and, thus, favors premature senescence. OBJECTIVES: The purpose of the study was to evaluate whether a clustering of metabolic risk factors might accelerate the progression of arterial stiffness with age in subjects with metabolic syndrome (MS). BACKGROUND: Arterial stiffness is increased in MS, but the genetic and environmental factors that might influence its progression are unknown. METHODS: Four hundred seventy-six subjects were classified at baseline according to their number of cardiovascular (CV) risk factors (from zero to three and more), after adjustment for smoking habits. The CV risk factors were: hypertension, body mass index, dyslipidemia, hypertriglyceridemia, and hyperglycemia, classified according to traditional criterions. Subjects were followed for six years and had, at the beginning and end of the survey, determinations of blood pressure (BP), heart rate (HR), and aortic pulse wave velocity (PWV). RESULTS: At baseline, BP, HR, plasma creatinine, and PWV were significantly higher (p < 0.001) in the group with three and more CV risk factors than in groups with zero to two risk factors. During the follow-up, the increase in PWV, but not in pulse pressure, was significantly higher (p < 0.01) in the group with three and more risk factors (i.e., metabolic syndrome) than in other groups. Results were unmodified after adjustments for age, gender, baseline values, drug treatment, smoking habits, and mean arterial pressure. CONCLUSIONS: Metabolic syndrome is associated with an increased progression of aortic stiffness with age, supporting premature senescence in these patients.     

Influence of the metabolic syndrome on aortic stiffness in never treated hypertensive patients

BACKGROUND AND AIM: Metabolic syndrome (MS) carries an increased risk for cardiovascular events and there is a growing awareness that large artery stiffening is a powerful predictor of cardiovascular morbidity and mortality. Little is known about the relationship of MS with aortic stiffness. The aim of our study was to analyze, in patients with essential hypertension, the influence of MS, defined according to the criteria proposed by the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP-ATP III), on carotid-femoral pulse wave velocity (PWV), a measure of aortic stiffness. METHODS: Ninety-three untreated essential hypertensives, aged between 23 and 61 years, without diabetes mellitus, were studied. All subjects underwent routine blood chemistry, oral glucose tolerance test with glucose and insulin determinations, albumin excretion rate (AER) measurement, 24-h ambulatory blood pressure monitoring, and measurement of carotid-femoral PWV, by means of a computerized method. RESULTS: Patients with MS (n = 28) showed higher age-adjusted carotid-femoral PWV (10.1 +/- 1.4 vs 9.3 +/- 1.4 m/s; p = 0.01) when compared to subjects without MS. This difference held after controlling for gender and for 24-h mean blood pressure (MBP) (p = 0.02) and lost its statistical significance after further adjustment for AER. In a multiple regression model, excluding the individual components of MS, in which metabolic syndrome was added along with age, gender, smoking habit, LDL cholesterol, HOMA index, 24-h MBP and 24-h heart rate, MS remained independently associated with carotid-femoral PWV (beta = 0.29; p = 0.002). The statistical significance of this association disappeared after the inclusion into this model of AER. CONCLUSIONS: Metabolic syndrome is associated with an increased aortic stiffness. Main explanatory factors of this association are age, systolic blood pressure and albumin excretion rate.