Arterial stiffness as underlying mechanism of disagreement between an oscillometric blood pressure monitor and a sphygmomanometer

Oscillometric blood pressure devices tend to overestimate systolic blood pressure and underestimate diastolic blood pressure compared with sphygmomanometers. Recent studies indicate that discrepancies in performance between these devices may differ between healthy and diabetic subjects. Arterial stiffness in diabetics could be the underlying factor explaining these differences. We studied differences between a Dinamap oscillometric blood pressure monitor and a random-zero sphygmomanometer in relation to arterial stiffness in 1808 healthy elderly subjects. The study was conducted within the Rotterdam Study, a population-based cohort study of subjects aged 55 years and older. Systolic and diastolic blood pressure differences between a Dinamap and a random-zero sphygmomanometer were related to arterial stiffness, as measured by carotid-femoral pulse wave velocity. Increased arterial stiffness was associated with higher systolic and diastolic blood pressure readings by the Dinamap compared with the random-zero sphygmomanometer, independent of age, gender, and average mean blood pressure level of both devices. The beta-coefficient (95% CI) was 0.25 (0.00 to 0.50) mm Hg/(m/s) for the systolic blood pressure difference and 0.35 (0.20 to 0.50) mm Hg/(m/s) for the diastolic blood pressure difference. The results indicate that a Dinamap oscillometric blood pressure device, in comparison to a random-zero sphygmomanometer, overestimates systolic and diastolic blood pressure readings in subjects with stiff arteries

Measurement of cerebral microvascular compliance in a model of atherosclerosis with optical coherence tomography

Optical coherence tomography (OCT) has recently been used to produce 3D angiography of microvasculature and blood flow maps of large vessels in the rodent brain in-vivo. However, use of this optical method for the study of cerebrovascular disease has not been fully explored. Recent developments in neurodegenerative diseases has linked common cardiovascular risk factors to neurodegenerative risk factors hinting at a vascular hypothesis for the development of the latter. Tools for studying cerebral blood flow and the myogenic tone of cerebral vasculature have thus far been either highly invasive or required ex-vivo preparations therefore not preserving the delicate in-vivo conditions. We propose a novel technique for reconstructing the flow profile over a single cardiac cycle in order to evaluate flow pulsatility and vessel compliance. A vascular model is used to simulate changes in vascular compliance and interpret OCT results. Comparison between atherosclerotic and wild type mice show a trend towards increased compliance in the smaller arterioles of the brain (diameter < 80μm) in the disease model. These results are consistent with previously published ex-vivo work confirming the ability of OCT to investigate vascular dysfunction

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

Association between arterial stiffness and atherosclerosis: the Rotterdam Study

BACKGROUND AND PURPOSE: Studies of the association between arterial stiffness and atherosclerosis are contradictory. We studied stiffness of the aorta and the common carotid artery in relation to several indicators of atherosclerosis. METHODS: This study was conducted within the Rotterdam Study in >3000 elderly subjects aged 60 to 101 years. Aortic stiffness was assessed by measuring carotid-femoral pulse wave velocity, and common carotid artery stiffness was assessed by measuring common carotid distensibility. Atherosclerosis was assessed by common carotid intima-media thickness, plaques in the carotid artery and in the aorta, and the presence of peripheral arterial disease. Data were analyzed by ANCOVA with adjustment for age, sex, mean arterial pressure, and heart rate. RESULTS: Both aortic and common carotid artery stiffness were found to have a strong positive association with common carotid intima-media thickness, severity of plaques in the carotid artery, and severity of plaques in the aorta (P: for trend <0.01 for all associations). Subjects with peripheral arterial disease had significantly increased aortic stiffness (P:=0.001) and borderline significantly increased common carotid artery stiffness (P:=0.08) compared with subjects without peripheral arterial disease. Results were similar after additional adjustment for cardiovascular risk factors and after exclusion of subjects with prevalent cardiovascular disease. CONCLUSIONS: This population-based study shows that arterial stiffness is strongly associated with atherosclerosis at various sites in the vascular tree

The Relationship between Brachial Ankle Pulse Wave Velocity and Complement 1 Inhibitor

Complement 1 (C1) inhibitor is an acute phase protein with anti-inflammatory properties. The aim of the present study was to elucidate the relationship between brachial ankle pulse wave velocity (baPWV), the parameter of arterial stiffness, and C1 inhibitor. One hundred subjects were randomly enrolled in this study. Data about baPWV, age, gender, hypertension, smoking, and body mass index (BMI) were measured. Blood tests for total cholesterol, low density lipoprotein, high density lipoprotein, triglycerides, hemoglobin A1c, erythrocyte sedimentation rate, C-reactive protein, complement 3, and C1 inhibitor were performed. Based on the Pearson correlation, the C1 inhibitor showed a positive relation to the baPWV (P<0.001). Multiple regression analysis revealed the significant predictors of baPWV were not only the conventional risk factors of arteriosclerosis and/or atherosclerosis, such as age (P<0.001), gender (P<0.001), hypertension (P<0.001), and BMI (P=0.006), but also the acute phase protein, C1 inhibitor (P=0.025). In conclusion, C1 inhibitor is associated with arterial stiffness through its association with increased inflammation

Risk factors for metabolic syndrome independently predict arterial stiffness and endothelial dysfunction in patients with chronic kidney disease and minimal comorbidity

OBJECTIVE: Metabolic syndrome (MS) is common in patients with chronic kidney disease (CKD), but its contribution to arterial stiffness and endothelial dysfunction in CKD is not well defined. We hypothesized that risk factors for MS would independently predict arterial stiffness and endothelial dysfunction in CKD patients. RESEARCH DESIGN AND METHODS: Risk factors for MS, carotid-femoral pulse wave velocity (CF-PWV) and flow-mediated dilation (FMD) as measures of arterial stiffness and endothelial dysfunction, respectively, were assessed in 113 minimally comorbid CKD patients and in 23 matched control subjects. RESULTS: CF-PWV correlated with systolic blood pressure (SBP), waist circumference, and plasma glucose (r(2) = 0.25, 0.09, and 0.09; P < 0.01 for all). FMD correlated with SBP (r(2) = 0.09; P < 0.01) and waist circumference (r(2) = 0.03; P < 0.05). CF-PWV increased progressively (r(2) = 0.07; P < 0.01) with increasing number of risk factors for MS. In multiple linear regression, SBP and waist circumference were independent determinants of CF-PWV, whereas only SBP predicted FMD. CONCLUSIONS: The number of MS risk factors is an important determinant of arterial stiffness in CKD patients irrespective of the degree of renal impairment. Although BP remains the major determinant of arterial stiffness and endothelial dysfunction, waist circumference independently predicts arterial stiffness. MS risk factors, particularly abdominal girth, are potential targets for future interventional studies in patients with CKD