Obstructive sleep apnea, circulating microRNAs, and risk of cardiovascular disease.

OBJECTIVE: while obstructive sleep apnea is strongly associated with incident cardiovascular diseases (CVD), the underlying mechanisms remain to be elucidated. This study aimed to compare the patterns of microRNAs expression between OSA and control patients with and without incident CVD. METHODS: 218 matched adult participants with and without OSA and with and without incident CVD were selected from two independent community-based prospective cohorts in France and Switzerland, and 168 microRNAs on average were detected per sample. OSA was diagnosed using the validated Berlin questionnaire in one study (Paris Prospective Study 3) and during a full-night polysomnography in the second study (HypnoLaus Study). RESULTS: there were 78 OSA patients (39 with and 39 without CVD) and 140 controls (70 with and 70 without CVD). Participants were male in 54.6% (n = 119) and mean age was 58.7 years (±9.2). Of the 183 miRNAs screened, a mean 168 assays were detected per sample, and 129 in all samples. There was no pattern of blood microRNAs expression that discriminated OSA patients with and without CVD events. CONCLUSIONS: this binational study failed to find any association between a large panel of microRNAs and OSA patients with and without incident CVD.

Oral Condition and Incident Coronary Heart Disease: A Clustering Analysis.

Poor oral health has been linked to coronary heart disease (CHD). Clustering clinical oral conditions routinely recorded in adults may identify their CHD risk profile. Participants from the Paris Prospective Study 3 received, between 2008 and 2012, a baseline routine full-mouth clinical examination and an extensive physical examination and were thereafter followed up every 2 y until September 2020. Three axes defined oral health conditions: 1) healthy, missing, filled, and decayed teeth; 2) masticatory capacity denoted by functional masticatory units; and 3) gingival inflammation and dental plaque. Hierarchical cluster analysis was performed with multivariate Cox proportional hazards regression models and adjusted for age, sex, smoking, body mass index, education, deprivation (EPICES score; Evaluation of Deprivation and Inequalities in Health Examination Centres), hypertension, type 2 diabetes, LDL and HDL serum cholesterol (low- and high-density lipoprotein), triglycerides, lipid-lowering medications, NT-proBNP and IL-6 serum level. A sample of 5,294 participants (age, 50 to 75 y; 37.10% women) were included in the study. Cluster analysis identified 3,688 (69.66%) participants with optimal oral health and preserved masticatory capacity (cluster 1), 1,356 (25.61%) with moderate oral health and moderately impaired masticatory capacity (cluster 2), and 250 (4.72%) with poor oral health and severely impaired masticatory capacity (cluster 3). After a median follow-up of 8.32 y (interquartile range, 8.00 to 10.05), 128 nonfatal incident CHD events occurred. As compared with cluster 1, the risk of CHD progressively increased from cluster 2 (hazard ratio, 1.45; 95% CI, 0.98 to 2.15) to cluster 3 (hazard ratio, 2.47; 95% CI, 1.34 to 4.57; P < 0.05 for trend). To conclude, middle-aged individuals with poor oral health and severely impaired masticatory capacity have more than twice the risk of incident CHD than those with optimal oral health and preserved masticatory capacity (ClinicalTrials.gov NCT00741728).

Masticatory Capacity and Mortality: The Preventive and Clinical Investigation Center (IPC) Cohort Study.

Poor oral health (OH) has been associated with mortality, but the association between OH components and mortality remains imprecise. The present observational study aimed to investigate if there is an association between oral masticatory efficiency and cardiovascular (CV) mortality in a large French subject cohort. The study was based on a cohort of 85,830 subjects aged between 16 and 94 y at recruitment. The follow-up extended from 2001 to 2014 and the mean follow-up was 8.06 ± 2.73 y. The number of deaths totaled 1,670. Full-mouth examinations were performed. Dental plaque, dental calculus, gingival inflammation, missing teeth, and masticatory units were recorded. Masticatory units represent the number of natural or prosthetic opposing premolars and molar pairs and can be considered an accurate indicator for masticatory efficiency. Causes of death were ascertained from death certificates. Cox regression analyses were used to calculate hazard ratios (HRs). In the fully adjusted model, the number of masticatory units <5 is associated with an HR of 1.72 (95% confidence interval [CI], 1.54 to 1.91) for all-cause mortality, HR of 1.41 (95% CI, 1.01 to 1.99) for CV mortality, HR of 1.76 (95% CI, 1.44 to 2.15) for cancer mortality, and HR of 1.85 (95% CI, 1.55 to 2.20) for non-CV and noncancer mortality. Significant statistical associations with the other oral variables were also found for all-cause mortality, cancer mortality, and non-CV and noncancer mortality in the adjusted models. Our study indicates that after full adjustment, all oral parameters are associated with all-cause, cancer, and non-CV and noncancer mortality. However, the low number of masticatory units is associated with an increased risk of CV mortality. We highlight the association of masticatory units and CV mortality.

Body Silhouette Trajectories Over the Lifespan and Insomnia Symptoms: The Paris Prospective Study 3.

Insomnia symptoms are highly prevalent and associated with several adverse medical conditions, but only few determinants, including non-modifiable ones, have been highlighted. We investigated associations between body silhouette trajectories over the lifespan and insomnia symptoms in adulthood. From a community-based study, 7 496 men and women aged 50-75 years recalled their body silhouette at age 8, 15, 25, 35 and 45, and rated the frequency of insomnia symptoms on a standardized sleep questionnaire. An Epworth Sleepiness Scale ≥11 defined excessive daytime sleepiness (EDS). Using a group-based trajectory modeling, we identified five body silhouette trajectories: a 'lean-stable' (32.7%), a 'heavy-stable' (8.1%), a 'moderate-stable' (32.5%), a 'lean-increase' (11%) and a 'lean-marked increase' (15.7%) trajectory. In multivariate logistic regression, compared to the 'lean-stable' trajectory, the 'lean-marked increase' and 'heavy-stable' trajectories were associated with a significant increased odd of having ≥1 insomnia symptoms as compared to none and of having a proxy for insomnia disorder (≥1 insomnia symptom and EDS). The association with the 'lean-marked increase' trajectory' was independent from body mass index measured at study recruitment. In conclusion, increasing body silhouette over the lifespan is associated with insomnia symptoms in adulthood, emphasizing the importance of weight gain prevention during the entire lifespan.

New techniques for assessing arterial stiffness.

Arterial stiffness is now included in the guidelines of the European Society of Hypertension. In this paper, we review the evidence for the predictive value of arterial stiffness. More than 11 longitudinal trials have proven the predictive value of aortic stiffness measured through carotid to femoral pulse wave velocity, beyond and above classical risk factors. Such evidence is scarcer for central pressure and local arterial stiffness. If we add this evidence to the easiness of performing such measure, carotid to femoral pulse wave velocity is the reference technique for assessing arterial stiffness. Its place in the investigation of patients remains to be precised.

Inheritance of arterial lesions in renal fibromuscular dysplasia.

We have previously shown that patients with renal fibromuscular dysplasia (FMD) have asymptomatic carotid lesions and that familial forms may occur. The objective of this study was to test whether carotid lesions could be detected in relatives of familial cases. High-resolution echotracking of the carotid artery was performed in 47 relatives of 13 cases from six families. This non-invasive investigation led to a semiquantitative arterial score that was compared with that obtained for 47 controls matched for age and sex and that for 125 sporadic cases. Familial resemblance was tested by using a generalized estimating equation approach taking into account the clustering of scores in families. As expected, FMD cases had a significantly higher score than controls (4.02 vs 2.52, P<10(-5)). Familial cases were not significantly different from sporadic cases. Of interest, the 47 apparently healthy relatives of familial cases had also a high carotid score (4.17), very significantly higher than that of controls (2.52, P<10(-5)) even though lower than the corresponding index FMD cases (4.81, P=0.01). Segregation analysis showed that 52% of the descendants of subjects with a score >4 had a score >4, a proportion consistent with autosomal-dominant transmission of the trait. Altogether these results strengthen the hypothesis of renal FMD being a systemic arterial disease and argue for a familial resemblance that may be due to a major genetic effect. The carotid score obtained by high-resolution echotracking may provide a non-invasive surrogate marker for renal FMD of potential value for use in linkage strategies on large pedigrees.

[Silhouettes at different age of life: Retrospective appreciation of corpulence and his impact on prevalence of hypertension at 60years]. / Silhouettes aux différents âges de la vie : méthode d'appréciation rétrospective de la corpulence et de son impact sur la prévalence de l'hypertension à 60 ans.

PURPOSE OF THE STUDY: In epidemiological studies, recall of weight and height are not readily available at different ages of life. In order to improve the knowledge of the weight history, Sörensen et al. in 1983, developed a tool from silhouettes allowing an individual to evaluate his corpulence at different ages of life. Validity studies showed that measured weight and size were correlated to 80% in the reported silhouette. Studies have also shown that silhouettes are a good way to trace the weight history in an individual's life. Very few epidemiological studies have used this tool. A French study revealed a decrease of the risk of breast cancer in obese girls between the age of 8 and adolescence. Another study showed that a low birth weight or a thin silhouette before adulthood was associated with an increased risk of diabetes. On the basis of these findings, it was interesting to evaluate the relationship between the silhouette at 20years and the risk of hypertension at the age of 60years. RESULTS: It was shown that the prevalence of hypertension at age 60 was higher among obese subjects at 20years than among thin subjects (45.3% vs 36.7% (P<0.05). CONCLUSION: The classification between slimness and obesity is relevant using this tool. The history of corpulence is an important element to consider in the determinants of pathology, especially in hypertension.

[Arterial ageing and coronary artery disease: physiopathological and epidemiological data]. / Vieillissement artériel et maladie coronaire: données physiopathologiques et épidémiologiques.

Vascular remodelling describes any change in arterial structure or function during physiological (ageing) and pathological processes such as atherosclerosis and hypertension. Adaptive changes in the short-term may carry pathological consequences in the long-term. The effects of ageing are additive with those of hypertension. The consequences are different according to whether the small resistance arteries or the large arteries of conduction are taken into consideration. The resistance arteries undergo three types of changes: (1) concentric or entrophic remodelling; this is a reorganisation of the same amount of tissue around a smaller diameter; (2) a rarefaction of the arteriolar bed; this is a smaller density of arterioles per unit weight of tissue perfused; (3) early disease of endothelial function with a reduced bio-availability of NO. The global result is an increase in peripheral resistance, a reduced capacity for vasodilatation and tissue ischaemia under critical conditions of perfusion. The methods of investigation of these different factors are not sufficiently well developed for use in routine clinical practice. Disease of the large arteries is principally an excentric hypertrophy, an increase in rigidity and loss of compliance. The increase in rigidity depends on the arterial territory: it is important in the aorta, moderate for elastic arteries but paradoxically decreased for muscular arteries, reflecting the combined effect of vascular smooth muscle hypertrophy ( mainly in the periphery) and changes in the extracellular matrix (mainly in the elastic arteries). The increased arterial rigidity is accompanied by an increase in cardiac work, hypertrophy, decreased coronary perfusion, favourising myocardial ischaemia. Peripheral artery remodelling also occurs in the coronary network. Therefore, the predictive positive value of hypertrophy and, above all, of aortic rigidity for coronary artery disease has now been well established in many populations. This predictive value is a complement to risk algorithms (SCORE, Framingham) and further predicts the coronary risk. Remodelling and arterial rigidity constitute disease of the artery as a target organ. Arch Mal Coeur Vaiss

High level of depressive symptoms as a barrier to reach an ideal cardiovascular health. The Paris Prospective Study III.

We hypothesized that depression might represent a barrier to reach an ideal cardiovascular health (CVH) as estimated by the 7-item tool proposed by the American Heart Association. Between 2008 and 2012, 9,417 subjects 50-75 years of age were examined in a large health center and enrolled in the Paris Prospective Study III (PPS3). Participants with 0-2, 3-4 and 5-7 health metrics at the ideal level were categorized as having poor, intermediate and ideal CVH, respectively. Participants with a score ≥ 7 on the 13-item Questionnaire of Depression 2nd version, Abridged or who were on antidepressants were referred as having high level of depressive symptoms (HLDS). The mean age of the 9417 study participants was 59.57 (SD 6.28) years and 61.16% were males. A total of 9.55% had HLDS. Poor, intermediate and ideal CVH was present in 40.38%, 49.52% and 10.10% of the participants. In multivariate polytomous logistic regression analysis, HLDS was inversely associated with ideal CVH (odds ratio = 0.70; 95% CI: 0.55;0.90). This was driven by an association with the behavioural component of the CVH. Participants with HLDS had a substantial reduced chance of reaching an ideal CVH.

Cross-sectional analysis of deprivation and ideal cardiovascular health in the Paris Prospective Study 3.

AIMS: We hypothesised that deprivation might represent a barrier to attain an ideal cardiovascular health (CVH) as defined by the American Heart Association (AHA). METHODS AND RESULTS: The baseline data of 8916 participants of the Paris Prospective Study 3, an observational cohort on novel markers for future cardiovascular disease, were used. The AHA 7-item tool includes four health behaviours (smoking, body weight, physical activity and optimal diet) and three biological measures (blood cholesterol, blood glucose and blood pressure). A validated 11-item score of individual material and psychosocial deprivation, the Evaluation de la Précarité et des Inégalités dans les Centres d'Examens de Santé-Evaluation of Deprivation and Inequalities in Health Examination centres (EPICES) score was used. The mean age was 59.5 years (standard deviation 6.2), 61.2% were men and 9.98% had an ideal CVH. In sex-specific multivariable polytomous logistic regression, the odds ratio (OR) for ideal behavioural CVH progressively decreased with quartile of increasing deprivation, from 0.54 (95% CI 0.41 to 0.72) to 0.49 (0.37 to 0.65) in women and from 0.61 (0.50 to 0.76) to 0.57 (0.46 to 0.71) in men. Associations with ideal biological CVH were confined to the most deprived women (OR=0.60; 95% CI 0.37 to 0.99), whereas in men, greater deprivation was related to higher OR of intermediate biological CVH (OR=1.28; 95% CI 1.05 to 1.57 for the third quartile vs the first quartile). CONCLUSIONS: Higher material and psychosocial deprivation may represent a barrier to reach an ideal CVH. TRIAL REGISTRATION NUMBER: NCT00741728.

Association between local pulse pressure, mean blood pressure, and large-artery remodeling.

BACKGROUND: The aim of the present study was to determine the respective influences of local pulse pressure and mean blood pressure on arterial remodeling in humans at 2 arterial sites: a central, predominantly elastic artery (the common carotid artery) and a peripheral muscular artery (the radial artery). METHODS AND RESULTS: Forty-three healthy subjects and 124 never-treated hypertensive patients were included in the study. Intima-media thickness and internal diameter of the carotid and radial arteries were noninvasively determined with high-definition echo-tracking devices. Pulse pressure was measured locally with applanation tonometry. Multivariate regression models including mean blood pressure and local pulse pressure were established in the whole population. Carotid internal diameter and intima-media thickness were strongly influenced (P<0.0001) by carotid pulse pressure but not by mean blood pressure or brachial pulse pressure, independently of age and sex. Radial artery internal diameter was correlated with age but not with mean blood pressure or radial pulse pressure. Radial artery intima-media thickness was correlated with mean blood pressure (P<0.001) but not with radial pulse pressure. CONCLUSIONS: Carotid pulse pressure was a strong independent determinant of carotid artery enlargement and wall thickening, whereas mean blood pressure and brachial pulse pressure were not, indicating the prominent influence of local pulsatile mechanical load on arterial remodeling. These relationships were observed at the site of an elastic artery but not at the site of a muscular artery, suggesting the contribution of cyclic stretching to the pulse pressure-induced arterial remodeling.

Local pulse pressure and regression of arterial wall hypertrophy during long-term antihypertensive treatment.

BACKGROUND: Local pulse pressure (PP) is an independent determinant of carotid artery wall thickness, stronger than mean blood pressure (BP). The present study was designed to assess whether a beta-adrenoceptor antagonist-based or an ACE inhibitor-based treatment was able to reduce carotid artery wall hypertrophy through a reduction in carotid PP rather than by lowering mean BP and whether the influence of local PP reduction could also be detected at the site of a muscular artery, the radial artery. METHODS AND RESULTS: Ninety-eight essential hypertensive patients were randomized to 9 months of double-blind treatment with either celiprolol or enalapril. Arterial parameters were determined with high-resolution echo-tracking systems. PP was measured locally with applanation tonometry and independently of mean BP. After 9 months of treatment, mean BP, carotid PP, and intimal-medial thickness (IMT) decreased significantly, with no difference between the 2 groups. The reduction in carotid PP but not in mean BP was a major independent determinant of the reduction in carotid IMT. Radial artery IMT and PP decreased significantly with both treatments. However, the reduction in radial artery IMT was not related to the changes in radial artery PP. CONCLUSIONS: The regression of carotid artery wall hypertrophy during long-term antihypertensive treatment was dependent on the reduction in local PP rather than on the lowering of mean BP. The effect of PP lowering on IMT reduction was observed at the site of an elastic artery but not at the site of a muscular artery.

Central pulse pressure is a major determinant of ascending aorta dilation in Marfan syndrome.

BACKGROUND: In patients with Marfan syndrome (MFS), brachial pulse pressure (PP) has been recognized as a risk factor for aortic dilatation, leading to aortic dissection, the main cause of premature death. However, the relationships between aortic PP, aortic stiffness, and aortic root dilation have not been investigated. Our main objective was to determine whether central PP, which takes into account wave reflections and aortic stiffness, is a better determinant of ascending aorta diameter than brachial PP in MFS patients. METHODS AND RESULTS: Twenty patients with confirmed MFS and 20 age- and sex-matched control subjects were included in this cross-sectional, noninvasive study. Elastic properties of the abdominal aorta and common carotid, common femoral, and radial arteries were calculated from the pulsatile changes in arterial diameter and pressure. The ascending aorta diameter, measured with conventional echocardiography, was 37% larger in MFS than in control subjects (P<0.001). Arterial distensibility was 38% lower in MFS than in control subjects at the site of the abdominal aorta (P<0.01) but not at other sites (common carotid, common femoral, and radial arteries). Independently of age and body surface area, ascending aorta diameter was positively correlated with carotid PP in MFS (P<0. 01) and negatively in control subjects (P<0.01) but was not correlated with brachial PP and mean blood pressure. CONCLUSIONS: In patients with MFS, local PP, estimated from carotid PP, was a major determinant of ascending aorta diameter, whereas brachial PP was not. Increased arterial stiffness was confined to the aorta.

Influence of tamoxifen on carotid intima-media thickness in postmenopausal women.

BACKGROUND: Intima-media thickness of the common carotid artery (IMT-CCA) is an early marker of atherosclerosis. Tamoxifen is a selective estrogen-receptor modulator with estrogen-like effects on cardiovascular risk factors but as-yet unexplored effects on carotid artery structure. The goal of this study was to determine the influence of tamoxifen on IMT-CCA in menopausal women. METHODS AND RESULTS: With a predefined calculation of the sample size, 67 menopausal women with cancer who were treated with tamoxifen for > or =1 year and 37 menopausal women with cancer who were never treated with tamoxifen were enrolled. IMT-CCA, internal diameter, and pulse pressure were determined with a high-definition echotracking device and applanation tonometry in a central core laboratory that was blinded to treatment. Both groups were similar for clinical characteristics, including cardiovascular risk factors. IMT and internal diameter were significantly lower in the tamoxifen group (mean duration of treatment, 2.4+/-0.9 years) than in the control group (609+/-117 microm versus 662+/-147 microm, P=0.04, and 4.89+/-0.60 mm versus 5.12+/-0.58 mm, P=0.03, respectively). Pulse pressure was not influenced by the use of tamoxifen. After adjustment for age, cardiovascular risk factors, carotid pulse pressure, duration of menopause, and previous use of hormone replacement therapy, IMT remained significantly lower among tamoxifen users (P<0.00001), with an impact on IMT (-70 microm) equivalent to spontaneous evolution with 12 years of aging (5 microm/y). CONCLUSION: The use of tamoxifen was associated with a significantly lower carotid IMT in menopausal women with cancer. Randomized trials are needed to confirm the cardioprotective effect of selective estrogen-receptor modulators in terms of prevention of atherosclerosis.

Mechanical properties and structure of carotid arteries in mice lacking desmin.

OBJECTIVE: Our aim was to determine in desmin homozygous mutant mice the viscoelastic properties, the mechanical strength and the structure of the carotid artery. METHODS: To assess the viscoelastic properties of large arteries, we have performed an in vivo analysis of the diameter-, and distensibility-pressure curves of the common carotid artery (CCA) in homozygous (Des -/-), heterozygous (Des +/-) and wild-type (Des +/+) mice. To evaluate the mechanical strength, we have measured the in vitro intraluminal pressure producing the rupture of the carotid artery wall. The structure analysis of the arterial wall was based on histology and electronic microscopy. RESULTS: A lower distensibility and an increase of arterial wall viscosity were observed in Des -/- compared with Des +/+. Arterial thickness of Des -/- was similar to those of Des +/+, without changes in elastin and collagen contents. Electron microscopy revealed that the perimeter of cellular fingerlike-projections was smaller in Des -/-, indicating that the cells have lost part of their connections to the extracellular matrix. The rupture pressure was significantly lower in Des -/- (1500+/-200 mmHg) compared with Des +/+ (2100+/-80 mmHg) indicating a lower mechanical strength of the vascular wall. No significant difference was found between Des +/- and Des +/+. CONCLUSION: The desmin is essential to maintain proper viscoelastic properties, structure and mechanical strength of the vascular wall.

Opposite effects of remodeling and hypertrophy on arterial compliance in hypertension.

Sustained hypertension is associated with a reduction in large artery compliance. However, we previously showed that, at the site of the radial artery, a distal muscular artery, the compliance of hypertensive patients was not significantly different from those of normotensive controls when the two groups were studied at their respective mean arterial pressures, despite increased wall thickness in hypertensives. To determine whether this paradoxical finding could be related to a specific pattern of geometrical changes, we studied arterial compliance in never-treated hypertensive patients characterized either by radial artery hypertrophy or remodeling, and compared them to normotensive controls. By analogy with Devereux's classification for left ventricular hypertrophy, we defined remodeling as an increased thickness to radius ratio (h/r) and a normal vascular mass (VM), and arterial hypertrophy as an increased VM irrespective of the values of h/r. Internal diameter and wall thickness were measured at the site of the radial artery using a high resolution echo-tracking system. The lumen cross-section-pressure curve was determined from the two simultaneous and continuous recordings of arterial diameter and blood pressure. Then, the cross-sectional compliance (CC)-pressure curve was calculated. Isobaric compliance was calculated at 100 mm Hg. Thresholds for h/r and VM were determined according to gender as the 95th percentile of a group of 100 normotensive subjects. The group of hypertensive patients included 58 patients with hypertrophy (h/r: 0.25+/-0.04; VM: 31+/-6 mg/cm; mean+/-SD) and 25 patients with remodeling (h/r: 0.29+/-0.06; VM: 20+/-4 mg/cm) and was compared to a group of 50 age- and gender-matched normotensives (h/r: 0.16+/-0.02; VM: 17+/-4 mg/cm). Compared to normotensives, isobaric compliance of the radial artery was increased in hypertensive patients with hypertrophy (HH) whereas it was not different in hypertensive patients with remodeling (RH). These results indicate that compliance is dependent on hypertrophy or remodeling pattern and suggest that in the face of hypertension, only arterial hypertrophy is an adaptive process leading to normal operating compliance through an increased isobaric compliance.

Smooth muscle tone and arterial wall viscosity: an in vivo/in vitro study.

The relationships between steady and pulsatile pressures, smooth muscle tone, and arterial viscoelastic behavior remain a matter of controversy. We previously showed that arterial wall viscosity (AWV) was 3-fold lower in vivo than in vitro and suggested that in vivo active mechanisms could minimize intrinsic AWV to improve the efficiency of heart-vessel coupling energy balance. The aim of the present study was to determine the role of smooth muscle tone on AWV, under various levels of steady and pulsatile pressures, both in vivo and in vitro. AWV of rat abdominal aorta was studied first in vivo after bolus injections of phenylephrine (PE) or sodium nitroprusside (SNP), then in vitro in response to PE or SNP. In vitro, arterial segments were submitted first to steady pressure (0 to 200 mm Hg) by increments of 20 mm Hg, then to increasing levels of pulse pressure (20 to 50 mm Hg) at various mean arterial pressures (75 to 150 mm Hg). AWV was quantified as the area of the pressure/diameter relationship hysteresis, issued from the simultaneous measurements of pressure (Millar micromanometer) and diameter (NIUS echotracking device). In vivo, AWV increased after PE and decreased after SNP, in parallel with pressure changes. In vitro, AWV was not significantly influenced by PE and SNP. After both PE and SNP, AWV increased with pulse pressure but was not influenced by mean arterial pressure. At any given pulse pressure, AWV was higher in vitro than in vivo. The relation between AWV and pulse pressure was significantly steeper in vitro than in vivo. These results show that AWV is strongly influenced by steady and pulsatile mechanical load but not by smooth muscle tone, both in vivo and in vitro. Factors other than sustained smooth muscle activation should be explored to explain the minimization of AWV in vivo compared with intrinsic in vitro values.

Common carotid artery stiffness and patterns of left ventricular hypertrophy in hypertensive patients.

The aim of this study was to determine the relationship between the lumen diameter and function of the common carotid artery, a vessel representative of the capacitance portion of the circulation, and the different patterns of left ventricular hypertrophy in uncomplicated essential hypertensive patients. Carotid luminal diastolic cross-sectional area, distensibility, and compliance were derived from measurements by a high-definition echotracking system. Left ventricular dimensions were from echocardiography. The 86 hypertensive patients included 31 who had never been treated (group 1), 31 in whom treatment had been stopped for at least 2 weeks (group 2), and 24 treated patients (group 3). In multivariate analysis of the population as a whole, the following relations were statistically independent of age, blood pressure, gender, and group: Left ventricular end-diastolic volume index was positively correlated to carotid luminal cross-sectional area (r = .46, P < .0001) and compliance (r = .47, P < .0001); left ventricular mean wall thickness and mass-volume ratio were negatively correlated to distensibility (r = -.68, P < .0001; r = -.46, P < .0001, respectively) and compliance (r = -.40, P < .0001; r = -.37; P < .001, respectively); and left ventricular mass index was positively correlated to luminal cross-sectional area (r = .23, P < .02) and negatively to distensibility (r = -.26, P < .01). These results indicate that geometric and functional changes in the common carotid artery accompany geometric changes in the left ventricle. More specifically, they suggest that a reduction in distensibility paralleled cardiac concentric hypertrophy and remodeling, whereas an increase in arterial volume paralleled increased left ventricular cavity size.

Carotid artery distensibility and distending pressure in hypertensive humans.

Whether the decrease in large-artery distensibility observed in hypertensive patients is due primarily to an increase in distending pressure or to hypertension-induced changes in structural properties has been much debated. We determined noninvasively the diameter-pressure curve of the common carotid artery over the systolic-diastolic range by continuously recording both the pulsatile changes in internal diameter (high-resolution echo-tracking system) and, simultaneously on the contralateral artery, the pressure waveform (high-fidelity applanation tonometry). We then derived the distensibility/pressure curve and compared arterial distensibility in 14 normotensive subjects and 15 age- and sex-matched hypertensive subjects at their respective mean arterial pressures (MAP) and at a common distending pressure: 100 mm Hg. Distensibility decreased as blood pressure increased, and distensibility at MAP was significantly lower in hypertensive than in normotensive subjects (7.8 +/- 0.7 versus 11.7 +/- 1.7 kPa-1.10(-3), mean +/- SEM; P < .05). In hypertensive subjects, the distensibility-pressure curve was shifted toward higher levels of blood pressure, and a large part of the curve overlapped that of normotensive subjects. No significant downward shift of the distensibility-pressure curve was observed in hypertensive subjects, and distensibility at 100 mm Hg was not significantly different from that of normotensive subjects (10.0 +/- 1.0 versus 9.0 +/- 1.1 kPa-1.10(-3)). Distensibility at 100 mm Hg decreased with aging (P < .05) and was not reduced in hypertensive subjects compared with normotensive subjects after adjustment for age.(ABSTRACT TRUNCATED AT 250 WORDS)

Remodeling of the radial artery in response to a chronic increase in shear stress.

Chronic changes in large artery blood flow rates induce corresponding adjustments in arterial diameter, but little is known about structural adaptations of the vessel wall in humans. We used a high-resolution echo-tracking system to measure radial artery internal diameter, wall thickness, and mean blood flow on both arms of 11 patients with end-stage renal disease. Measurements were performed on the wrist side of the arteriovenous fistula. The contralateral radial artery was investigated as control. Wall cross-sectional area, circumferential wall stress, and mean wall shear stress were calculated. Results indicate a sixfold increase in blood flow on the side of the arteriovenous fistula compared with the control side, with a 1.4-fold increase in internal diameter. The diameter enlargement was sufficient to normalize wall shear stress. Changes in diameter were not associated with arterial wall hypertrophy because wall cross-sectional area was not increased and rather suggest a "remodeling" of the arterial wall. For the same level of blood pressure, circumferential wall stress was increased on the side of the arteriovenous fistula. These results suggest that the structural adaptations of the arterial wall to a chronic increase in blood flow normalize wall shear stress and overcome stretch-induced changes in the particular circumstance of arteriovenous fistula.