Sex-specific association of age with carotid artery distensibility: multi-ethnic study of atherosclerosis

Methods of arterial stiffness calculation and cardiovascular disease events: the multiethnic study of atherosclerosis

BACKGROUND

A wide variety of different formulae have been used to calculate local arterial stiffness with little external validation in relationship to cardiovascular events. We compared the associations of several arterial stiffness calculations in a large, multiethnic cohort.

METHODS

The multi-ethnic study of atherosclerosis (MESA) is a longitudinal study of 6814 adults without clinical cardiovascular disease (CVD) at enrollment. MESA participants with CVD surveillance through year 2018 and carotid ultrasound ( n  = 5873) or aorta MRI ( n  = 3175) at the baseline exam (2000-2002) were included. We analyzed 21 different calculations of local arterial stiffness. Cross-sectional and longitudinal statistical analyses were performed in addition to Cox hazard modeling for associations with CVD events (myocardial infarction, resuscitated cardiac arrest, stroke, adjudicated angina, and cardiovascular death).

RESULTS

Carotid artery stiffness calculations had variable correlations with each other ( r  = 0.56-0.99); aortic stiffness measures were similar ( r  = 0.66-0.99). Nevertheless, for CVD events, the hazard ratio (HR) per standard deviation change were similar for all carotid stiffness calculations with HRs in the range of 1.00-1.10 (equivalence P  < 0.001). For the aorta, aortic distensibility coefficient had a stronger association with CVD events (HR 1.18 [1.02-1.37]) compared to aorta Peterson's elastic modulus (HR 0.98 [0.89-1.07]) and aorta pulse wave velocity (HR 1.00 [0.90-1.11]). HRs between all other aortic stiffness calculations were equivalent ( P  < 0.01).

CONCLUSION

Different methods of calculating local arterial stiffness largely gave equivalent results, indicating that the variety of different arterial stiffness calculations in use do not cause inconsistent findings.

Sex-specific prediction value of common carotid artery diameter for stroke risk in a hypertensive population: a cross-sectional study

BACKGROUND

The importance of sex as a risk factor for stroke has been established. This study aimed to assess sex-related disparities in carotid artery diameter and stroke in a hypertensive population.

METHODS

The cross-sectional survey was conducted in rural areas of northeast China. A multistage cluster sampling method was employed to select a representative population. The study comprised 3,245 individuals with hypertension. The common carotid artery (CCA) interadventitial diameter was measured by ultrasound. A linear model of restricted cubic spline function was used to characterize the concentration-response (C-R) relationship between CCA diameter and stroke.

RESULTS

The overall prevalence of stroke was 8.9% among hypertensive individuals, with a higher rate in men than in women (10.8% vs. 7.6%). When the women's CCA diameters were divided into quartiles, the top quartile (>8.10 mm) had a 2.49 (95% CI: 1.36-4.56) times greater risk of stroke compared to the bottom quartile (≤6.80 mm) after adjustment was made for other variables. The C-R relationship further confirmed a positive association between CCA diameter and stroke prevalence in women. Moreover, a category-free net reclassification index (0.325; 95% CI: 0.173-0.476; P<0.001) and an integrated discrimination index (0.008; 95% CI: 0.004-0.012, P<0.001) showed improvement in predicting the probability of stroke from CCA diameter. However, no significant relationship between CCA diameter and prevalence of stroke was found in men.

CONCLUSIONS

The risk of stroke increased proportionally with the enlargement of the CCA diameter in women, supporting the sex-specific value of CCA diameter in optimizing the risk stratification of stroke.

Sex difference in the correlation between carotid artery diameter and prevalence of stroke: General insights from a Chinese population

BACKGROUND

The atherosclerotic process can cause compensatory enlargement of artery diameter. However, the association between common carotid artery (CCA) diameter and stroke remains unclear.

METHODS

This cross-sectional study included 5668 participants ≥40 years of age residing in rural northeast China, in whom the inter-adventitial diameter of CCA was measured. The association between CCA diameter and stroke prevalence was explored using multivariate logistic regression and concentration-response relationship in females and males, respectively.

RESULTS

CCA diameter (mm) was greater in stroke than in non-stroke populations in both males (7.73 versus [vs.] 7.49; P < 0.05) and females (7.69 vs. 7.13; P < 0.001). Among males, when dividing CCA diameters into quartiles, the second quartile (6.86-7.5 mm) had a 1.64 times higher risk for stroke than the bottom quartile (≤6.85 mm) (P < 0.05) in the adjusted model. In females, the top quartile (>7.95 mm) had a 2.08 (1.07-4.04) times higher risk than the bottom quartile (≤6.50 mm) (P < 0.01) (overall trend 1.19 [1.00-1.43]). Moreover, dose-response relationship confirmed correlations between CCA diameter and stroke in females (P < 0.05). The net reclassification index (NRI) and integrated discrimination index (IDI) confirmed the incremental value of CCA diameter in predicting probability of stroke in females (NRI 0.353 [95% confidence interval (CI) 0.198-0.497], P < 0.001; IDI 0.004 [95% CI 0.001-0.006], P < 0.01) and males (NRI 0.201 [95% CI 0.158-0.241], P < 0.001; IDI 0.005 [95% CI 0.001-0.009], P < 0.01).

CONCLUSIONS

This study highlighted the incremental value of CCA diameter in optimizing risk classification and stroke prevention in a Chinese population.

Carotid Artery Stiffening With Aging: Structural Versus Load-Dependent Mechanisms in MESA (the Multi-Ethnic Study of Atherosclerosis)

Elastic arteries stiffen via 2 main mechanisms: (1) load-dependent stiffening from higher blood pressure and (2) structural stiffening due to changes in the vessel wall. Differentiating these closely coupled mechanisms is important to understanding vascular aging. MESA (Multi-Ethnic Study of Atherosclerosis) participants with B-mode carotid ultrasound and brachial blood pressure at exam 1 and exam 5 (year 10) were included in this study (n=2604). Peterson and Young elastic moduli were calculated to represent total stiffness. Structural stiffness was calculated by adjusting Peterson and Young elastic moduli to a standard blood pressure of 120/80 mm Hg with participant-specific models. Load-dependent stiffness was the difference between total and structural stiffness. Changes in carotid artery stiffness mechanisms over 10 years were compared by age groups with ANCOVA models adjusted for baseline cardiovascular disease risk factors. The 75- to 84-year age group had the greatest change in total, structural, and load-dependent stiffening compared with younger groups (P<0.05). Only age and cessation of antihypertensive medication were predictive of structural stiffening, whereas age, race/ethnicity, education, blood pressure, cholesterol, and antihypertensive medication were predictive of increased load-dependent stiffening. On average, structural stiffening accounted for the vast majority of total stiffening, but 37% of participants had more load-dependent than structural stiffening. Rates of structural and load-dependent carotid artery stiffening increased with age. Structural stiffening was consistently observed, and load-dependent stiffening was highly variable. Heterogeneity in arterial stiffening mechanisms with aging may influence cardiovascular disease development.

Race and sex-based disparities associated with carotid endarterectomy in the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

The indications for carotid endarterectomy (CEA) are well established. The aim of the current study was to investigate sex and race-based disparities in the incidence of CEA after adjusting for carotid artery stenosis risk factors.

METHODS

We conducted a prospective cohort analysis of 14,492 black and white participants in the Atherosclerosis Risk in Communities (ARIC) study without prevalent stroke at baseline (1987-1989). We used Kaplan-Meier curves and Cox proportional hazards models adjusting for sociodemographic, cardiovascular, and disease severity risk factors to quantify the associations of sex and race with incident CEA.

RESULTS

CEA was performed in 330 of 14,492 ARIC participants during a median of 27 years of follow-up [incidence rate 1.00 (95% CI 0.90-1.12) per 1000 persons-years]. The crude incidence of CEA varied significantly by sex [female vs. male: HR 0.60 (95% CI 0.48-0.74)] and race [black vs. white: HR 0.65 (95% CI 0.49-0.86)]. Adjustment for sociodemographic and cardiovascular risk factors, carotid intima-media thickness, and symptomatic status attenuated the association of sex with CEA [females vs. males HR 0.96 (0.76-1.22)], but black participants had a lower risk of incident CEA after adjustment [HR 0.68 (95% CI 0.49-0.95)].

CONCLUSIONS

We found significant variation in the incidence of CEA procedures based on race that was independent of traditional risk factors and carotid IMT. Whether this disparity is a reflection of differences in disease presentation or access to care deserves investigation.

Pregnancy complications and later vascular ultrasound measures: A cohort study

OBJECTIVES

Pregnancy complications predict or even predispose to later cardiovascular disease in the mother. We examined whether pregnancy complications are associated with post-pregnancy measures of endothelial dysfunction and arterial stiffness.

STUDY DESIGN

Prospective cohort; Data for 847 women female participants in the Cardiovascular Risk in Young Finns study were linked with the national birth registry. Preterm birth (<37weeks), low birthweight (<2500g), small-for-gestational-age (weight <10th percentile for gestational age), and hypertensive disorders of pregnancy were examined as predictors of later vascular measures.

MAIN OUTCOME MEASURES

Flow-mediated dilatation (FMD), carotid intima-media thickness (IMT), Young's elastic modulus (YEM), and carotid artery distensibility.

RESULTS

In some analyses, gestational hypertension and pre-eclampsia were associated with increased YEM. Low birthweight was also associated with an increase in IMT, and this increased risk was present prior to the pregnancy.

CONCLUSIONS

The increased cardiovascular risk in the mother observed after low birthweight and hypertensive disorders may be due to vascular changes, and some of this increased risk may be present before pregnancy.

Prognostic value of high-resolution magnetic resonance imaging in evaluating carotid atherosclerotic plaque in patients with ischemic stroke

BACKGROUND

Ischemic stroke (IS) is a devastating occurrence affecting millions worldwide. This study aimed to evaluate the prognostic value of high-resolution magnetic resonance imaging (HRMRI) in assessing carotid atherosclerotic plaque in IS patients.

METHODS

Between January 2013 and March 2015, 338 IS patients were recruited for the investigative purposes of the study. All participants of the study underwent an HRMRI inspection procedure after being admitted into the hospital. During this study, we systematically analyzed and measured various types of fibrous caps, lipid compositions, and plaque lipid ratios. Univariate and multivariate logistic regression analyses were performed for predicting prognosis of IS patients. A receiver-operating characteristic (ROC) curve was employed to determine the accuracy of the IS prognosis.

RESULTS

The percentage of type I fibrous caps exhibited significant decrease, while the percentage of type III fibrous caps, lipid compositions, and lipid ratios all displayed increase. The results of the univariate analysis indicated that age, hypertension, hyperlipidemia, treatment regimens, fibrous cap type, plaque type, lipid composition, and lipid ratio shared a correlation in regards to the poor prognosis of IS patients. Multivariate logistic regression analysis demonstrated that the prognosis of IS patients was not necessarily dependent on fibrous cap type, plaque type, or age. ROC curves revealed that the HRMRI possessed a strong predicative ability in relation to the identification of the prognosis of IS patients through factors such as type of plaque and fibrous caps determination.

CONCLUSION

Our study conclusively intimated the promise of HRMRI as an evaluative tool for the determination of carotid atherosclerotic plaques in patients with IS.

Association of sex hormones with carotid artery distensibility in men and postmenopausal women: multi-ethnic study of atherosclerosis

The decline in carotid distensibility with age is steeper in women than in men, however, the correlates of this sex difference are not known. We examined the association of bioavailable testosterone, estradiol, dehydroepiandrosterone, and sex hormone-binding globulin, in 2783 postmenopausal women and 2987 men aged 45 to 84 years at the Multi-Ethnic Study of Atherosclerosis baseline examination. Carotid artery lumen diameters by ultrasound and brachial artery blood pressures were measured at systole and diastole. Regression models to determine the association of carotid distensibility coefficient and lumen diameter with sex-specific quartiles of sex hormones were adjusted for age, race, height, weight, diabetes mellitus, current smoking, antihypertensive medication use, total and high-density lipoprotein cholesterol levels, and hormone replacement therapy in women. A higher DC indicates a more distensible vessel. In women, higher dehydroepiandrosterone (P=0.008) and lower sex hormone-binding globulin (P=0.039) were associated with lower distensibility; higher dehydroepiandrosterone and lower estradiol were associated with smaller carotid diameters. In men, higher Bio-T (P=0.009) and lower estradiol (P=0.007) were associated with greater distensibility and also with smaller diameters (P=0.012 and 0.002, respectively). An androgenic internal milieu is associated with lesser carotid distensibility and diameter remodeling in women, but the opposite is true for men. Higher levels of estradiol are associated with smaller carotid diameters in both the sexes. Future longitudinal and experimental studies are needed to reveal the mechanism and clinical consequences of these associations.

Sex differences in predictors of longitudinal changes in carotid artery stiffness: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To identify sex differences in predictors of longitudinal changes in carotid arterial stiffness in a multiethnic cohort.

APPROACH AND RESULTS

Carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM) were measured in 2650 Multi-Ethnic Study of Atherosclerosis participants (45-84 years old and free of cardiovascular disease) at baseline and after a mean of 9.4 years. Predictors of changes in DC and YEM for each sex were evaluated using multivariable linear regression models. The 1236 men (46.6%) were 60.0 (SD, 9.3) years: 40% were white, 22% black, 16% Chinese, and 22% Hispanic. The 1414 (53.4%) women were 59.8 (9.4) years old with a similar race distribution. Despite similar rates of change in DC and YEM, predictors of changes in distensibility markers differed by sex. In men, Chinese (P=0.002) and black (P=0.003) race/ethnicity, systolic blood pressure (P=0.012), and diabetes mellitus (P=0.05) were associated with more rapidly decreasing DC (accelerated stiffening). Starting antihypertensive medication was associated with improved DC (P=0.03); stopping antihypertensives was associated with more rapid stiffening (increased YEM, P=0.05). In women, higher education was associated with slower stiffening (DC, P=0.041; YEM, P<0.001) as was use of lipid-lowering medication (P=0.03), whereas baseline use of antihypertensive medications (YEM, P=0.01) and systolic blood pressure (DC, P=0.02; P=0.04) predicted increasing stiffening in women.

CONCLUSIONS

Longitudinal changes in carotid artery stiffness are associated with systolic blood pressure and antihypertensive therapy in both sexes; however, race/ethnicity (in men) and level of education (in women) may have different contributions between the sexes.

Association of parity with carotid diameter and distensibility: multi-ethnic study of atherosclerosis

Pregnancy and childbirth are associated with hemodynamic changes and vascular remodeling. It is not known whether parity is associated with later adverse vascular properties such as larger arterial diameter, wall thickness, and lower distensibility. We used baseline data from 3283 women free of cardiovascular disease aged 45 to 84 years enrolled in the population-based Multi-Ethnic Study of Atherosclerosis. Participants self-reported parity status. Ultrasound-derived carotid artery lumen diameters and brachial artery blood pressures were measured at peak-systole and end-diastole. Common carotid intima-media thickness was also measured. Regression models to determine the association of carotid distensibility coefficient, lumen diameter, and carotid intima-media thickness with parity were adjusted for age, race, height, weight, diabetes mellitus, current smoking, blood pressure medication use, and total and high-density lipoprotein cholesterol levels. The prevalence of nulliparity was 18%. In adjusted models, carotid distensibility coefficient was 0.09×10−5 Pa−1 lower (P=0.009) in parous versus nulliparous women. Among parous women, there was a nonlinear association with the greatest carotid distensibility coefficient seen in women with 2 live births and significantly lower distensibility seen in primiparas (P=0.04) or with higher parity >2 (P=0.005). No such pattern of association with parity was found for lumen diameter or carotid intima-media thickness. Parity is associated with lower carotid artery distensibility, suggesting arterial remodeling that lasts beyond childbirth. These long-term effects on the vasculature may explain the association of parity with cardiovascular events later in life.

The association of brachial artery diameter with noncalcified coronary plaque burden in apparently healthy individuals

OBJECTIVE

Coronary atherosclerosis has been associated with systemic arterial remodeling even in nonatherosclerotic vessels. However, it is not known whether systemic remodeling is differentially associated with the cumulative atherosclerotic process, reflected by putatively quiescent calcified plaque (CP), or with active atherosclerosis, consisting of noncalcified plaque (NCP). We thus examined the association of brachial artery diameter (BAD), an artery that does not suffer clinical atherosclerosis, with the presence and the extent of coronary CP and NCP.

METHODS

We studied 688 apparently healthy, asymptomatic participants from 350 families with a history of early-onset coronary artery disease (<60 years of age) by measuring coronary artery disease risk factors and coronary plaque using dual-source computed tomographic angiography. Plaque volumes were quantified using a validated automated method. BAD was measured during diastole using B-mode ultrasound. The association of resting BAD with any detectable plaque, and log-transformed CP and NCP volumes if detectable, was tested using generalized estimating equations adjusted for age, sex, race, current smoking, diabetes, hypertension, BMI, and non-HDL and HDL cholesterol.

RESULTS

Higher quintiles of BAD were associated with greater age and male sex (both P<0.001). In the fully adjusted analysis, CP volume was not associated with BAD (P=0.65) but a 1 ml greater NCP volume was associated with a 0.65 mm larger BAD (P=0.027).

CONCLUSION

Our results suggest that systemic arterial remodeling of nonatherosclerotic arteries is a dynamic process that is correlated with the extent of putatively active atherosclerotic processes in distant beds but not with inactive accumulated plaque burden.

Sex-specific associations of cardiovascular risk factors with carotid stiffness--results from the SAPALDIA cohort study

OBJECTIVE

Manifestation of cardiovascular disease (CVD) occurs with clear sex differences. Carotid stiffness (CS) parameters are increasingly used for CVD risk assessment but the sex-specific association with CVD risk factors as well as association patterns between CS parameters are largely unknown, which we investigated in SAPALDIA population-based cohort participants.

METHODS

Risk factors of 2545 participants without clinically manifest disease were evaluated in 2001-2003 and different CS parameters were assessed in carotid ultrasound scans in 2010-2011. Stratified and non-stratified mixed linear models and multivariate regression analyses were used to examine sex-specific associations, differences and association patterns of single risk factors and CS parameters.

RESULTS

HDL cholesterol was the only significant protective determinant of reduced CS for both sexes (ranges of CS parameters: -3.7; -0.8% of changes in geometric mean per 1SD of the risk factor on an inverted scale) and significant adverse risk factors were BMI (-0.5; 4.7%), systolic (-1.23; 4.7%) and diastolic blood pressure (1.4; 4.4%), heart rate (2.7; 7.9%), C-reactive protein (0.6; 3.3%) and smoking (-2.82; 1%), all p-values of multivariate analyses were <0.01. Sex differences with stiffer CS parameters in men were observed for increased heart rate (p = 0.001) and LDL cholesterol (p < 0.001) and in women for triglyceride (p < 0.003). Similar association patterns were found for most CS parameters.

CONCLUSION

Sex-specific associations of cardiovascular risk factors may reflect a sex-specific burden of atherosclerotic risk factors and similar association patterns across different CS parameters within men and women may allow the use of CS parameters in an exchangeable manner.

Longitudinal effects of a decade of aging on carotid artery stiffness: the multiethnic study of atherosclerosis

BACKGROUND AND PURPOSE

Arterial stiffening is associated with hypertension, stroke, and cognitive decline; however, the effects of aging and cardiovascular disease risk factors on carotid artery stiffening have not been assessed prospectively in a large multiethnic longitudinal study.

METHODS

Distensibility coefficient and the Young's elastic modulus (YEM) of the right common carotid artery were calculated at baseline and after a mean of 9.4 (standard deviation [SD], 0.5) years in 2650 participants. Effects of age and cardiovascular disease risk factors were evaluated by multivariable mixed regression and ANCOVA models.

RESULTS

At baseline, participants were 59.9 (SD, 9.4) years old (53% women; 25% black, 22% Hispanic, 14% Chinese). YEM increased from 1581 (SD, 927) to 1749 (SD, 1306) mm Hg (P<0.0001), and distensibility coefficient decreased from 3.1 (SD, 1.3) to 2.7 (SD, 1.1)×10(-3) mm Hg(-1) (P<0.001), indicating progressive arterial stiffening. YEM increased more among participants who were aged>75 years old at baseline (P<0.0001). In multivariable analyses, older age and less education independently predicted worsening YEM and distensibility coefficient. Stopping antihypertensive medication during the study period predicted more severe worsening of YEM (β=360.2 mm Hg; P=0.008). Starting antihypertensive medication after examination 1 was predictive of improvements in distensibility coefficient (β=1.1×10(-4) mm Hg(-1); P=0.024).

CONCLUSIONS

Arterial stiffening accelerates with advanced age. Older individuals experience greater increases in YEM than do younger adults, even after considering the effects of traditional risk factors. Treating hypertension may slow the progressive decline in carotid artery distensibility observed with aging and improve cerebrovascular health.