@article {1466, title = {Compensatory increase in common carotid artery diameter. Relation to blood pressure and artery intima-media thickness in older adults. Cardiovascular Health Study.}, journal = {Stroke}, volume = {27}, year = {1996}, month = {1996 Nov}, pages = {2012-5}, abstract = {

BACKGROUND AND PURPOSE: Common carotid artery (CCA) diameter is thought to increase as a consequence of hypertension and may increase as the thickness of the arterial wall increases. The purpose of this study was to determine CCA dimensions and correlate them with clinical features.

METHODS: We performed a cross-sectional, community-based study of adults 65 years of age and older, measuring inner and outer diameter of the CCA in vivo with carotid sonography. Findings were correlated against risk factors for atherosclerosis, CCA intima-media thickness (IMT), and echocardiographically determined left ventricular (LV) mass.

RESULTS: Independent variables showing strong positive associations with outer and inner CCA diameter included age, male sex, height, weight, and systolic blood pressure. As an independent variable, LV mass (r = .40 and r = .37, respectively; P < .00001) had a strong positive relation to inner and outer CCA diameters. The relationship between diameter and IMT was different. In a model that controlled for age, sex, and estimated LV mass, an increase of 1 mm in CCA IMT corresponded to a 1.9 mm increase in the outer diameter of the artery (P < .00001) but was not significantly related to the inner diameter (slope = +0.07 mm; P = .26).

CONCLUSIONS: Increase in the outer diameter of the CCA is associated with subject size, sex, age, echocardiographically estimated LV mass, and CCA IMT. Increases in internal diameter of the CCA have similar relationships but are not related to IMT. This supports the hypothesis that the human CCA dilates as the thickness of the artery wall increases.

}, keywords = {Aged, Blood Pressure, Carotid Artery, Common, Cross-Sectional Studies, Echocardiography, Female, Heart Ventricles, Humans, Hypertension, Male, Tunica Intima, Tunica Media}, issn = {0039-2499}, author = {Polak, J F and Kronmal, R A and Tell, G S and O{\textquoteright}Leary, D H and Savage, P J and Gardin, J M and Rutan, G H and Borhani, N O} } @article {1453, title = {Thickening of the carotid wall. A marker for atherosclerosis in the elderly? Cardiovascular Health Study Collaborative Research Group.}, journal = {Stroke}, volume = {27}, year = {1996}, month = {1996 Feb}, pages = {224-31}, abstract = {

BACKGROUND AND PURPOSE: We investigated the relationships between prevalent coronary heart disease (CHD), clinically manifest atherosclerotic disease (ASD), and major established risk factors for atherosclerosis and intima-media thickness (IMT) in the common carotid arteries (CCA) and internal carotid arteries (ICA) separately and in combination in older adults. We wished to determine whether a noninvasive measurement can serve as an indicator of clinically manifest atherosclerotic disease and to determine which of the two variables, CCA IMT or ICA IMT, is a better correlate.

METHODS: IMT of the CCA and ICA was measured with duplex ultrasound in 5117 of 5201 individuals enrolled in the Cardiovascular Health Study, a study of the risk factors and the natural history of cardiovascular disease in adults aged 65 years or more. Histories of CHD, peripheral arterial disease, and cerebrovascular disease were obtained during baseline examination. Risk factors included cholesterol levels, cigarette smoking, elevated blood pressure, diabetes, age, and sex. Relationships between risk factors and IMT were studied by multiple regression analysis and canonical variate analysis. Prediction of prevalent CHD and ASD by IMT measurements in CCAs and ICAs were made by logistic regression, adjusting for age and sex.

RESULTS: IMT measurements of the CCAs and ICAs were greater in persons with CHD and ASD than those without, even after controlling for sex (P < .001). IMT measurements in the ICA were greater than those in the CCA. Risk factors for ASD accounted for 17\% and 18\% of the variability in IMT in the CCA and ICA, respectively. These same risk factors accounted for 25\% of the variability of a composite measurement consisting of the sum of the ICA IMT and CCA IMT. The ability to predict CHD and ASD was greater for ICA IMT (odds ratio [confidence interval]: 1.36 [1.31 to 1.41] and 1.35 [1.25 to 1.44], respectively) than for CCA IMT (1.09 [1.05 to 1.13] and 1.17 [1.09 to 1.25]).

CONCLUSIONS: Whereas CCA IMT is associated with major risk factors for atherosclerosis and existing CHD and ASD in older adults, this association is not as strong as that for ICA IMT. The combination of these measures relates more strongly to existing CHD and ASD and cerebrovascular disease risk factors than either taken alone.

}, keywords = {Adult, Aged, Arteriosclerosis, Blood Pressure, Carotid Artery, Common, Carotid Artery, Internal, Cholesterol, HDL, Cholesterol, LDL, Cohort Studies, Coronary Disease, Diabetes Mellitus, Diabetic Angiopathies, Electrocardiography, Female, Humans, Male, Medical History Taking, Physical Examination, Prospective Studies, Regression Analysis, Risk Factors, Sex Characteristics, Smoking, Tunica Intima, Tunica Media, Ultrasonography}, issn = {0039-2499}, author = {O{\textquoteright}Leary, D H and Polak, J F and Kronmal, R A and Savage, P J and Borhani, N O and Kittner, S J and Tracy, R and Gardin, J M and Price, T R and Furberg, C D} } @article {1486, title = {Does the association of risk factors and atherosclerosis change with age? An analysis of the combined ARIC and CHS cohorts. The Atherosclerosis Risk in Communities (ARIC) and Cardiovascular Health Study (CHS) investigators.}, journal = {Stroke}, volume = {28}, year = {1997}, month = {1997 Sep}, pages = {1693-701}, abstract = {

INTRODUCTION: A decrease in the estimated relative risk of cerebrovascular and cardiovascular diseases associated with known disease risk factors has been observed among elderly cohorts, perhaps suggesting that continued risk factor management in the elderly may not be as efficacious as with younger age groups. In this paper, the differential magnitude of the association of risk factors with atherosclerosis across the age spectrum from 45 years to older than 75 years is presented.

METHODS: Subclinical atherosclerosis as measured by carotid ultrasonography and risk factor prevalence were assessed using similar methods among participants aged 45 to 64 years in the Atherosclerosis Risk in Communities (ARIC) study and among participants 65 years and older in the Cardiovascular Health Study (CHS). Pooling these two cohorts provided data on the relationship of risk factors and atherosclerosis on nearly 19,000 participants over a broad age range. Regression analyses were used to assess the consistency of the magnitude of the association of risk factors with atherosclerosis across the age spectrum separately for black and white participants in cross-sectional analyses.

RESULTS: As expected, each of the risk factors was globally (across all ages) associated with increased atherosclerosis. However, the magnitude of the association did not differ across the age spectrum for hypertension, low density lipoprotein cholesterol (LDL-c), fibrinogen, or body mass index (BMI). For whites, there was a significantly greater impact of smoking and HDL-C among older age strata but a smaller impact of diabetes. For black women, the impact of HDL-C decreased among the older age strata.

CONCLUSIONS: These data suggest that most risk factors continue to be associated with increased atherosclerosis at older ages, possibly suggesting a continued value in investigation of strategies to reduce atherosclerosis by controlling risk factors at older ages.

}, keywords = {African Americans, African Continental Ancestry Group, Aged, Aging, Arteriosclerosis, Body Mass Index, Cardiovascular Physiological Phenomena, Cardiovascular System, Carotid Arteries, Cholesterol, HDL, Cholesterol, LDL, Cohort Studies, European Continental Ancestry Group, Female, Fibrinogen, Health Status, Humans, Hypertension, Male, Middle Aged, Regression Analysis, Risk Factors, Sex Factors, Smoking, Tunica Intima, Tunica Media, Ultrasonography}, issn = {0039-2499}, author = {Howard, G and Manolio, T A and Burke, G L and Wolfson, S K and O{\textquoteright}Leary, D H} } @article {1520, title = {Carotid-artery intima and media thickness as a risk factor for myocardial infarction and stroke in older adults. Cardiovascular Health Study Collaborative Research Group.}, journal = {N Engl J Med}, volume = {340}, year = {1999}, month = {1999 Jan 07}, pages = {14-22}, abstract = {

BACKGROUND: The combined thickness of the intima and media of the carotid artery is associated with the prevalence of cardiovascular disease. We studied the associations between the thickness of the carotid-artery intima and media and the incidence of new myocardial infarction or stroke in persons without clinical cardiovascular disease.

METHODS: Noninvasive measurements of the intima and media of the common and internal carotid artery were made with high-resolution ultrasonography in 5858 subjects 65 years of age or older. Cardiovascular events (new myocardial infarction or stroke) served as outcome variables in subjects without clinical cardiovascular disease (4476 subjects) over a median follow-up period of 6.2 years.

RESULTS: The incidence of cardiovascular events correlated with measurements of carotid-artery intima-media thickness. The relative risk of myocardial infarction or stroke increased with intima-media thickness (P<0.001). The relative risk of myocardial infarction or stroke (adjusted for age and sex) for the quintile with the highest thickness as compared with the lowest quintile was 3.87 (95 percent confidence interval, 2.72 to 5.51). The association between cardiovascular events and intima-media thickness remained significant after adjustment for traditional risk factors, showing increasing risks for each quintile of combined intima-media thickness, from the second quintile (relative risk, 1.54; 95 percent confidence interval, 1.04 to 2.28), to the third (relative risk, 1.84; 95 percent confidence interval, 1.26 to 2.67), fourth (relative risk, 2.01; 95 percent confidence interval, 1.38 to 2.91), and fifth (relative risk, 3.15; 95 percent confidence interval, 2.19 to 4.52). The results of separate analyses of myocardial infarction and stroke paralleled those for the combined end point.

CONCLUSIONS: Increases in the thickness of the intima and media of the carotid artery, as measured noninvasively by ultrasonography, are directly associated with an increased risk of myocardial infarction and stroke in older adults without a history of cardiovascular disease.

}, keywords = {Aged, Carotid Arteries, Cerebrovascular Disorders, Disease-Free Survival, Female, Humans, Incidence, Male, Myocardial Infarction, Proportional Hazards Models, Prospective Studies, Risk Factors, Tunica Intima, Tunica Media, Ultrasonography}, issn = {0028-4793}, doi = {10.1056/NEJM199901073400103}, author = {O{\textquoteright}Leary, D H and Polak, J F and Kronmal, R A and Manolio, T A and Burke, G L and Wolfson, S K} }