Radical-Trapping Activity, Blood Pressure, and Carotid Enlargement in Women

Abstract

Abstract-The aim of this study was to evaluate the influence of traditional and nontraditional (oxidation markers) cardiovascular risk factors on the degree of adaptive response of the carotid wall to atherosclerotic disease, a process known as arterial enlargement. Five thousand sixty-two clinically healthy, middle-aged women living in the area of Naples participated in the "Progetto Atena" study; 310 of these women (potentially at higher atherosclerotic risk) underwent a high-resolution ultrasound scan of the carotid arteries. In addition to routine biochemical tests, these women had the determination of serum IgG antibody titer against oxidized LDL and measurement of thiobarbituric acid reactive substances and total radical-trapping activity potential of plasma. Age, systolic blood pressure, body mass index, and radical-trapping activity were all positively correlated with external and internal common carotid diameters, whereas triglycerides (positively) and HDL cholesterol (inversely) were related only to external diameter. After controlling for traditional cardiovascular risk factors, associations still persisted for age, systolic blood pressure, and plasma radical-trapping activity with external carotid diameters. However, in the quartile of women with highest total cholesterol (Ͼ7.38 mmol/L), the slope of the regression line between systolic blood pressure and external diameter was significantly flatter than in the three other quartiles (test for difference, Pϭ0.014). Outward carotid enlargement is related to traditional and nontraditional risk factors and comes even before plaque development. Women with poor resistance to oxidative stress potentially have a difficulty to remodel their arteries in response to atherosclerotic stimuli. Key Words: carotid arteries Ⅲ ultrasonography Ⅲ antioxidants Ⅲ blood pressure Ⅲ women Q uantitative determination of carotid intima-media thickness (IMT) by high-resolution B-mode ultrasound has been shown to be strongly correlated with traditional cardiovascular risk factors and is an independent predictor of clinical events, for example, myocardial infarction and stroke. 1-4 B-mode ultrasound has also been used to prospectively evaluate the natural history of carotid atherosclerosis by monitoring lesion growth over time and plaque stabilization resulting from medical interventions in clinical trials. [5][6][7] However, studies performed with carotid ultrasonography have preferentially involved men because of the lower prevalence of atherosclerotic lesions in premenopausal women.B-mode ultrasound imaging allows noninvasive study not only of carotid intima-media thickening and plaques but also the degree of adaptive response of the arterial wall to atherosclerotic disease, a process known as carotid enlargement. Although arterial enlargement has been demonstrated to have an important role in atherosclerosis, for example, preserving lumen diameter despite plaque growth, 8 -10 few studies focused on variation in carotid diameters in response to arterial wall thickening. [11][12...

Common carotid artery wall thickness and external diameter as predictors of prevalent and incident cardiac events in a large population study

“…Thus, conditions related to diameter such as the metabolic syndrome [20] or novel risk factors [48,49] may lead to diameter enlargement early in the atherosclerotic process. Later, outward vascular remodeling in response to atherosclerotic plaques may result in diameter enlargement.…”

Association between Risk Factors and Carotid Enlargement

“…In the Suita study, a positive association both in men and women was found between CCA diameters and age, BMI, SBP, smoking, alcohol consumption and IMT, whereas a negative association was observed between T-C and CCA diameters (11). In a community-based study of middle-aged women, CCA diameters were directly related to age, BMI, SBP, DBP and total radical antioxidant potential (22). Especially, increased SBP appeared to be one of the most important and strongest correlates of CCA diameter (10).…”

Sex Hormones as Potential Modulators of Vascular Function in Hypertension

“…42 The vascular effects of sex hormones could also vary with aging. 16,17,43 For example, ovariectomy augments hypertension in aging female Dahl salt-sensitive rats, 44 and age-related reduction in ER-mediated mechanisms of vascular relaxation has been observed in blood vessels of female SHR. 45 Because the vascular effects of estrogen and progesterone involve modulation of the Ca 2ϩ channels, HRT may represent a more natural approach for treatment of certain forms of hypertension that respond to Ca 2ϩ channel blockers.…”