Risk factors for the progression of early carotid atherosclerosis in a male working population.

Increased intima-media thickness (IMT) of the carotid artery may represent early atherosclerosis. Although several studies have evaluated risk factors for carotid IMT, only limited information is available concerning risk factors for the progression of carotid IMT. The present study was designed to determine risk factors for the progression of carotid IMT in a male working population. Male employees of a regional transport company (n = 220, 50.9 +/- 4.4 years) underwent baseline physical and laboratory examinations, and ultrasonographic assessment of the maximum common carotid IMT between 1992 and 1994, and they were reexamined 5 years later. In a multivariate analysis at baseline, carotid IMT was positively associated with age, diastolic blood pressure and total cholesterol, and negatively with high density lipoprotein (HDL) cholesterol. During the follow-up period, carotid IMT increased from 0.669 +/- 0.135 mm to 0.784 +/- 0.229 mm, or at a rate of 0.023 +/- 0.039 mm/year. In a multivariate regression analysis using baseline values of carotid IMT, age, body mass index, diastolic blood pressure, total cholesterol, HDL cholesterol and HbA1c as independent variables, the progression of carotid IMT was associated only with baseline total cholesterol. These findings suggest that in middle-aged men, although age, blood pressure, and total cholesterol were associated with baseline carotid IMT, total cholesterol level appeared to be the strongest determinant of the progression of carotid IMT, a result which underscores the importance of maintaining lower cholesterol levels to prevent early atherosclerosis.     

Intima-media thickness in cardiovascularly asymptomatic hypopituitary adults with growth hormone deficiency: relation to body mass index,gender, and other cardiovascular risk factors

OBJECTIVE: Increased cardiovascular mortality and carotid atherosclerosis have been observed in hypopituitary patients with untreated GH deficiency (GHD), but results are contradictory and relations to cardiovascular risk factors are not clear. The aim of this study was to investigate intima-media thickness (IMT) in relation to cardiovascular risk factors in adults with GHD. DESIGN: Cross-sectional observational study of 21 men and 13 women with GHD, but without cardiovascular disease, compared to two healthy control groups matched for age, sex and smoking habits. One control group was matched for body mass index (BMI) and the other group was nonobese. MEASUREMENTS: IMT of the carotid and femoral arteries, blood pressure, blood samples and anthropometric data. RESULTS: Patients had 12% thicker composite carotid IMT [(IMT of common carotid artery + IMT of bulb)/2] compared to nonobese controls (P = 0.022), but IMT was not different compared to BMI-matched controls. Femoral IMT did not differ between patients and controls. Patients had higher waist : hip ratio (WHR), heart rate, serum triglycerides and fasting insulin concentrations in combination with lower high-density lipoprotein (HDL) cholesterol and smaller low-density lipoprotein (LDL) peak particle size compared to both nonobese and to BMI-matched controls. This cardiovascular risk pattern was more pronounced in female patients than in male patients compared to their gender controls. Carotid IMT was related to age, serum cholesterol, LDL cholesterol and smoking in the patient group. Only age was independently related to carotid IMT in multivariate analysis. CONCLUSIONS: These results indicate that high BMI in GH-deficient patients contribute to their increased intima-media thickness. However, several cardiovascular risk factors are present in this patient group independent of their increased BMI, especially in women.     

Association of hyperandrogenemic and metabolic phenotype with carotid intima-media thickness in young women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a common endocrinopathy of women of reproductive age, is associated with the early appearance of multiple risk factors for cardiovascular disease, such as abdominal obesity, dyslipidemia, and diabetes mellitus. However, premature atherosclerosis of the carotid artery has not yet been demonstrated in young women with PCOS. Measurement of carotid intima-media thickness (IMT) is considered an easy and reliable index of subclinical atherosclerosis, which is predictive of subsequent myocardial infarction and stroke. To evaluate the cardiovascular risk of PCOS and the participation of the hyperandrogenemic and metabolic pattern, we measured carotid IMT by B-mode ultrasound as well as hormonal and several cardiovascular disease-associated parameters in 75 young women with PCOS and 55 healthy, age- and body mass index-matched women. The PCOS women had significantly increased carotid IMT (0.58 vs. 0.47 mm, P < 0.001) and abdominal adiposity; higher levels of androgens, insulin, homeostasis model assessment score of insulin sensitivity, and total and low-density lipoprotein-cholesterol; and significantly lower levels of SHBG and high-density lipoprotein-cholesterol. In the studied population (n = 130), PCOS status, age, body mass index, and parental history of coronary heart disease were strong positive predictors of carotid IMT, whereas dehydroepiandrosterone sulfate was a strong negative predictor. In PCOS patients lower delta4-androstenedione and high-density lipoprotein-cholesterol levels were additionally strong positive predictors of carotid IMT, whereas in control women only total cholesterol was the additional positive predictor of carotid IMT. In conclusion, young women with PCOS have an early increase of cardiovascular risk factors and greater carotid IMT, both of which may be responsible for subclinical atherosclerosis. The hyperandrogenemic phenotype of the syndrome may attenuate the consequences of the dysmetabolic phenotype on the vascular wall.     

Carotid intima-media thickness and coronary heart disease risk factors in a low-risk population.

OBJECTIVE: Coronary heart disease (CHD) risk factors have been consistently related to an increase in carotid intima-media thickness (IMT) in selected populations. However, few studies were population-based and furthermore little attention has been given to the influence of CHD risk factors on IMT in low-risk populations for CHD. DESIGN: We examined the association between carotid IMT and CHD risk factors in a large (n = 1013) and representative sample of middle-aged men and women in one of the European populations with the lowest CHD risk. METHODS: High-resolution B-mode ultrasonography of the common carotid arteries was performed. RESULTS: Age, smoking (not significant in women), body mass index, waist to hip ratio, systolic (SBP) and diastolic blood pressure, alcohol consumption, total and low-density lipoprotein cholesterol, triglycerides, glycaemia, fibrinogen (not significant in women), haematocrit (not significant in men) and insulin (not significant in women) were positively and significantly associated with mean IMT. High-density lipoprotein (HDL) cholesterol (not significant in women) was negatively and significantly associated with mean IMT. In a subsample of 355 men, IMT was not associated with angiotensin I-converting enzyme gene polymorphism. Multivariate analyses showed, in men, independent associations between mean IMT (0.61+/-0.11 mm) and age, pack-years, SBP, HDL cholesterol, alcohol and the interaction between age and alcohol. In women, only age and SBP were independently associated with mean IMT (0.58+/-0.09 mm). CONCLUSIONS: We found thinner IMT than those found in high-risk populations, suggesting that an increased IMT might reflect local atherosclerosis. Protective factors such as HDL cholesterol or regular and moderate alcohol consumption are probably important determinants of the early stages of atherosclerosis in these low-risk populations.     

Age and sex differences in the relationship between inherited and lifestyle risk factors and subclinical carotid atherosclerosis: the Tromsø study

BACKGROUND: Ultrasound measurement of carotid artery intima-media thickness (IMT) is regarded as a valid index of atherosclerosis. Age and sex differences in the distribution of, and risk factors for, IMT have not been investigated thoroughly. METHODS: In 1994-1995 a total of 6408 men and women aged 25-84 years living in the municipality of Troms?, Norway, underwent ultrasound examination of carotid artery IMT and measurements of cardiovascular risk factors. RESULTS: Age, systolic blood pressure, total cholesterol, HDL cholesterol, body mass index, and smoking were independent predictors of IMT in both sexes. Fibrinogen levels and physical activity were associated with IMT in men only, whereas triglyceride levels were associated with IMT independently of HDL cholesterol in women only. A family history of cardiovascular disease (CVD) was an independent predictor of IMT in both sexes, also when controlling for traditional CVD risk factors. The magnitude of the association between most risk factors and IMT did not differ depending on age, but the effects of physical activity and triglycerides were more pronounced at higher age. CONCLUSION: These data suggest that there are significant age and sex differences in the distribution and the determinants of subclinical atherosclerosis.     

Relationship between endothelial dysfunction, intima media thickness and cardiovascular risk factors in asymptomatic subjects.

AIM: The aim of the study was to evaluate endothelial function and intima media thickness (IMT) in relation to cardiovascular risk factors (RF). METHODS: We enrolled 113 patients, mean age 62 +/- 12 years; patients underwent: anamnesis, physical examination, measurement of body weight and height and blood pressure. Biochemistry variables were also measured: total cholesterol, high- and low-density lipoprotein cholesterol (HDL-C and LDL-C), triglycerides and glycemia. Vascular echography was performed to analyze flow mediated vasodilatation (FMD) at the brachial artery and IMT of the carotid and femoral arteries. RESULTS: Compared with patients without RF, patients with cardiovascular RF showed an impaired FMD (p < 0.05) and higher values of mean carotid IMT (p = 0.03). Age (p < 0.005) and diabetes (p < 0.05) were directly correlated with carotid IMT, while femoral IMT is correlated with age (p < 0.005) and male gender (p < 0.02). Regarding the relationship between endothelial function cardiovascular RF, we showed an inverse linear correlation between systolic blood pressure (p < 0.005), smoking (p < 0.05) and FMD, and concerning biochemical parameters, we founded that total cholesterol (p < 0.05) and LDL-C plasma levels (p < 0.005) were inversely correlated with FMD. Finally, we showed a lower FMD in patients with carotid and femoral IMT in comparison with patients without peripheral atherosclerosis (p = 0.01). CONCLUSIONS: The present data indicate that cardiovascular RF are associated with impaired endothelial function and increased IMT, and that the presence of carotid and femoral IMT is significantly correlated with endothelial dysfunction.     

High prevalence of subclinical atherosclerosis in psoriatic arthritis patients without clinically evident cardiovascular disease or classic atherosclerosis risk factors

OBJECTIVE: To assess the presence of subclinical atherosclerosis in patients with psoriatic arthritis (PsA) without clinically evident atherosclerosis or its complications, and to assess whether demographic or clinical factors affect the development of atherosclerotic disease in a series of patients with PsA attended to in a community hospital. METHODS: Fifty-nine patients with PsA who fulfilled the Moll and Wright criteria were recruited from Hospital Xeral-Calde (Lugo, Spain). Patients seen during the period of recruitment who had classic cardiovascular risk factors or had experienced cardiovascular or cerebrovascular events were excluded. Fifty-nine healthy matched controls were also studied. Carotid artery intima-media thickness (IMT) and carotid plaques were measured in the right common carotid artery. The study was performed using high-resolution B-mode ultrasound. RESULTS: Patients with PsA exhibited greater carotid artery IMT than did matched controls (mean +/- SD 0.699 +/- 0.165 mm versus 0.643 +/- 0.111 mm; P = 0.031; difference of means 0.056; 95% confidence interval 0.005-0.108). Adjusted for age, the carotid IMT was correlated with age at the time of PsA diagnosis (partial correlation coefficient [r] = -0.264, P = 0.04), disease duration (r = 0.264, P = 0.04), total cholesterol (r = 0.233, P = 0.01), and low-density lipoprotein cholesterol (r = 0.243, P = 0.01). CONCLUSION: The present study demonstrates that patients with PsA without cardiovascular risk factors or clinically evident cardiovascular disease have a high prevalence of macrovascular disease in the form of increased carotid artery IMT compared with ethnically matched controls.     

The determination of carotid intima medial thickness in adults--a population-based twin study

INTRODUCTION: Although cardiovascular events are known to cluster in families it is unclear the extent to which atherosclerosis per se is genetically determined. The aim of this study was to assess the heritability of carotid intima media thickness (IMT) measurements, a surrogate marker of early atherosclerosis, using a population-based twin study methodology. METHODS: B-mode carotid artery ultrasound images were acquired on 264 twin subjects (142 monozygotic (MZ); mean age 54.3 years and 122 dizygotic (DZ); mean age 51.7 years). An estimate of genetic determination, heritability, was calculated for the IMT parameters before and after correction for confounding variables. RESULTS: An increased carotid IMT was associated with known cardiovascular risk factors (total cholesterol r=0.24, P<0.001 and systolic blood pressure r=0.42, P<0.001) and with a history of coronary events (0.79+/-0.12 vs. 0.72+/-0.14, P=0.01). Carotid IMT measurements demonstrated a familial influence (intra-class correlation of 0.54 for MZ vs. 0.39 for DZ) but no specific genetic determination (heritability estimate 0.31, P=0.15). CONCLUSION: Within a normal population carotid IMT is under a familial, but not genetic influence. The mechanism of genetic control over cardiovascular events may not be mediated through atherosclerotic load as measured by IMT.     

Association of interleukin-6 and C-reactive protein with subclinical carotid atherosclerosis (the Rancho Bernardo Study)

Studies of interleukin-6 (IL-6) and C-reactive protein (CRP) as predictors of atherosclerosis have had mixed results. The purpose of this study was to assess the associations of IL-6 and CRP with the severity of subclinical carotid atherosclerosis measured 12 years later. Participants were 392 adults (56.9% women, mean age 63.2 years) from the Rancho Bernardo Study who had biomarkers measured from 1984 to 1987 and carotid intima-media thickness (IMT) measured from 1996 to 1998. Age-adjusted mean carotid IMT was significantly greater in men than women. After adjusting for traditional cardiovascular risk factors, carotid IMT increased significantly with increasing IL-6 quartiles (p <0.001). In similar analyses, the association between CRP quartiles and carotid IMT was weaker but remained statistically significant (p <0.05). In multiple regression analysis, IL-6 was significantly associated with carotid IMT regardless of CRP. Conversely, CRP was significantly associated with carotid IMT when IL-6 was not included in the model, but this association became nonsignificant when IL-6 was included. In conclusion, baseline IL-6 and CRP were significantly associated with carotid atherosclerosis independent of traditional cardiovascular disease risk factors. The association of IL-6 was independent of CRP, but not vice versa, suggesting an effect of IL-6 on an earlier state of atherosclerosis.     

Association of carotid intima-media thickness with mesenteric, preperitoneal and subcutaneous fat thickness

Carotid intima-media thickness (IMT) is an established surrogate marker for atherosclerosis. We have previously reported that abdominal fat, notably mesenteric fat, was a major explanatory variable for multiple cardiovascular risk factors. Given the intimate relationships between visceral fat, cardiovascular risk factors and atherosclerosis, we hypothesize that there are independent relationships between mesenteric fat and carotid IMT. Two hundred and eighty-two Chinese subjects (M: 129, F: 153; mean body mass index (BMI): 23.8 kg/m(2); age range: 20-68 years) were recruited. Maximum carotid IMT as well as maximum mesenteric, preperitoneal and subcutaneous fat thickness were measured by carotid and abdominal ultrasound examinations, respectively. Obesity index and conventional cardiovascular risk factors were assessed by physical examination and blood taking. On univariate analysis, mesenteric but not preperitoneal fat thickness was the major correlate with carotid IMT in both men and women. There was also a weak correlation between carotid IMT and subcutaneous fat thickness in women. On multivariate analysis, mesenteric fat thickness was an independent determinant of carotid IMT after adjustment for subcutaneous and preperitoneal fat thickness, age, gender, blood pressure, insulin resistance, lipid and glycaemic parameters. The association of mesenteric fat thickness with carotid IMT appeared stronger in women than in men, which however was not confirmed on multivariate analysis. In conclusion, mesenteric fat thickness measured on ultrasound showed significant association with carotid IMT, lending further support to the linking role of portal adipose tissue in obesity-related atherosclerosis. Effect of gender on the relationships of mesenteric fat with atherosclerosis risk require further elucidation. Measurement of mesenteric fat thickness may be a useful indicator of regional fat distribution in the assessment of cardiovascular risks.     

Risk factors for subclinical atherosclerosis in a prospective cohort of patients with systemic lupus erythematosus

OBJECTIVE: To evaluate traditional and non-traditional risk factors for subclinical atherosclerosis in systemic lupus erythematosus (SLE). METHODS: A prospective cohort of 78 patients with SLE without overt atherosclerotic disease was studied. SLE clinical and laboratory parameters, disease activity and damage, treatment and traditional risk factors for atherosclerosis were evaluated. At baseline (T1) and after five years' follow up (T2), the serum levels of anti-oxidised palmitoyl arachidonoyl phosphocholine (oxPAPC), anti-heat shock protein 65, and anti-beta(2)-glycoprotein I antibodies and C reactive protein were tested. At T2, intima-media thickness (IMT) was measured using duplex carotid sonography. Thickened intima, plaque, mean IMT (m-IMT), and maximum IMT (M-IMT) were assessed. RESULTS: A thickened intima was seen in 22/78 (28%) patients and plaque in 13/78 (17%). M-IMT and m-IMT were (mean (SD)) 0.77 (0.34) mm and 0.55 (0.15) mm, respectively. Patients with carotid abnormalities were significantly older, had higher blood pressure and total serum cholesterol levels, and had taken a higher prednisone cumulative dosage than those without any lesions. The carotid abnormalities were associated with renal disease and ECLAM >2 at T1, and with azathioprine treatment. In multivariate analysis, age and cumulative prednisone dose were associated with carotid abnormalities; age, hypertension, and anti-oxPAPC at T2 were correlated with higher M-IMT and m-IMT. CONCLUSIONS: In patients with SLE some non-traditional risk factors for atherosclerosis were identified, the most important of which was the cumulative prednisone dose. The role of some traditional risk factors, such as age and hypertension, was also confirmed. The predictive value of the new immunological and inflammatory markers of atherosclerosis seems to be masked by some disease related features.     

Determinants of carotid intima-medial thickness in an urban Australian Aboriginal population

INTRODUCTION: We studied the determinants of carotid atherosclerosis in urban-dwelling Australian Aboriginals at high risk of atherosclerotic mortality and morbidity. METHODS: Cross-sectional study of self-selected adult Australian Aboriginals. Participants (n=602) aged 18-74 years had risk factor assessment and carotid ultrasound to determine carotid intima-medial thickness (IMT) and the presence of plaque. The upper quartile (>0.71 mm in males and >0.62 mm in females) was used as a measure of increased carotid IMT. RESULTS: Over 80% of participants were overweight or obese; the prevalence of diabetes was 25%. Age was the major predictor of thick IMT, OR 3.0 (95% CI 2.0-4.5) per decade for males and OR 6.3 (3.3-12.0) for females. Waist circumference and blood glucose were independent predictors of IMT for men, with hypertension, pack-years of smoking, diabetes, and cholesterol ratio additional predictors for women. Plaque was highly prevalent (>40%) in this relatively young population and was predicted by increasing age, a history of smoking and total cholesterol/HDL ratio, but not sex. CONCLUSIONS: Urban-dwelling Aboriginal Australians are at increased risk for early atherosclerosis. In this study an excess of obesity-related cardiovascular risk factors were the important contributors to increased IMT carotid atherosclerosis, but not inflammatory markers or other novel risk factors.     

Vascular function and carotid intimal-medial thickness in children with insulin-dependent diabetes mellitus

OBJECTIVES: The objective of this study was to evaluate endothelium-dependent vasodilation and carotid intimal-medial thickness (IMT) in children with insulin-dependent diabetes mellitus. BACKGROUND: Diabetes mellitus is an established risk factor for atherosclerosis. Vascular complications of diabetes are not clinically evident in diabetic children. However, preclinical atherosclerosis is more common in young subjects exposed to cardiovascular risk factors. Endothelial function and carotid IMT, known to be abnormal in preclinical atherosclerosis, have not been studied concurrently in a pediatric population exposed to a risk factor for atherosclerosis. METHODS: We studied 31 diabetic teenagers (age 15.0 +/- 2.4 years; duration of diabetes 6.8 +/- 3.9 years) and 35 age-matched healthy children (age 15.7 +/- 2.7 years). Using high-resolution vascular ultrasound, we compared carotid IMT and brachial artery responses to reactive hyperemia (endothelium-dependent vasodilation) and to sublingual nitroglycerin (endothelium-independent vasodilation). RESULTS: There was no difference in baseline brachial artery diameter between the two groups. Endothelium-dependent vasodilation was significantly lower in diabetic children compared with healthy children (4.2 +/- 3.8% vs. 8.2 +/- 4.2%, p < 0.001). There was no difference in endothelium-independent vasodilation (17 +/- 6% vs. 18 +/- 6%, p = NS) or mean carotid IMT between the groups (0.33 +/- 0.05 vs. 0.32 +/- 0.08 mm, p = NS). Endothelium-dependent brachial vasodilation correlated with blood glucose levels (r = 0.58, p = 0.001) and was weakly and inversely related to the duration of diabetes (r = -0.4, p = 0.02), total cholesterol, and low-density lipoprotein cholesterol levels. CONCLUSIONS: Endothelial function is impaired in children with diabetes mellitus within the first decade of its onset and precedes an increase in carotid IMT. The relative timing of these events is important in the evaluation of strategies to prevent progression of atherosclerosis and other vascular complications in this patient population.     

Monocyte cyclooxygenase-2 overactivity: a new marker of subclinical atherosclerosis in asymptomatic subjects with cardiovascular risk factors?

AIMS: Cyclooxygenase-2 (COX-2)-mediated prostaglandin production by activated macrophages is associated with inflammation and atherosclerosis. We investigated the relationship between COX-2-mediated prostaglandin-E2 (PGE2) release, cardiovascular risk factors, and carotid atherosclerosis in apparently healthy subjects. METHODS AND RESULTS: PGE2 release by lipopolysaccharide-stimulated blood monocytes was measured by ELISA in 291 subjects (76.5% men, mean age 58) who underwent global vascular risk assessment and carotid ultrasonography. COX-2 expression (real-time RT-PCR) was analysed in a subgroup of 100 subjects (76% men, mean age 59). Inducible PGE2 production was associated with smoking and diabetes (P<0.05), but not with arterial hypertension, dyslipidaemia, or obesity. Subjects in the highest tertile of PGE2 (>8.1 ng/mL) had significantly higher mean carotid intima-media thickness (IMT) than those in the lowest tertile (P<0.01). No significant differences among tertiles were observed in the levels of inflammatory markers (C-reactive protein, fibrinogen, and von Willebrand factor). The association between PGE2 and carotid IMT remained statistically significant (P=0.012) after adjustment for a number of cardiovascular and inflammatory risk factors. A correlation between COX-2 expression and PGE2 production was observed (P<0.005). CONCLUSIONS: COX-2-mediated PGE2 overproduction by stimulated monocytes might provide a new marker of subclinical atherosclerosis in asymptomatic subjects exposed to cardiovascular risk factors.     

Is high-sensitivity C-reactive protein associated with carotid atherosclerosis in healthy Koreans?

BACKGROUND: There is a positive association between chronic inflammation and the risk of cardiovascular disease, but whether there is an association between C-reactive protein (CRP) and carotid atherosclerosis is controversial. We investigated the relationship between high-sensitivity CRP (hsCRP) levels and carotid intima-media thickness (IMT) in healthy Koreans. DESIGN: We measured hsCRP levels, the carotid IMT, and conventional cardiovascular risk factors including obesity parameters, blood pressure, lipid profiles, insulin resistance, and smoking habits in 820 volunteers (35-79 years old) in a cross-sectional study. RESULTS: Higher hsCRP quartile groups had higher mean IMTs, as compared with the lowest quartile (P < 0.001 for the trend across quartiles). However, after adjustment for age, the relationship between hsCRP level and IMT was substantially weaker (P = 0.018). After additional adjustments for conventional cardiovascular risk factors, no significant association was observed (P = 0.548). The unadjusted risk for a high carotid IMT value (> or = 1.0 mm) was also positively related to hsCRP quartile, but this relationship was not significant after adjustment for age and other cardiovascular risk factors. CONCLUSIONS: Both hsCRP levels and the carotid IMT were strongly correlated with conventional cardiovascular risk factors, but there was no independent association between hsCRP levels and carotid IMT in healthy Korean adults.     

Atherosclerotic calcification and intimal medial thickness of the carotid arteries

BACKGROUND AND PURPOSE: Carotid intimal medial thickness (IMT) is a measure of subclinical atherosclerosis and is predictive of future cardiovascular events. The purpose of this study was to determine the significance and magnitude of association between IMT and atherosclerotic calcification of the carotid arteries. METHODS: Forty-five subjects underwent electron beam computed tomography of the neck to ascertain the extent of atherosclerotic calcification in the carotid arteries followed by B-mode carotid ultrasonography for IMT. RESULTS: The mean age, BMI and total cholesterol to HDL ratio were 61.4, 26.2 and 4.3, respectively. Forty-one percent were women. The overall mean IMT was 0.91 mm with the mean for the right and left being 0.93 and 0.87 mm, respectively. The median total carotid calcium score (CCS) was 48.4 [range: 0-973]. Age-adjusted correlations were significant between the overall mean IMT and total CCS (r=0.53, p<0.01), mean right IMT and right CCS (0.31, 0.05), mean left IMT and left CCS (0.31, 0.05), right common carotid IMT and right CCS (0.53, <0.01) and left common carotid IMT and left CCS (0.31, 0.05). The mean IMT was 0.14 mm greater in subjects with any carotid calcification adjusted for risk factors. A 0.05 mm increase in the carotid IMT was associated with an approximate 3-fold increase in risk for the presence of atherosclerotic calcification. CONCLUSIONS: Carotid IMT is significantly correlated with and predictive of atherosclerotic calcification. Conversely, individuals with any carotid calcification have significantly greater intimal medial thicknesses.     

Impact of C-reactive protein on the likelihood of carotid atherosclerosis in Japanese adults

OBJECTIVE: Several cohort studies have shown a link between serum C-reactive protein (CRP) and subsequent cardiovascular disease; however, the role of CRP as an independent risk factor remains controversial. We therefore investigated the association between CRP and sclerotic lesions of common carotid atherosclerosis. PATIENTS AND METHODS: We evaluated sclerotic lesions of common carotid arterial intima-media thickness (IMT) by ultrasonography in 139 men aged 67 +/- 15 years and 201 women aged 75 +/- 10 years. To investigate the relation between CRP and various confounding factors, subjects were divided into four groups based on the quartile of CPR. RESULTS: Carotid IMT values were significantly higher in groups with higher CRP (p = 0.022). To identify the possible CRP level and risk factor interactions for IMT, multiple regression analysis for IMT was performed based on risk factors in subjects with a specific CRP level. It was shown that age, smoking status, systolic blood pressure (SBP) and LDL cholesterol were significantly associated with IMT in subjects in the lower CRP groups (CRP-1 approximately CRP-3), and age, SBP and presence of diabetes mellitus in the highest CRP group (CRP-4). To further investigate whether the interaction between CRP and conventional risk factors could influence IMT, a general linear model demonstrated that interaction between CRP and the presence of diabetes mellitus (F = 4.754 p = 0.030) was significantly associated with IMT, in addition to sex, age, SBP, antihypertensive drug use, LDL cholesterol and HDL cholesterol. CONCLUSIONS: This finding indicates that the association between CRP and IMT significantly differed between subjects with and without diabetes mellitus.     

Relationship between carotid artery intima-media thickness and brachial artery flow-mediated dilation in middle-aged healthy men

OBJECTIVES: We aimed to determine the relationship between carotid intima-media thickness (IMT) and brachial artery flow-mediated dilation (FMD) in healthy middle-age men. BACKGROUND: Carotid IMT and brachial artery FMD are frequently used as surrogate measures of subclinical atherosclerosis. Whereas carotid IMT identifies early structural abnormalities, brachial artery FMD, considered a bioassay of endothelial function, measures functional vascular integrity. The relationship between carotid IMT and brachial artery FMD has not been well studied. METHODS: We measured traditional risk factors, carotid IMT, and brachial artery FMD in 1,578 middle-aged men without known cardiovascular disease and analyzed the relationship between carotid IMT and brachial FMD. RESULTS: Carotid IMT correlated with age, systolic blood pressure, body mass index, fasting glucose, total and low-density lipoprotein (LDL) cholesterol, and with the overall Framingham risk score (p < 0.001 for all), whereas impaired brachial artery FMD correlated with systolic and diastolic blood pressure (p < 0.01). No relationship was observed between carotid IMT and brachial artery FMD for the entire cohort (r = -0.006, p = 0.82) and in subgroups defined by traditional risk factors or by quintiles of carotid IMT and brachial FMD. CONCLUSIONS: In middle-aged healthy men, there is no significant correlation between carotid IMT and brachial artery FMD. This finding suggests that these are unique, independent surrogates that measure different aspects and stages of early atherosclerosis. Further studies are needed to define their role in clinical research and in cardiovascular risk assessment.     

Association of plasma viscosity and carotid thickening in a French working cohort

Plasma viscosity and intima-media thickness (IMT) are frequently associated with cardiovascular disease and its risk factors. We evaluated the association of rheologic and vascular factors in asymptomatic subjects. Plasma viscosity (coaxial cylinder viscometry) and both preintrusive and intrusive atherosclerosis in the carotid arteries (ultrasonography) were investigated in 246 men and 337 women aged 17 to 65 years from the AXA study, a prospective cohort of healthy workers. Plasma viscosity was positively related to age-adjusted mean bifurcation carotid artery IMT (P < .01 for men; P < .04 for women) and maximum carotid artery IMT (P < .01 for men; P < .02 for women), but not to mean common carotid artery IMT. Multivariate adjustment affected these relations to a greater extent in men than in women. The odds ratio (range) of having intrusive atherosclerosis in relation to 1 SD greater plasma viscosity was 2.27 (1.52 -3.38) in men and 1.63 (1.17-2.26) in women. Adjustment of age, waist-to-hip ratio, smoking, hypercholesterolemia, hypertension, diabetes, and fibrinogen had very little effect on the magnitude of these odds ratios. Thus, plasma viscosity was associated with carotid thickening, suggesting that rheologic factors are involved in the subclinical phase of atherosclerosis.     

Low free-thyroxine levels are a risk factor for subclinical atherosclerosis in euthyroid hyperlipidemic patients.

BACKGROUND: Patients displaying overt and subclinical hypothyroidism have more cardiovascular risk factors. Consequently, they are more likely to develop atherosclerosis and cardiovascular diseases. OBJECTIVE: To analyze whether low free-thyroxine levels (FTL) would also be associated with atherosclerosis in euthyroid patients. METHODS: We selected a group of 1434 healthy euthyroid male patients without known histories of thyroid disease and with levels of thyroid-stimulating hormone values within the normal range (mean 1.70+/-0.76 mUl/l, range 0.13-4.01 mUl/l). Mean age of these patients who had been referred for assessment of hyperlipidemia was 44.6 years and mean FTL was 14.25+/-3.06 pmol/l. We divided the population according to the degree of atherosclerosis in the carotid arteries. RESULTS: Mean age, body mass index, systolic blood pressure, cigarettes/day, blood level of glucose, cholesterol levels, and fibrinogen levels were significantly higher for the patients with atherosclerotic lesions whereas mean FTL was lower for patients with carotid atherosclerosis (P = 0.0002). The relationship between FTL and carotid atherosclerosis was independent from the following cardiovascular risk factors: age, hypertension, amount of excess weight, cholesterol level, fibrinogen level, smoking status, and presence versus absence of diabetes mellitus. CONCLUSIONS: Low FTL is a risk factor for atherosclerosis in male euthyroid hyperlipidemic patients.