Mean Intima-media Thickness Research Articles

Normal Value of Carotid Intima-Media Thickness–A Surrogate Marker of Atherosclersosis: Quantitative Assessment by B-Mode Carotid Ultrasound

Carotid intima-media thickness (IMT) is a surrogate marker of atherosclerosis and imparts prognostic information independent of traditional cardiovascular risk factors. Quantitative assessment of IMT using semiautomated border detection software is a new and easy technique that has been previously shown to be accurate, effective, and reproducible. The study is aimed to define the upper limit of carotid IMT at the common carotid artery (CCA) and its bifurcation among a healthy population in the United Kingdom. Asymptomatic men and women aged 35 to 75 years, without evidence of clinical atherosclerosis, underwent B-mode carotid duplex ultrasound (Sonos 7500, Philips, Best, The Netherlands). Mean carotid IMT at the far wall of both left and right CCA were quantitatively determined using a semiautomated edge-detection algorithm (Q-lab 4, Philips). Healthy population was defined as participants with no cardiovascular disease and no evidence of diabetes mellitus or hypertension with a body mass index less than 30 kg/m2, serum cholesterol less than 6 mmol/L, and absence of carotid plaque on ultrasound. Of the 453 participants, 137 were found to be healthy. IMT measured at the bifurcation was found to be significantly higher compared with that at the CCA. Carotid IMT in both CCA and its bifurcation increased significantly with age. The upper limits (97.5 percentile) of IMT at CCA for participants age 35 to 39, 40 to 49, 50 to 59, and 60 years or older were 0.60, 0.64, 0.71, and 0.81 mm, respectively, whereas for that at bifurcation were 0.83, 0.77, 0.85, and 1.05 mm, respectively. This study demonstrated the value of IMT at CCA and its bifurcation in a healthy population in the United Kingdom using a semiautomated edge-detection software, which is easy to use and reproducible.

Sequential based analysis of Intima-Media Thickness (IMT) in common carotid artery studies

Introduction Carotid Intima-Media Thickness (IMT) is used widely to assess an individual's risk of myocardial infarction and stroke. Although significant associations have been showed, IMT as used in major studies does not improve prediction of cardiovascular events much compared to traditional risk factors. Therefore, a new approach to IMT-measurements is sought-after by examining the wall structure continuously throughout several heart cycles. Materials and methods Computerized single-image analysis (IA) and sequential analysis (SA) were used to assess latter's capability in predicting risk of cardiovascular disease and to compare both. Healthy subjects (mean ± S.D., age 46.1 ± 5.6 years, n = 490) were compared with subjects suffering from confirmed coronary artery disease (CAD) (mean ± S.D., age 47.3 ± 6.2 years, n = 51). Results SA could differentiate between both groups better then single IA, especially when looking at the maximal and mean IMT-values (SA ↔ IA, p < 0.01 ↔ p < 0.05). The area under the curve (AUC) for maximal and mean IMT was greater for sequences then for single images as well. Discussion Due to our findings sequential analysis can offer an extensive and complete examination of the carotid wall with a maximal reduction of bias. Commonly used IA may disguise vascular conditions and therefore the patient's risk, since IMT-values, as proven with SA, seems to usually be higher. Therefore, the need for further studies arises, examining if and to what extend common IMT-studies underestimate differences between groups.

Reproductive history and carotid intima‐media thickness

Intima-media thickness (IMT) of the carotid arteries is a valid measure of preclinical atherosclerosis which may predict cardiovascular outcomes. Metabolic and hormonal changes associated with the reproductive history of women may contribute to the development of cardiovascular disease (CVD). In a population-based cross-sectional study comprising 746 Finnish women, aged 45-74 years, associations of reproductive history (assessed by questionnaire) and measures of subclinical atherosclerosis (by ultrasonographic detection) were studied. Statistical methods included linear and logistic regression models. Mean carotid IMT was positively associated with parity, but after adjustment for age its statistical significance disappeared. Women with a history of stillbirth tended to have higher IMT than other women. History of hysterectomy was an independent determinant of carotid plaque in models with age, blood pressure, fasting blood glucose and cholesterol, body mass index (BMI), education and smoking (odds ratio (OR): 0.32; 95% confidence interval (CI): 0.11-0.96). But when oophorectomy (yes/no) was included in the model, this association lost its statistical significance (adjusted OR: 0.36; 95% CI: 0.11-1.22). A history of stillbirth was associated with an increased age-adjusted risk of plaque (OR=3.43; 95% CI: 1.07-11.05), but in the fully adjusted model it lost its statistical significance (OR=3.61; 95% CI: 0.86-15.23). Stillbirth was associated with increased risk of atherosclerotic plaque. Atherosclerosis is a lifelong process to which stillbirth is related. However, due to the cross-sectional design of this study, the causality of this association remains unclear.

Lower Central Serotonergic Responsivity Is Associated With Preclinical Carotid Artery Atherosclerosis

Central nervous system serotonergic neurotransmission appears to play a role in mood disorders, eating habits, and sleep, and also modulates blood pressure and metabolism. This investigation tested a hypothesized association between central serotonergic functioning and preclinical atherosclerosis. Subjects were 244 adults 30 to 55 years of age and free of clinically evident vascular disease (52% men, 84% white). Central serotonergic responsivity was measured as the rise in serum prolactin concentration (area under the curve) over 2.5 hours, adjusted for baseline prolactin, after citalopram administered intravenously at 0.33 mg/kg lean body weight. Carotid artery morphology served as a marker of preclinical atherosclerosis, and carotid artery intima-media thickness and plaque occurrence were determined by B-mode ultrasonography. In linear regression models including age, gender, race, and citalopram concentration, a 1 SD lower prolactin response was associated with greater maximum intima-media thickness (+0.016 mm; P=0.006) and with greater mean intima-media thickness (+0.009 mm; P=0.03). The odds ratio for carotid artery plaque corresponding to a 1 SD decrease in prolactin response, adjusted for age, race, sex, and citalopram concentration, was 1.47 (95% CI, 0.98 to 2.19; P=0.06). The metabolic syndrome mediated (P<0.01), but did not fully account for, the association between lower prolactin response and greater maximum intima-media thickness. In this young and relatively healthy sample, blunted prolactin response to citalopram was associated with carotid artery thickening, suggesting that individual differences in central serotonergic responsivity are inversely related to preclinical vascular disease.

The effects of pioglitazone on cerebrovascular resistance in patients with type 2 diabetes mellitus

Atherosclerosis is one of the major causes of morbidity and mortality in patients with type 2 diabetes mellitus. Pioglitazone has been reported to have antiatherogenic effects. The aim of this study was to investigate whether pioglitazone affects pulsatility index (PI) of the cerebral arteries and the carotid intima-media thickness in type 2 diabetic patients. A total of 40 type 2 diabetic patients were included in this study. They were divided into 2 groups: the pioglitazone-treated group (pioglitazone 15 mg/d with gliclazide 80-320 mg/d for 12 weeks) and the gliclazide-treated group (gliclazide 80-320 mg/d for 12 weeks). Transcranial Doppler ultrasonography was performed for each cerebral artery, and PI was calculated as (systolic velocity − diastolic velocity)/mean velocity. The pioglitazone treatment significantly increased high-density lipoprotein cholesterol and decreased triglyceride levels and insulin resistance. This study revealed that the change in mean intima-media thickness was not significant in both groups, but the change in PI was significantly decreased with pioglitazone compared to gliclazide. In conclusion, pioglitazone decreased PI and improved cerebrovascular resistance in type 2 diabetic patients.

Carotid artery intima media thickness is inversely related to serum free thyroxine in euthyroid subjects

The effect of thyroid function on cardiovascular risk may extend to the euthyroid range. In euthyroid subjects, we determined whether carotid artery intima media thickness (IMT), a measure of subclinical atherosclerosis, is related to thyroid function. Cross-sectional study in a cohort of 78 nonsmoking, predominantly middle-aged, euthyroid subjects (44 men and 34 women, mean age 56 years, TSH between 0.5 mU/l and 4.0 mU/l and FT4 between 11.0 pmol/l and 19.5 pmol/l). IMT (mean of three segments in both carotid arteries by ultrasonography), clinical factors, insulin resistance (HOMA(ir)), plasma lipids, C-reactive protein (CRP), serum FT4, TSH and thyroid autoantibodies. In several multiple linear regression models, age- and sex-adjusted IMT was found to be independently related to either pulse pressure and body mass index (BMI), to high density lipoprotein (HDL) cholesterol or to FT4, but not to TSH, thyroid autoantibodies, HOMA(ir), CRP, non-HDL cholesterol and triglycerides. In a subsequent model which included age, sex, pulse pressure, body mass index (BMI), HDL cholesterol and FT4, IMT was independently and positively related to age (beta = 0.43, P < 0.001), male sex (beta = 0.34, P = 0.014), pulse pressure (beta = 0.29, P = 0.002), BMI (beta = 0.24, P = 0.007) and inversely related to FT4 (beta = -0.19, P = 0.046). IMT was also inversely related to FT4 in a model which included HDL cholesterol, non-HDL cholesterol and triglycerides. In euthyroid subjects, IMT is associated with FT(4), after controlling for clinical factors, lipid levels and thyroid autoantibodies. These findings raise the possibility that, even within the euthyroid range, low normal thyroid function may adversely affect cardiovascular risk.

Association Between Carotid Artery Intima-Media Thickness and Early-Stage CKD in a Chinese Population

Increased carotid artery intima-media thickness (IMT) predicts future vascular events in the general population. However, the relationship between IMT and chronic kidney disease (CKD) seldom was tested in subjects with early-stage CKD. Cross-sectional study. 1,046 residents in 1 district of Beijing participated in the study. Carotid artery IMT was measured by means of high-resolution B-mode ultrasonography. Estimated glomerular filtration rate (eGFR) was calculated using the modified Modification of Diet in Renal Disease Study equation based on data for Chinese patients with CKD. Albuminuria was evaluated by means of urinary albumin-creatinine ratio on a morning spot urine sample. Compared with subjects with eGFR greater than 90 mL/min/1.73 m(2) (>1.50 mL/s/1.73 m(2)), subjects with eGFR of 60 to 89 mL/min/1.73 m(2) (1.00 to 1.49 mL/s/1.73 m(2)) and 30 to 59 mL/min/1.73 m(2) (0.50 to 0.99 mL/s/1.73 m(2)) had higher mean IMT (0.74 +/- 0.27 versus 0.82 +/- 0.30 versus 0.94 +/- 0.38 mm; P < 0.001). IMTs of subjects with albuminuria tended to be higher than the mean value (0.79 +/- 0.29 versus 0.93 +/- 0.38 mm; P < 0.001). eGFR and urinary albumin-creatinine ratio significantly correlated with IMT in univariable analysis, but not after adjusting for traditional cardiovascular disease risk factors. Selection bias and low prevalence of CKD might affect the strength of the study. In this Chinese population older than 40 years, carotid artery IMT was significantly higher in subjects with early-stage CKD. The greater prevalence of cardiovascular disease risk factors in patients with CKD appeared to account for the higher carotid artery IMT.

Intima‐Media Thickness

Accelerated atherosclerosis is an emerging problem in patients with systemic lupus erythematosus (SLE). We planned an observational study to determine whether in patients with SLE carotid intima-media thickness (IMT) represents an early sign of accelerated atherosclerosis and to confirm that SLE adds to the traditional cardiovascular Framingham risk factors. Thirty females with SLE (age 18-65 years) underwent anamnestic, clinical, and laboratory evaluation and B-mode ultrasonography of carotid arteries, which provides a direct and noninvasive assessment of subclinical atherosclerosis. IMT measurements were performed on the right and left common carotid arteries 1.0 cm proximal to the carotid bulb and the mean IMT value was calculated with a dedicated software. The Framingham Point Score was also calculated for each subject. SLE patients showed a mean IMT value of 0.73 +/- 0.12 (SD) mm. This value is significantly (P < 0.05) higher than that reported for an age-matched healthy female control population (0.66 +/- 0.11 SD mm). A preliminary evaluation of the Framingham Point Score, estimating the 10-year risk for women to develop cardiovascular events, indicated an increased risk of early cardiovascular events in SLE patients. In our study we have shown that patients with SLE have an increased mean IMT value compared with a healthy females control. Moreover, the evaluation of the Framingham Point Score suggests that SLE is an additional risk factor for cardiovascular disease.

Association of single nucleotide polymorphisms in endothelin family genes with the progression of atherosclerosis in patients with essential hypertension

Endothelin-1 (ET-1) is a potent vasoconstrictive peptide and its activity is mediated by the receptors ET type A (EDNRA) and ET type B (EDNRB). Although ET-1 is thought to play an important role in the development of atherosclerosis, it remains unclear whether polymorphisms of ET-1 family genes, including the ET-1 gene (EDN1), EDNRA, EDNRB and the genes for endothelin converting enzymes 1 and 2 (ECE1 and ECE2), are associated with the progression of atherosclerosis. We investigated the relationship between 11 single nucleotide polymorphisms (SNPs) of ET-1 family genes (including three in EDN1, one in EDNRA, two in EDNRB, four in ECE1 and one in ECE2) and atherosclerotic changes assessed using pulse wave velocity (PWV) and carotid ultrasonography in 630 patients with essential hypertension (EHT). In male subjects, we found significant differences in brachial-ankle PWV (baPWV) in additive and recessive models in EDNRB-rs5351 after Bonferroni correction. Also in male subjects, there were significant differences in mean intima-media thickness (IMT) in additive and recessive models in EDNRA-rs5333 after Bonferroni correction. We found no significant correlation between any SNPs in the ET family genes and baPWV, IMT and Plaque score (PS) in female subjects. Furthermore, after multiple logistic regression analysis, only EDNRB-rs5351 indicated as an independent risk of atherosclerosis in male hypertensive subjects. Of the endothelin-related genes, EDNRB-rs5351 was the most susceptible SNP associated with atherosclerosis in male hypertensives, and the genetic background may be involved in the progression of atherosclerosis in EHT patients.

Effects of the Renin-Angiotensin System Genes and Salt Sensitivity Genes on Blood Pressure and Atherosclerosis in the Total Population and Patients With Type 2 Diabetes

Most studies on the genetic determinants of blood pressure and vascular complications of type 2 diabetes have focused on the effects of single genes. These studies often have yielded conflicting results. Therefore, we examined the combined effects of three renin-angiotensin system (RAS) genes and three salt sensitivity genes in relation to blood pressure and atherosclerosis in the total population and type 2 diabetic patients. The study was a part of the Rotterdam Study, a population-based cohort study. We have genotyped three RAS gene polymorphisms and three salt sensitivity gene polymorphisms. Diabetic patients with three risk genotypes of the RAS genes had a 6.9 mmHg higher systolic blood pressure (P for trend = 0.04) and a 6.0 mmHg higher pulse pressure (P for trend = 0.03) than those who did not carry any risk genotypes. Diabetic patients with three risk genotypes of the salt sensitivity genes had a 9.0 mmHg higher systolic blood pressure (P = 0.19) and a 13.1 mmHg higher pulse pressure (P = 0.02). Diabetic patients who carried three risk genotypes for the RAS genes had a higher mean intima-media thickness than those with two risk genotypes (mean difference 0.04 mm, P = 0.02). We found that among type 2 diabetic patients, mean systolic blood pressure, pulse pressure, and risk of hypertension increased with the number of risk genotypes for the RAS genes and the salt sensitivity genes.

Association between serum resistin and carotid intima media thickness in hypertension patients

Background Resistin is an adipocytokine belonging to the family of cysteine rich secretory proteins. We sought to determine if a correlation between resistin levels and carotid atherosclerosis exists in hypertensive patients. Methods This study consisted of 307 treated hypertensive patients. Subjects were grouped into tertiles according to their resistin level. Results Carotid intima media thickness (IMT) was significantly highest in the third tertile. The first tertile had a mean carotid IMT and a mean of maximum carotid IMT of 0.63 ± 0.08 and 0.81 ± 0.10 mm, respectively. The 2nd tertile had measurements of 0.63 ± 0.08 and 0.81 ± 0.12 mm, and the 3rd tertile 0.67 ± 0.12 and 0.86 ± 0.11 for the same parameters. ( p = 0.002). Resistin levels were independently associated with the carotid IMT (mean carotid IMT: R 2 = 0.159, p < 0.001 and mean of maximum carotid IMT: R 2 = 0.162, p < 0.001) after controlling for age, gender, HDL cholesterol, triglyceride, LDL cholesterol, smoking and DM. The tertile level of resistin was significantly associated with (odds ratio = 3.097, p = 0.004) risk of coronary artery disease after controlling for age, gender, HDL cholesterol, triglyceride, LDL cholesterol, smoking, DM and carotid IMT. Conclusion Serum resistin is independently associated with increasing carotid IMT in treated hypertensive patients.

Common Carotid Artery Intima-Media Thickness Determinants in a Population Study

Common carotid artery (CCA) intima-media thickness (IMT) is considered an atherosclerosis risk marker. Thickening of the intima-media complex is accelerated by vascular risk factors, in particular, by age and elevated blood pressure. Nonetheless, it also reflects intimal hyperplasia and intimal fibrocellular hypertrophy provoked by nonatherosclerotic mechanisms such as tensile wall stress. The aims of our study were to investigate the relationship between CCA IMT and the presence of vascular risk factors and to correlate CCA IMT with the degree of distal internal carotid artery (ICA) stenosis and the proximal CCA resistive index (RI), representative of wall stress. We assessed CCA IMT, the CCA RI, and the presence of carotid plaques in 1655 consecutive patients. Demographic features and vascular risk factors were collected. A positive linear relationship between mean IMT and age was observed (R(2) = 0.27; P < .001). In the multiple stepwise regression model, the presence of ICA plaques and vascular risk factors were all independently associated with higher IMT. When considering IMT values for left and right sides separately, there was an independent relationship between CCA IMT and the lateralized percentage of ICA stenosis (right IMT-right ICA percentage, R(2) = 0.10; P < .0001; left IMT-left ICA percentage, R(2) = 0.16; P < .0001) and the CCA RI, even after correcting for age and vascular risk factors. Risk factors for atherosclerosis and the percentage of ICA stenosis were independently associated with higher IMT values and an increase in the RI. The synergic action of risk factors may cause further deterioration of mechanical forces independent of carotid atherosclerosis.

The Relationship between Carotid and Coronary Atherosclerotic Damage in Dialysis Patients

Data relating carotid ultrasound (CU) to atherosclerotic damage evaluated by coronary angiography in hemodialysis patients are scarce. We carried out a cross-sectional study in 33 uremic subjects (age 55 +/- 12 years, 22 male, 7 diabetic), who have been on dialysis for 41 +/- 48 months (range 2-192). Twenty-two underwent a coronary angiography in order to complete clinical evaluation for inclusion on the kidney transplantation waiting list, and 11 because of coronary artery disease (CAD); Gensini's score was calculated. Intima-media thickness (IMT) and presence of plaques were related to the degree of coronary stenosis and to cardiovascular risk factors. Patients were divided into two groups depending on mean IMT (group 1 IM <or= 0.9 mm, n=18; group 2 IMT>0.9 mm, n=15). Group 2 was older (60 +/- 8 vs 50 +/- 12 year, p=0.01), had higher frequency of CAD (53 vs 16%, p=0.02) and had higher prevalence of coronary artery stenosis >or= 75% in the right (60 vs 22%, p=0.02), left anterior descending (46 vs 16%, p=0.06) and left circumflex coronary arteriers (60 vs 11%, p=0.05) than group 1. IMT was not related to the degree of CAD evaluated by Gensini's score. IMT sensibility and specificity in detecting the presence of hemodynamically significant coronary stenosis were 64% and 68%, respectively. Coronary narrowing was correlated with the degree of stenosis of common, internal and external carotid arteries (Spearman's rank correlation coefficient). During two years of follow-up, six major cardiac events were recorded and they were related to Gensini's score. In uremic patients, ultrasonographic evaluation of carotid arteries is a simple, noninvasive examination that could be a helpful tool in detecting coronary atherosclerotic damage, but IMT does not appear to add more information regarding risk stratification of CAD.

Reduced coronary flow reserve in young adults with renal transplant

Some degree of cardiovascular disease should be suspected in young adults who have been paediatric renal transplant recipients also if no systematic data collection is routinely performed in clinical setting. The aim of our work was to evaluate the degree of cardiovascular damage in these young patients, using a minimally invasive technique. We then evaluated coronary flow reserve (CFR) and carotid intima-media thickness (IMT) in 25 patients (13 males, median age 23.7 years). Coronary flow velocity on the left anterior descending coronary artery was assessed by transthoracic echocardiography, before and after dipyridamole, after standard echocardiography. CFR was compared with that of a small control group (n = 16; median age 25 yrs). In this relatively young sample, mean CFR was 2.8 +/- 0.6 (median 2.75), and half of the patients had reduced coronary reserve (P = 0.01). Mean IMT (0.48 +/- 0.08 mm) was only slightly, though significantly larger compared with the reference standard (P < 0.05) but was significantly thinner in normotensive than in hypertensive patients (0.42 +/- 0.06 vs 0.49 +/- 0.05 mm, P < 0.05). The time on dialysis prior to transplantation, hypertension and age at the time of CFR evaluation affect CFR. IMT did not correlate with CFR. CFR and IMT abnormalities are common in young transplant recipients, in spite of the fact that our paediatric population has much less of the atherosclerotic 'legacy' common to adult patients.

Metabolic syndrome and preclinical atherosclerosis: focus on femoral arteries

Several evidences revealed the relationship between the earliest stages of atherosclerosis and the components of metabolic syndrome. The aim of this study was to disclose preclinical atherosclerotic lesions in a cross-sectional observational study involving 147 patients with metabolic syndrome by the assessment of brachial flow–mediated vasodilation (FMV) and intima-media thickening at both carotid and femoral sites. The purpose was to investigate the association of this metabolic disorder with prevalent atherosclerotic damage in different vascular sites. A control group of 87 healthy subjects was also investigated. Patients had lower values of FMV and a higher mean intima-media thickness (IMT) at both the carotid and femoral sites with respect to controls. Flow-mediated vasodilation had a positive correlation with high-density lipoprotein (HDL) cholesterol and a negative one with low-density lipoprotein (LDL) cholesterol, glycemia, and insulinemia. Carotid mean IMT was directly related to LDL cholesterol and age, and inversely with HDL cholesterol; femoral mean IMT had a direct association with LDL cholesterol, triglycerides, glycemia, and insulinemia and an inverse correlation with HDL cholesterol and LDL size. LDL cholesterol, HDL cholesterol, insulin, and brachial artery diameter were predictive of brachial FMV ( β = −0.17, 0.21, −0.27, and −0.29, respectively; P < .05), whereas age, LDL cholesterol, and HDL cholesterol were independent predictors of mean carotid IMT ( β = 0.19, 0.37, and −0.27, respectively; P < .05); on the other hand, LDL cholesterol, triglycerides, and insulin were independent predictors of mean femoral IMT ( β = 0.32, 0.26, and 0.25, respectively; P < .05). In conclusion, the present study documented an altered endothelial function and intima-media thickening in patients with metabolic syndrome without overt cardiovascular disease. Moreover, it focused on the strong influence of metabolic syndrome on preclinical atherosclerotic lesions at the femoral site.

Lower plasma adiponectin is a marker of increased intima-media thickness associated with type 2 diabetes mellitus and with male gender

We tested the extent to which altered plasma adipokine levels may contribute to the increased carotid artery intima-media thickness (IMT) associated with type 2 diabetes mellitus and with male gender, independently of conventional cardiovascular risk factors, insulin resistance, and plasma C-reactive protein (CRP). IMT (mean of three segments of both carotid arteries by ultrasonography), insulin resistance (homeostasis model assessment; HOMA(ir)), plasma CRP, lipids, adiponectin, leptin, resistin, and tumor necrosis factor-alpha (TNF-alpha) were measured in 84 type 2 diabetic patients and 85 control subjects. In diabetic patients, IMT (P<0.001), mean arterial pressure (P<0.001), HOMA(ir) (P<0.001), plasma CRP (P=0.003), triglycerides (P=0.037), leptin (P=0.023), resistin (P=0.003), and TNF-alpha (P=0.003) levels were higher, whereas high-density lipoproteins (HDL) cholesterol (P<0.001) and adiponectin (P<0.001) levels were lower compared with control subjects. Plasma adiponectin (P<0.001) and leptin (P<0.001) were substantially lower in men than in women. IMT was positively and independently associated with age (P<0.001), diabetes (P=0.049), and male gender (P=0.002) in a multivariate regression model, not including other variables. Further analyses showed that IMT was positively related to age (P<0.001) and plasma triglycerides (P=0.038) and negatively to adiponectin (P<0.001), without independent effects of diabetes, gender, and HOMA(ir). Increased IMT in type 2 diabetes may in part be explained by lower plasma adiponectin and higher triglycerides, but not by leptin, resistin, and TNF-alpha. The gender effect on IMT is related to lower plasma adiponectin.

Evidence for Association Between Insulin Resistance and Premature Carotid Atherosclerosis in Childhood Obesity

The present study was undertaken to determine the presence and predictors of the subclinical atherosclerosis in obese children. Fifty obese children [mean age: 11.7 +/- 2.5 y, mean body mass index (BMI): 28.2 +/- 4.0 kg/m] and 50 age- and sex-matched healthy nonobese controls (mean age: 11.4 +/- 3.73 y, mean BMI: 17.6 +/- 3.0 kg/m) were enrolled in the present study. Oral glucose tolerance test was performed to all obese subjects. Common carotid artery intima-media thickness (IMT) was measured by high-resolution B-mode ultrasonography. Carotid artery IMT was significantly increased (0.0476 +/- 0.007 versus 0.033 +/- 0.011 cm; p < 0.001) in the obese group. There were significant relations between carotid artery IMT and insulin sensitivity indexes derived from fasting samples (fasting glucose to insulin ratio (FGIR; p = 0.004, r = -0.404), quantitative insulin-sensitivity check index (QUICK-I; p = 0.002, r = -0.401) and homeostasis model assessment of insulin resistance (HOMA-IR; p = 0.034, r = 0.300) in the obese group. In a multivariate regression model, QUICK-I emerged as independent correlates for mean IMT in obese children with the total variance explained being 20.7% (beta = -0.58, p < 0.001). We concluded that insulin resistance is an independent risk factor for increased carotid artery IMT in obese children.

Elevated plasma asymmetric dimethyl‐L‐arginine levels are linked to endothelial progenitor cell depletion and carotid atherosclerosis in rheumatoid arthritis

Similarities between rheumatoid arthritis (RA) and atherosclerosis include endothelial dysfunction (an antecedent of plaque formation) and depletion of circulating bone marrow-derived endothelial progenitor cells. This study was undertaken to test the hypothesis that endothelial progenitor cell depletion and subclinical atherosclerosis in RA may be related to accumulation of an endogenous inhibitor of nitric oxide (NO) synthesis, asymmetric dimethyl-L-arginine. We studied 30 patients with active RA and 20 age- and sex-matched healthy controls. Exclusion criteria were clinically evident atherosclerosis, traditional risk factors, hyperhomocysteinemia, and renal dysfunction. The blood endothelial progenitor cell count was assayed by flow cytometry and expressed as a percentage of lymphocytes. Plasma L-arginine, asymmetric dimethyl-L-arginine, and symmetric dimethyl-L-arginine were measured with liquid chromatography-mass spectrometry. Mean carotid intima-media thickness (IMT) was assessed by B-mode ultrasound. In RA patients, we found elevated levels of asymmetric dimethyl-L-arginine (mean +/- SD 0.49 +/- 0.07 micromoles/liter versus 0.40 +/- 0.07 micromoles/liter in controls; P < 0.001), a depressed endothelial progenitor cell count (0.039 +/- 0.025% versus 0.063 +/- 0.035%; P < 0.05), and increased IMT (0.65 +/- 0.13 mm versus 0.55 +/- 0.10 mm; P < 0.01), with no differences in levels of L-arginine or symmetric dimethyl-L-arginine. The endothelial progenitor cell count was inversely correlated with the level of asymmetric dimethyl-L-arginine. IMT was positively related to the ratio of asymmetric dimethyl-L-arginine to L-arginine and negatively related to the endothelial progenitor cell count, in univariate and multivariate analyses. Plasma asymmetric dimethyl-L-arginine levels are elevated in RA patients free of cardiovascular disease or risk factors. Asymmetric dimethyl-L-arginine accumulation may contribute to endothelial progenitor cell depletion via depressed NO-dependent endothelial progenitor cell mobilization and/or survival, with consequent impairment of endothelial progenitor cell-mediated endothelial repair, which can promote atherogenesis in RA.

Carotid intima-media thickness is inversely associated with olive oil consumption

Background Intima-media thickness (IMT) is a valid marker for generalized vascular disease whose main risk factors are associated with food habits and lifestyle. A Mediterranean food pattern may have a protective effect on cardiovascular mortality. Objective To assess the relationship between carotid IMT and olive oil consumption. Methods One hundred and ninety nine patients were randomly extracted from 1055 asymptomatic high cardiovascular risk participants at the AP-UNAV recruitment center of the PREDIMED (PREvención con DIeta MEDiterránea) project. Demographic and clinical variables were collected, and a validated semiquantitative food frequency questionnaire (137 items) was administered at the inclusion interview. A B-mode ultrasound imaging technique was used to measure the mean common carotid IMT. Results The mean age was 67.3 years and 53.3% were women. Energy-adjusted olive oil consumption quintiles were assessed as the main exposure after adjusting for potential dietary and non-dietary confounders. Using continuous carotid IMT as the outcome in an ANCOVA analysis, the adjusted IMT means throughout quintiles showed an inverse association with a plateau after the second quintile, with statistical differences when the adjusted IMT mean of the merged four upper quintiles were compared with the lowest quintile ( p < 0.05). The averaged (both sides) mean IMT of the common carotid was dichotomised and values above the median (0.804 mm) were used to identify carotid atherosclerotic damage. We also found an inverse association of olive oil consumption with high IMT, throughout the second to the fifth quintile as compared with the lowest quintile. The adjusted OR was of 0.08 (95% confidence interval, CI, of 0.02–0.37; p = 0.001) after merging the four upper quintiles. Conclusion The inverse association between the olive oil consumption and the carotid IMT could suggest a protective role of olive oil against the development of carotid atherosclerosis in persons at high cardiovascular risk.

Inflammation as a risk factor for carotid intimal‐medial thickening, a measure of subclinical atherosclerosis in haemodialysis patients: The role of chlamydia and cytomegalovirus infection

Atherosclerotic vascular disease is the most frequent complication seen in haemodialysis (HD) patients. Evidence suggests that inflammation may play a role in the pathogenesis and progression of atherosclerosis. Our aim was to evaluate the causative role of inflammation in atherosclerosis among HD patients. Intima-media thickness (IMT) in carotid arteries was determined in 54 HD patients and 52 controls. Plasma levels of lipids, glucose, albumin and several acute phase proteins, and immunoglobulin G titres against chlamydia and cytomegalovirus were measured in all subjects. Mean carotid IMT was significantly greater in HD patients than in controls (0.75 mm vs 0.56 mm, P < 0.005). While plasma levels of C-reactive protein (CRP), serum amyloid A (SAA), lipoprotein (a) Lp(a), fibrinogen and ferritin were higher in HD patients, albumin levels were lower. In HD patients, carotid IMT was correlated positively with CRP (R = 0.29, P = 0.019), SAA (R = 0.69, P < 0.001), Lp(a) (R = 0.42, P = 0.001), fibrinogen (R = 0.57, P < 0.001) and chlamydia pneumonia immunoglobulin G titres (R = 0.50, P < 0.001), and negatively with albumin levels (R = -0.33, P = 0.02); there was no relationship between carotid IMT and hypertension, plasma lipid levels and cytomegalovirus. In multivariate regression analysis, these variables still showed a significant relationship with IMT (R(2) = 0.694 and P < 0.001). We conclude that atherosclerotic changes are more common in HD patients than in controls, and that inflammatory processes may play a role in the pathogenesis of atherosclerosis.