Soluble adhesion molecules and prediction of coronary heart disease: a prospective study and meta-analysis

Documented traditional cardiovascular risk factors and mortality in non-ST-segment elevation myocardial infarction

BACKGROUND

Although documented traditional cardiovascular risk factors (hypertension, diabetes, smoking, and dyslipidemia) increase the risk of developing coronary artery disease, their influence on the treatments and outcomes of patients with non-ST-segment elevation myocardial infarction (NSTEMI) has not been fully elucidated.

METHODS

Using data from the CRUSADE Quality Improvement Initiative, we sought to characterize the effect that the absence of documented traditional risk factors has on inhospital treatments and outcomes in a population of patients with NSTEMI treated in routine practice. We compared clinical characteristics and inhospital outcomes according to the presence and number of risk factors in 74,220 patients with NSTEMI (defined as creatine kinase-MB and/or troponin I/T values above the local upper limit of normal) treated in 476 US hospitals from January 2001 through March 2004.

RESULTS

The 7755 (10.5%) patients with no documented traditional risk factors on admission were less likely to receive short-term guideline-recommended therapies and revascularization procedures. Despite a higher prevalence of normal left ventricular function and insignificant angiographic coronary artery disease, these patients had a slightly higher risk of adjusted inhospital mortality (odds ratio 1.15, 95% CI 1.03-1.29) compared with patients with any combination of risk factors.

CONCLUSIONS

Patients without documented traditional cardiovascular risk factors represent 10.5% of the non-ST-segment elevation myocardial infarction population. Because the absence of documented traditional risk factors does not yield a favorable prognosis, further study is needed to delineate the effects of the interplay between novel and documented traditional risk factors and treatment differences on the outcomes of these patients.

Vascular cell adhesion molecule-1: a viable therapeutic target for atherosclerosis?

Atherosclerosis is now well recognised as a chronic inflammatory process which may ultimately lead to myocardial infarction, stroke and peripheral vascular disease. The role of inflammation in the pathogenesis of atherosclerosis has lead to interest in developing therapies that target vascular inflammation. Leucocytes play a key role during atherosclerotic plaque development. Activated vascular endothelium expresses vascular cell adhesion cell molecule-1 (VCAM-1), a member of the adhesion molecule superfamily, to which monocytes and lymphocytes can bind. These inflammatory cells can then move through the endothelium by diapedesis and release cytokines and enzymes, important components in the progression of the lesion. Researchers have demonstrated that the extent of atherosclerotic lesions is significantly reduced in animal models with decreased VCAM-1 expression. VCAM-1 has therefore been identified as a potential anti-inflammatory therapeutic target, the hypothesis being that reduced expression of VCAM-1 will slow the development of atherosclerosis. Succinobucol (AGI-1067), an anti-oxidant compound also capable of inhibiting VCAM-1 gene expression, is an example of such an agent and is currently being investigated in a phase III cardiovascular end-point trial due to report in 2007. If the results are positive, further investigations should derive to what extent blockade of VCAM-1 by succinobucol, rather than its other effects, accounts for the reduction in vascular events.

Intercellular adhesion molecules in systemic lupus erythematosus patients with lupus nephritis

Cardiovascular events are markedly increased in systemic lupus erythematosus (SLE), and the mechanism of atherogenesis remains poorly understood. Several methods have been employed to assess endothelial function, among these is the measurement of biomarkers of endothelial activation and dysfunction [intercellular adhesion molecule (ICAM-1)]. It has been reported that such biomarkers play a more important role than traditional risk factors in cardiovascular disease. The objectives of this study were to determine the level of ICAM-1 as markers of endothelial dysfunction in 40 Egyptian patients who have SLE with various degrees of activity and to investigate their relationship to disease activity. Sixty people (40 with SLE and 20 healthy as the control group) were the subject of this study; their clinical disease activity was scored according to the SLE disease activity index (SLEDAI), and serum sampling was obtained for ICAM-1 level assay. Renal biopsy was carried out and examined by light microscopy by a pathologist blinded to the clinical activity. The mean level of ICAM-1 was significantly higher in SLE patients with active disease (826.05 +/- 367.1 Pg/ml) compared to those with inactive disease (441.33 +/- 225.19 Pg/ml) and the healthy control volunteers (111.5 +/- 17.36 Pg/ml). There was a positive correlation between serum ICAM-1 and SLEDAI (r = 0.66). A high concentration of soluble ICAM-1 in SLE patients with nephritis is reported in this paper. Our finding of increased concentrations of ICAM-1 in SLE patients with nephritis underlines the importance of inflammation and endothelial involvement in this disease, but their predictive value in the disease monitoring need to be further studied.

Do novel risk factors differ between men and women aged 18 to 39 years with a high risk of coronary heart disease?

This study aimed to clarify whether high-risk premenopausal women have less atherogenic levels of markers of endothelial dysfunction, oxidation, thrombosis and inflammation, and adipokines than high-risk men of the same age. Thus, we studied levels of these markers and their determinants in 207 men and women aged 18 to 39 years with dyslipidemia and a family history of premature coronary heart disease. Women had favorable levels of E and P selectins, tumor necrosis factor alpha, tissue plasminogen activator, plasminogen activator inhibitor 1, thrombomodulin, thiobarbituric acid reactive substances, and adiponectin compared with men, but had higher levels of high-sensitivity C-reactive protein and leptin (all P < .05) and no difference in the L-arginine/asymmetric dimethyl arginine (ADMA) ratio. This ratio was higher among nonusers of hormonal contraception than among users (P = .02). In multivariate analyses, levels of intercellular adhesion molecule 1 and E selectin were associated with cigarette smoking and dietary sucrose (both P < .05), whereas the L-arginine/ADMA ratio was paradoxically associated with smoking (P < .05). Of 17 novel risk markers, 11 were associated with body mass index after adjustment for age, sex, smoking, and percentage of dietary energy from sucrose (regression coefficients, 0.14-0.62; all P < .05). In conclusion, the findings underscore the female advantage regarding determinants of novel risk markers in young adults at risk of coronary heart disease, although some endothelial dysfunction markers (cellular adhesion molecules, L-arginine/ADMA ratio) were not more favorable in women compared with men. Lifestyle factors including body mass index, dietary sucrose, smoking, and hormones were associated with levels of the markers independent of sex with body mass index being the most prominent factor.

Air pollution and inflammation in type 2 diabetes: a mechanism for susceptibility

BACKGROUND

Particulate air pollution has been associated with several adverse cardiovascular health outcomes, and people with diabetes may be especially vulnerable. One potential pathway is inflammation and endothelial dysfunction-processes in which cell adhesion molecules and inflammatory markers play important roles.

AIM

To examine whether plasma levels of soluble intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and von Willebrand factor (vWF) were associated with particle exposure in 92 Boston area residents with type 2 diabetes.

METHODS

Daily average ambient levels of air pollution (fine particles (PM2.5), black carbon (BC) and sulphates) were measured approximately 500 m from the patient examination site and evaluated for associations with ICAM-1, VCAM-1 and vWF. Linear regressions were fit to plasma levels of ICAM-1, VCAM-1 and vWF, with the particulate pollutant index, apparent temperature, season, age, race, sex, glycosylated haemoglobin, cholesterol, smoking history and body mass index as predictors.

RESULTS

Air pollutant exposure measures showed consistently positive point estimates of association with the inflammatory markers. Among participants not taking statins and those with a history of smoking, associations between PM(2.5), BC and VCAM-1 were particularly strong.

CONCLUSIONS

These results corroborate evidence suggesting that inflammatory mechanisms may explain the increased risk of air pollution-associated cardiovascular events among those with diabetes.

Inflammatory biomarkers in stable atherosclerosis

Inflammation is a key mechanism in atherosclerotic progression and destabilization that precedes clinical events such as myocardial infarction. The inflammatory biomarkers provide a window into many of these inflammatory processes. In research studies, average levels of these biomarkers in groups of subjects are often related to the risk of clinical events, and modification of risk factors can change the plasma concentrations of many biomarkers, reflecting suppression of inflammation. More evidence exists for C-reactive protein (CRP) than for other inflammatory biomarkers, and the discussion of the clinical value of plasma levels of these markers is focused mainly on CRP. Although the inflammatory biomarkers are useful research tools, their value as a clinical instrument for assessment of cardiovascular risk and/or treatment efficacy is still widely debated. Each biomarker has passionate supporters who advocate these applications, but, at this stage, no inflammatory biomarker has universal support for clinical use and their potential for fulfilling this role requires further study.

Plasma hemostatic factors and endothelial markers in four racial/ethnic groups: the MESA study

BACKGROUND

Hemostatic factors and endothelial markers may play some role in racial/ethnic differences in cardiovascular disease (CVD) rates. However, little information exists on hemostatic factors and endothelial markers across racial/ethnic groups.

OBJECTIVES

To describe, in four American racial/ethnic groups (Caucasian, Black, Hispanic, and Chinese), mean levels of selected hemostatic factors and endothelial markers.

PATIENTS AND METHODS

Multi-ethnic Study of Atherosclerosis baseline data were used (participant age: 45-84 years). Sex-specific analysis of covariance models, and t-tests for pairwise comparisons, were used to compare means of factors and markers. Adjustments were made for demographics and traditional CVD risk factors. Differences were significant at P < 0.05.

RESULTS

Blacks had the highest levels of factor VIII, D-Dimer, plasmin-antiplasmin (PAP), and von Willebrand factor, among the highest levels of fibrinogen and E-selectin (women only), but among the lowest levels of intercellular adhesion molecule 1 (ICAM-1), and, in men, the lowest levels of plasminogen activator inhibitor-1 (PAI-1). Whites and Hispanics tended to have intermediate levels of factors and markers, although they had the highest levels of ICAM-1, and Hispanics had the highest mean levels of fibrinogen and E-selectin (women only). Chinese participants had among the highest levels of PAI-1, but the lowest, or among the lowest, of all other factors and markers. No soluble thrombomodulin differences were observed.

CONCLUSIONS

In this large cohort, hemostatic factor and endothelial marker mean levels varied by race/ethnicity, even after adjustment for traditional CVD risk factors.

Age-related increases in circulating inflammatory markers in men are independent of BMI, blood pressure and blood lipid concentrations

OBJECTIVE

To examine whether age-related increase in concentrations of circulating inflammatory mediators is due to concurrent increases in cardiovascular risk factors or is independent of these.

METHODS AND RESULTS

Cytokines (IL-6, IL-18), chemokines (6Ckine, MCP-1, IP-10), soluble adhesion molecules (sICAM-1, sVCAM-1, sE-selectin) and adipokines (adiponectin) were measured in the plasma of healthy male subjects aged 18-84 years (n=162). These were related to known cardiovascular risk factors (age, BMI, systolic and diastolic blood pressure, plasma total cholesterol, LDL cholesterol, HDL cholesterol and triacylglycerol concentrations) in order to identify significant associations. Plasma concentrations of sVCAM-1, sE-selectin, IL-6, IL-18, MCP-1, 6Ckine, IP-10 and adiponectin, but not sICAM-1, were significantly positively correlated with age, as well as with several other cardiovascular risk factors. The correlations with other risk factors disappeared when age was controlled for. In contrast, the correlations with age remained significant for sVCAM-1, IL-6, MCP-1, 6Ckine and IP-10 when other cardiovascular risk factors were controlled for.

CONCLUSIONS

Plasma concentrations of some inflammatory markers (sVCAM-1, IL-6, MCP-1, 6Ckine, IP-10) are positively correlated with age, independent of other cardiovascular risk factors. This suggests that age-related inflammation may not be driven by recognised risk factors.

Soluble intercellular adhesion molecules, soluble vascular cell adhesion molecules, and risk of coronary heart disease

OBJECTIVE

We examined the association of circulating levels of soluble intercellular adhesion molecules (sICAM-1) and soluble vascular cell adhesion molecules (sVCAM-1) with coronary heart disease (CHD) risk factors and whether the adhesion molecules alone, and in combination, can serve as predictors of coronary CHD.

RESEARCH METHODS AND PROCEDURES

Among 18,225 men from the Health Professional Follow-up Study who provided blood in 1994, we documented 266 incidents of non-fatal myocardial infarction or fatal CHD during 6 years of follow-up. The cases were matched 1:2 with non-cases on age, smoking, and month of blood draw. We found both adhesion molecules directly associated with BMI, inflammatory biomarkers, and triglycerides and inversely associated with high-density lipoprotein and alcohol intake (p < 0.05). After adjustment for C-reactive protein, cholesterol-to-high-density lipoprotein ratio, age, smoking, BMI, physical activity, alcohol intake, history of diabetes, parental history of CHD, aspirin use, antihypertensive drug use, and fasting status, the relative risk of CHD was 1.69 [95% confidence interval (CI), 1.14 to 2.51] for sICAM-1 and 1.34 (95% CI, 0.91 to 1.96) for sVCAM-1, when comparing the top quintile with the lower four quintiles. Control for other inflammatory or lipid biomarkers did not appreciably attenuate the associations. When we cross-classified participants based on their sICAM-1 and sVCAM-1 levels, only the men in the top quintile of both biomarkers [relative risk = 2.39 (95% CI, 1.45 to 3.91)] had a significantly elevated risk of CHD (P interaction = 0.01, multivariate model).

DISCUSSION

sICAM-1 and sVCAM-1 are directly associated with obesity and other CHD risk factors. The combination of high levels of both adhesion molecules might be associated with the development of CHD, independent of other CHD risk factors.

Relation between soluble intercellular adhesion molecule-1, statin therapy, and long-term risk of clinical cardiovascular events in patients with previous acute coronary syndrome (from PROVE IT-TIMI 22)

High levels of adhesion molecules, such as soluble intercellular adhesion molecule-1 (sICAM-1), are associated with long-term risk of cardiac events in patients with and without stable coronary artery disease. The relation between sICAM-1 and long-term risk after acute coronary syndromes (ACSs) and the influence of statin treatment has not been explored. Using a nested case-control design, patients with ACS who were enrolled in the PROVE IT-TIMI 22 trial were matched for age, gender, smoking, diabetes, type of ACS presentation, and revascularization for index event (583 patients with recurrent events vs 581 controls). Patients with recurrent events were identified as such by death, myocardial infarction, or hospitalization for recurrent ACS. Soluble ICAM-1 was measured at study entry (approximately 7 days after ACS). After adjusting for statin regimen and other risk factors, patients in quartiles 2 to 4 were at a higher risk of clinical events compared with those in quartile 1 (odds ratio 1.6 for quartile 4 vs 1, 95% confidence interval 1.1 to 2.3, p = 0.02). The risk of adverse events in patients with sICAM-1 levels in quartiles 2 to 4 was most marked in subjects who were allocated to standard dose statin therapy, even after adjusting for low-density lipoprotein cholesterol and C-reactive protein at day 30. The risk in quartiles 2 to 4 was somewhat attenuated in the intensive therapy group. In conclusion, in this large study of patients with ACS, we provide evidence that increased endothelial activation after ACS is independently associated with increased long-term risk of death, myocardial infarction, or recurrent ACS.

A functional variant in the CARD4 gene and risk of premature coronary heart disease

Infection and innate immunity have been suggested as playing an important role in the pathogenesis of atherosclerosis. The recently discovered pattern-recognition receptor (PRR) proteins initiate signalling after host-pathogen interactions and several PRRs, especially the Toll-like receptor 4 (TLR4), have been shown to be involved in the development and progression of atherosclerosis. A new addition to the PRRs is CARD4, a gene that encodes the protein nucleotide-binding oligomerization domain 1 (NOD1) and that seems to be associated with barrier function in chronic inflammatory disorders. Recently, a functional variant in the CARD4 gene, the insertion-deletion polymorphism ND(1)+32656, has been associated with inflammatory barrier diseases (inflammatory bowel diseases and asthma). We analysed the frequencies of this known functional mutation in the CARD4 gene and of the two adjacent variants, rs2075822 and rs2907748, in a German sample of 1440 unrelated early onset coronary heart disease (CHD) patients and healthy controls. Genotype and haplotype data showed no evidence for a significant association of these CARD4 variants with CHD. Our results suggest that the analysed CARD4 mutations do not play a major role in the aetiology of CHD.

Plasma markers of activated hemostasis in the early diagnosis of acute coronary syndromes

BACKGROUND

Because acute coronary syndromes (ACS) are caused by intracoronary thrombosis, plasma markers of coagulation have relevance for early diagnosis.

AIMS AND OBJECTIVES

To provide a critical review of these studies and specific attempts to close the diagnostic time gap left by traditional plasma markers of heart injury.

METHODS

Studies of ACS patients, with at least one control group, were included when blood samples were taken within 24 h after first symptoms prior to medication or intervention. Special attention was paid to studies reporting diagnostic performance, or combination of several markers into a single diagnostic index.

RESULTS

Markers with short plasma half-life (FPA, TAT, etc.) reflect ongoing thrombosis and may identify patients at increased risk. Markers with longer half-life (F1+2, D-Dimer, etc.) may be more useful to indicate a single acute thrombotic event. However, results are highly variable and depend on sampling time, clot property, degree of coronary obstruction and physiological condition. Early diagnostic performance of hemostatic markers was poor even when combined with heart injury markers.

CONCLUSIONS

Early measurement of hemostatic plasma markers in ACS patients provides pathophysiological information and may be helpful in risk stratification or to monitor anticoagulant therapy, but does not seem useful in routine clinical diagnosis of ACS.

Measures of Thrombosis and Fibrinolysis

Our recent understanding of acute coronary syndrome as an atherothrombotic process has led to research efforts in the development of markers of thrombosis and fibrinolysis for risk prediction in cardiovascular heart disease. Although American Heart Association/American College of Cardiology guidelines recommend fibrinogen as a category I risk factor and also suggest factor VII, plasminogen activator inhibitor-1, tissue-type plasminogen activator, and von Willebrand factor as other potentially clinically useful markers, these tests have not come into routine clinical use. Their development as predictors of risk may be hampered by inconsistent laboratory methodology, which causes difficulty in comparing result interpretation with published trial studies. This article presents the history of development for these tests, proper laboratory handling, the best trial data that present evidence of their accuracy, and current guidelines for clinical use.

Cardiovascular Biomarkers in CKD: Pathophysiology and Implications for Clinical Management of Cardiac Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with all forms of chronic kidney disease (CKD). The underlying pathological state is caused by a complex interplay of traditional and nontraditional risk factors that results in atherosclerosis, arteriosclerosis, and altered cardiac morphological characteristics. This multifactorial disease introduces new challenges in predicting and treating patients with CVD sufficiently early in the course of CKD to positively alter patient outcome. Asymptomatic individuals with progressive CVD are a group of patients that deserve focused attention because early detection and intervention may provide the best opportunity for improved outcome. However, identifying CVD in asymptomatic patients with CKD or end-stage renal disease remains a significant hurdle in the management of these patients. Recently, a number of cardiovascular biomarkers were identified as predictors of patient outcome in individuals with CVD and, with additional research, may be used to guide the early diagnosis of and therapy for CVD in patients with CKD. This review examines the pathophysiological characteristics and potential clinical role of these novel cardiovascular biomarkers in risk stratification, risk monitoring, and selection of preventive therapies for patients with CKD.

A longitudinal population-based study of prothrombotic factors in elderly subjects with atrial fibrillation: the Rotterdam Study 1990-1999

BACKGROUND

A prothrombotic or hypercoagulable state in atrial fibrillation may contribute to stroke and thromboembolism. Results of longitudinal population-based studies in elderly people with atrial fibrillation are not yet available.

METHODS

In the Rotterdam Study, a population-based prospective cohort study, 162 participants with atrial fibrillation at baseline, aged 55 years and over, were matched for age and gender with 324 people in sinus rhythm. Associations were examined between three coagulation factors and the risk of total and cardiac mortality and stroke. Hazard rate ratios were calculated with 95% confidence intervals using Cox's proportional hazards model, adjusted for potential confounders.

RESULTS

Plasma von Willebrand factor was, age- and gender-adjusted, associated with cardiac mortality in the total population (relative risk 1.16; 1.06-1.27, per 10 IU dL(-1) increase), but statistical significance was lost after additional adjustments. A strong association (1.27; 1.08-1.50, per 5-unit increase) was found between soluble P-selectin (sP-sel) and cardiac mortality in atrial fibrillation patients but not in participants in sinus rhythm. Furthermore, the expected association between fibrinogen and cardiac mortality was observed only in those in sinus rhythm (2.60; 1.69-4.01, per unit increase), and not in atrial fibrillation. No associations were found between coagulation factors and stroke.

CONCLUSIONS

In this population-based study, plasma levels of sP-sel predicted clinical adverse outcomes in atrial fibrillation, suggesting a role of platelets in the prothrombotic state associated with atrial fibrillation. Fibrinogen was a risk factor of cardiac and all-cause mortality in sinus rhythm, but not in atrial fibrillation.

Circulating adhesion molecules levels in type 2 diabetes mellitus and hypertension

BACKGROUND

Risk factors for atherosclerosis such as hypertension, type 2 diabetes, obesity and dyslipidemia affect endothelial function and stimulate adhesion molecules expression. The aim of the study was to examine endothelial activation in type 2 diabetes and hypertension as indicated by adhesion molecule levels and further to investigate whether the coexistence of the above conditions has a different effect.

METHODS

Serum levels of soluble E-selectin, ICAM-1 and VCAM-1 were measured in 17 hypertensive type 2 diabetic patients (DM-HY), 32 normotensive type 2 diabetic patients (DM), 11 hypertensive nondiabetic patients (HY) and 15 healthy subjects.

RESULTS

In diabetic patients (either DM-HY or DM), soluble E-selectin levels were significantly increased compared to healthy subjects (p<0.001). In HY patients, both sE-selectin (66.44+/-71.59 vs. 29.42+/-15.56 ng/ml, p=0.033) and sVCAM-1 (1529+/-433.33 vs. 1027+/-243.56 ng/ml, p=0.03) levels were found significantly higher compared to healthy subjects (p<0.05). The coexistence of diabetes and hypertension (DM-HY) did not have an additive effect on circulating adhesion molecules levels compared with the levels observed in either diabetes or hypertension. Systolic and diastolic blood pressure (BP) were independent factors correlated respectively with sE-selectin and sVCAM-1 levels (R=0.454, p=0.034 and R=0.578, p=0.005) in nondiabetic subjects (hypertensive and normotensive).

CONCLUSIONS

Type 2 diabetes mellitus and hypertension induce endothelial activation as indicated by elevated levels of soluble adhesion molecules. This effect is not different when comorbidity is present.

Adiponectin and coronary heart disease: a prospective study and meta-analysis

BACKGROUND

There is uncertainty about the association between circulating concentrations of adiponectin and coronary heart disease (CHD) risk. We report new data from a prospective study in the context of a meta-analysis of previously published prospective studies.

METHODS AND RESULTS

We measured baseline adiponectin levels in stored serum samples of 589 men with fatal CHD or nonfatal myocardial infarction and in 1231 controls nested within a prospective study of 5661 men (aged 40 to 59 years) recruited during 1978-1980, as well as in paired samples obtained 4 years apart from 221 of these participants. Baseline adiponectin concentrations correlated (P < 0.0001) positively with HDL cholesterol (r = 0.33) and inversely with C-reactive protein (r = -0.11) and BMI (r = -0.21), and the year-to-year consistency of adiponectin values was comparable to those of blood pressure and total cholesterol levels. No significant difference between median adiponectin levels at baseline was observed between cases and controls (10.2 versus 10.8 microg/mL; P = 0.5), despite the fact that body mass index, HDL, and C-reactive protein were all significant predictors of events in this cohort. The odds ratio for CHD was 0.89 (95% CI, 0.67 to 1.18) in a comparison of men in the top third of adiponectin concentrations compared with those in the bottom third, similar to a meta-analysis (including the present study) of 7 prospective studies involving a total of 1318 CHD cases (odds ratio, 0.84 [95% CI, 0.70 to 1.01]).

CONCLUSIONS

In contrast to the strong associations previously reported between adiponectin levels and risk of type 2 diabetes, any association with CHD risk is comparatively moderate and requires further investigation.

Markers of inflammation and atherosclerosis in Egyptian patients with systemic lupus erythematosus

BACKGROUND

Cardiovascular events are markedly increased in systemic lupus erythematosus (SLE) and the mechanism of atherogenesis remains poorly understood. Low-grade inflammation and endothelial dysfunction play pivotal roles in the initiation, progression and propagation of the atherosclerotic process. Several methods have been employed to assess endothelial function, among them the measurement of biomarkers of endothelial activation and dysfunction (intercellular adhesion molecule (ICAM)-1). Since then, it has been reported that such biomarkers play a more important role than traditional risk factors in cardiovascular disease.

OBJECTIVE

To measure (tumour necrosis factor (TNF)-alpha, interleukin (IL)-6 and ICAM-1) levels as markers of inflammation and atherosclerosis in 40 Egyptian patients with SLE with various degrees of activity in comparison with 20 healthy volunteers, and to investigate their relationship to disease activity and hypertension.

METHODS

Sixty subject (40 with SLE and 20 healthy controls) were the subject of this study, their clinical disease activity was scored according to the SLE Disease Activity Index (SLEDAI), and serum sampling was obtained for TNF-alpha, IL-6 and ICAM-1 level assay. Renal biopsy was carried out and examined by light microscopy. The mean level of TNF-alpha, IL-6 and ICAM-1 were significantly higher in SLE patients with active disease (766.95 +/- 357.82 Pg/mL, 135.4 +/- 54.23 Pg/mL, 826.05 +/- 367.1 Pg/mL) when compared with those with inactive disease (314.01 +/- 100.87 Pg/mL, 47.33 +/- 18.61 pg/mL, 441.33 +/- 225.19 Pg/mL) and healthy control volunteers (172.7 +/- 39.19 Pg/mL, 21.15 +/- 10.99 Pg/mL, 111.5 +/- 17.36 Pg/mL), respectively. Furthermore, these levels were significantly higher in hypertensive (614.08 +/- 333.05 Pg/mL, 107.86 +/- 54.96 Pg/mL and 862.13 +/- 333.29 Pg/mL) compared to normotensive patients (267.5 +/- 112.72 Pg/mL, P = 0.008, 35.75 +/- 20.26 Pg/mL, P = 0.02I, and 337.25 +/- 235.62 Pg/mL, P = 0.02) for TNF-alpha, IL-6 and ICAM, respectively. There were no statistically significant difference regarding age, sex, smoking, cholesterol and high-density lipoprotein (HDL) levels between hypertensive and normotensive patients.

CONCLUSION

A high concentration of soluble ICAM-1 in Egyptian patients with SLE and nephritis is reported here for the first time. Our finding of increased concentrations of TNF-alpha, IL-6 and ICAM-1 in Egyptian patients with SLE and lupus nephritis underlines the importance of inflammation and endothelial involvement in this disorder, but their predictive value in the disease monitoring needs to be further studied.

Increased systemic inflammation and oxidative stress in patients with worsening congestive heart failure: improvement after short-term inotropic support

In the present study, we evaluated circulating pro-inflammatory mediators and markers of oxidative stress in patients with decompensated CHF (congestive heart failure) and assessed whether clinical recompensation by short-term inotropic therapy influences these parameters. Patients with worsening CHF (n=29, aged 61.9+/-2.7 years), NYHA (New York Heart Association) class III-IV, and left ventricular ejection fraction of 23.7+/-1.8% were studied. Controls comprised age-matched healthy volunteers (n=15; 54.1+/-3.2 years). Plasma levels of cytokines [IL (interleukin)-6 and IL-18], chemokines [MCP-1 (monocyte chemotactic protein-1)], adhesion molecules [sICAM (soluble intercellular adhesion molecule), sE-selectin (soluble E-selectin)], systemic markers of oxidation [TBARS (thiobarbituric acid-reactive substances), 8-isoprostaglandin F(2alpha) and nitrotyrosine] and hs-CRP (high-sensitivity C-reactive protein) were measured by ELISA and colorimetric assays at admission and 30 days following 72-h milrinone (n=15) or dobutamine (n=14) infusion. Plasma IL-6, IL-18, sICAM, E-selectin, hs-CRP and oxidative markers were significantly higher in patients on admission before inotropic treatment compared with controls (P<0.05). Short-term inotropic support improved clinical status as assessed by NYHA classification and by the 6-min walk test and significantly decreased plasma levels of IL-6, IL-18, sICAM, hs-CRP and markers of oxidation (P<0.05) at 30 days. The effects of milrinone and dobutamine were similar. In conclusion, our results demonstrate that patients with decompensated CHF have marked systemic inflammation and increased production of oxygen free radicals. Short-term inotropic support improves functional status and reduces indices of inflammation and oxidative stress in patients with decompensated CHF.

Dietary patterns are associated with biochemical markers of inflammation and endothelial activation in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Dietary patterns may influence cardiovascular disease risk through effects on inflammation and endothelial activation.

OBJECTIVE

We examined relations between dietary patterns and markers of inflammation and endothelial activation.

DESIGN

At baseline, diet (food-frequency questionnaire) and concentrations of C-reactive protein (CRP), interleukin 6 (IL-6), homocysteine, soluble intercellular adhesion molecule-1 (sICAM-1), and soluble E selectin were assessed in 5089 nondiabetic participants in the Multi-Ethnic Study of Atherosclerosis.

RESULTS

Four dietary patterns were derived by using factor analysis. The fats and processed meats pattern (fats, oils, processed meats, fried potatoes, salty snacks, and desserts) was positively associated with CRP (P for trend < 0.001), IL-6 (P for trend < 0.001), and homocysteine (P for trend = 0.002). The beans, tomatoes, and refined grains pattern (beans, tomatoes, refined grains, and high-fat dairy products) was positively related to sICAM-1 (P for trend = 0.007). In contrast, the whole grains and fruit pattern (whole grains, fruit, nuts, and green leafy vegetables) was inversely associated with CRP, IL-6, homocysteine (P for trend < or = 0.001), and sICAM-1 (P for trend = 0.034), and the vegetables and fish pattern (fish and dark-yellow, cruciferous, and other vegetables) was inversely related to IL-6 (P for trend = 0.009). CRP, IL-6, and homocysteine relations across the fats and processed meats and whole grains and fruit patterns were independent of demographics and lifestyle factors and were not modified by race-ethnicity. CRP and homocysteine relations were independent of waist circumference.

CONCLUSIONS

These results corroborate previous findings that empirically derived dietary patterns are associated with inflammation and show that these relations in an ethnically diverse population with unique dietary habits are similar to findings in more homogeneous populations.

Endothelial dysfunction in Buerger's disease and its relation to markers of inflammation

BACKGROUND

Buerger's disease (BD) is a segmental occlusive vascular disease. The aim of this study was to detect functional changes in brachial artery and asymptomatic morphological changes in extra-cranial carotid arteries not affected by the disease process and to assess markers of inflammation and endothelial damage.

MATERIALS AND METHODS

Fourteen patients in the remission phase of BD and the same number of age- and sex-matched healthy controls were included in the study. The capability of endothelium-dependent (flow-mediated) and endothelium-independent dilation of the brachial artery and intima-media thickness of the carotid arteries were measured using high-resolution ultrasound. Laboratory parameters of endogenous fibrinolytic activity, inflammation and endothelial dysfunction were also measured.

RESULTS

Patients with BD had a diminished capability of endothelium-dependent vasodilation and higher levels of some circulating markers of inflammation, such as leukocytes, C-reactive protein, intercellular adhesion molecule-1 and E-selectin. Intercellular adhesion molecule-1 levels were related to some of the inflammatory markers (sedimentation rate, C-reactive protein, alpha2-globulins and fibrinogen), while E-selectin was correlated with decreased endogenous blood fibrinolytic activity. Endothelium-dependent vasodilation was in negative correlation with the relative share of neutrophil granulocytes. There were no significant differences in intima-media thickness between patients with BD and controls.

CONCLUSIONS

Our study has expressed generalized functional arterial disorder in patients with BD not accompanied by any measurable morphological changes of the carotid arterial wall. Functional deterioration of brachial artery could be related to increased levels of various inflammatory markers--the process which is most probably the basic pathogenetic mechanism of the disease.

Soluble vascular cell adhesion molecule-1 and soluble E-selectin are associated with micro- and macrovascular complications in Type 1 diabetic patients

OBJECTIVE

There are no large studies in Type 1 diabetic patients that have examined the relation between soluble adhesion molecules and micro- and macrovascular outcomes, although the risks of such complications are high. Therefore, the main objective is to examine the relationship between soluble (s) vascular cell adhesion molecule-1 (sVCAM-1) and sE-selectin and retinopathy, albuminuria, and cardiovascular disease (CVD) in Type 1 diabetic patients.

METHODS

Cross-sectional data on 540 Type 1 diabetic patients, with a mean age of 40 years and diabetes duration of 22 years, from the EURODIAB Prospective Complications Study (PCS) were analysed. Retinopathy was assessed by centrally graded retinal photographs. Albumin excretion rate (AER) was used to define micro- and macroalbuminuria. CVD was defined as having physician diagnosed myocardial infarction (MI), stroke, coronary artery bypass graft (CABG) or angina, or Minnesota coded ischaemic electrocardiograms (ECGs).

RESULTS

Unadjusted, there was a positive relationship between sVCAM-1 and sE-selectin with nonproliferative and proliferative retinopathy, micro- and macroalbuminuria, and CVD. After adjustment for age, sex, duration of diabetes, systolic blood pressure (BP), LDL-cholesterol, fasting triglycerides (TGs), smoking, body mass index (BMI), and glycated haemoglobin, as well as other complications, the strongest significant associations were shown between sVCAM-1 and macroalbuminuria, with an odds ratio of 1.83 (1.33-2.53) for every 100 ng/ml increase in sVCAM-1.

CONCLUSIONS

In this large sample of Type 1 diabetic patients, it was shown that sVCAM-1 and sE-selectin have positive associations with retinopathy, albuminuria, and CVD. This suggests that adhesion molecules are important in the pathogenesis of vascular complications in Type 1 diabetes.

Role of FLAP and PDE4D in myocardial infarction and stroke: Target discovery and future treatment options

Biomarkers such as C-reactive protein (CRP) and myeloperoxidase (MPO) are elevated in patients with coronary artery disease and confer risk of acute cardiovascular events, such as myocardial infarction (MI) and stroke. More recently, variants in the 5-lipoxygenase-activating protein (FLAP) gene were shown to confer risk to both MI and stroke, effects that appear to be mediated through elevated LTB(4), a chemoattractant mediator shown to be upregulated in patients with MI. Another gene in the leukotriene (LT) pathway, LTA(4) hydrolase, was subsequently found to confer increased risk to MI, effects that were ethnicity-specific with an approximately threefold higher risk in African Americans than in whites. In another study, markers in the phosphodiesterase (PDE) 4D gene were found to confer risk to large-vessel occlusive and cardiogenic stroke. Interestingly, there is a cross-link between the 5-LO and the PDE4D pathways with converging biology. To address the role of an inhibitor of FLAP on biomarkers of MI risk, a randomized placebo-controlled phase II trial was conducted in patients with MI. This trial showed that LTB(4) and MPO production was reduced in whole blood leukocytes that were stimulated with ionomycin and the effects of the inhibitor were dose dependent. Serum CRP and plasma MPO were also reduced at the highest dose, which was well tolerated. These data suggest that LTB(4) is a risk factor of MI and that inhibition of FLAP and the LT pathway produces suppression of biomarkers that are associated with MI risk, including but not limited to LTB(4), MPO, and CRP, supporting the notion that the LTB(4) arm of the LT pathway may play a fundamental role in heart attacks and stroke.

Folic acid, inflammation, and atherosclerosis: False hopes or the need for better trials?

An increasing body of evidence supports the existence of a strong link between inflammation, endothelial dysfunction, and the onset and progression of atherosclerosis. However, a cause-effect relationship between these phenomena has not been demonstrated yet. Although some inflammatory markers, such as C-reactive protein, have been recently shown to improve risk stratification and to strongly predict cardiovascular outcome, it is largely unknown whether modifications of these markers might provide salutary effects and reduce cardiovascular morbidity and mortality. The B-vitamin folic acid has recently gained attention because of its potential to provide beneficial effects on surrogate end-points, such as endothelial function, in patients at high cardiovascular risk. However, the role of folic acid in mitigating the pro-inflammatory state associated with atherosclerosis is controversial. Despite the theoretical arguments supporting the potential anti-atherosclerotic and anti-inflammatory effects of folic acid, the current evidence is limited, deriving from small trials on different study populations, using folic acid often in combination with other vitamins and for different treatment periods. This review will consider the current evidence supporting the role of some well-established inflammatory markers in predicting cardiovascular outcomes, the mechanisms by which folic acid might exert anti-inflammatory effects, the epidemiological data relating folic acid concentrations with inflammatory markers, the published interventional studies on the effects of folic acid supplementation on these markers, and the factors that need to be considered in designing future trials.

Association of educational level with inflammatory markers in the Framingham Offspring Study

Socioeconomic position consistently predicts coronary heart disease; however, the biologic mechanisms that may mediate this association are not well understood. The objective of this study was to determine whether socioeconomic position (measured as educational level) is associated with inflammatory risk factors for coronary heart disease, including C-reactive protein, interleukin-6, soluble intercellular adhesion molecule-1, monocyte chemoattractant protein-1, and P-selectin. The study sample included 2,729 participants (53.4% women; mean age, 62 +/- 10 years) from the US Framingham Offspring Study cohort who attended examination cycles 3 (1984-1987) and 7 (1998-2001) and provided educational attainment data. Inflammatory markers were measured in fasting serum samples. Multivariable linear regression analyses were performed, adjusting for potential confounders including age, sex, and clinical risk factors. In age- and sex-adjusted analyses, educational attainment was significantly inversely associated with C-reactive protein (p < 0.0001), interleukin-6 (p < 0.0001), soluble intercellular adhesion molecule-1 (p < 0.0001), and monocyte chemoattractant protein-1 (p = 0.0004). After further adjustment for clinical risk factors, educational level remained significantly associated with C-reactive protein (p = 0.0002), soluble intercellular adhesion molecule-1 (p = 0.01), and monocyte chemoattractant protein-1 (p = 0.01). In conclusion, educational attainment is associated with inflammatory risk factors for coronary heart disease. The association provides evidence suggestive of a biologic pathway by which socioeconomic position may predispose to coronary heart disease.

Circulating markers of endothelial function in cardiovascular disease

Endothelial dysfunction is a key event in cardiovascular disease. Measurement of endothelial dysfunction in vivo presents a major challenge, but has important implications since it may identify the clinical need for therapeutic intervention, specifically in primary prevention. Several biological markers have been used as indicators of endothelial dysfunction. The soluble adhesion molecules sICAM-1 and sVCAM-1 lack specificity and are increased in inflammatory processes. Both markers are increased in coronary artery disease. sICAM-1 level predicts the risk for cardiovascular disease or diabetes mellitus in healthy individuals. sE-selectin is specific for the endothelium and is increased in coronary artery disease and diabetes mellitus. sE-selectin is also associated with diabetic risk. The endothelium-specific marker, soluble thrombomodulin, is associated with severity of coronary artery disease, stroke or peripheral occlusive arterial disease and is not increased in healthy or asymptomatic subjects. Interestingly, thrombomodulin decreases during treatment of hypercholesterolemia or hyperhomocysteinemia. In contrast, von Willebrand factor is the best endothelial biomarker and predicts risk for ischemic heart disease or stroke.

Common genetic vulnerability to depressive symptoms and coronary artery disease: a review and development of candidate genes related to inflammation and serotonin

OBJECTIVE

Although it is well established that depressive symptoms are associated with recurrent cardiac events among cardiac patients and novel cardiac events among participants with no known coronary artery disease (CAD), the nature of this association remains unclear. In this regard, little attention has been paid to the possibility that common genetic vulnerability contributes to both depressive symptoms and CAD. In this paper, we review the existing evidence for common genetic contributions to depression and CAD, primarily using evidence from twin and family studies, followed by a review of two major pathophysiological mechanisms thought to underlie covariation between depressive symptoms and CAD: inflammation and serotonin. We conclude with an overview of select candidate genes within these pathways.

METHODS

Literature review.

RESULTS

In twin studies, both depression and CAD appear heritable. In the only twin study to consider depression and CAD jointly, the correlation across heritabilities was 0.42, suggesting that nearly 20% of variability in depressive symptoms and CAD was attributable to common genetic factors. In addition, although it is plausible that genetic variation related to inflammation and serotonin may be associated with both depression and CAD, genetic variation related to inflammation has been primary examined in relation to CAD, whereas genetic variation in the serotonin system has been primarily examined in relation to depression.

CONCLUSIONS

It appears that the covariation of depressive symptoms and CAD may be attributable, in part, to a common genetic vulnerability. Although several pathways may be involved, genes within the inflammation and serotonin pathways may serve as good candidates for the first steps in identifying genetic variation important for depression, CAD or both.

The metabolic syndrome and cardiovascular disease

The metabolic syndrome, which is very common in the general population, is defined by the clustering of several classic cardiovascular risk factors, such as type 2 diabetes, hypertension, high triglycerides and low high-density lipoprotein cholesterol (HDL). Central obesity and insulin resistance, which are the two underlying disorders of the syndrome, are further risk factors for cardiovascular disease. Moreover, a panel of novel (non-traditional) risk factors are ancillary features of the metabolic syndrome. They include biomarkers of chronic mild inflammation (e.g. C-reactive protein, CRP), increased oxidant stress (e.g. oxidized low density lipoprotein, LDL), thrombophilia (e.g. plasminogen activator inhibitor-1, PAI-1) and endothelial dysfunction (e.g. E-selectin). Therefore, subjects with the metabolic syndrome are potentially at high risk of developing atherosclerosis and clinical cardiovascular events.In recent years several longitudinal studies have confirmed that subjects with the metabolic syndrome present with atherosclerosis and suffer from myocardial infarction and stroke at rates higher than subjects without the syndrome. The risk of cardiovascular disease (CVD) is particularly high in women with the syndrome and in subjects with pre-existing diabetes, CVD and/or high CRP. However, an increased risk is already present in subjects with a cluster of multiple mild abnormalities. The risk related to the metabolic syndrome is definitely higher when subjects affected are compared to subjects free of any metabolic abnormality.

Soluble intracellular adhesion molecule-1 is associated with cardiovascular disease risk and mortality in older adults

BACKGROUND

Intracellular adhesion molecule-1 (ICAM-1) regulates leukocyte-endothelial attachment, a process crucial to atherosclerosis. Circulating soluble ICAM-1 (sICAM-1) may serve as a marker of cardiovascular disease (CVD) progression.

OBJECTIVES

We examined the association of sICAM-1 with measures of subclinical CVD and risk of incident CVD events and death in older men and women (age > or = 65 years) from the Cardiovascular Health Study.

METHODS

Selected participants were free of clinical CVD at baseline. Non-exclusive incident case groups were angina (n = 534), myocardial infarction (n = 304), stroke (n = 327), and death (n = 842; CVD death = 310). A total 643 subjects were free of events during follow-up.

RESULTS

sICAM-1 was positively associated with C-reactive protein, interleukin-6 and fibrinogen and measures of subclinical CVD in these older men and women. In Cox regression models adjusted for age, gender, and race, increasing levels of sICAM-1 were associated with increased risk of all cause mortality in men and women. Hazard ratios (95% confidence intervals) for a one standard deviation increase in sICAM-1 (89.7 ng mL(-1)) were 1.3 (1.1-1.4) in men and 1.2 (1.1-1.3) in women. sICAM-1 was associated with increased risk of CVD death in women (1.2; 1.0-1.5), but not men (1.1; 0.9-1.3). There were no associations of sICAM-1 with non-fatal CVD events.

CONCLUSIONS

While sICAM-1 was associated with death in older men and women, there was a more marked association between sICAM-1 and CVD death in women.

Atherothrombosis and high-risk plaque: part I: evolving concepts

Atherothrombosis is a complex disease in which cholesterol deposition, inflammation, and thrombus formation play a major role. Rupture of high-risk, vulnerable plaques is responsible for coronary thrombosis, the main cause of unstable angina, acute myocardial infarction, and sudden cardiac death. In addition to rupture, plaque erosion may also lead to occlusive thrombosis and acute coronary events. Atherothrombosis can be evaluated according to histologic criteria, most commonly categorized by the American Heart Association (AHA) classification. However, this classification does not include the thin cap fibroatheroma, the most common form of high-risk, vulnerable plaque. Furthermore, the AHA classification does not include plaque erosion. As a result, new classifications have emerged and are reviewed in this article. The disease is asymptomatic during a long period and dramatically changes its course when complicated by thrombosis. This is summarized in five phases, from early lesions to plaque rupture, followed by plaque healing and fibrocalcification. For the early phases, the role of endothelial dysfunction, cholesterol transport, high-density lipoprotein, and proteoglycans are discussed. Furthermore, the innate and adaptive immune response to autoantigens, the Toll-like receptors, and the mechanisms of calcification are carefully analyzed. For the advanced phases, the role of eccentric remodeling, vasa vasorum neovascularization, and mechanisms of plaque rupture are systematically evaluated. In the final thrombosis section, focal and circulating tissue factor associated with apoptotic macrophages and circulatory monocytes is examined, closing the link between inflammation, plaque rupture, and blood thrombogenicity.

Anti-Inflammatory Effects of Statins: Clinical Evidence and Basic Mechanisms

Chronic inflammation is a key feature of vascular disease states such as atherosclerosis. Multiple clinical studies have shown that a class of medications termed statins lower cardiovascular morbidity and mortality. Originally developed to lower serum cholesterol, increasing evidence suggests that these medications have potent anti-inflammatory effects that contribute to their beneficial effects in patients. Here, we discuss the clinical and experimental evidence underlying the anti-inflammatory effects of these agents.

Predictive value of soluble intercellular adhesion molecule-1 for risk of ischemic events in individuals with cerebrovascular disease

BACKGROUND AND PURPOSE

Cellular adhesion molecules may play a critical role in the inflammatory process leading to atherosclerosis. The purpose of this study was to determine whether soluble intercellular adhesion molecule-1 (sICAM-1) is a predictor of future ischemic events in high-risk individuals and also whether it is associated with carotid artery stenosis.

METHODS

We conducted a prospective study of sICAM-1 concentration in 3 groups: (1) subjects with recent (< 7 days) ischemic stroke or TIA, (2) asymptomatic subjects with carotid stenosis > or = 50% and (3) asymptomatic individuals with vascular risk factors. Subjects were followed for a minimum of 3 years. sICAM-1 levels were compared between the groups and correlated with the risk of ischemic events and the degree of carotid artery stenosis.

RESULTS

We studied 275 subjects. Mean sICAM-1 levels were significantly higher in those with recent ischemic stroke or TIA compared to those with risk factors alone. During follow-up, ischemic events occurred almost nine times more frequently in subjects in group 1 compared to group 3. sICAM-1 concentration was not predictive of future ischemic events (OR 1.001, 95% CI 0.998-1.004). There was no significant association between sICAM-1 concentration and carotid artery stenosis (OR 1.001, 95% CI 0.999-1.004).

CONCLUSIONS

Mean sICAM-1 levels were higher in subjects with recent cerebral ischemia. No association between sICAM-1 and carotid artery stenosis was observed. Neither baseline nor subsequent sICAM-1 levels were predictive of the risk of future ischemic events.

Systemic inflammatory markers in acute coronary syndrome: association with cardiovascular risk factors and effect of early lipid lowering

BACKGROUND

Evidence for statin therapy in prevention of coronary artery disease is overwhelming. In spite of theoretical benefits, any additional advantage of its early introduction in the management of acute coronary syndrome is, however, uncertain. We therefore investigated differences between plasma levels of the systemic inflammatory markers intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, C-reactive protein and interleukin-6 in patients presenting with unstable angina or acute myocardial infarction, and assessed whether the 30-day levels of these markers are influenced by early instigation of the HMG-CoA reductase inhibitor pravastatin.

MATERIALS AND METHODS

170 (134 male) patients presenting with acute coronary syndrome, but without previous statin therapy, participated. Blood was taken within 24 h of onset of ischaemic pain and again at 30 days. In all, 87 (71 male) participants were treated with pravastatin (20-40 mg daily) and 83 (63 male) with a matched placebo.

RESULTS

At presentation, interleukin-6 was higher in males than in females (P=0.008) and lower in those with a pre-existing history of myocardial infarction (P=0.038). C-reactive protein and interleukin-6 were greater in myocardial infarction, but this difference was lost at 30 days. Thirty-day changes in all parameters were inversely related to level at presentation but not to treatment with pravastatin. Hypertension (P=0.011) and smoking (P=0.042) were associated with elevation of C-reactive protein with no difference between unstable angina or acute myocardial infarction. The effect of these individual factors was cumulative.

CONCLUSIONS

Interleukin-6 was greater in acute myocardial infarction than in unstable angina; E-selectin was positively associated with a previous myocardial infarction and inversely related to age. We found no effect of early introduction of pravastatin on systemic inflammatory markers 30 days after acute coronary syndrome.

C-Reactive Protein, Interleukin-6, and Soluble Adhesion Molecules as Predictors of Progressive Peripheral Atherosclerosis in the General Population

Background— The relationship between levels of circulating inflammatory markers and risk of progressive atherosclerosis is relatively undetermined. We therefore studied inflammatory markers as predictors of peripheral atherosclerotic progression, measured by the ankle-brachial index (ABI) at 3 consecutive time points over 12 years.

Methods and Results— The Edinburgh Artery Study is a population cohort study of 1592 men and women aged 55 to 74 years. C-reactive protein (CRP), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), and E-selectin were measured at baseline. Valid ABI measurements were obtained on 1582, 1081, and 813 participants at baseline and 5-year and 12-year follow-up examinations, respectively. At baseline, a significant trend was found between higher plasma levels of CRP ( P ≤0.05) and increasing severity of peripheral arterial disease (PAD), after adjustment for baseline cardiovascular risk factors. IL-6 at baseline ( P ≤0.001) was associated with progressive atherosclerosis at 5 years (ABI change from baseline), and CRP ( P ≤0.01), IL-6 ( P ≤0.001), and ICAM-1 ( P ≤0.01) were associated with changes at 12 years, independently of baseline ABI, cardiovascular risk factors, and baseline cardiovascular disease. Only IL-6 independently predicted ABI change at 5 years ( P ≤0.01) and 12 years ( P ≤0.05) in analyses of all inflammatory markers simultaneously and adjusted for baseline ABI, cardiovascular risk factors, and cardiovascular disease at baseline.

Conclusions— These findings suggest that CRP, IL-6, and ICAM-1 are molecular markers associated with atherosclerosis and its progression. IL-6 showed more consistent results and stronger independent predictive value than other inflammatory markers.

Plasma concentration of soluble vascular cell adhesion molecule-1 and oncoming cardiovascular risk in patients with unstable angina pectoris and non-ST-segment elevation myocardial infarction

In patients who had unstable angina pectoris and non-ST-segment elevation myocardial infarction, initial blood levels of soluble vascular cell adhesion molecule-1 were found not to be higher than those in asymptomatic patients who had coronary artery disease. Although troponin T and high-sensitivity C-reactive protein were found to have prognostic value, blood levels of soluble vascular cell adhesion molecule-1 were not predictive of an increased risk of major cardiac events during 6-month follow-up.

Potential role of ultrafine particles in associations between airborne particle mass and cardiovascular health

Numerous epidemiologic time-series studies have shown generally consistent associations of cardiovascular hospital admissions and mortality with outdoor air pollution, particularly mass concentrations of particulate matter (PM) < or = 2.5 or < or = 10 microm in diameter (PM2.5, PM10). Panel studies with repeated measures have supported the time-series results showing associations between PM and risk of cardiac ischemia and arrhythmias, increased blood pressure, decreased heart rate variability, and increased circulating markers of inflammation and thrombosis. The causal components driving the PM associations remain to be identified. Epidemiologic data using pollutant gases and particle characteristics such as particle number concentration and elemental carbon have provided indirect evidence that products of fossil fuel combustion are important. Ultrafine particles < 0.1 microm (UFPs) dominate particle number concentrations and surface area and are therefore capable of carrying large concentrations of adsorbed or condensed toxic air pollutants. It is likely that redox-active components in UFPs from fossil fuel combustion reach cardiovascular target sites. High UFP exposures may lead to systemic inflammation through oxidative stress responses to reactive oxygen species and thereby promote the progression of atherosclerosis and precipitate acute cardiovascular responses ranging from increased blood pressure to myocardial infarction. The next steps in epidemiologic research are to identify more clearly the putative PM casual components and size fractions linked to their sources. To advance this, we discuss in a companion article (Sioutas C, Delfino RJ, Singh M. 2005. Environ Health Perspect 113:947-955) the need for and methods of UFP exposure assessment.

Circulating inflammatory markers and risks of cardiovascular and non-cardiovascular disease

There is current interest in the associations of circulating inflammatory markers (C-reactive protein, fibrinogen, white cell count, albumin, erythrocyte sedimentation rate, the factor VIII:von Willebrand factor complex, the tissue plasminogen activator:plasminogen activator inhibitor type 1 complex, fibrin D-dimer) not only with prognosis in acute coronary syndromes and acute stroke, but also in prediction of cardiovascular events in the general population. Recent meta-analyses of long-term prospective studies have established their associations with coronary heart disease (CHD) events, which may be cause, consequence or coincidence. These markers are also associated in epidemiologic studies of general populations with many cardiovascular risk factors (which may confound their associations with CHD risk), and also with asymptomatic arterial disease (of which they be consequences: 'reverse causality'). The causality of their associations with cardiovascular events is questioned by their lack of specificity for risk of cardiovascular events; and by the lack of association of their functional genotypes with CHD in 'Mendelian randomized trials'. Hence, proof of causality awaits testing in randomized-controlled trials of long-term selective reduction by future agents. Markers are of little additional predictive value to current cardiovascular risk scores, and it is premature to advocate their use in screening for cardiovascular risk prior to careful evaluation of costs, risks, and benefits.

Cardiovascular risk parameters in men with ankylosing spondylitis in comparison with non-inflammatory control subjects: relevance of systemic inflammation

Men with AS (ankylosing spondylitis) are at elevated risk for CHD (coronary heart disease) but information on risk factors is sparse. We compared a range of conventional and novel risk factors in men with AS in comparison with healthy controls and, in particular, determined the influence of systemic inflammation. Twenty-seven men with confirmed AS and 19 controls matched for age were recruited. None of the men was taking lipid-lowering therapy. Risk factors inclusive of plasma lipids, IL-6 (interleukin-6), CRP (C-reactive protein), vWF (von Willebrand factor), fibrin D-dimer, ICAM-1 (intercellular cell-adhesion molecule-1) and fibrinogen were measured, and blood pressure and BMI (body mass index) were determined by standard techniques. A high proportion (70%) of men with AS were smokers compared with 37% of controls (P=0.024). The AS patients also had a higher BMI. In analyses adjusted for BMI and smoking, men with AS had significantly higher IL-6 and CRP (approx. 9- and 6-fold elevated respectively; P<0.001), fibrinogen (P=0.013) and vWF (P=0.008). Total cholesterol and HDL-C (high-density lipoprotein cholesterol) were lower (P<0.05 and P=0.073 respectively) in AS and thus the ratio was not different. Pulse pressure was also significantly higher in AS (P=0.007). Notably, adjustment for IL-6 and CRP levels rendered all case-control risk factor differences, except pulse pressure, non-significant. In accordance with this finding, IL-6 correlated positively (r=0.74, P<0.001) with fibrinogen, but negatively (r=−0.46, P=0.016) with total cholesterol concentration. In conclusion, men with AS have perturbances in several CHD risk factors, which appear to be driven principally by systemic inflammatory mediators. Inflammation-driven atherogenesis potentially contributes to the excess CHD risk in AS.

Is the association between flow-mediated dilation and cardiovascular risk limited to low-risk populations?

OBJECTIVES

The aim of this research was to study whether the relation between endothelial function measured by flow-mediated dilation (FMD) of the brachial artery and cardiovascular risk factors is affected by the baseline cardiovascular risk.

BACKGROUND

Flow-mediated dilation of the brachial artery is widely used as a measure of endothelial function. Relations between FMD and most cardiovascular risk factors have been described.

METHODS

We performed a meta-regression analysis of 211 selected articles (399 populations) reporting on FMD and cardiovascular risk factors. Mean values of FMD; age; proportion of men; proportion of smokers; blood pressure; lipids; glucose; and the presence of diabetes mellitus, of hyperlipidemia, and of hypertension were retrieved from the articles. The 10-year risk of coronary heart disease (CHD) for each population was estimated based on the Framingham risk score. The relation between FMD and cardiovascular risk factors was assessed within each risk category by linear regression analysis, adjusting for age and gender, and weighted for the study size.

RESULTS

A relation between FMD and cardiovascular risk factors was most clear in the category with lowest baseline risk (below 2.8% per decade). In populations with low baseline risk, for each % increase in Framingham risk, FMD decreased by 1.42% (95% confidence interval: 0.65 to 2.19). In medium- and high-risk populations, FMD was not related to risk (-0.02% [-0.27 to 0.22] and 0.06% [-0.02 to 0.13], respectively). These findings were independent of differences in brachial lumen diameter and technical aspects of the FMD measurement.

CONCLUSIONS

Only in populations at low risk, endothelial function measured by FMD is related to the principal cardiovascular risk factors, and to the estimated 10-year risk of CHD.

Quantitative genetic analysis of cellular adhesion molecules: the Fels Longitudinal Study

Circulating concentrations of inflammatory markers predict cardiovascular disease (CVD) risk and are closely associated with obesity. However, little is known concerning genetic influences on serum levels of inflammatory markers. In this study, we estimated the heritability (h2) of soluble cellular adhesion molecule (sCAM) concentrations and examined the correlational architecture between different sCAMs. The study population included 234 men and 270 women aged 18-76 years, belonging to 121 families participating in the Fels Longitudinal Study. Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sESEL-1) and P-selectin (sPSEL-1) were assayed using commercially available kits. A variance components-based maximum likelihood method was used to estimate the h2 of the different serum inflammatory markers while simultaneously adjusting for the effects of known CVD risk factors, such as age and smoking. Additionally, we used bivariate extensions of these methods to estimate genetic and random environmental correlations among sCAMs. Levels of sCAMs were significantly heritable: h2=0.24+/-0.10 for sICAM-1, h2=0.22+/-0.10 for sVCAM-1, h2=0.50+/-0.11 for sESEL-1, and h2=0.46+/-0.10 for sPSEL-1. In addition, a significant genetic correlation (rho(G)=0.63) was found between sICAM-1 and sVCAM-1 indicating some degree of shared genetic control. In the Fels Longitudinal Study, the levels of four sCAMs are significantly influenced by genetic effects, and sICAM-1 shares a common genetic background with sVCAM-1.

A comparison of the PROCAM and Framingham point-scoring systems for estimation of individual risk of coronary heart disease in the Second Northwick Park Heart Study

We have compared the predictive value of the PROCAM and Framingham risk algorithms in healthy UK men from the Second Northwick Park Heart Study (NPHS-II) (50-64 years at entry), followed for a median of 10.8 years for coronary heart disease (CHD) events. For PROCAM, the area under the receiver operating characteristic (ROC) curve was 0.63 (95% CI, 0.59-0.67), and not significantly different (p = 0.46) from the Framingham score, 0.62 (0.58-0.66). Sensitivities for a 5% false-positive rate (DR(5)) were 13.8 and 12.4%, respectively. Calibration analysis for PROCAM gave a ratio of observed to expected events of 0.46 (Hosmer-Lemeshow test, p < 0.0001) and 0.47 for Framingham (p < 0.0001). Using measures taken at 5 years of high-density lipoprotein cholesterol and (estimated) low-density lipoprotein cholesterol levels increased the ROC by only 1%. An NPHS-II risk algorithm, developed using a 50% random subset, and including age, triglyceride, total cholesterol, smoking status, and systolic blood pressure at recruitment, gave an ROC of 0.64 (0.58-0.70) with a DR(5) of 10.7% when applied to the second half of the data. Adding family history and diabetes increased the DR(5) to 18.4% (p = 0.28). Adding lipoprotein(a) >26.3 mg/dL (relative risk 1.6, 1.1-2.4) gave a DR(5) of 15.5% (p = 0.55), while adding fibrinogen levels (relative risk for 1S.D. increase = 1.5, 1.1-2.0) had essentially no additional impact (DR(5) = 16.9%, p = 0.95). Thus, the PROCAM algorithm is marginally better as a risk predictor in UK men than the Framingham score, but both significantly overestimate risk in UK men. The algorithm based on NPHS-II data performs similarly to those for PROCAM and Framingham with respect to discrimination, but gave an improved ratio of observed to expected events of 0.80 (p = 0.01), although no score had a high sensitivity. Any novel factors added to these algorithms will need to have a major impact on risk to increase sensitivity above that given by classical risk factors.

Markers of Endothelial and Hemostatic Activation and Progression of Cerebral White Matter Hyperintensities

Background and Purpose— The pathogenesis of cerebral small vessel disease (SVD) is poorly understood, but endothelial activation and dysfunction may play a causal role. Cross-sectional studies have found increased circulating markers of endothelial activation, but this study design cannot exclude causality from secondary elevations. Confluent white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) appear to represent asymptomatic cerebral SVD. In a prospective study, we determined whether circulating markers of endothelial activation predicted progression of WMH.

Methods— In the community-based Austrian Stroke Prevention Study, MRI was performed at baseline in 296 subjects and repeated at 3 and 6 years. The following were measured on baseline plasma samples: intercellular adhesion molecule (ICAM), thrombomodulin, tissue factor plasma inhibitor, prothrombin fragments 1 and 2, and D-dimers.

Results— ICAM was associated with age- and gender-adjusted WMH lesion progression at both 3 and 6 years, respectively; (odds ratio [OR], 1.007; 95% confidence interval [CI], 1.002 to 1.012; P =0.004; and OR, 1.004; 95% CI, 1.000 to 1.009 per ng/mL; P =0.057). After multivariate analysis controlling for other cardiovascular risk factors and C-reactive protein, 3-year OR was 1.010 (95% CI, 1.004 to 1.017; P =0.001) and 6-year OR was 1.008 (1.002 to 1.014 per ng/mL; P =0.006). Baseline log lesion volume was a strong independent predictor of progression but associations remained after controlling for this (3-year OR, 1.011; 95% CI, 1.002 to 1.020; P =0.013; and 6-year OR, 1.009; 95% CI, 1.000 to 1.017; P =0.039 per ng/mL). There was no association between WMH progression and other markers.

Conclusions— ICAM levels are related to progression of WMH on MRI. The prospective study design increases the likelihood that this association is causal and supports a role of endothelial cell activation in disease pathogenesis. In contrast, we found no evidence for coagulation activation being important.

Markers of endothelial dysfunction in the prediction of coronary artery disease in type 1 diabetes. The Pittsburgh Epidemiology of Diabetes Complications Study

Low-density lipoprotein (LDL) oxidation, the immune response it provokes, and lipoprotein subclasses measured by nuclear magnetic resonance (NMR) spectroscopy have explained some of the enhanced coronary artery disease (CAD) risks in Type 1 diabetes. We examined whether cellular adhesion molecules further improve CAD prediction. Participants were identified from the Epidemiology of Diabetes Complications (EDC) cohort, a 10-year prospective study of childhood-onset Type 1 diabetes. Mean age at baseline was 28 years, and diabetes duration was 19 years. CAD incidence was determined by EDC physician-diagnosed angina, confirmed myocardial infarction (MI), stenosis > or =50%, ischemic ECG, or revascularization. Cases were gender, age, and diabetes duration (+/-3 years) matched with the controls. The samples and risk factors used in the analyses were identified from the earliest exam prior to incidence in the cases. Sixty cases and 72 controls (including 43 pairs) had complete information on all covariates. Cox proportional hazard models with backward elimination and conditional logistic regression (for paired analyses) were conducted. Separate analyses were conducted to examine whether E-selectin related differently to soft (ischemic ECG and angina; n=68) or hard (revascularization, MI, and fatal events; n=37) CAD endpoints. Mean E-selectin concentration was elevated among cases (P=.0009) compared to controls. Adjusting for previously established CAD risk factors, E-selectin remained an independent predictor of CAD (HR=1.07, 95% Cl=1.01-1.15). Multivariable models confirmed the importance of E-selectin as a risk factor of soft (HR=1.13, 95% Cl=1.03-1.24; HRs are per standard deviation increase) but not hard CAD. Study results suggest that E-selectin may enhance CAD prediction beyond traditional risk factors or markers of oxidative stress in Type 1 diabetes.