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

Life course socioeconomic position is associated with inflammatory markers: the Framingham Offspring Study

Associations between life course socioeconomic position (SEP) and novel biological risk markers for coronary heart disease such as inflammatory markers are not well understood. Most studies demonstrate inverse associations of life course SEP with C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen, however little is known about associations between life course SEP and other inflammatory markers including intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor II (TNFR2), lipoprotein phospholipase A2 (Lp-PLA2) activity, monocyte chemoattractant protein-1 (MCP-1) or P-selectin. The objectives of this analysis were to determine whether three life course SEP frameworks ("accumulation of risk", "social mobility" and "sensitive periods") are associated with the aforementioned inflammatory markers. We examined 1413 Framingham Offspring Study participants (mean age 61.2+/-8.6 years, 54% women), using multivariable regression analyses. In age- and sex-adjusted regression analyses, cumulative SEP ("accumulation of risk" SEP framework), for low vs. high SEP, was inversely associated with CRP, IL-6, ICAM-1, TNFR2, Lp-PLA2 activity, MCP-1 and fibrinogen. We found that there were few consistent trends between social mobility trajectories and most inflammatory markers. Own educational attainment was inversely associated with 7 of 8 studied inflammatory markers, while father's education, father's occupation and own occupation were inversely associated with 4, 5 and 4 inflammatory markers, respectively, in age- and sex-adjusted analyses. The strengths of association between SEP and inflammatory markers were typically substantially accounted for by CHD risk markers (smoking, body mass index, systolic blood pressure, total:HDL cholesterol ratio, fasting glucose, medications, depressive symptomatology) suggesting these may be important mechanisms that explain associations between SEP and the studied inflammatory markers.

Multimarker prediction of coronary heart disease risk: the Women's Health Initiative

OBJECTIVES

The aim of this study was to investigate whether multiple biomarkers contribute to improved coronary heart disease (CHD) risk prediction in post-menopausal women compared with assessment using traditional risk factors (TRFs) only.

BACKGROUND

The utility of newer biomarkers remains uncertain when added to predictive models using only TRFs for CHD risk assessment.

METHODS

The Women's Health Initiative Hormone Trials enrolled 27,347 post-menopausal women ages 50 to 79 years. Associations of TRFs and 18 biomarkers were assessed in a nested case-control study including 321 patients with CHD and 743 controls. Four prediction equations for 5-year CHD risk were compared: 2 Framingham risk score covariate models; a TRF model including statin treatment, hormone treatment, and cardiovascular disease history as well as the Framingham risk score covariates; and an additional biomarker model that additionally included the 5 significantly associated markers of the 18 tested (interleukin-6, d-dimer, coagulation factor VIII, von Willebrand factor, and homocysteine).

RESULTS

The TRF model showed an improved C-statistic (0.729 vs. 0.699, p = 0.001) and net reclassification improvement (6.42%) compared with the Framingham risk score model. The additional biomarker model showed additional improvement in the C-statistic (0.751 vs. 0.729, p = 0.001) and net reclassification improvement (6.45%) compared with the TRF model. Predicted CHD risks on a continuous scale showed high agreement between the TRF and additional biomarker models (Spearman's coefficient = 0.918). Among the 18 biomarkers measured, C-reactive protein level did not significantly improve CHD prediction either alone or in combination with other biomarkers.

CONCLUSIONS

Moderate improvement in CHD risk prediction was found when an 18-biomarker panel was added to predictive models using TRFs in post-menopausal women.

Systemic vascular cell adhesion molecule-1 predicts the occurrence of post-operative atrial fibrillation

BACKGROUND

Post-operative atrial fibrillation occurs in 30% of patients after on-pump heart surgery and is associated to elevated inflammatory markers. We have evaluated if the systemic biomarkers of inflammation and endothelial damage, vascular cell adhesion molecule-1 (VCAM-1) and soluble thrombomodulin may help in identifying patients prone to development of post-operative atrial fibrillation.

METHODS

One hundred and forty-four patients in sinus rhythm submitted to elective coronary artery bypass surgery. Systemic inflammatory, oxidative stress and endothelial damage markers were measured at baseline and 72 h after surgery. During the procedure, a sample of the right atrial appendage was obtained for histochemistry. Electrocardiogram was monitored for 72 h after surgery for event adjudication.

RESULTS

22% of the patients developed post-operative atrial fibrillation. Baseline systemic inflammatory markers did not differ between patients with or without post-operative atrial fibrillation. However, baseline plasma VCAM-1 and thrombomodulin levels were significantly higher in patients who developed post-operative atrial fibrillation. After adjustment for age, gender, comorbidities and concurrent medication, circulating VCAM-1 remained as an independent predictor for post-operative atrial fibrillation development. No association was observed between systemic plasma VCAM-1 and VCAM-1 tissue expression in the right atrial appendage.

CONCLUSIONS

In patients undergoing coronary artery bypass surgery, elevated VCAM-1 levels predict a higher risk for post-operative atrial fibrillation. Plasma VCAM-1 elevation is not related to its expression in the right atria, suggesting that systemic endothelial damage rather than local changes pre-exist in patients who develop the arrhythmia.

Repetitive element DNA methylation and circulating endothelial and inflammation markers in the VA normative aging study

BACKGROUND

Lower blood DNA methylation has been associated with atherosclerosis and high cardiovascular risk. Mechanisms linking DNA hypomethylation to increased cardiovascular risk are still largely unknown. In a population of community-dwelling elderly individuals, we evaluated whether DNA methylation in LINE-1 repetitive element, heavily methylated sequences dispersed throughout the human genome, was associated with circulating Vascular Cell Adhesion Molecule-1 (VCAM-1), Inter- Cellular Adhesion Molecule-1 (ICAM-1), and C-reactive protein (CRP).

METHODS AND RESULTS

We measured LINE-1 methylation by bisulfite PCR-Pyrosequencing on 742 blood DNA samples from male participants in the Boston area Normative Aging Study (mean age=74.8 years). Mean serum VCAM-1 increased progressively in association with LINE-1 hypomethylation (from 975.2 to 1063.4 ng/ml in the highest vs. lowest methylation quintiles; ptrend= 0.004). The association between VCAM-1 and LINE-1 hypomethylation was significant in individuals without ischemic heart disease or stroke (n=480; p=0.001), but not in those with prevalent disease (n=262; p=0.57). Serum ICAM-1 and CRP were not associated with LINE-1 methylation (p-trend=> 0.25). All results were confirmed by multivariable analyses adjusting for age, BMI, smoking, pack-years, and ischemic heart disease/stroke.

CONCLUSIONS

LINE-1 element hypomethylation is associated with higher serum VCAM-1. Our data provide new insights into epigenetic events that may accompany the development of cardiovascular disease.

[Gender difference in hipolipemic and anti-inflammatory effects of statins in diabetics with coronary artery disease]

BACKGROUND/AIM

Statins produce hipolipemic and pleotropic effects on markers of inflammation with stabilization of atheromatous plaque. The aim of this paper was to examine gender difference in hipolipemic and antiinflammatory effects of statins in patients with diabetes mellitus (DM) type 2 with coronary artery disease (CAD).

METHODS

Sixty dyslipidemic patients with DM type 2 were analyzed. Lifestyle modification and hipolipemic diet were applied in all patients divided into two groups: 30 patients with statins therapy (20 mg of simvastatin or equivalent dose of some other statins, during 3 months) and 30 patients without statins therapy. Estimation of obesity, quality of glicoregulation, and determination of inflammatory parameters: C-reactive protein (CRP), fibrinogen, total and differential leukocyte count, intracellular adhesive molecules (ICAM-1), vascular adhesive molecule-(VCAM-1) and lipid profile (total cholesterol--TC, LDL-C, HDL-C, triglicerides--TG) were done.

RESULTS

Women with DM type 2 were more obese and had significant disturbances in lipid profiles, glicoregulation and inflammatory markers compared to men. Statins therapy significantly improved all lipid parameters and quality of glicoregulation in women, while there were only significant reduction of LDL-C and nonHDL-C in males. There were more significant reductions of inflammatory markers in women as compared to men with statins therapy. In the group without statins there was not such significant reduction. Concentration of ICAM-1 was the lowest in men on statins therapy, while there were no significant variability of VCAM-1 values between groups and genders.

CONCLUSION

Women with DM type 2 and CAD have more prominent lipoprotein disorders and impaired glicoregulation with expression of enhanced proinflammatory state which could not be seen in men. Statins therapy exerts more favorable effects in women leading to stabilization of lipoprotein profiles, improvement of glicoregulation and reduction of inflammatory markers. More superior antiinflammatory effects of statins therapy in men were registered only in significant ICAM-1 reduction.

Genetic variants in ABO blood group region, plasma soluble E-selectin levels and risk of type 2 diabetes

Blood soluble E-selectin (sE-selectin) levels have been related to various conditions such as type 2 diabetes. We performed a genome-wide association study among women of European ancestry from the Nurses' Health Study, and identified genome-wide significant associations between a cluster of markers at the ABO locus (9q34) and plasma sE-selectin concentration. The strongest association was with rs651007, which explained approximately 9.71% of the variation in sE-selectin concentrations. SNP rs651007 was also nominally associated with soluble intracellular cell adhesion molecule-1 (sICAM-1) (P = 0.026) and TNF-R2 levels (P = 0.018), independent of sE-selectin. In addition, the genetic-inferred ABO blood group genotypes were associated with sE-selectin concentrations (P = 3.55 x 10(-47)). Moreover, we found that the genetic-inferred blood group B was associated with a decreased risk (OR = 0.44, 0.27-0.70) of type 2 diabetes compared with blood group O, adjusting for sE-selectin, sICAM-1, TNF-R2 and other covariates. Our findings indicate that the genetic variants at ABO locus affect plasma sE-selectin levels and diabetes risk. The genetic associations with diabetes risk were independent of sE-selectin levels.

Current developments in salivary diagnostics

Salivary diagnostics is an emerging field that has progressed through several important developments in the past decade, including the publication of the human salivary proteome and the infusion of federal funds to integrate nanotechnologies and microfluidic engineering concepts into developing compact point-of-care devices for rapid analysis of this secretion. In this article, we discuss some of these developments and their relevance to the prognosis, diagnosis and management of periodontitis, as an oral target, and cardiovascular disease, as a systemic example for the potential of these biodiagnostics. Our findings suggest that several biomarkers are associated with distinct biological stages of these diseases and demonstrate promise as practical biomarkers in identifying and managing periodontal disease, and acute myocardial infarction. The majority of these studies have progressed through biomarker discovery, with the identified molecules requiring more robust clinical studies to enable substantive validation for disease diagnosis. It is predicted that with continued advances in this field the use of a combination of biomarkers in multiplex panels is likely to yield accurate screening tools for these diagnoses in the near future.

Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: a systematic review

BACKGROUND

High stearic acid (STA) soybean oil is a trans-free, oxidatively stable, non-LDL-cholesterol-raising oil that can be used to replace trans fatty acids (TFAs) in solid fat applications.

OBJECTIVE

The objective was to assess the cardiovascular health effects of dietary STA compared with those of trans, other saturated, and unsaturated fatty acids.

DESIGN

We reviewed epidemiologic and clinical studies that evaluated the relation between STA and cardiovascular disease (CVD) risk factors, including plasma lipids and lipoproteins, hemostatic variables, and inflammatory markers.

RESULTS

In comparison with other saturated fatty acids, STA lowered LDL cholesterol, was neutral with respect to HDL cholesterol, and directionally lowered the ratio of total to HDL cholesterol. STA tended to raise LDL cholesterol, lower HDL cholesterol, and increase the ratio of total to HDL cholesterol in comparison with unsaturated fatty acids. In 2 of 4 studies, high-STA diets increased lipoprotein(a) in comparison with diets high in saturated fatty acids. Three studies showed increased plasma fibrinogen when dietary STA exceeded 9% of energy (the current 90th percentile of intake is 3.5%). Replacing industrial TFAs with STA might increase STA intake from 3.0% (current) to approximately 4% of energy and from 4% to 5% of energy at the 90th percentile. One-to-one substitution of STA for TFAs showed a decrease or no effect on LDL cholesterol, an increase or no effect on HDL cholesterol, and a decrease in the ratio of total to HDL cholesterol.

CONCLUSIONS

TFA intake should be reduced as much as possible because of its adverse effects on lipids and lipoproteins. The replacement of TFA with STA compared with other saturated fatty acids in foods that require solid fats beneficially affects LDL cholesterol, the primary target for CVD risk reduction; unsaturated fats are preferred for liquid fat applications. Research is needed to evaluate the effects of STA on emerging CVD risk markers such as fibrinogen and to understand the responses in different populations.

Detection of differentially expressed basal cell proteins by mass spectrometry

The ability of cells to modulate interactions with each other and the substrate is essential for epithelial tissue remodeling during processes such as wound healing and tumor progression. However, despite strides made in the field of proteomics, proteins involved in adhesion have been difficult to study. Here, we report a method for the enrichment and analysis of proteins associated with the basal surface of the cell and its underlying matrix. The enrichment involves deroofing the cells with 20 mM ammonium hydroxide and the removal of cytosolic and organellar proteins by stringent water wash. Proteomic profiling was achieved by LC-FTMS, which allowed comparison of differentially expressed or shared proteins under different cell states. First, we analyzed and compared the basal cell components of mouse keratinocytes lacking the cell-cell junction molecule plakoglobin with their control counterparts. Changes in the molecules involved in motility and invasion were detected in plakoglobin-deficient cells, including decreased detection of fibronectin, integrin beta(4), and FAT tumor suppressor. Second, we assessed the differences in basal cell components between two human oral squamous cell carcinoma lines originating from different sites in the oral cavity (CAL33 and UM-SCC-1). The data show differences between the two lines in the type and abundance of proteins specific to cell adhesion, migration, and angiogenesis. Therefore, the method described here has the potential to serve as a platform to assess proteomic changes in basal cell components including extracellular and adhesion-specific proteins involved in wound healing, cancer, and chronic and acquired adhesion-related disorders.

Lipoprotein-associated phospholipase A(2), inflammatory biomarkers, and risk of cardiovascular disease in the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER)

OBJECTIVE

Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is an inflammatory biomarker that circulates mainly bound to LDL. We evaluated the association of Lp-PLA(2) with vascular events in the elderly where the importance of LDL is diminished as a risk factor for coronary disease.

METHODS

Mass and activity of Lp-PLA(2) were related to risk over 3.2 years for vascular events (definite or suspected death from CHD, non-fatal MI, fatal or non-fatal stroke) in the 2804 men and 3000 women age 70-82 years in the Prospective Study of Pravastatin in the Elderly (PROSPER).

RESULTS

Lp-PLA(2) showed a moderate, positive association with risk of a vascular event with hazard ratios of 1.25 (confidence interval (CI) 1.02-1.54) for mass and 1.39 (CI 1.14-1.70) for activity for top versus bottom quartile. Risk associations were attenuated when classical risk factors, lipids and inflammatory markers - C-reactive protein and white cell count - were included in the models. Lp-PLA(2) was unrelated to stroke risk. Inclusion of all three inflammatory markers in multivariate models negated the association of HDL cholesterol with risk (hazard ratio 0.98; CI 0.88-1.10) and increased prediction of coronary events; the C statistic rose from 63.2% to 64.4% (P<0.001).

CONCLUSION

In elderly people Lp-PLA(2), alongside other inflammatory indices, is a potential biomarker for vascular events, particularly CHD.

Contribution of insulin resistance to vascular dysfunction

Insulin is a vascular hormone, able to influence vascular cell responses. In this review, we consider the insulin actions on vascular endothelium and on vascular smooth muscle cells (VSMC) both in physiological conditions and in the presence of insulin resistance. In particular, we focus the relationships between activation of insulin signalling pathways of phosphatidylinositol-3 kinase (PI3-K) and mitogen-activated protein kinase (MAPK) and the different vascular actions of insulin, with a particular attention to the insulin ability to activate the pathway nitric oxide (NO)/cyclic GMP/PKG via PI3-K, owing to the peculiar relevance of NO in vascular biology. We also discuss the insulin actions mediated by the MAPK pathway (such as endothelin-1 synthesis and secretion and VSMC proliferation and migration) and by the interactions between the two pathways, both in insulin-sensitive and in insulin-resistant states. Finally, we consider the influence of free fatty acids, cytokines and endothelin on vascular insulin resistance.

Differential associations between soluble cellular adhesion molecules and atherosclerosis in the Dallas Heart Study: a distinct role for soluble endothelial cell-selective adhesion molecule

OBJECTIVE

Endothelial cell-selective adhesion molecule (ESAM) is a junctional-type cellular adhesion molecule (CAM) that is uniquely expressed in vascular endothelium and activated platelets and mediates neutrophil and monocyte diapedesis across the endothelium. Given its role in endothelial pathobiology, we hypothesized that soluble ESAM (sESAM) would be independently associated with atherosclerosis and vascular stiffness.

METHODS AND RESULTS

We measured sESAM, soluble intercellular adhesion molecule (sICAM)-1, and soluble vascular cell adhesion molecule (sVCAM)-1 in 3222 subjects participating in the Dallas Heart Study, a probability-based population sample. Coronary artery calcium (CAC) was measured by electron beam computed tomography, and abdominal aortic wall thickness (AWT), aortic plaque burden (APB), and aortic compliance (AC) by MRI. Increasing levels of sESAM were associated with all major cardiovascular risk factors as well as with inflammatory markers such as monocyte chemoattractant protein-1, but only weakly correlated with sICAM-1 and sVCAM-1. In multivariate analyses, sESAM was independently associated with prevalent CAC (OR 1.2 per SD increase, 95% CI 1.1 to 1.3; P=0.005), AWT (P=0.035), and AC (P=0.006), but not APB (P=0.15). In contrast, no independent associations were observed between sICAM-1 or sVCAM-1 and any of the atherosclerosis phenotypes.

CONCLUSIONS

In this first reported clinical study of sESAM in humans, sESAM levels were independently associated with CAC, AWT, and AC, whereas sICAM-1 and sVCAM-1 were not. These findings support a unique role of this cellular adhesion molecule in atherosclerosis and suggest the need for further exploration of sESAM as a predictive biomarker and potential mediator of atherosclerosis.

Biomarkers in cardiovascular medicine

Cardiovascular disease is the principal cause of death in developed countries. The underlying pathological process is arterial wall thickening due to the formation of atherosclerotic plaque, which is frequently complicated by thrombus, thereby giving rise to the possibility of acute coronary syndrome or stroke. One of the major challenges in cardiovascular medicine is to find a way of predicting the risk that an individual will suffer an acute thrombotic event. During the last few decades, there has been considerable interest in finding diagnostic and prognostic biomarkers that can be detected in blood. Of these, C-reactive protein is the best known. Others, such as the soluble CD40 ligand, can be used to predict cardiovascular events. However, to date, no biomarker has been generally accepted for use in clinical practice. At present, there are a number of high-performance techniques, such as proteomics, that have the ability to detect multiple potential biomarkers. In the near future, these approaches may lead to the discovery of new biomarkers that, when used with imaging techniques, could help improve our ability to predict the occurrence of acute vascular events.

Biomarkers of premature atherosclerosis

C-reactive protein (CRP) is an acute phase protein and a biochemical marker with important prognostic value for cardiovascular events. Interleukins IL-1 and IL-6 are implicated in the pathogenesis of atherosclerosis and are associated with CRP. Apolipoproteins ApoA-I and ApoB are the main lipid metabolic markers implicated in the development and progression of atherosclerosis. Fibrinogen has also been proposed to be a major independent risk factor for cardiovascular events. Because premature atherosclerosis precedes the development of cardiovascular disease, identification of the associated biomarkers is of great importance. However, further studies will be needed to determine whether or not these markers are useful predictors of future cardiovascular events. Here, we review the roles of specific biomarkers that have been implicated in premature atherosclerosis.

Association of soluble intercellular adhesion molecule-1 with insulin resistance and metabolic syndrome in Taiwanese

Circulating concentrations of soluble cell adhesive molecules are useful predictors for the risk of development and progression of atherosclerosis. This study was initiated to investigate the association between soluble intercellular adhesive molecule-1 (sICAM-1) levels and traditional and emerging cardiovascular risk factors, as well as insulin resistance and metabolic syndrome, in a Taiwanese population. Six hundred nine unrelated individuals recruited during routine health examinations were enrolled for the analysis. In age- and sex-adjusted regression models, sICAM-1 levels were negatively associated with high-density lipoprotein cholesterol levels and positively associated with systolic, mean, and diastolic blood pressure; body mass index; waist circumference; waist-hip ratio; the homeostasis model assessment index; fasting serum insulin; triglyceride; and C-reactive protein levels. The sICAM-1 levels were also higher in subjects with current smoking (P = .001), diabetes mellitus (P = .004), insulin resistance (P < .001), and metabolic syndrome (P < .001). The sICAM-1 levels increased in a stepwise fashion with increasing Framingham risk score quartiles (P = .001) and with increasing number of metabolic syndrome components (P < .001). In subjects with metabolic syndrome, increased C-reactive protein levels were associated with increased sICAM-1 levels (P = .003). In stepwise linear regression models, sICAM-1 levels remained associated with current smoking, insulin resistance, and metabolic syndrome. In conclusion, our data revealed that insulin resistance and metabolic syndrome were associated with sICAM-1 levels in Taiwanese. These data provide further evidence of the mechanisms of sICAM-1 as a molecular marker for atherosclerosis.

Biomarkers of oxidant stress, insulin sensitivity and endothelial activation in rheumatoid arthritis: a cross-sectional study of their association with accelerated atherosclerosis

BACKGROUND

Women with rheumatoid arthritis (RA) have increased morbidity and mortality due to coronary heart disease. Chronic systemic inflammation is known to accelerate atherosclerosis and increase arterial stiffness in patients, but other mechanisms may also be involved. Biomarkers of oxidant stress, inflammation, insulinaemia and endothelial dysfunction were measured in blood and urine from 46 RA patients and 48 age-matched controls. Plaque formation and intima-medial thickness (IMT) were measured using B-mode carotid Doppler scan.

FINDINGS

The prevalence of plaque was increased (p = 0.042) in RA patients between 50-59 years old compared to the same age group in controls. 8-isoprostane (p = 0.004), C-reactive protein (p < 0.001), interleukin-6 (p < 0.001), insulin (p = 0.035), adiponectin (p = 0.012), vascular cell adhesion molecule (VCAM) (p = 0.029) and E-selectin (p < 0.001) were all increased while selenium (p = 0.003) and LDL-cholesterol (p = 0.025) were both decreased in all RA patients. 8-isoprostane correlated with 10 year cardiac risk (r = 0.55, p < 0.001), VCAM with IMT (r = 0.37, p = 0.012) and E-selectin with rheumatoid factor titre (r = 0.43, p = 0.003) in RA patients. In the control group, age, carotid IMT, VCAM, systolic blood pressure and smoking status were all associated with plaque development whereas in RA patients only age was associated with plaque.

CONCLUSION

The burden of atherosclerosis is particularly increased in middle-aged women with RA. Patients with RA have increased levels of oxidant stress, inflammation, insulin and soluble adhesion molecules. As the association between classical risk factors was much weaker in RA patients compared to controls, these additional factors may be more important in the accelerated development of atheroma in RA.

Blood markers for the prognosis of ischemic stroke: a systematic review

BACKGROUND AND PURPOSE

The performance of validated prognostic clinical models in acute ischemic stroke might be improved by addition of data on blood biomarkers.

METHODS

We searched Medline and EMBASE from 1966 to January 2007 for studies of blood markers in patients with ischemic stroke and an assessment of outcome (death, disability, or handicap). We adopted several strategies to reduce bias.

RESULTS

Studies were generally small (median number of subjects, 85; interquartile range, 49 to 184). Few had evidence of a sample size calculation (7 of 82 [9%]) or reported blinding to whether patients had stroke (21 of 82 [26%]). Of the 66 studies reporting a measure of association, 10 did not adjust for age or stroke severity, 14 adjusted for age, 7 adjusted for severity, and 35 adjusted for both; 30% (20 of 66) used a data-dependent threshold to predict good or bad outcome. There was evidence of within-study reporting bias and publication bias. Cardiac markers showed the most consistent association with poor outcome.

CONCLUSIONS

Blood biomarkers might provide useful information to improve the prediction of outcome after acute ischemic stroke. However, this review showed that many studies were subject to bias. Although some markers had some predictive ability, none of the studies was able to demonstrate that the biomarker added predictive power to a validated clinical model. The clinical usefulness of blood biomarkers for predicting prognosis in the setting of ischemic stroke has yet to be established.

Heterogeneity of systemic inflammatory responses to periodontal therapy

AIMS

We investigated the effect of comprehensive periodontal therapy on the levels of multiple systemic inflammatory biomarkers.

MATERIAL AND METHODS

Thirty patients with severe periodontitis received comprehensive periodontal therapy within a 6-week period. Blood samples were obtained at: 1-week pre-therapy (T1), therapy initiation (T2), treatment completion (T3), and 4 weeks thereafter (T4). We assessed the plasma concentrations of 19 biomarkers using multiplex assays, and serum IgG antibodies to periodontal bacteria using checkerboard immunoblotting. At T2 and T4, dental plaque samples were analysed using checkerboard hybridizations.

RESULTS

At T3, PAI-1, sE-selectin, sVCAM-1, MMP-9, myeloperoxidase, and a composite summary inflammatory score (SIS) were significantly reduced. However, only sE-selectin, sICAM, and serum amyloid P sustained a reduction at T4. Responses were highly variable: analyses of SIS slopes between baseline and T4 showed that approximately 1/3 and 1/4 of the patients experienced a marked reduction and a pronounced increase in systemic inflammation, respectively, while the remainder were seemingly unchanged. Changes in inflammatory markers correlated poorly with clinical, microbiological and serological markers of periodontitis.

CONCLUSIONS

Periodontal therapy resulted in an overall reduction of systemic inflammation, but the responses were inconsistent across subjects and largely not sustainable. The determinants of this substantial heterogeneity need to be explored further.

Are elevated circulating intercellular adhesion molecule 1 levels more strongly predictive of diabetes than vascular risk? Outcome of a prospective study in the elderly

AIMS/HYPOTHESIS

The aim of this prospective study was to determine whether circulating intercellular adhesion molecule (ICAM) 1, as a potential surrogate of 'endothelial activation', is more strongly associated with risk of vascular events than with incident diabetes.

METHODS

We related baseline ICAM-1 levels to vascular events (866 CHD and stroke events in 5,685 participants) and incident diabetes (292 in 4,945 without baseline diabetes) in the elderly over 3.2 years of follow-up.

RESULTS

ICAM-1 levels correlated positively with triacylglycerol but negatively with LDL- and HDL-cholesterol. ICAM-1 levels were higher in those who developed diabetes (388.6 +/- 1.42 vs 369.4 +/- 1.39 ng/ml [mean+/-SD], p = 0.011) and remained independently associated with new-onset diabetes (HR 1.84, 95% CI 1.26-2.69, p = 0.0015 per unit increase in log[ICAM-1] after adjusting for classical risk factors and C-reactive protein). By contrast, ICAM-1 levels were not significantly (p = 0.40) elevated in those who had an incident vascular event compared with those who remained event-free, and corresponding adjusted risk associations were null (HR 0.98, 95% CI 0.80-1.22, p = 0.89) in analyses adjusted for other risk factors.

CONCLUSIONS/INTERPRETATION

We show that elevated ICAM-1 levels are associated with risk of incident diabetes in the elderly at risk, despite no association with incident cardiovascular disease risk. We suggest that perturbations in circulating ICAM-1 levels are aligned more towards diabetes risk.

Leptin and coronary heart disease: prospective study and systematic review

OBJECTIVES

This study sought to better determine the link between leptin and coronary heart disease (CHD).

BACKGROUND

Circulating leptin is considered a risk factor for CHD but larger studies are needed.

METHODS

Leptin levels were measured in 550 men with fatal CHD or nonfatal myocardial infarction and in 1,184 controls nested within a prospective study of 5,661 British men and set in context with a meta-analysis.

RESULTS

Baseline leptin correlated with body mass index (BMI), blood pressure, total cholesterol, triglyceride, and inflammatory markers; correlations persisted after BMI adjustment. The within-person consistency of leptin values over 4 years (correlation coefficient: 0.79; 95% confidence interval [CI]: 0.73 to 0.83) was higher than those of some established cardiovascular risk factors. In a comparison of individuals in the top third with those in the bottom third of baseline leptin, the age- and town-adjusted odds ratio for CHD was 1.25 (95% CI: 0.96 to 1.62), decreasing to 0.98 (95% CI: 0.72 to 1.34) after adjustment for BMI. A systematic review identified 7 prospective reports with heterogeneous findings (I(2) = 60%, 13% to 82%). The combined adjusted risk ratio across all studies was 1.44 (95% CI: 0.95 to 2.16) in a comparison of extreme thirds of leptin levels. The inconsistency between studies was partially explained by sample size, with combined estimates from studies involving >100 CHD cases (1.28, 95% CI: 0.80 to 2.04) being somewhat weaker than those from smaller studies (1.81, 95% CI: 0.76 to 4.31).

CONCLUSIONS

Previous studies appear to have overestimated associations of leptin and CHD risk. Our results suggest a moderate association that is largely dependent on BMI.

The effects of cilostazol on exercise-induced ischaemia-reperfusion injury in patients with peripheral arterial disease

OBJECTIVES

Cilostazol improves walking distance in peripheral arterial disease (PAD) patients. The study objectives were to assess the effects of cilostazol on walking distance, followed by the additional assessment of cilostazol on exercise-induced ischaemia-reperfusion injury in such patients.

METHODS

PAD patients were prospectively recruited to a double-blinded, placebo-controlled trial. Patients were randomised to receive either cilostazol 100mg or placebo twice a day. The primary end-point was an improvement in walking distance. Secondary end-points included the assessment of oxygen-derived free-radical generation, antioxidant consumption and other markers of the inflammatory cascade. Initial and absolute claudication distances (ICDs and ACDs, respectively) were measured on a treadmill. Inflammatory response was assessed before and 30 min post-exercise by measuring lipid hydroperoxide, ascorbate, alpha-tocopherol, beta-carotene, P-selectin, intracellular and vascular cell-adhesion molecules (I-CAM and V-CAM), thromboxane B(2) (TXB(2)), interleukin-6, interleukin-10, high-sensitive C-reactive protein (hsCRP), albumin-creatinine ratio (ACR) and urinary levels of p75TNF receptor. All tests were performed at baseline and 6 and 24 weeks.

RESULTS

One hundred and six PAD patients (of whom 73 were males) were recruited and successfully randomised from December 2004 to January 2006. Patients who received cilostazol demonstrated a more significant improvement in the mean percentage change from baseline in ACD (77.2% vs. 26.6% at 6 weeks, p=0.026 and 161.7% vs. 79.0% at 24 weeks, p=0.048) as compared to the placebo. Cilostazol reduced lipid hydroperoxide levels compared to a placebo-related increase before and after exercise (6 weeks: pre-exercise: -11.8% vs. +5.8%, p=0.003 and post-exercise: -12.3% vs. +13.9%, p=0.007 and 24 weeks: pre-exercise -15.5% vs. +12.0%, p=0.025 and post-exercise: -9.2% vs. +1.9%, p=0.028). beta-Carotene levels were significantly increased in the cilostazol group, compared to placebo, before exercise at 6 and 24 weeks (6 weeks: 34.5% vs. -7.4%, p=0.028; 24 weeks: 34.3% vs. 17.7%, p=0.048). Cilostazol also significantly reduced P-selectin, I-CAM and V-CAM levels at 24 weeks as compared to baseline (p<0.05). There was no difference between treatment groups for ascorbate, alpha-tocopherol, interleukin-6 and -10, hsCRP and p75TNF receptor levels.

CONCLUSIONS

Cilostazol significantly improves ACD, in addition to attenuating exercise-induced ischaemia-reperfusion injury, in PAD patients.

ICAM1 and VCAM1 polymorphisms, coronary artery calcium, and circulating levels of soluble ICAM-1: the multi-ethnic study of atherosclerosis (MESA)

Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) may be important contributors to the development and progression of atherosclerosis. Using a stratified random sample of 2880 participants of the Multi-Ethnic Study of Atherosclerosis we investigated the relationship of 12 ICAM1 and 17 VCAM1 SNPs and coronary artery calcium (CAC) and ICAM1 SNPs and circulating levels of soluble ICAM-1 (sICAM-1). There were no ICAM1 or VCAM1 SNPs significantly associated with CAC in any of the four race/ethnic groups. In a subset of 1451 subjects with sICAM-1 measurements, we observed a significant association with rs5491 in all four race/ethnic groups corroborating previous research that has shown that the T-allele of rs5491 interferes with the monoclonal antibody used to measure sICAM-1 in this study. After excluding all rs5491 T-allele carriers, several ICAM1 SNPs were significantly associated with sICAM-1 levels; rs5496 in African Americans, rs5498 and rs3093030 in European Americans, and rs1799969 in Hispanics. Our results identified ICAM1 polymorphisms that were significantly associated with sICAM-1 level but not CAC, a subclinical marker of atherosclerosis.

Serum matrix metalloproteinase-9 and coronary heart disease: a prospective study in middle-aged men

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) has a potential role in arterial plaque rupture, but its relation to risk of coronary heart disease (CHD) is uncertain.

AIM

To determine whether circulating levels of serum MMP-9 are prospectively related to the risk of CHD in the general population.

METHODS

We measured baseline MMP-9 levels in stored serum samples of subjects in a case-control study nested within a prospective study of 5661 men followed up for 16 years for CHD events (465 cases, 1076 controls).

RESULTS

MMP-9 values were associated with cigarette smoking, and with several inflammatory and haemostatic markers, but not with age, body mass index, blood pressure or lipid measurements. Men in the top third of baseline MMP-9 levels had an age-adjusted odds ratio (OR) for CHD of 1.37 (95% CI 1.04-1.82) compared with those in the bottom third. Adjustment for conventional risk factors (smoking in particular) reduced the odds ratio to borderline significance: OR 1.28 (95% CI 0.95-1.74), while additional adjustment for two markers of generalized inflammation, interleukin-6 and C-reactive protein, further attenuated the association: OR 1.13 (0.82-1.56).

CONCLUSION

Serum MMP-9 has a modest association with incident CHD in the general population, which is not independent of cigarette smoking exposure and circulating markers of generalized inflammation. MMP-9 is unlikely to be a clinically useful biomarker of CHD risk, but may still play a role in the pathogenesis of CHD.

Effect of Conventional and More Aggressive Rosuvastatin Treatment on Markers of Endothelial Activation

Treatment of hypercholesterolemia with HMG-CoA reductase inhibitors results in an earlier reduction of morbidity and mortality than expected from trials using conventional cholesterol-lowering therapies. Possible explanations for this effect include improvement of endothelial function, plaque stabilization, and inhibition of the inflammatory response associated with atherosclerosis. In this study we assessed the effects of low and moderate dose rosuvastatin treatment, on circulating markers of endothelial activation in patients admitted for acute coronary syndromes without ST segment elevation. Thirty patients with unstable angina and non ST segment elevation myocardial infarction were rando - mized into two groups, and received rosuvastatin 10 mg/day (n =16) or rosuvastatin 20 mg/day (n =14) for 12 weeks. Circulating levels of soluble vascular cell adhesion molecule (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) were measured at admission, and at the end of the study. Lipid values were significantly reduced in both treatment groups, but with significantly greater reduction in the aggressively treated group. Serum levels of sICAM-1 and sVCAM-1 were significantly decreased in both rosuvastatin-treated groups during 12 weeks of follow-up with a more pronounced decrease in the more aggressively treated group. Therefore, rosuvastatin modulates endothelial activation in patients after acute coronary syndromes.

Soluble P-selectin, SELP polymorphisms, and atherosclerotic risk in European-American and African-African young adults: the Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

To characterize the genetic and clinical correlates of soluble P-selectin, and the relationship of P-selectin to atherosclerotic risk, in young European-American (EA) and African-American (AA) adults.

METHODS AND RESULTS

We assessed the interrelationships between 25 common SELP polymorphisms, soluble P-selectin, and atherosclerotic risk in 1222 EA and 1072 AA from the longitudinal population-based CARDIA study. Male sex, smoking, blood pressure, and metabolic status were strong cross-sectional correlates of soluble P-selectin among CARDIA subjects aged 33 to 45 years, explaining 13% of the variance. Among EAs, higher soluble P-selectin predicted carotid intima-media thickness (IMT) measured 5 years later, even after accounting for traditional risk factors. Common SELP nucleotide sequence variants explained 11% and 5% of the interindividual variation in soluble P-selectin levels in EAs and AAs, respectively. Four distinct variants contributed to P-selectin phenotype in EAs, including a polymorphism of the 5' SELP haplotype block associated with carotid IMT. Half of the phenotypic variation attributable to SELP in EAs could be explained by the Thr715Pro polymorphism, whereas Val599Leu was more strongly associated with soluble P-selectin among AAs.

CONCLUSIONS

Common SELP polymorphisms were associated with soluble P-selectin and carotid IMT in young adults, but the patterns of association differed between EAs and AAs. These results support the role of P-selectin in the preclinical stages of atherosclerosis.

Circulating soluble ICAM-1 levels shows linkage to ICAM gene cluster region on chromosome 19: the NHLBI Family Heart Study follow-up examination

Atherogenesis is a chronic inflammatory process in which intercellular adhesion molecule 1 (ICAM-1) plays a critical role. Circulating soluble ICAM-1 (sICAM-1) is thought to be the result of cleavage of membrane-bound ICAM-1 and its concentration in serum/plasma has been shown to be heritable. Genome-wide linkage scans were conducted for quantitative trait loci influencing sICAM-1. Phenotype and genetic marker data were available for 2617 white and 531 black individuals in the NHLBI Family Heart Study follow-up examination. Heritability for sICAM-1 was 0.39 in whites and 0.59 in blacks. Significant linkage was observed on chromosome 19 (LOD=4.0 at 14cM) in whites near the ICAM gene cluster that includes the structural gene for ICAM-1. The T-allele of ICAM-1 SNP rs5491 has been strongly associated with the specific sICAM-1 assay we used in our study. Through additional genotyping we were able to rule out rs5491 as the cause of the linkage finding. This study provides preliminary evidence linking genetic variation in the ICAM1 structural gene to circulating sICAM-1 levels.

Novel biochemical risk factors for type 2 diabetes: pathogenic insights or prediction possibilities?

This review critically appraises studies examining the association of novel factors with diabetes. We show that many of the most studied novel and apparently 'independent' risk factors are correlated with each other by virtue of their common origins or pathways, and that residual confounding is likely. Available studies also have other limitations, including differences in methodology or inadequate statistical analyses. Furthermore, although most relevant work in this area has focused on improving our understanding of the pathogenesis of diabetes, association studies in isolation cannot prove causality; intervention studies with specific agents (if available) are required, and genetic studies may help. With respect to the potential value of novel risk factors for diabetes risk prediction, we illustrate why this work is very much in its infancy and currently not guaranteed to reach clinical utility. Indeed, the existence of several more easily measured powerful predictors of diabetes, suggests that the additional value of novel markers may be limited. Nevertheless, several suggestions to improve relevant research are given. Finally, we show that several risk factors for diabetes are only weakly associated with the risk of incident vascular events, an observation that highlights the limitations of attempting to devise unified criteria (e.g. metabolic syndrome) to identify individuals at risk of both CHD and diabetes.

Fish oil in combination with high or low intakes of linoleic acid lowers plasma triacylglycerols but does not affect other cardiovascular risk markers in healthy men

Both (n-3) long-chain PUFA (LCPUFA) and linoleic acid [LA, 18:2(n-6)] improve cardiovascular disease (CVD) risk factors, but a high-LA intake may weaken the effect of (n-3) LCPUFA. In a controlled, double-blind, 2 x 2-factorial 8-wk intervention, we investigated whether fish oil combined with a high- or low-LA intake affects overall CVD risk profile. Healthy men (n = 64) were randomized to 5 mL/d fish oil capsules (FO) [mean intake 3.1 g/d (n-3) LCPUFA] or olive oil capsules (control) and to oils and spreads with either a high (S/B) or a low (R/K) LA content, resulting in a 7.3 g/d higher LA intake in the S/B groups than in the R/K groups. Diet, (n-3) LCPUFA in peripheral blood mononuclear cells, blood pressure (BP), heart rate (HR), and plasma CVD risk markers were measured before and after the intervention. FO lowered fasting plasma triacylglycerol (TAG) (P < 0.001) by 51% and 19% in the FO+R/K-group and FO+S/B-group, respectively, which was also reflected in postprandial TAG measured after the intervention (P < 0.01). Although a fat x FO interaction was found for monocyte chemoattractant protein-1, neither the FO nor fat intervention affected fasting plasma cholesterol, glucose, insulin, fibrinogen, C-reactive protein, interleukin-6, vascular cell adhesion molecule-1, P-selectin, oxidized LDL, cluster of differentiation antigen 40 ligand (CD40L), adiponectin, or fasting or postprandial BP or HR after adjustment for body weight changes. In conclusion, neither fish oil supplementation nor the LA intake had immediate pronounced effects on the overall CVD risk profile in healthy men, but fish oil lowered plasma TAG in healthy subjects with initially low concentrations.

Components of the Mediterranean-type food pattern and serum inflammatory markers among patients at high risk for cardiovascular disease

OBJECTIVE

To evaluate associations between components of the Mediterranean diet and circulating markers of inflammation in a large cohort of asymptomatic subjects at high risk for cardiovascular disease.

SUBJECTS/METHODS

A total of 339 men and 433 women aged between 55 and 80 years at high cardiovascular risk because of presence of diabetes or at least three classical cardiovascular risk factors, food consumption was determined by a semi-quantitative food frequency questionnaire. Serum concentrations of high-sensitivity C-reactive protein (CRP) were measured by immunonephelometry and those of interleukin-6 (IL-6), intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by enzyme-linked immunosorbent assay.

RESULTS

After adjusting for age, gender, body mass index, diabetes, smoking, use of statins, non-steroidal antiinflammatory drugs and aspirin, a higher consumption of fruits and cereals was associated with lower concentrations of IL-6 (P for trend 0.005;both). Subjects with the highest consumption of nuts and virgin olive oil showed the lowest concentrations of VCAM-1, ICAM-1, IL-6 and CRP; albeit only for ICAM-1 was this difference statistically significant in the case of nuts (for trend 0.003) and for VCAM-1 in the case of virgin olive oil (P for trend 0.02). Participants with higher adherence to the Mediterranean-type diet did not show significantly lower concentrations of inflammatory markers (P<0.1 for VCAM-1 and ICAM-1).

CONCLUSIONS

The consumption of some typical Mediterranean foods (fruits, cereals, virgin olive oil and nuts) was associated with lower serum concentrations of inflammatory markers especially those related to endothelial function, in subjects with high cardiovascular risk living in a Mediterranean country.

Vascular versus myocardial dysfunction in acute coronary syndrome: are the adhesion molecules as powerful as NT-proBNP for long-term risk stratification?

OBJECTIVES

To determine if elevations of adhesion molecules in acute coronary syndrome (ACS) are useful for risk stratification.

DESIGN AND METHODS

A cell adhesion array (Randox Ltd.) and NT-proBNP were measured in 216 ACS patients.

RESULTS

Kaplan-Meier and Cox models indicate early elevations of NT-proBNP but not the adhesion molecules are predictive of future death/myocardial infarction.

DISCUSSION

Elevations of adhesion molecules early after pain onset in ACS are not useful for long-term risk stratification.

Differential effect of soluble intercellular adhesion molecule-1 on the progression of atherosclerosis as compared to arterial thrombosis: a prospective analysis of the Women's Health Study

BACKGROUND

Soluble intercellular adhesion molecule-1 (sICAM-1) is a transmembrane protein involved in the migration and adhesion of leukocytes to the vascular endothelium. While some studies indicate that elevated baseline sICAM-1 levels predict cardiovascular events, most of these studies were done in men; moreover, uncertainty exists regarding whether sICAM-1 levels predict vascular events consistent with acute thrombosis versus atherosclerotic disease progression.

METHODS AND RESULTS

In this prospective evaluation of 23,984 apparently healthy women, we measured sICAM-1 levels and followed participants for the development of cardiovascular (CVD) endpoints typically associated with atherosclerotic disease progression with resultant vessel narrowing (percutaneous transluminal angioplasty and coronary artery bypass grafting) and endpoints typically associated with vascular thrombosis and vessel occlusion (myocardial infarction (MI), ischemic stroke and death from a coronary cause). During a mean follow-up of 10 years, there were 741 events. For vascular events indicative of coronary atherosclerotic disease progression with luminal narrowing, Cox-proportional hazards models revealed an increase in vascular event rates from the lowest to highest quintile of baseline sICAM-1 after adjustment for CVD risk factors [hazard ratios (HR): 1.0, 1.4, 1.1, 1.6, 1.6, p(trend)=0.008]. By contrast, for endpoints reflective of acute vessel thrombosis, we found no association with sICAM-1 levels [HR for myocardial infarction: 1.0, 1.2, 0.9, 1.2, 1.0, p(trend)=0.7; HR for stroke (CVA): 1.0, 0.9, 1.0, 1.0, 1.1, p(trend)=0.6; HR for cardiovascular death: 1.0, 0.9, 0.7, 0.7, 0.8, p(trend)=0.7] except among smokers (RR=1.0, 1.4, 2.8, 3.8, 3.7, p=0.007).

CONCLUSIONS

Among women without a history of cardiovascular disease, sICAM-1 levels are predictive of CVD events that reflect coronary atherosclerotic disease progression and vessel narrowing, but not those events associated with acute thrombosis/vessel occlusion.

Inflammatory biomarkers, race/ethnicity and cardiovascular disease

Cardiovascular disease (CVD) remains the leading cause of death in the developed world. In the United States alone, cardiovascular disease accounts for nearly 40% of deaths, at an estimated annual cost of at least US $430 billion. Notable, racial/ethnic differences in morbidity and mortality have been observed; in the United States, African Americans have the highest age-adjusted death rate from CVD, followed by Whites, Hispanics, and Asians. The underlying basis for the observed racial/ethnic disparities in CVD morbidity and mortality is likely multifactorial. Although hyperlipidemia screening and treatment has proven to be one of the most effective strategies for reducing CVD burden in the US population, it often fails to identify a substantial proportion of persons at high risk for CVD-related events. Elevations in markers of inflammation and thrombosis such as high sensitivity C-reactive protein, soluble intercellular adhesion molecule, homocysteine, and fibrinogen are also associated with increased CVD risk. However, data relating markers of inflammation and hemostasis to CVD principally come from White populations, little data are available across racial/ethnic groups. A range of barriers exist related to ethnic minority subject participation in research studies in the United States. If we are to better understand the racial differences in cardiovascular risk, these barriers must be overcome.

"Upstream markers" provide for early identification of patients at high risk for myocardial necrosis and adverse outcomes

BACKGROUND

For patients presenting with acute coronary syndrome (ACS) to the emergency department, early identification of those that are at high risk for subsequent myocardial necrosis or adverse outcomes would allow earlier or more aggressive treatment. We determined if a panel of biomarkers can be used to identify high risk patients.

METHODS

A cohort (84 females/132 males) from our 1996 ACS study population that had EDTA specimens stored (-70 degrees C) was selected and the earliest available specimen was analyzed for 11 biomarkers (IL-6, IL-8, MCP-1, VEGF, L-selectin, P-selectin, E-selectin, ICAM-1, VCAM-1, NT-proBNP, cTnT). These data were linked to the existing cTnI and health outcome databases for this population. ROC curve analysis for myocardial necrosis (i.e., peak cTnI >0.04 microg/l) identified 3 candidate biomarkers. These 3 biomarkers were applied together to generate a panel test (2 of the 3 biomarkers increased for a positive result) and assessed for its ability to identify patients at risk for myocardial necrosis and the combined endpoint of death, myocardial infarction (MI) and heart failure (HF).

RESULTS

The panel test (IL-6, NT-proBNP, E-selectin) alone detected 60% (95% CI: 49-69; false positive rate: 26%) of subjects that would be classified with myocardial necrosis. Kaplan-Meier and Cox proportional analyses indicated that patients positive by the biomarker panel (including those with cTnI < or =0.04 microg/l) had significantly worse outcomes (death/MI/HF) as compared to those negative by both cTnI and the panel test.

CONCLUSION

A biomarker panel analyzed early after pain onset can identify individuals at risk for both myocardial necrosis and the combined endpoint of death/MI/HF. Additional prospective studies are required to assess this panel for both early MI detection and to further refine which health outcomes (death, MI, HF) are associated with positive panel results.

Recent development in pharmacogenomics: from candidate genes to genome-wide association studies

Genetic diversity, most notably through single nucleotide polymorphisms and copy-number variation, together with specific environmental exposures, contributes to both disease susceptibility and drug response variability. It has proved difficult to isolate disease genes that confer susceptibility to complex disorders, and as a consequence, even fewer genetic variants that influence clinical drug responsiveness have been uncovered. As such, the candidate gene approach has largely failed to deliver and, although the family-based linkage approach has certain theoretical advantages in dealing with common/complex disorders, progress has been slower than was hoped. More recently, genome-wide association studies have gained increasing popularity, as they enable scientists to robustly associate specific variants with the predisposition for complex disease, such as age-related macular degeneration, Type 2 diabetes, inflammatory bowel disease, obesity, autism and leukemia. This relatively new methodology has stirred new hope for the mapping of genes that regulate drug response related to these conditions. Collectively, these studies support the notion that modern high-throughput single nucleotide polymorphism genotyping technologies, when applied to large and comprehensively phenotyped patient cohorts, will readily reveal the most clinically relevant disease-modifying and drug response genes. This review addresses both recent advances in the genotyping field and highlights from genome-wide association studies, which have conclusively uncovered variants that underlie disease susceptibility and/or variability in drug response in common disorders.

Intercellular adhesion molecule 1 (ICAM1) Lys56Met and Gly241Arg gene variants, plasma-soluble ICAM1 concentrations, and risk of incident cardiovascular events in 23,014 initially healthy white women

BACKGROUND AND PURPOSE

The objective of this study was to examine the association of 2 nonsynonymous intercellular adhesion molecule 1 (ICAM1) gene variants (Lys56Met and Gly241Arg) with baseline plasma soluble ICAM1 concentrations and with risk of total and selected cardiovascular disease (CVD) events in a prospective cohort of 23 014 apparently healthy white American women followed for 10 years. ICAM1 variations have been associated with plasma soluble ICAM1 concentrations and inflammatory conditions, including atherosclerosis. However, to date, no large prospective, genetic-epidemiological data set is available that would allow evaluation of the degree of association of these gene variants with risk of CVD.

METHODS

ICAM1 genotypes and baseline plasma soluble ICAM1 concentrations were determined. The primary outcome measure was a composite CVD end point (incident ischemic stroke, myocardial infarction, or death due to ischemic CVD); other measures were incident ischemic stroke, myocardial infarction, and coronary revascularization. During follow-up, 751 total incident CVD events, 187 incident myocardial infarction cases, 203 incident ischemic stroke cases, and 433 coronary revascularization events occurred.

RESULTS

All observed genotype frequencies were in Hardy-Weinberg equilibrium across the whole sample population. We found baseline plasma soluble ICAM1 concentrations to be significantly reduced among carriers of Met56 allele (P<0.0001) and Arg241 allele (P<0.0001) as compared with the respective noncarriers of these variants. However, the polymorphisms tested and the respective haplotypes were neither associated with overall risk nor with risk with risk for selected CVD events regardless of whether analyses were adjusted for traditional CVD risk factors/confounders (all P values >0.10).

CONCLUSIONS

In this large prospective study, we found an association of the nonsynonymous gene variants tested with reduced baseline plasma soluble ICAM1 concentrations. However, no evidence was found for an association of the gene variants tested with the overall or selected CVD end points examined, suggesting that these variants may not add useful aids to current risk predictors for early assessment of cardiovascular events.

Relationship between estrogen receptor-alpha polymorphism and serum levels of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, C-reactive protein and homocysteine in postmenopausal women

BACKGROUND AND AIM

Genetic variation in the estrogen receptor-gene (ERalpha) may influence the risk of cardiovascular diseases in postmenopausal women. This effect, at least in part, may be dependent on the decrease in expression of injury and inflammatory markers in the vascular wall. The aim of the present study was to evaluate the relationship between ERalpha PvuII and XbaI polymorphisms and serum levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), C-reactive protein (CRP) and homocysteine in postmenopausal women.

SUBJECTS AND METHODS

Subjects of the study were 64 postmenopausal women. PvuII and XbaI ERalpha gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Mean sVCAM-1 level was significantly higher in pp homozygotes in comparison with PP homozygotes and Pp heterozygotes, as well as higher in xx homozygotes in comparison with XX homozygotes and Xx heterozygotes. Levels of sVCAM-1 were also significantly higher in women with px haplotype compared with PX and Px haplotypes. There were no relationships between investigated genotypes or haplotypes and levels of sICAM-1, CRP and homocysteine.

CONCLUSION

The results of our study suggest that genetic variation in ER gene may influence blood levels of VCAM-1 in women after the menopause.

Positive association of adiponectin with soluble vascular cell adhesion molecule sVCAM-1 levels in patients with vascular disease or dyslipidemia

The aim of our study was to evaluate the relationship of adiponectin to soluble forms of vascular cell adhesion molecule-1 (sVCAM-1) and intercellular cell adhesion molecule-1 (sICAM-1) in patients with cardiovascular disease or dyslipidemia. Two hundred and sixty-four patients (134 men/130 women, mean age 43.8+/-14.8/46.0+/-14.9 years) of Lipid Center, University Hospital Olomouc, off hypolipidemic therapy for at least 6 weeks, participated in the study. In multiple regression analysis, adiponectin was independently positively associated with serum HDL-cholesterol (p<0.0001) and sVCAM-1 (p<0.0001), female gender (p<0.0001) and negatively with hs-CRP (p=0.014). Serum concentration of adiponectin and sICAM-1 did not correlate but sICAM-1 was independently, positively associated with sVCAM-1 (p<0.0001) and negatively with markers of insulin resistance and inflammation, namely atherogenic index log[triglycerides/HDL-cholesterol] (p<0.0001), hs-CRP (p<0.001) and HOMA (p<0.05). Positive association of adiponectin with HDL-C and negative association with hs-CRP indicate anti-atherogenic properties of adiponectin. The finding of the positive association of adiponectin with sVCAM-1 in patients at risk is unexpected. We hypothesize that adiponectin may be involved (directly or indirectly) in shedding of ectodomains of VCAM-1 from endothelial surface and in this way down-regulates their effects. This process may be protective in the initial stages of atherosclerosis.

HMG-CoA reductase inhibitors reduce nicotine-induced expression of cellular adhesion molecules in cultured human coronary endothelial cells

BACKGROUND

Smoking predisposes to the development of atherosclerosis and of its complications. The mechanisms responsible for these effects are not completely understood. We have investigated whether nicotine might promote a proatherosclerotic state in human coronary endothelial cells (HCAECs), studying the role of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in preventing these phenomena.

METHODS AND RESULTS

Real-time PCR showed that nicotine induced a dose-dependent increase in mRNA levels for vascular cellular adhesion molecule-1 (VCAM-1)/intercellular adhesion molecule-1 (ICAM-1). Fluorescent-activated cell sorting analysis showed that nicotine induced expression of functionally active VCAM-1/ICAM-1, since they increased leukocyte adherence to HCAECs. Oxygen free radicals, Rho A and nuclear factor kappaB (NF-kappaB) play a pivotal role in modulating these effects. Indeed, nicotine caused oxygen free radical production as well as activation of Rho A and NF-kappaB pathways, evaluated by malondialdehyde levels, pulldown assay and by electrophoretic mobility shift assay, respectively. Superoxide dimutase, Rho A (Y-27639) and NF-kappaB inhibitors (pyrrolidine dithiocarbamate ammonium, Bay 11-7082) suppressed nicotine effects on CAM expression. HMG-CoA reductase inhibitors prevented these nicotine-mediated effects by inhibiting free radical generation and by modulating activation of Rho A and NF-kappaB pathways.

CONCLUSIONS

Nicotine promotes CAM expression on HCAECs, shifting them toward a proatherosclerotic state. These effects might explain, at least in part, the deleterious cardiovascular consequences of cigarette smoking. HMG-CoA reductase inhibitors play an important role in preventing these phenomena.

Markers for endothelial dysfunction, but not markers for oxidative stress correlate with classical risk factors and the severity of coronary artery disease. (A subgroup analysis from the Ludwigshafen Risk and Cardiovascular Health Study)

OBJECTIVE

Endothelial dysfunction and oxidative stress are involved in atherogenesis. In the search for predictors of vascular disease markers for endothelial dysfunction and oxidative stress were analyzed.

METHODS

Of 208 consecutive patients 22% were controls (CO) without coronary artery disease (CAD), 52% presented with stable angina (SAP) and 26% had acute coronary syndromes (ACS). Nitric oxide (NO), thrombomodulin (TM), von Willebrand factor (vW), sVCAM-1, sICAM-1, sP-selectin, sE-selectin, sL-selectin and C-reactive protein (CRP) were determined as markers for endothelial dysfunction, glutathione (GSH), glutathione peroxidase (Gpx), myeloperoxidase (Mpx), lipid peroxides (Lpx), 8-isoprostane (Iso), superoxide dismutase (SOD), total antioxidant capacity (TAC) and homocysteine (Hc) as markers for oxidative stress.

RESULTS

The increases of TM, vW, sVCAM-1, CRP, SOD and Mpx correlated with the CAD status in the order CO < SAP < ACS, whereas NO and sL-selectin were inversely correlated (p < 0.05, resp.). The other markers remained unchanged. For several markers a significant relationship to risk factors was detected.

CONCLUSIONS

Markers for endothelial dysfunction rather than those for oxidative stress may serve as indicators for the presence and severity of CAD.

Associations between markers of subclinical atherosclerosis and dietary patterns derived by principal components analysis and reduced rank regression in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

The association between diet and cardiovascular disease (CVD) may be mediated partly through inflammatory processes and reflected by markers of subclinical atherosclerosis.

OBJECTIVE

We investigated whether empirically derived dietary patterns are associated with coronary artery calcium (CAC) and common and internal carotid artery intima media thickness (IMT) and whether prior information about inflammatory processes would increase the strength of the associations.

DESIGN

At baseline, dietary patterns were derived with the use of a food-frequency questionnaire, and inflammatory biomarkers, CAC, and IMT were measured in 5089 participants aged 45-84 y, who had no clinical CVD or diabetes, in the Multi-Ethnic Study of Atherosclerosis. Dietary patterns based on variations in C-reactive protein, interleukin-6, homocysteine, and fibrinogen concentrations were created with reduced rank regression (RRR). Dietary patterns based on variations in food group intake were created with principal components analysis (PCA).

RESULTS

The primary RRR (RRR 1) and PCA (PCA factor 1) dietary patterns were high in total and saturated fat and low in fiber and micronutrients. However, the food sources of these nutrients differed between the dietary patterns. RRR 1 was positively associated with CAC [Agatston score >0: OR (95% CI) for quartile 5 compared with quartile 1 = 1.34 (1.05, 1.71); ln(Agatston score = 1): P for trend = 0.023] and with common carotid IMT [>or=1.0 mm: OR (95% CI) for quartile 5 compared with quartile 1 = 1.33 (0.99, 1.79); ln(common carotid IMT): P for trend = 0.006]. PCA 1 was not associated with CAC or IMT.

CONCLUSION

The results suggest that subtle differences in dietary pattern composition, realized by incorporating measures of inflammatory processes, affect associations with markers of subclinical atherosclerosis.

Relative Value of Inflammatory, Hemostatic, and Rheological Factors for Incident Myocardial Infarction and Stroke

Background— The aim of our present study was to compare the association of a wide range of 17 biomarkers of inflammation, hemostasis, and blood rheology with incident heart disease and stroke after accounting for an indicator of subclinical atherosclerotic disease and traditional risk factors and also to determine their incremental predictive ability.

Methods and Results— We used data from the Edinburgh Artery Study, a population cohort study started in 1987 that comprised 1592 men and women aged 55 to 74 years. Subjects were followed for a mean of 17 years, and 416 of them suffered at least 1 cardiovascular event. In analyses adjusted for cardiovascular risk factors and history of cardiovascular disease (CVD): C-reactive protein, interleukin-6, fibrinogen, fibrin D-dimer, tissue plasminogen activator (t-PA), leukocyte elastase, and lipoprotein(a) (all P <0.01), as well as von Willebrand factor and plasma viscosity (both P <0.05), had significant hazard ratios for incident CVD. Further adjustment for a measure of subclinical atherosclerosis (ankle brachial index) had little impact on these associations. The hazard ratios (95% CI) for incident CVD between top and bottom tertiles in the latter analysis were 1.78 (1.30 to 2.45) for C-reactive protein, 1.85 (1.33 to 2.58) for interleukin-6, and 1.76 (1.35 to 2.31) for fibrinogen. Single biomarkers provided little additional discrimination of incident CVD to that obtained from cardiovascular risk factors and the ankle brachial index. An incremental score of multiple markers [interleukin-6, t-PA, intercellular adhesion molecule 1, and lipoprotein(a)] provided some added discrimination.

Conclusions— Several “novel” risk factors predicted CVD after adjustments for conventional risk factors and also for a measure of asymptomatic disease. However, their incremental predictive ability was modest and their clinical utility remains uncertain.