Plasma fibrinogen level and the risk of major cardiovascular diseases and nonvascular mortality: an individual participant meta-analysis

Direct comparisons of three alternative plasma fibrinogen assays with the von Clauss assay in prediction of cardiovascular disease and all-causes mortality: the Scottish Heart Health Extended Cohort

There is strong evidence from meta-analyses of prospective epidemiological studies that increasing plasma fibrinogen levels are associated with an increasing risk of cardiovascular disease (CVD) and all-cause mortality. However, there are few published direct comparisons of the several different available fibrinogen assays in association with CVD or mortality. We therefore prospectively compared the standardized von Clauss assay of clottable fibrinogen with three other assays: prothrombin time (PT)-derived clottable fibrinogen, immunonephelometric fibrinogen, and heat precipitable fibrinogen in the Scottish Heart Health Extended Cohort. Hazard ratios (HRs) for a standard deviation increase in fibrinogen for risk of CVD, adjusted for age and sex, were 1.17 (95% confidence interval [CI] 1.14; 1.21) for the von Clauss assay; 1.19 (1.06; 1.33) for the heat precipitation assay; 1.16 (1.01; 1.35) for the PT-derived assay; and 1.28 (1.10; 1.51) for the immunonephelometric assay. HRs for all-cause mortality were 1.21 (1.18; 1.24); 1.13 (1.01; 1.26), 1.17 (1.00; 1.37) and 1.17 (0.99; 1.39), respectively. No significant differences were observed between the assays in such comparisons. We therefore conclude that the choice between plasma fibrinogen assays in routine clinical haematology and biochemistry laboratories should depend on practical factors, and not on expected differences in the strength of associations.

Risk factors for cardiovascular mortality in patients with systemic lupus erythematosus, a prospective cohort study

Introduction

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. Cardiovascular disease (CVD) is common and a major cause of mortality. Studies on cardiovascular morbidity are abundant, whereas mortality studies focusing on cardiovascular outcomes are scarce. The aim of this study was to investigate causes of death and baseline predictors of overall (OM), non-vascular (N-VM), and specifically cardiovascular (CVM) mortality in SLE, and to evaluate systematic coronary risk evaluation (SCORE).

Methods

208 SLE patients were included 1995-1999 and followed up after 12 years. Clinical evaluation, CVD risk factors, and biomarkers were recorded at inclusion. Death certificates and autopsy protocols were collected. Causes of death were divided into CVM (ischemic vascular and general atherosclerotic diseases), N-VM and death due to pulmonary hypertension. Predictors of mortality were investigated using multivariable Cox regression. SCORE and standardized mortality ratio (SMR) were calculated.

Results

During follow-up 42 patients died at mean age of 62 years. SMR 2.4 (CI 1.7-3.0). 48% of deaths were caused by CVM. SCORE underestimated CVM but not to a significant level. Age, high cystatin C levels and established arterial disease were the strongest predictors for all- cause mortality. After adjusting for these in multivariable analyses, only smoking among traditional risk factors, and high soluble vascular cell adhesion molecule-1 (sVCAM-1), high sensitivity C-reactive protein (hsCRP), anti-beta2 glycoprotein-1 (abeta2GP1) and any antiphospholipid antibody (aPL) among biomarkers, remained predictive of CVM.

Conclusion

With the exception of smoking, traditional risk factors do not capture the main underlying risk factors for CVM in SLE. Rather, cystatin C levels, inflammatory and endothelial markers, and antiphospholipid antibodies (aPL) differentiate patients with favorable versus severe cardiovascular prognosis. Our results suggest that these new biomarkers are useful in evaluating the future risk of cardiovascular mortality in SLE patients.

Derangement of hemostasis in rheumatoid arthritis: association with demographic, inflammatory and metabolic factors

Disturbance of fibrinolysis is common in rheumatoid arthritis (RA), and it may be associated with the increased cardiovascular risk observed in this population. We aimed to assess coagulation derangement and investigate whether abnormalities are influenced by demographic, inflammatory or metabolic factors in patients with RA. Levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI-1), fibrinogen, prothrombin fragment 1 + 2 (PF1 + 2), thrombomodulin (TM), protein C and Von Willebrand factor (vWF) were compared between 141 RA patients and 50 healthy hospital controls. Within RA, coagulation factors were assessed alongside several demographic, inflammation and metabolic indicators. RA patients had higher levels of coagulation factors than controls. After correction for age and sex, having RA predicted increased tPA (B = 0.15, P < 0.001), PAI-1 (B = 0.21, P < 0.001), fibrinogen (B = 0.86, P < 0.001), PF1 + 2 (B = 0.20, P < 0.001), and TM (B = 0.01, P = 0.03) levels. CRP correlated positively with tPA (P < 0.05), fibrinogen (P < 0.001), TM (P < 0.05), PF1 + 2 (P < 0.001) and vWF (P < 0.001). Metabolic factors linked with coagulation factors were hypertriglyceridaemia (tPA, P < 0.05; PAI-1, P < 0.05; protein C, P < 0.05) and insulin resistance (tPA, P < 0.01; PAI-1, P < 0.01; vWF, P < 0.05). Imbalance of coagulation and fibrinolytic mechanisms is common in RA and associates with age, inflammation, and metabolic factors. Further studies may determine whether these abnormalities are the consequence of acute inflammation or markers of vascular dysfunction.

Circulating biomarkers for predicting cardiovascular disease risk; a systematic review and comprehensive overview of meta-analyses

BACKGROUND

Cardiovascular disease is one of the major causes of death worldwide. Assessing the risk for cardiovascular disease is an important aspect in clinical decision making and setting a therapeutic strategy, and the use of serological biomarkers may improve this. Despite an overwhelming number of studies and meta-analyses on biomarkers and cardiovascular disease, there are no comprehensive studies comparing the relevance of each biomarker. We performed a systematic review of meta-analyses on levels of serological biomarkers for atherothrombosis to compare the relevance of the most commonly studied biomarkers.

METHODS AND FINDINGS

Medline and Embase were screened on search terms that were related to "arterial ischemic events" and "meta-analyses". The meta-analyses were sorted by patient groups without pre-existing cardiovascular disease, with cardiovascular disease and heterogeneous groups concerning general populations, groups with and without cardiovascular disease, or miscellaneous. These were subsequently sorted by end-point for cardiovascular disease or stroke and summarized in tables. We have identified 85 relevant full text articles, with 214 meta-analyses. Markers for primary cardiovascular events include, from high to low result: C-reactive protein, fibrinogen, cholesterol, apolipoprotein B, the apolipoprotein A/apolipoprotein B ratio, high density lipoprotein, and vitamin D. Markers for secondary cardiovascular events include, from high to low result: cardiac troponins I and T, C-reactive protein, serum creatinine, and cystatin C. For primary stroke, fibrinogen and serum uric acid are strong risk markers. Limitations reside in that there is no acknowledged search strategy for prognostic studies or meta-analyses.

CONCLUSIONS

For primary cardiovascular events, markers with strong predictive potential are mainly associated with lipids. For secondary cardiovascular events, markers are more associated with ischemia. Fibrinogen is a strong predictor for primary stroke.

Circulating biomarkers for predicting cardiovascular disease risk; a systematic review and comprehensive overview of meta-analyses

BACKGROUND

Cardiovascular disease is one of the major causes of death worldwide. Assessing the risk for cardiovascular disease is an important aspect in clinical decision making and setting a therapeutic strategy, and the use of serological biomarkers may improve this. Despite an overwhelming number of studies and meta-analyses on biomarkers and cardiovascular disease, there are no comprehensive studies comparing the relevance of each biomarker. We performed a systematic review of meta-analyses on levels of serological biomarkers for atherothrombosis to compare the relevance of the most commonly studied biomarkers.

METHODS AND FINDINGS

Medline and Embase were screened on search terms that were related to "arterial ischemic events" and "meta-analyses". The meta-analyses were sorted by patient groups without pre-existing cardiovascular disease, with cardiovascular disease and heterogeneous groups concerning general populations, groups with and without cardiovascular disease, or miscellaneous. These were subsequently sorted by end-point for cardiovascular disease or stroke and summarized in tables. We have identified 85 relevant full text articles, with 214 meta-analyses. Markers for primary cardiovascular events include, from high to low result: C-reactive protein, fibrinogen, cholesterol, apolipoprotein B, the apolipoprotein A/apolipoprotein B ratio, high density lipoprotein, and vitamin D. Markers for secondary cardiovascular events include, from high to low result: cardiac troponins I and T, C-reactive protein, serum creatinine, and cystatin C. For primary stroke, fibrinogen and serum uric acid are strong risk markers. Limitations reside in that there is no acknowledged search strategy for prognostic studies or meta-analyses.

CONCLUSIONS

For primary cardiovascular events, markers with strong predictive potential are mainly associated with lipids. For secondary cardiovascular events, markers are more associated with ischemia. Fibrinogen is a strong predictor for primary stroke.

Parental obesity and risk factors for cardiovascular disease among their offspring in mid-life: findings from the 1958 British Birth Cohort Study

Background:

Few studies have investigated whether parental adiposity is associated with offspring cardiovascular health or the underlying pathways. Studying these associations may help to illuminate the paradox of increasing prevalence of obesity and declining trends in cardiovascular disease (CVD) mortality, which may be partially explained by beneficial adaptations to an obesogenic environment among people exposed to such environments from younger ages.

Objective:

To investigate associations between parental body mass index (BMI) and risk factors for CVD among their offspring in mid-life and to test whether associations of offspring BMI with CVD risk factors were modified by parental BMI.

Methods:

Data from parents and offspring in the 1958 British birth cohort were used (N=9328). Parental BMI was assessed when offspring were aged 11 years; offspring BMI, waist circumference and CVD risk factors (lipid levels, blood pressure, glycosylated haemoglobin (HbA1c) and inflammatory and haemostatic markers) were measured at 44–45 years.

Results:

Higher parental BMI was associated with less favourable levels of offspring risk factors for CVD. Most associations were maintained after adjustment for offspring lifestyle and socioeconomic factors but were largely abolished or reversed after adjustment for offspring adiposity. For some CVD risk factors, there was evidence of effect modification; the association between higher BMI and an adverse lipid profile among offspring was weaker if maternal BMI had been higher. Conversely, offspring BMI was more strongly associated with HbA1c if parental BMI had been higher.

Conclusions:

Intergenerational influences may be important in conferring the effect of high BMI on CVD risk among offspring.

Relation of fibrinogen level with cardiovascular events in patients with coronary artery disease

Evidence on the usefulness of fibrinogen for the risk stratification of patients with coronary artery disease remains inconclusive. The aims of this study were to investigate the association of fibrinogen with cardiovascular events and to assess whether this biomarker provides additional prognostic information on top of that provided by traditional cardiovascular risk factors. This study included 13,195 patients with angiography-proved coronary artery disease and fibrinogen measurements available. Receiver-operating characteristic curve analysis showed that the best fibrinogen cutoff for mortality prediction was 402.0 mg/dl. On the basis of this cutoff, patients were divided into 2 groups: the group with fibrinogen >402.0 mg/dl (n = 5,198) and the group with fibrinogen ≤402.0 mg/dl (n = 7,997). The primary outcome was 1-year mortality. All-cause deaths occurred in 393 patients with fibrinogen >402.0 mg/dl and in 246 patients with fibrinogen ≤402.0 mg/dl (Kaplan-Meier estimates of mortality 7.7% and 3.1%, log-rank test p <0.001). The relation between fibrinogen and mortality followed a J-shaped pattern, with lowest mortality in patients with fibrinogen concentrations of 295 to 369 mg/dl. After adjustment for cardiovascular risk factors and relevant clinical variables, fibrinogen remained an independent correlate of all-cause mortality (adjusted hazard ratio 1.07, 95% confidence interval 1.04 to 1.10, p <0.001, for each 50 mg/dl increase in fibrinogen level), but it did not improve the discriminatory power of the model for mortality prediction (integrated discrimination improvement 0.002, p = 0.32). In conclusion, in patients with coronary artery disease, fibrinogen is an independent correlate of mortality, but it does not provide additional prognostic information on top of that provided by traditional cardiovascular risk factors.

Thrombophilia and arteriovenous fistula survival in ESRD

BACKGROUND AND OBJECTIVES

The role of thrombophilia in failing arteriovenous fistula (AVF) among patients with ESRD undergoing hemodialysis is not established. This study aimed to assess whether AVF primary patency is associated with thrombophilia and coagulation abnormalities.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This observational study screened 219 patients between 2002 and 2004 for thrombophilia before AVF surgery. Thrombophilia included factor V Leiden and prothrombin G20210A mutations, protein C and antithrombin activities, and protein S. Coagulation abnormalities included high factor VIII:C, homocysteine, fibrinogen, and d-dimer levels; presence of antiphospholipid antibodies; and short thrombin time. We reviewed patient charts for comorbid conditions, AVF maturation and interventions, kidney transplantation, and patient survival (mean follow-up duration, 3.6 [range, 2.3-5.8] years). Primary patency from the AVF placement and functional primary patency from the first AVF cannulation were analyzed with Kaplan-Meier and Cox proportional hazards models.

RESULTS

Thrombophilia was present in 9% of the patients, and coagulation abnormalities occurred in 77%. One-year primary patency was 68%; 46% of the AVF failures occurred before the initiation of hemodialysis. Female sex (hazard ratio [HR], 2.6; 95% confidence interval [CI], 1.7-4.1) and thrombophilia (HR, 2.2; 95% CI, 1.2-4.2) were independent risk factors for loss of primary patency. Thrombophilia mutations or low antithrombin level (HR, 3.8), female sex (HR, 2.5), and diabetes (HR, 1.9) were associated with shortened functional primary patency of AVF.

CONCLUSIONS

Against the background of frequent coagulation abnormalities, thrombophilia and female sex predispose patients with ESRD to access failure, mostly due to thrombosis or stenosis.

A high intake of dietary fiber influences C-reactive protein and fibrinogen, but not glucose and lipid metabolism, in mildly hypercholesterolemic subjects

PURPOSE

The aim of the study was to investigate how a diet high in dietary fiber, with several fiber sources included, modulates glucose and lipid metabolism and the inflammatory response in humans.

METHODS

Subjects (n = 25) aged 58.6 (1.1) years (mean and SD) with a BMI of 26.6 (0.5) kg/m(2) and a total cholesterol (TC) of 5.8 (0.1) mmol/L (mean and SEM) were given a high fiber (HF) and low fiber (LF) diet, in a randomized controlled 5-week crossover intervention, separated by a 3-week washout. The HF diet consisted of oat bran, rye bran, and sugar beet fiber incorporated into test food products; one bread roll, one ready meal, and two beverages consumed daily. Equivalent food products, without added fibers, were provided in the LF diet.

RESULTS

Total dietary fiber intake was 48.0 g and 30.2 g per day for the HF and LF diet, respectively. Significant reduction in C-reactive protein (CRP) was observed between the diets (P = 0.017) and a significant reduction in fibrinogen within the HF diet (P = 0.044). There were no significant effects in other measured circulating cytokines or in glucose, insulin, and lipid levels.

CONCLUSIONS

Our study suggests that a 5-week high dietary fiber intake of oat bran, rye bran, and sugar beet fiber might reduce the low-grade inflammatory response measured as CRP which could, together with reduced fibrinogen, help to prevent the risk of cardiovascular disease.

Peripheral arterial disease in the Middle East: Underestimated predictor of worse outcome

Peripheral arterial disease (PAD) is a common manifestation of systemic atherosclerosis and is associated with significant morbidity and mortality. The prevalence of PAD in the developed world is approximately 12% among adult population, which is age-dependent and with men being affected slightly more than women. Despite the strikingly high prevalence of PAD, the disease is underdiagnosed. Surprisingly, more than 70% of primary health care providers in the US were unaware of the presence of PAD in their patients. The clinical presentation of PAD may vary from asymptomatic to intermittent claudication, atypical leg pain, rest pain, ischemic ulcers, or gangrene. Claudication is the typical symptomatic expression of PAD. However, the disease may remains asymptomatic in up to 50% of all PAD patients. PAD has also been reported as a marker of poor outcome among patients with coronary artery disease. Despite the fact that the prevalence of atherosclerotic disease is increasing in the Middle East with increasing cardiovascular risk factors (tobacco use, diabetes mellitus and the metabolic syndrome), data regarding PAD incidence in the Middle East are scarce.

13-year long-term associations between changes in traditional cardiovascular risk factors and changes in fibrinogen levels: the Coronary Artery Risk Development in Young Adults (CARDIA) study

OBJECTIVE

Cross-sectional and prospective studies have linked cardiovascular events and traditional risk factors (TRFs) with higher plasma fibrinogen levels. In a young cohort, we sought to determine longitudinal associations between changes in/development of TRFs and fibrinogen levels over 13 years.

METHODS

We included 2525 adults from the CARDIA study, aged 25-37 with fibrinogen and TRFs measured at year 7 (study baseline; 1992-1993); and year 20 (follow-up). Multiple linear regressions were used to compare mean changes in fibrinogen to TRFs.

RESULTS

Mean fibrinogen increased by 71 mg/dL vs. 70 mg/dL (p = NS) in black vs. white men, and 78 mg/dL vs. 68 mg/dL (p < 0.05) in black vs. white women, respectively over 13 years. After multivariable adjustments, fibrinogen generally rose with increasing BMI (p < 0.001; all sex/race groups), LDL cholesterol, log triglycerides and diastolic blood pressure; and fell with increasing HDL cholesterol and physical activity. 13-year increase in fibrinogen for persons who quit smoking or became non-obese were comparable (p = NS) to that of never-smokers and never-obese persons.

CONCLUSIONS

Among young black and white men and women with few baseline cardiovascular risk factors, fibrinogen tracked longitudinally with changes in TRFs over 13 years through middle age. There was a strong inverse longitudinal relationship between modifiable risk factors (weight loss/smoking cessation) and 13-year change in fibrinogen. Our study helps provide some insight into the role of fibrinogen as a disease marker in the associations between fibrinogen and CVD.

Long-term change in alcohol-consumption status and variations in fibrinogen levels: the coronary artery risk development in young adults (CARDIA) study

OBJECTIVE

To examine long-term associations between change in alcohol-consumption status and cessation of alcohol use, and fibrinogen levels in a large, young, biracial cohort.

DESIGN

Analysis of covariance models were used to analyse participants within the Coronary Artery Risk Development in Young Adults Study (CARDIA) cohort who had fibrinogen and alcohol use data at year 7 (1992-1993; ages 25-37) and year 20 examinations.

SETTING

4 urban US cities.

PATIENTS

2520 men and women within the CARDIA cohort.

MAIN OUTCOME MEASURES

13-year changes in alcohol use related to changes in fibrinogen.

RESULTS

Over 13 years, mean fibrinogen increased by 71 vs 70 mg/dL (p=NS) in black men (BM) versus white men (WM), and 78 vs 68 mg/dL (p<0.05) in black women (BW) versus white women (WW), respectively. Compared with never-drinkers, there were smaller longitudinal increases in fibrinogen for BM, BW and WW (but a larger increase in WM) who became or stayed drinkers, after multivariable adjustment. For BM, WM and WW, fibrinogen increased the most among persons who quit drinking over 13 years (p<0.001 for WM (fibrinogen increase=86.5 (7.1) (mean (SE))), compared with never-drinkers (fibrinogen increase=53.1 (5.4)).

CONCLUSIONS

In this young cohort, compared with the participants who never drank, those who became/stayed drinkers had smaller increases, while those who quit drinking had the highest increase in fibrinogen over 13 years of follow-up. The results provide a novel insight into the mechanism for the established protective effect of moderate alcohol intake on cardiovascular disease outcomes.

Endogenous oestradiol as a positive correlate of plasma fibrinogen among older postmenopausal women: a population-based study (the Three-City cohort study)

BACKGROUND

Plasma fibrinogen is a strong predictor of ischaemic arterial disease in women. Sex steroid hormones including hormone therapy may play an important role in the development of cardiovascular disease. However, whether endogenous sex steroid hormones influence the plasma fibrinogen concentrations among postmenopausal women remains unclear.

OBJECTIVES

To investigate the association of plasma fibrinogen levels with endogenous sex steroid hormones and sex hormone binding globulin (SHBG) among postmenopausal women.

METHODS

We used data from the French prospective Three-City cohort study that included 9294 noninstitutionalized men and women over 65 years of age. Total 17β-oestradiol (E2, pg/ml), total testosterone (T, ng/ml), SHBG (nm) and fibrinogen (g/l) were measured in stored plasmas in a subcohort of 602 randomly selected postmenopausal women who used neither hormone medication nor anticoagulation therapy. Multivariate linear regression models were used to estimate the regression coefficients assessed in fibrinogen unit by 1 SD increase in log-distribution of sex steroid hormones and SHBG.

RESULTS

E2 but neither T nor SHBG was positively associated with plasma fibrinogen levels (β = 0·148, P < 0·001). Adjustment for cardiovascular risk factors including diabetes made no substantial change to the results (β = 0·145, P < 0·001). The association of fibrinogen with E2 was stronger among women with body mass index over 25 kg/m(2) compared with those with normal weight (β = 0·156, P < 0·001 and β = 0·092, P = 0·02, respectively, P for interaction = 0·04).

CONCLUSION

E2 emerges as a positive and independent correlate of plasma fibrinogen among postmenopausal women, especially in subjects who are overweight. These findings suggest a deleterious effect of endogenous oestrogens on cardiovascular risk profile among postmenopausal women.

Prothrombotic gene polymorphisms and plasma factors in young North Indian survivors of acute myocardial infarction

The aim of this study was to evaluate the association of prothrombotic gene polymorphisms [factor V Leiden (FVL) 1691GA, factor VII (FVII) 10976GA, FVII HVR4, platelet membrane glycoproteins GP1BA 1018CT, GP1BA VNTR, integrin ITGB3 1565TC, integrin ITGA2 807CT and methylenetetrahydrofolate reductase (MTHFR) 677C/T], plasma factors (fibrinogen and homocysteine) and traditional risk factors with acute myocardial infarction (AMI) in 184 patients ≤ 40 years of age and 350 controls (≤ 40 years) from north India. Multiple logistic-regression analysis showed that hypertension (OR 1.9, 95 % CI 1.1-3.8, p = 0.042), diabetes mellitus (OR 10.5, 95 % CI 2.0-56.7, p = 0.006), smoking (OR 7.1, 95 % CI 3.7-13.6, p < 0.001), low socio-economic status (OR 13.5, 95 % CI 2.3-78.4, p = 0.004), high waist-hip ratio (OR 35.6, 95 % CI 11.1-53.7, p < 0.001) and FVL 1691GA (OR 6.0, 95 % CI 1.2-13.4, p = 0.03) were independent risk predictors of AMI in young. Elevated plasma fibrinogen also showed association with increased AMI risk. ITGA2 807C/T polymorphism showed protection against AMI in univariate analysis only, while GP1BA VNTR-ac (OR 0.4, 95 % CI 0.2-0.9, p = 0.033) showed significant protection even after adjusting for age and sex. Multinominal logistic-regression analysis showed gene-gene (GP1BA 1018C/T with GP1BA VNTR and ITGA2 807C/T with ITGB3 1565T/C polymorphisms) and gene-environment interactions (gene polymorphisms with smoking) operating in the occurrence of AMI in young. In conclusion, the role of inherited predisposition to thrombosis in complex, polygenic and multifactorial disease like AMI is limited to certain genetic factors, in combination with environmental factor like smoking.

Blood biomarkers role in acute ischemic stroke patients: higher is worse or better?

Background

Thrombolytic therapy (TT) for acute ischemic stroke (AIS) can provoke bleeding’s complication depending on the ischemic lesion (IL) dimension. Inflammation involved in the setting of acute ischaemic stroke, is associated with infarct size. We aimed to study the independent correlation and association between clinical panel of routinely identified biomarkers, including inflammatory parameters, and cerebral IL dimension and site.

Results

We evaluated eleven biomarkers in 105 unrelated patients during their hospitalization after acute stroke event. Our data indicate a significant association of: a) confluent IL size with 4th quartile of Erythrocyte Sedimentation Rate (ESR) (OR = 5.250; 95% CI, 1.002 to 27.514) and an independent correlation with sex; b) confluent IL size with 3rd quartile of fibrinogen (OR = 5.5; 95% CI, 1.027 to 29.451); c) confluent IL size with 3rd quartile of platelets (OR= 0.059; 95% CI, 0.003 to 1.175) and independent correlation with sex; d) smaller IL size (OR = 5.25; 95% CI, 1.351 to 20.396) with 3rd quartile of albumin levels and nodular and parenchimal IL size with 2nd (OR = 0.227; 95% CI, 0.053 to 0.981), 3rd (OR = 0.164; 95% CI, 0.038 to 0.711) and 4th (OR = 0.205; 95% CI, 0.048 to 0.870) quartiles albumin levels; e) smaller IL size with 3rd quartile triglycerides (TG) levels (OR = 9; 95% CI, 2.487 to 32.567) and an independent correlation with anterior location. Smaller IL size, anterior AIS turned out to be independently correlated with high serum albumin levels. Finally, high INR and PTT values were associated with worse NIHSS clinical outcomes in contrast to that observed with higher albumin level.

Conclusions

We provide evidence of routine biomarkers levels correlation with acute IL size, independently of age and sex. In addition, we highlight the importance of differentiation of biomarkers normal interval levels for further improvement not only of the clinical decision making but also in post-acute clinical outcome management.

C-reactive protein, fibrinogen, and cardiovascular disease prediction

BACKGROUND

There is debate about the value of assessing levels of C-reactive protein (CRP) and other biomarkers of inflammation for the prediction of first cardiovascular events.

METHODS

We analyzed data from 52 prospective studies that included 246,669 participants without a history of cardiovascular disease to investigate the value of adding CRP or fibrinogen levels to conventional risk factors for the prediction of cardiovascular risk. We calculated measures of discrimination and reclassification during follow-up and modeled the clinical implications of initiation of statin therapy after the assessment of CRP or fibrinogen.

RESULTS

The addition of information on high-density lipoprotein cholesterol to a prognostic model for cardiovascular disease that included age, sex, smoking status, blood pressure, history of diabetes, and total cholesterol level increased the C-index, a measure of risk discrimination, by 0.0050. The further addition to this model of information on CRP or fibrinogen increased the C-index by 0.0039 and 0.0027, respectively (P<0.001), and yielded a net reclassification improvement of 1.52% and 0.83%, respectively, for the predicted 10-year risk categories of "low" (<10%), "intermediate" (10% to <20%), and "high" (≥20%) (P<0.02 for both comparisons). We estimated that among 100,000 adults 40 years of age or older, 15,025 persons would initially be classified as being at intermediate risk for a cardiovascular event if conventional risk factors alone were used to calculate risk. Assuming that statin therapy would be initiated in accordance with Adult Treatment Panel III guidelines (i.e., for persons with a predicted risk of ≥20% and for those with certain other risk factors, such as diabetes, irrespective of their 10-year predicted risk), additional targeted assessment of CRP or fibrinogen levels in the 13,199 remaining participants at intermediate risk could help prevent approximately 30 additional cardiovascular events over the course of 10 years.

CONCLUSIONS

In a study of people without known cardiovascular disease, we estimated that under current treatment guidelines, assessment of the CRP or fibrinogen level in people at intermediate risk for a cardiovascular event could help prevent one additional event over a period of 10 years for every 400 to 500 people screened. (Funded by the British Heart Foundation and others.).

Role of Omega-3 fatty acids in preventing metabolic disturbances in patients on olanzapine plus either sodium valproate or lithium: a randomized double-blind placebo-controlled trial

Background

Metabolic and cardiovascular side effects have been noted with the use of second generation antipsychotics (SGAs) and mood stabilizers. Since Omega-3 fatty acids have been known to prevent some cardiovascular risks, this preliminary study was designed to evaluate the cardiovascular benefits of omega-3 when added to the combinations of olanzapine with mood stabilizers.

Methods

This study was a randomized, double-blind, placebo-controlled, within-subject trial in adult psychiatric patients who were receiving olanzapine combined with lithium (Li) or valproate sodium (VPA). Omega-3 as fish oil with less than 1 g/day of EPA/DHA or its placebo was added to patients’ olanzapine and mood stabilizer regimens for 6 weeks. Metabolic parameters including anthropometric variables, lipid profile, metabolic syndrome indices, C-reactive protein, fibrinogen and lipoprotein (a) [(Lp) (a)] were assessed for participants.

Results

Forty one participants completed this study; 20 patients received omega-3 and 21 patients received placebo, added to their regimen of SGA and mood stabilizer. Omega-3 addition did not modulate anthropometric, metabolic syndrome and lipid parameter changes in 6 weeks. However, fibrinogen levels significantly decreased, Lp (a) did not increase and non-high-density lipoprotein cholesterol (non-HDL-C) did not go beyond its target level after omega-3 supplementation. Additionally, a significant inter-group effect was noted for Lp(a).

Conclusions

This study suggests that use of short-term omega-3 supplementation added to a combined regimen of olanzapine and mood stabilizer may have a small modulating effect on some cardiovascular risk factors. Trials in longer periods of time and with larger number of patients are needed to further evaluate the effects of omega-3 supplements on preventing cardiovascular risk factors.

This trial is registered at irct.ir and its Identifier is as following: IRCT138712231764N1

Biobanking in atherosclerotic disease, opportunities and pitfalls

Cardiovascular disease is the leading cause of death in Western countries and current research is still focusing on optimizing therapeutic approaches in the battle against this multifactorial disease. Concepts regarding the pathogenesis of many cardiovascular diseases originate from observations of human atherosclerotic tissue obtained from autopsies or during vascular surgery. These observations have helped us to disentangle the pathophysiology of atherosclerosis. However, identifying vulnerable patients, those prone to developing cardiovascular complications, remains difficult. The search for predictive cardiovascular biomarkers continues and large, well organized biobanks are needed to discover or validate novel biomarkers. Biobanks are an extremely valuable resource that enables us to study the influence of both genetic and environmental factors on the development of multifactorial diseases such as atherosclerosis. This review will focus on the advantages and pitfalls in atherosclerotic biobanking.

Assessing the clinical utility of biomarkers in medicine

Biomarkers in medicine have gained immense scientific and clinical interest in recent years. Biomarkers are potentially useful in the contexts of primary, secondary and tertiary prevention. Some of the characteristics of an ideal biomarker include that they are safe and easy to measure, are associated with acceptable costs (including those of the follow-up tests), and there is scientific evidence to suggest that biomarker use/modification influences disease outcomes. Additionally, variation in biomarker levels with gender and ethnicity should be elucidated, and the biomarker should have 'good performance characteristics' (i.e., sensitivity, specificity, positive- and negative-predictive values and positive- and negative-likelihood ratios). Risk prediction scores can combine information from several different biomarkers in order to estimate an individual's risk of developing an outcome, such as disease or death. Three commonly employed methods to test if a biomarker will add to traditional risk prediction models are model discrimination, model calibration and risk reclassification. 'Multimarker' strategies serve to integrate information from multiple biomarkers into risk prediction but may be limited by the presence of highly correlated biomarkers, economic costs and selection bias of biomarker candidates in a particular study sample. In the future, integration of biomarkers identified using emerging technologies from the 'omics fields (including genomics, proteomics, metabolomics, lipomics, ribomics and pharmacogenomics) may be useful for the 'personalization' of treatment/disease prevention.

Lactase persistence and lipid pathway selection in the Maasai

The Maasai are a pastoral people in Kenya and Tanzania, whose traditional diet of milk, blood and meat is rich in lactose, fat and cholesterol. In spite of this, they have low levels of blood cholesterol, and seldom suffer from gallstones or cardiac diseases. Field studies in the 1970s suggested that the Maasai have a genetic adaptation for cholesterol homeostasis. Analysis of HapMap 3 data using Fixation Index (Fst) and two metrics of haplotype diversity: the integrated Haplotype Score (iHS) and the Cross Population Extended Haplotype Homozygosity (XP-EHH), identified genomic regions and single nucleotide polymorphisms (SNPs) as strong candidates for recent selection for lactase persistence and cholesterol regulation in 143-156 founder individuals from the Maasai population in Kinyawa, Kenya (MKK). The non-synonmous SNP with the highest genome-wide Fst was the TC polymorphism at rs2241883 in Fatty Acid Binding Protein 1(FABP1), known to reduce low density lipoprotein and tri-glyceride levels in Europeans. The strongest signal identified by all three metrics was a 1.7 Mb region on Chr2q21. This region contains the genes LCT (Lactase) and MCM6 (Minichromosome Maintenance Complex Component) involved in lactase persistence, and the gene Rab3GAP1 (Rab3 GTPase-activating Protein Catalytic Subunit), which contains polymorphisms associated with total cholesterol levels in a genome-wide association study of >100,000 individuals of European ancestry. Sanger sequencing of DNA from six MKK samples showed that the GC-14010 polymorphism in the MCM6 gene, known to be associated with lactase persistence in Africans, is segregating in MKK at high frequency (∼58%). The Cytochrome P450 Family 3 Subfamily A (CYP3A) cluster of genes, involved in cholesterol metabolism, was identified by Fst and iHS as candidate loci under selection. Overall, our study identified several specific genomic regions under selection in the Maasai which contain polymorphisms in genes associated with lactase persistence and cholesterol regulation.

Cardiovascular risk

Cardiovascular disease is a major, growing, worldwide problem. It is important that individuals at risk of developing cardiovascular disease can be effectively identified and appropriately stratified according to risk. This review examines what we understand by the term risk, traditional and novel risk factors, clinical scoring systems, and the use of risk for informing prescribing decisions. Many different cardiovascular risk factors have been identified. Established, traditional factors such as ageing are powerful predictors of adverse outcome, and in the case of hypertension and dyslipidaemia are the major targets for therapeutic intervention. Numerous novel biomarkers have also been described, such as inflammatory and genetic markers. These have yet to be shown to be of value in improving risk prediction, but may represent potential therapeutic targets and facilitate more targeted use of existing therapies. Risk factors have been incorporated into several cardiovascular disease prediction algorithms, such as the Framingham equation, SCORE and QRISK. These have relatively poor predictive power, and uncertainties remain with regards to aspects such as choice of equation, different risk thresholds and the roles of relative risk, lifetime risk and reversible factors in identifying and treating at-risk individuals. Nonetheless, such scores provide objective and transparent means of quantifying risk and their integration into therapeutic guidelines enables equitable and cost-effective distribution of health service resources and improves the consistency and quality of clinical decision making.

Plasma fibrinogen levels and restenosis after primary percutaneous coronary intervention

Plasma fibrinogen levels influence restenosis following elective percutaneous coronary intervention (PCI) for stable angina. It is unknown whether the same is true in the setting of primary PCI. The aim of the study was therefore to assess whether fibrinogen levels were associated to 6-month in-stent restenosis (ISR) in STEMI patients undergoing successful primary PCI. From January 2003 to October 2004, 267 patients were admitted to our Institution for STEMI and treated by primary PCI. Of these, 171 patients met the inclusion criteria and were enrolled in our study. Fibrinogen levels were assessed at admission, 12 h, 24 h, 48 h, 72 h following PCI and at discharge. Six-month angiographic follow-up was 100% complete. Subjects with 6-month ISR showed higher fibrinogen levels than patients without ISR. Patients in the upper fibrinogen tertile showed a higher 6-month incidence of symptoms and/or inducible myocardial ischemia (27.1% vs. 7.1%, P = 0.006) and a larger late lumen loss (1.3 ± 0.8 vs. 1.0 ± 0.9 mm, P = 0.049). Logistic regression analysis demonstrated a significant and independent association between fibrinogen levels and ISR. Our study suggests that increased plasma fibrinogen levels are related to ISR in STEMI patients undergoing primary PCI. Larger studies are warranted to assess the prognostic value of fibrinogen over harder end-points.

Patients with prostate cancer treated by ADT have significantly higher fibrinogenemia than healthy control

PURPOSE

Androgen deprivation therapy (ADT) for prostate cancer (PCa) may increase peripheral insulin resistance, induce type 2 diabetes, change body composition, and alter lipoprotein profile. Some studies have reported an association between ADT and increased risk of cardiovascular events. It is known that serum level of fibrinogen (SF) is associated with coronary artery disease and increased cardiovascular risk (CVR). The aim of this study is to determine the increase in SF and C-reactive protein (CRP) of PCa patients on ADT.

METHODS

Ninety-seven patients with locally advanced PCa (study group) were analyzed [mean age 73.4 years ± 6.3 SD, mean prostate specific antigen (PSA) 15.4 ng/ml ± 7.5 SD]. They were examined with blood chemistry including serum cholesterol (CHL), high density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoproteins, triacylglycerol (TAG), serum fibrinogen (FB), CRP and serum fasting glucose (SFG), serum testosterone, free testosterone at baseline, and after 12 months of ADT.

RESULTS

Patients after 12 months of ADT (study group) had significantly higher overall serum CHL (p < 0.001), higher LDL (p = 0.01), higher FB (p < 0.001), higher serum SFG (p = 0.03) in comparison with the control group. Increase in HDL (p = 0.245) and CRP (p = 0.1) was not significant. Two patients from the study group were diagnosed with new-onset diabetes.

CONCLUSIONS

This is the first study that demonstrates the significant increase in FB in PCa patients on ADT, while CRP as inflammatory marker did not increase. Elevation of SF may contribute to increased CVR in PCa patients. Further prospective studies are warranted to confirm this association.

Coagulability in obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is a common disorder that affects both quality of life and cardiovascular health. The causal link between OSA and cardiovascular morbidity⁄mortality remains elusive. One possible explanation is that repeated episodes of nocturnal hypoxia lead to a hypercoagulable state that predisposes patients to thrombotic events. There is evidence supporting a wide array of hematological changes that affect hemostasis (eg, increased hematocrit, blood viscosity, platelet activation, clotting factors and decreased fibrinolytic activity).

OBJECTIVE

To provide a comprehensive review of the current evidence associating OSA with increased coagulability, and to highlight areas for future research.

METHODS

Keyword searches in Ovid Medline were used to identify relevant articles; all references in the articles were searched for relevant titles. The Web of Science was used to identify articles citing the relevant articles found using the Ovid Medline search. All original peer-reviewed articles, meta-analyses and systematic reviews regarding the pertinent topics between 1990 and present were selected for review.

RESULTS

Hematocrit, blood viscosity, certain clotting factors, tissue factor, platelet activity and whole blood coagulability are increased in patients with OSA, while fibrinolysis is impaired.

CONCLUSION

There is considerable evidence that OSA is associated with a procoagulant state. Several factors are involved in the procoagulant state associated with OSA. There is a need for adequately powered clinical studies involving well-matched control groups to address potential confounding variables, and to accurately delineate the individual factors involved in the procoagulant state associated with OSA and their response to treatment.

Fibrinogen gene regulation

The Aα, Bβ and γ polypeptide chains of fibrinogen are encoded by a three gene cluster on human chromosome four. The fibrinogen genes (FGB-FGA-FGG) are expressed almost exclusively in hepatocytes where their output is coordinated to ensure a sufficient mRNA pool for each chain and maintain an abundant plasma fibrinogen protein level. Fibrinogen gene expression is controlled by the activity of proximal promoters which contain binding sites for hepatocyte transcription factors, including proteins which influence fibrinogen transcription in response to acute-phase inflammatory stimuli. The fibrinogen gene cluster also contains cis regulatory elements; enhancer sequences with liver activities identified by sequence conservation and functional genomics. While the transcriptional control of this gene cluster is fascinating biology, the medical impetus to understand fibrinogen gene regulation stems from the association of cardiovascular disease risk with high level circulating fibrinogen. In the general population this level varies from about 1.5 to 3.5 g/l. This variation between individuals is influenced by genotype, suggesting there are genetic variants contributing to fibrinogen levels which reside in fibrinogen regulatory loci. A complete picture of how fibrinogen genes are regulated will therefore point towards novel sources of regulatory variants. In this review we discuss regulation of the fibrinogen genes from proximal promoters and enhancers, the influence of acute-phase stimulation, post-transcriptional regulation by miRNAs and functional regulatory variants identified in genetic studies. Finally, we discuss the fibrinogen locus in light of recent advances in understanding chromosomal architecture and suggest future directions for researching the mechanisms that control fibrinogen expression.

A novel regulatory element between the human FGA and FGG genes

High circulating fibrinogen levels correlate with cardiovascular disease (CVD) risk. Fibrinogen levels vary between people and also change in response to physiological and environmental stimuli. A modest proportion of the variation in fibrinogen levels can be explained by genotype, inferring that variation in genomic sequences that regulate the fibrinogen genes ( FGA , FGB and FGG ) may affect hepatic fibrinogen production and perhaps CVD risk. We previously identified a conserved liver enhancer in the fibrinogen gene cluster (CNC12), between FGB and FGA . Genome-wide Chromatin immunoprecipitation-sequencing (ChIP-seq) demonstrated that transcription factors which bind fibrinogen gene promoters also interact with CNC12, as well as two potential fibrinogen enhancers (PFE), between FGA and FGG . Here we show that one of the PFE sequences has potent hepatocyte enhancer activity. Using a luciferase reporter gene system, we found that PFE2 enhances minimal promoter- and FGA promoter-driven gene expression in hepatoma cells, regardless of its orientation with respect to the promoters. A region within PFE2 bears a short series of conserved nucleotides which maintain enhancer activity without flanking sequence. We also demonstrate that PFE2 is a liver enhancer in vivo, driving enhanced green fluorescent protein expression in transgenic zebrafish larval livers. Our study shows that combining public domain ChIP-seq data with in vitro and in vivo functional tests can identify novel fibrinogen gene cluster regulatory sequences. Variation in such elements could affect fibrinogen production and influence CVD risk.

New directions in cardiovascular risk assessment: the role of secondary risk stratification markers

Cardiovascular disease (CVD) risk screening is performed by multivariate methods relying on calculators derived from the Framingham study, other epidemiological studies or primary care records. However, it only identifies 70% of individuals at risk for CVD events and there has been interest in adding other risk factors to improve its predictive capacity. The addition of a family history of premature CVD is well established and there is evidence for adding lipoprotein (a) in some populations and possibly C-reactive protein may be suitable for general use in CVD risk assessment. Most new biochemical and imaging markers have been assessed in the context of improving risk classification in intermediate-risk groups rather than in the general population. There is evidence that N-terminal pro-B-type natriuretic peptide and coronary artery calcium score add significantly to risk prediction. The data for carotid intima-media thickness, ankle-brachial index are less strong and high sensitivity troponins look promising, but have had only limited data to date. Large scale meta-analyses ideally of pooled primary patient data will be required to determine the best additional markers to add to conventional risk prediction and in what groups to apply them.

Blood fibrinogen as a biomarker of chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a multicomponent condition that is characterised by airflow obstruction that is not fully reversible and is a major global cause of morbidity and mortality. The most widely used marker of disease severity and progression is FEV₁. However, FEV₁ correlates poorly with both symptoms and other measures of disease progression and thus there is an urgent need for other biological markers to better characterise individuals with COPD. Fibrinogen is an acute phase plasma protein that has emerged as a promising biomarker in COPD. Here we review the current clinical evidence linking fibrinogen with COPD and its associated co-morbidities and discuss its potential utility as a biomarker.

Methods

Searches for appropriate studies were undertaken on PubMed using search terms fibrinogen, COPD, emphysema, chronic bronchitis, FEV₁, cardiovascular disease, exacerbation and mortality.

Results

There is strong evidence of an association between fibrinogen and the presence of COPD, the presence and frequency of exacerbations and with mortality. Fibrinogen is associated with disease severity but does not predict lung function decline, a measure used as a surrogate for disease activity. The role of fibrinogen in identifying inflammatory co morbidities, particularly cardiovascular disease, remains unclear. Fibrinogen is reduced by p38 mitogen-activated protein kinase inhibitors in individuals with stable disease and by oral corticosteroids during exacerbations.

Conclusions

Fibrinogen is likely to be a useful biomarker to stratify individuals with COPD into those with a high or low risk of future exacerbations and may identify those with a higher risk of mortality.

Characterization of human gastric carcinoma-related methylation of 9 miR CpG islands and repression of their expressions in vitro and in vivo

Background

Many miR genes are located within or around CpG islands. It is unclear whether methylation of these CpG islands represses miR transcription regularly. The aims of this study are to characterize gastric carcinoma (GC)-related methylation of miR CpG islands and its relationship with miRNA expression.

Methods

Methylation status of 9 representative miR CpG islands in a panel of cell lines and human gastric samples (including 13 normal biopsies, 38 gastritis biopsies, 112 pairs of GCs and their surgical margin samples) was analyzed by bisulfite-DHPLC and sequencing. Mature miRNA levels were determined with quantitative RT-PCR. Relationships between miR methylation, transcription, GC development, and clinicopathological characteristics were statistically analyzed.

Results

Methylation frequency of 5 miR CpG islands (miR-9-1, miR-9-3, miR-137, miR-34b, and miR-210) gradually increased while the proportion of methylated miR-200b gradually decreased during gastric carcinogenesis (Ps < 0.01). More miR-9-1 methylation was detected in 62%-64% of the GC samples and 4% of the normal or gastritis samples (18/28 versus 2/48; Odds ratio, 41.4; P < 0.01). miR-210 methylation showed high correlation with H. pylori infection. miR-375, miR-203, and miR-193b methylation might be host adaptation to the development of GCs. Methylation of these miR CpG islands was consistently shown to significantly decrease the corresponding miRNA levels presented in human cell lines. The inverse relationship was also observed for miR-9-1, miR-9-3, miR-137, and miR-200b in gastric samples. Among 112 GC patients, miR-9-1 methylation was an independent favourable predictor of overall survival of GC patients in both univariate and multivariate analysis (P < 0.02).

Conclusions

In conclusion, alteration of methylation status of 6 of 9 tested miR CpG islands was characterized in gastric carcinogenesis. miR-210 methylation correlated with H. pylori infection. miR-9-1 methylation may be a GC-specific event. Methylation of miR CpG islands may significantly down-regulate their transcription regularly.

Risk factors associated with cardiovascular events during testosterone administration in older men with mobility limitation

BACKGROUND

Testosterone in Older Men with Mobility Limitations Trial found an increased incidence of cardiovascular events in men randomized to testosterone, resulting in enrollment cessation by trial's Data and Safety Monitoring Board. We evaluated changes in gonadal hormones and markers of inflammation and coagulation to elucidate risk factors associated with cardiovascular events.

METHODS

Men aged 65 years or more, with mobility limitation, total testosterone 100-350 ng/dL, or free testosterone less than 50 pg/mL, were randomized to placebo or 10 g testosterone gel daily for 6 months. Changes in total and free testosterone, estradiol and estrone, C-reactive protein, interleukin 6, fibrinogen, plasminogen activator inhibitor-1, and pro-brain naturetic peptide were compared between groups and within the testosterone group between subjects who experienced cardiovascular events and those who did not.

RESULTS

Of 209 men randomized (mean age 74 years), gonadal hormones and biomarkers were available in 179 men. Baseline body mass index, gonadal hormones, lipids, Framingham risk scores, and other biomarkers were similar in the two treatment groups. Within the testosterone group, the 6-month increase in free testosterone was significantly greater in men who experienced cardiovascular events than in those who did not [mean (95% confidence interval), 10.6 (4.6-16.7) vs 5.2 (3.0-7.5) ng/dL, p = .05]. In multivariable logistic regression analysis, the change in the serum levels of free testosterone was associated with cardiovascular events.

CONCLUSION

Mobility-limited older men who experienced cardiovascular events had greater increases in serum free testosterone levels than those who did not.

Effects of mealtime insulin aspart and bedtime neutral protamine Hagedorn insulin on postprandial coagulation and fibrinolysis in patients with type 2 diabetes

AIM

Acute hyperglycaemia induces coagulation activation in diabetes patients. We hypothesized that rapid-acting insulin has a beneficial postprandial effect on coagulation and fibrinolysis compared with intermediate-acting insulin because of its ability to lower postprandial hyperglycaemia.

METHODS

This was tested in a parallel controlled study in well-controlled patients with type 2 diabetes assigned to bedtime neutral protamine Hagedorn (NPH) insulin (n = 41) or mealtime insulin aspart (n = 37). They were served standard diabetic meals for breakfast (8:00 hours) and lunch (12:00 hours). Blood samples were collected at 7:40 hours (fasting), 9:30, 11:30, 13:30 and 15:30 hours and analysed for glucose, activated factor VII (FVIIa), D-dimer, prothrombin fragment 1+2 (F1+2), tissue plasminogen activator antigen (t-PA) and plasminogen activator inhibitor activity (PAI).

RESULTS

The postprandial glucose response differed significantly between insulin regimens with a postprandial increase on NPH insulin and a decrease on insulin aspart. There was a significant postprandial decrease in F1+2, PAI and t-PA, and no changes in FVIIa and D-dimer, on both insulin regimens, but with no differences between insulin treatment groups.

CONCLUSIONS

The rapid-acting insulin analogue aspart and the intermediate-acting insulin NPH had similar postprandial effects on markers of coagulation activation and fibrinolysis despite different effects on postprandial glucose response.

Clinical utility of novel biomarkers in the prediction of coronary heart disease

Coronary heart disease (CHD) is a significant cause of morbidity and mortality worldwide. Many risk prediction models have been developed in an effort to assist clinicians in risk assessment and the prevention of CHD. However, it is unclear whether the existing CHD prediction tools can improve clinical performance, and recently, there has been a lot of effort being made to improve the accuracy of the prediction models. A large number of novel biomarkers have been identified to be associated with cardiovascular risk, and studied with the goal of improving the accuracy and clinical utility of CHD risk prediction. Yet, controversy still remains with regard to the utility of novel biomarkers in CHD risk assessment, and in finding the best statistical methods to assess the incremental value of the biomarkers. This article discusses the statistical approaches that can be used to evaluate the predictive values of new biomarkers, and reviews the clinical utility of novel biomarkers in CHD prediction, specifically in the Korean population.

Dietary oil modifies the plasma proteome during aging in the rat

Fatty acids and other components of the diet may modulate, among others, mechanisms involved in homeostasis, aging, and age-related diseases. Using a proteomic approach, we have studied how dietary oil affected plasma proteins in young (6 months) or old (24 months) rats fed lifelong with two experimental diets enriched in either sunflower or virgin olive oil. After the depletion of the most abundant proteins, levels of less abundant proteins were studied using two-dimensional electrophoresis and mass spectrometry. Our results showed that compared with the sunflower oil diet, the virgin olive oil diet induced significant decreases of plasma levels of acute phase proteins such as inter-alpha inhibitor H4P heavy chain (at 6 months), hemopexin precursor (at 6 and 24 months), preprohaptoglobin precursor (at 6 and 24 months), and α-2-HS glycoprotein (at 6 and 24 months); antioxidant proteins such as type II peroxiredoxin (at 24 months); proteins related with coagulation such as fibrinogen γ-chain precursor (at 24 months), T-kininogen 1 precursor (at 6 and 24 months), and apolipoprotein H (at 6 and 24 months); or with lipid metabolism and transport such as apolipoprotein E (at 6 and 24 months) and apolipoprotein A-IV (at 24 months). The same diet increased the levels of apolipoprotein A-1 (at 6 and 24 months), diminishing in general the changes that occurred with age. Our unbiased analysis reinforces the beneficial role of a diet rich in virgin olive oil compared with a diet rich in sunflower oil, modulating inflammation, homeostasis, oxidative stress, and cardiovascular risk during aging.

Genetic admixture is associated with plasma hemostatic factor levels in self-identified African Americans and Hispanics: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Epidemiologic studies report that self-identified African Americans typically have higher hemostatic factor levels than do self-identified Caucasians or Hispanics.

OBJECTIVE

To enhance understanding of phenotypic variation in hemostatic factor levels by race/ethnicity, we evaluated the relationship between genetic ancestry and hemostatic factor levels among Multi-Ethnic Study of Atherosclerosis (MESA) study participants.

PATIENTS/METHODS

Our sample included 712 African American and 701 Hispanic men and women aged 45 to 84 years. Individual global ancestry was estimated from 199 genetic markers using STRUCTURE. Linear regression models were used to evaluate the relationship between ancestry and hemostatic factor levels, adjusting for age, gender, education, income and study site.

RESULTS

Among African Americans, mean ± standard deviation (SD) ancestry was estimated as 79.9% ± 15.9% African and 20.1% ± 15.9% European. Each SD (16%) greater African ancestry was associated with 2.1% higher fibrinogen levels (P = 0.007) and 3.5% higher plasmin-antiplasmin (PAP) levels (P = 0.02). Ancestry among African Americans was not related to levels of factor (F)VIII or D-dimer. Mean ± SD estimated ancestry among Hispanics was 48.3% ± 23.8% Native American, 38.8% ± 21.9% European, and 13.0% ± 8.9% African. In Hispanics, each SD (19%) greater African ancestry was associated with 2.7% higher fibrinogen levels (P = 0.009) and 7.9% higher FVIII levels (P = 0.0002). In Hispanics, there was no relation between African ancestry and D-dimer or PAP levels, or between European ancestry and hemostatic factor levels.

CONCLUSIONS

Greater African ancestry among African Americans and Hispanics was associated with higher levels of several hemostatic factors, notably fibrinogen. These results suggest that genetic heterogeneity contributes, albeit modestly, to racial/ethnic differences in hemostatic factor levels.

Changes in haemostatic and platelet activation markers in non-dipper hypertensive patients

BACKGROUND

Non-dipper hypertensive patients are at increased risk for cardiovascular disease. Coagulation and fibrinolysis activation factors are considered as risk factors for cardiovascular disease. The aim of this study was to examine the relationship between the haemostatic and platelet activation markers and the non-dipping pattern in treated hypertensive patients.

PATIENTS AND METHODS

Seventy-one treated hypertensive patients (53 with essential and 18 with secondary hypertension, due to chronic kidney disease-stage 4), aged 33 to 81 years (30 men), were classified as dippers and non-dippers, according to the presence or absence, respectively, of a decline of nocturnal average systolic blood pressure (BP) by more than 10% of the diurnal BP (non-dipping pattern) on 24-hour ambulatory BP monitoring. Plasma levels of factors VIII and IX, fibrinogen, prothrombin fragment 1 + 2, thrombin-antithrombin complex, protein C, plasmin-alpha-2 antiplasmin complex, D-dimer and platelet factor 4 were measured in all patients.

RESULTS

Thirty-seven patients were classified as dippers and 34 as non-dippers. The percentages of patients with essential and with secondary hypertension were similar in the dippers and in the non-dippers groups (both P = 0.754). Multivariate analysis of variance showed statistically significant differences in all measured variables between dippers and non-dippers (P = 0.043). Plasma levels of factors VIII and IX, fibrinogen, prothrombin fragment 1 + 2, protein C, plasmin-alpha-2-antiplasmin complex, and D-dimers were significantly higher in non-dippers when compared to dippers (P < 0.05 for all). In contrast, there were no significant differences in plasma levels of thrombin-antithrombin complex (P = 0.955) and platelet factor 4 (P = 0.431) between the two groups.

CONCLUSION

This study provides evidence that non-dipper treated hypertensive patients exhibit alterations in haemostasis, which may affect their cardiovascular risk.

Interleukin-6 receptor pathways in coronary heart disease: a collaborative meta-analysis of 82 studies

BACKGROUND

Persistent inflammation has been proposed to contribute to various stages in the pathogenesis of cardiovascular disease. Interleukin-6 receptor (IL6R) signalling propagates downstream inflammation cascades. To assess whether this pathway is causally relevant to coronary heart disease, we studied a functional genetic variant known to affect IL6R signalling.

METHODS

In a collaborative meta-analysis, we studied Asp358Ala (rs2228145) in IL6R in relation to a panel of conventional risk factors and inflammation biomarkers in 125,222 participants. We also compared the frequency of Asp358Ala in 51,441 patients with coronary heart disease and in 136,226 controls. To gain insight into possible mechanisms, we assessed Asp358Ala in relation to localised gene expression and to postlipopolysaccharide stimulation of interleukin 6.

FINDINGS

The minor allele frequency of Asp358Ala was 39%. Asp358Ala was not associated with lipid concentrations, blood pressure, adiposity, dysglycaemia, or smoking (p value for association per minor allele ≥0·04 for each). By contrast, for every copy of 358Ala inherited, mean concentration of IL6R increased by 34·3% (95% CI 30·4-38·2) and of interleukin 6 by 14·6% (10·7-18·4), and mean concentration of C-reactive protein was reduced by 7·5% (5·9-9·1) and of fibrinogen by 1·0% (0·7-1·3). For every copy of 358Ala inherited, risk of coronary heart disease was reduced by 3·4% (1·8-5·0). Asp358Ala was not related to IL6R mRNA levels or interleukin-6 production in monocytes.

INTERPRETATION

Large-scale human genetic and biomarker data are consistent with a causal association between IL6R-related pathways and coronary heart disease.

FUNDING

British Heart Foundation; UK Medical Research Council; UK National Institute of Health Research, Cambridge Biomedical Research Centre; BUPA Foundation.

Hemostatic markers are associated with the risk and prognosis of atrial fibrillation: the ARIC study

BACKGROUND

Various hemostatic markers are associated with the risk of cardiovascular disease; however, limited information exists on their relationship with the occurrence and prognosis of atrial fibrillation (AF).

OBJECTIVES

To assess whether hemostatic markers are associated with the incidence and prognosis of AF.

METHODS

We studied 14,858 men and women in the Atherosclerosis Risk in Communities cohort, aged 45-64 and free of AF at baseline (1987-1989). Fibrinogen, von Willebrand factor (vWf), factor VII activity (VIIc), factor VIII activity (VIIIc), protein C, antithrombin III (ATIII), and activated partial thromboplastin time (aPTT) were measured in blood samples at baseline. AF and other cardiovascular outcomes through 2005 were determined following standardized protocols.

RESULTS

During a median follow-up of 16.8 years, 1209 cases of AF were identified. In multivariable Cox models, the hazard ratios (HR) and 95% confidence intervals (CI) of incident AF associated with a 1-standard deviation (SD) increase in each marker were 1.13 (1.07-1.20) for fibrinogen, 1.17 (1.11-1.23) for vWf, 1.17 (1.11-1.24) for factor VIIIc, 0.93 (0.88-1.00) for factor VIIc, 0.98 (0.92-1.04) for protein C, 1.00 (0.94-1.06) for aPTT and 1.00 (0.95-1.06) for ATIII. Greater factor VIIIc, fibrinogen and vWf were consistently associated with a higher risk of cardiovascular outcomes and mortality in those with and without incident AF, while greater protein C was associated with a lower risk of ischemic stroke.

CONCLUSION

Several hemostatic markers are associated with the incidence of AF independently of other cardiovascular risk factors. Their role in the risk stratification of AF patients should be further studied.

A genetic instrument for Mendelian randomization of fibrinogen

Mendelian randomization studies on fibrinogen commonly use a single genetic variant as an instrument, but this may explain only a small proportion of the total phenotypic variance. We examined the contribution of multiple common single nucleotide polymorphisms (SNPs) and haplotypes in the entire fibrinogen gene cluster to plasma fibrinogen levels in two prospective cohorts, for use as instruments in future Mendelian randomization studies. Genotypes for 20 SNPs were determined in 2,778 middle-age (49-64 years) men from the Second-Northwick-Park-Heart Study (NPHS-II). These were replicated in 3,705 men from the Whitehall-II study (WH-II). Plasma fibrinogen levels were determined six times in NPHS-II and three times in WH-II. The minor alleles of four SNPs from the FGB gene, two from the FGA gene, and one from the FGG gene were associated with higher plasma fibrinogen levels. SNP rs1800790 (-455G>A) commonly used in Mendelian randomization studies was associated with R2=1.22% of the covariate adjusted residual variance in fibrinogen level. A variable selection procedure identified one additional SNP: rs2070011 (FGA) altogether explaining R2=1.45% of the residual variance in fibrinogen level. Using these SNPs no evidence for causality between the fibrinogen levels and coronary heart diseases was found in instrumental variables analysis. In the replication cohort, WH-II, the effects of the two SNPs on fibrinogen levels were consistent with the NPHS-II results. There is statistical evidence for several functional sites in the fibrinogen gene cluster that determine an individual's plasma fibrinogen levels. Thus, a combination of several SNPs will provide a stronger instrument for fibrinogen Mendelian randomization studies.

Significant inverse association of marine n-3 fatty acids with plasma fibrinogen levels in Japanese in Japan but not in whites or Japanese Americans

BACKGROUND/OBJECTIVES

Numerous studies reported beneficial effects of marine n-3 fatty acids (n-3 FAs) on cardiovascular disease (CVD) and its risk factors. However, the association of marine n-3 FAs with plasma fibrinogen, a risk factor for CVD, remains uncertain.

SUBJECTS/METHODS

In a population-based, cross-sectional study of 795 men aged 40-49 without CVD (262 whites in Allegheny County, Pennsylvania, USA, 302 Japanese in Kusatsu, Japan and 229 Japanese Americans in Honolulu, Hawaii, USA), we examined the association of marine n-3 FAs with plasma fibrinogen. Serum FAs were measured by capillary gas-liquid chromatography. Marine n-3 FAs were defined as the sum of docosahexaenoic, eicosapentaenoic and docosapentaenoic acids. Plasma fibrinogen was measured by an automated clot-rate assay. Multiple linear regression analyses were performed to assess the association.

RESULTS

White, Japanese and Japanese-American men had mean marine n-3 FAs levels of 3.47%, 8.78% and 4.46%, respectively. Japanese men had a significant inverse association of marine n-3 FAs with fibrinogen (standardized regression coefficient of -0.11, P=0.049), after adjusting for age, body-mass index and current smoking. The significant inverse association remained after further adjusting for diabetes, C-reactive protein, triglycerides and other variables. White or Japanese-American men did not show a significant association.

CONCLUSIONS

We observed the significant inverse association of marine n-3 FAs with fibrinogen in Japanese, but not in whites or Japanese Americans. The observation suggests that marine n-3 FAs at very high levels, as seen in the Japanese, may decrease plasma fibrinogen levels.

Novel risk factors of cardiovascular disease and their associations between obesity, physical activity and physical fitness

The prevalence of cardiovascular disease (CVD) is increasing around the globe and is the leading cause of death around the world. Though once thought of as an adult problem, it is now recognised that the early manifestations of disease may occur during childhood. Numerous risk factors have been linked to CVD with much of the research focusing on understanding the prevalence and relationship of traditional risk factors such as dyslipidemia, smoking, diabetes mellitus, hypertension, obesity, psychosocial stress, poor diet, physical inactivity and alcohol consumption to the early etiology of disease. While this line of investigation has greatly enhanced our understanding of the relationship between these risk factors and disease, they do not fully explain all cardiovascular events. To enhance our understanding and help with the management of CVD, investigations that involve the measurement of traditional as well as novel risk factors may be necessary. Public health strategies that aim to reduce the prevalence of obesity and overweight encourage youth to increase their physical activity levels as a means of protecting against poor cardiometabolic profiles. Interventions that increase physical activity levels and improve cardiorespiratory fitness cause a reduction in certain CVD risk factors but the lack of agreement between findings makes it impossible to give precise recommendations that will ensure CVD risk reduction. Yet it is important that research continues in order to establish the most appropriate means of improving the health and well-being of those at most risk of future CVD.

Circulatory syndrome: an evolution of the metabolic syndrome concept!

The metabolic syndrome has been a useful, though controversial construct in clinical practice as well as a valuable model in order to understand the interactions of diverse cardiovascular risk factors. However the increasing importance of the circulatory system in particular the endothelium, in both connecting and controlling organ function has underlined the limitations of the metabolic syndrome definition. The proposed "Circulatory Syndrome" is an attempt to refine the metabolic syndrome concept by the addition of recently documented markers of cardiovascular disease including renal impairment, microalbuminuria, arterial stiffness, ventricular dysfunction and anaemia to more classic factors including hypertension, dyslipidemia and abnormal glucose metabolism; all of which easily measured in clinical practice. These markers interact with each other as well as with other factors such as aging, obesity, physical inactivity, diet and smoking. The final common pathways of inflammation, oxidative stress and hypercoagulability thereby lead to endothelial damage and eventually cardiovascular disease. Nevertheless, the Circulatory (MARC) Syndrome, like its predecessor the metabolic syndrome, is only a small step toward an understanding of these complex and as yet poorly understood markers of disease.

Plasma fibrinogen: a possible link between job stress and cardiovascular disease among Chinese workers

BACKGROUND

Little is known about the effect of effort-reward imbalance (ERI) on fibrinogen. We aimed to examine the association between ERI and fibrinogen among Chinese workers.

METHODS

A total of 732 subjects without vascular diseases were analyzed. Associations between job stress evaluated by ERI model and plasma fibrinogen were explored by multiple regression.

RESULTS

Effort, overcommitment, and ERI were significantly positively associated with fibrinogen, while reward was negatively related with fibrinogen both for men and for women. Compared with low level group, high level of effort, overcommitment, and ERI significantly increased risk of elevated fibrinogen (more than mean concentration) with adjusted OR of 3.3, 12.5, and 7.7 for men; 2.9, 7.2, and 7.2 for women, respectively; however, high reward reduced 80% risk for elevated fibrinogen.

CONCLUSIONS

Effort, overcommitment, and ERI are significantly associated with fibrinogen among Chinese workers. High fibrinogen may be a possible link between job stress and cardiovascular disease.

High-sensitive C-reactive protein: universal prognostic and causative biomarker in heart disease?

C-reactive protein (CRP), a pentraxin protein, is an established marker of acute phase reactions. There is some experimental evidence that the CRP molecule could be causative in all stages of atherosclerotic disease starting from endothelial dysfunction, continuing to plaque formation and destabilization, and to atherothrombotic complications. However, each claim of causality has elicited a counterpoint argument, and Mendelian randomization studies have confidently shown that the concentration of CRP is unlikely to be causative. Meta-analyses have attributed a 1.5–1.7-fold risk to one standard deviation increase of high-sensitive CRP (a high-sensitivity CRP assay) for major cardiovascular events after adjustments for classical risk factors. Additional adjustments for metabolic factors reduced the risk to approximately 1.2–1.4-fold, which is still significant. Of interest, high-sensitive CRP also predicted all-cause and cancer mortality. Driven by the JUPITER trial that showed a benefit on outcome for treatment with rosuvastatin in primary prevention, treatment has been recommended in patients with a moderate Framingham Risk Score with a high-sensitive CRP of >2 mg/l. However, adding CRP to risk charts and biomarker panels mostly yielded small and inconsistent improvements.