The relative strength of C-reactive protein and lipid levels as determinants of ischemic stroke compared with coronary heart disease in women

Does Inflammation Predispose to Recurrent Vascular Events after Recent Transient Ischaemic Attack and Minor Stroke? the North West of England Transient Ischaemic Attack and Minor Stroke (NORTHSTAR) Study

Background and hypothesis

Inflammation is implicated in the pathogenesis and outcome of ischaemic injury. Poststroke inflammation is associated with outcome but it remains unclear whether such inflammation precedes or results from ischaemic injury. We hypothesised that inflammatory markers are associated with an increased risk of recurrent vascular events soon after transient ischaemic attack and minor stroke.

Methods

This was a multicentre, prospective, nested case–control study. Plasma concentrations of C-reactive protein, interleukin-6, interleukin-1-receptor antagonist and fibrinogen, leucocyte counts, erythrocyte sedimentation rate and inflammatory gene allele frequencies were analysed in 711 patients with recent transient ischaemic attack or minor stroke. Cases were defined by the incidence of one or more recurrent vascular events during the three-month follow-up. Association of inflammatory markers with case-status was determined using conditional logistic regression.

Results

Plasma concentrations of C-reactive protein, interleukin-1-receptor antagonist and interleukin-6 were not associated with case-status. In secondary analyses, only erythrocyte sedimentation rate was significantly associated with case-status (odds ratio 1·39, 95% confidence interval 1·03–1·85; P=0·03), but this effect did not persist after adjustment for smoking and past history of transient ischaemic attack or stroke. Single nucleotide polymorphisms in four inflammatory genes (interleukin-6, fibrinogen, P-selectin and vascular cell adhesion molecule-1) were nominally associated with case-status.

Conclusions

Circulating inflammatory markers were not associated with recurrent vascular events. Nominally significant associations between genetic markers and case-status will require replication. These data provide little evidence for an inflammatory state predisposing to stroke and other vascular events in a susceptible population.

Acute-phase proteins: As diagnostic tool

The varied reactions of the host to infection, inflammation, or trauma are collectively known as the acute-phase response and encompass a wide range of pathophysiological responses such as pyrexia, leukocytosis, hormone alterations, and muscle protein depletion combining to minimize tissue damage while enhancing the repair process. The mechanism for stimulation of hepatic production of acute-phase proteins is by proinflammatory cytokines. The functions of positive acute-phase proteins (APP) are regarded as important in optimization and trapping of microorganism and their products, in activating the complement system, in binding cellular remnants like nuclear fractions, in neutralizing enzymes, scavenging free hemoglobin and radicals, and in modulating the host's immune response. APP can be used as diagnostic tool in many diseases like bovine respiratory syncytial virus, prostate cancer, bronchopneumonia, multiple myeloma, mastitis, Streptococcus suis infection, starvation, or lymphatic neoplasia. Thus, acute-phase proteins may provide an alternative means of monitoring animal health.

Chronic periodontitis and C-reactive protein levels

BACKGROUND

This study aims to analyze the relationship between chronic periodontitis and C-reactive protein (CRP) by considering associated variables in individuals with or without cardiovascular disease.

METHODS

A sample of 359 individuals of both sexes (aged ≥40 years) was assessed. Among these individuals, 144 subjects were admitted to the hospital because of a first occurrence of acute myocardial infarction; 80 subjects were in the hospital for reasons other than acute myocardial infarction; and 135 subjects were living in the community. A questionnaire was applied to obtain demographic and lifestyle characteristics. Complete clinical periodontal examinations and anthropometric assessments were performed. CRP levels, plasma glucose levels, lipid profiles, and blood tests were performed to investigate any conditions that might have suggested infection and/or inflammation. CRP evaluations were performed using nephelometry. Individuals were considered to have periodontal disease if they simultaneously presented at least four teeth with one or more sites with probing depth ≥4 mm, clinical attachment loss ≥3 mm, and bleeding on probing. Procedures for descriptive analyses and logistic regression were used.

RESULTS

In the chronic periodontitis group, mean CRP levels were higher than those in the group without chronic periodontitis (2.6 ± 2.6 mg/L versus 1.78 ± 2.7 mg/L, respectively). The final model showed that individuals with chronic periodontitis were more likely to have high CRP levels (adjusted odds ratio: 2.26; 95% confidence interval: 1.30 to 3.93) considering the effects of age, schooling level, sex, smoking, high-density lipoprotein cholesterol, and diabetes.

CONCLUSION

In this study, chronic periodontitis is associated with elevated plasma CRP levels, even after controlling for several potential confounders.

Rosuvastatin reduces microglia in the brain of wild type and ApoE knockout mice on a high cholesterol diet; implications for prevention of stroke and AD

We have previously shown that a high cholesterol (HC) diet results in increases in microglia load and levels of the pro-inflammatory cytokine interleukin-6 (IL-6) in the brains of wild type (WT) and apolipoprotein E knockout (ApoE-/-) mice. In the present investigation, we analyzed whether treatment with rosuvastatin, an inhibitor of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, would prevent the increases in inflammatory microglia and IL-6 levels in the brain and plasma of WT and ApoE-/- mice. We report that a HC diet resulted in an increased microglia load in the brains of WT and ApoE-/- mice, in support of our previous study. Treatment with rosuvastatin significantly decreased the microglia load in the brains of WT and ApoE-/- mice on a HC diet. Rosuvastatin treatment resulted in lowered plasma IL-6 levels in WT mice on a HC diet. However, in the present study the number of IL-6 positive cells in the brain was not significantly affected by a HC diet. A recent clinical study has shown that rosuvastatin reduces risk of ischemic stroke in patients with high plasma levels of the inflammatory marker C-reactive protein by 50%. The results from our study show that rosuvastatin reduces inflammatory cells in the brain. This finding is essential for furthering the prevention and treatment of neurodegenerative diseases such as Alzheimer's disease (AD) and stroke.

Prehypertension subtype with elevated C-reactive protein: risk of ischemic stroke in a general Japanese population

BACKGROUND

Prehypertension (PreHT) and low-grade inflammation are both known to be related to the incidence of cardiovascular events. This cohort study investigated whether the high-risk group for future ischemic stroke among PreHT subjects can be predicted by stratification of high-sensitivity C-reactive protein (hsCRP).

METHODS

A total of 22,676 subjects aged 40-80 years from the general population who had no cardiovascular history underwent baseline measurement of serum hsCRP, and were followed for the incidence of ischemic stroke.

RESULTS

During the mean follow-up period of 2.7 years, 143 subjects had a first ischemic stroke. In a Cox multivariable model after adjustment for cardiovascular risk factors, there was no significant difference in hazard ratio (HR) for incidence of ischemic stroke between the normotension (NT) and PreHT subjects (HR = 1.72, 95% confidence interval (CI): 0.93-3.18, vs. NT subjects). In contrast, the HR for incidence of ischemic stroke in PreHT subjects with higher hsCRP levels (≥0.5 mg/l in men, ≥0.4 mg/l in women, more than median levels according to sex) was increased compared to NT subjects with lower hsCRP levels (HR = 2.63, 95% CI: 1.11-6.24). Moreover, the HR for incidence of ischemic stroke in PreHT subjects with lower CRP levels (HR = 0.91, 95% CI: 0.31-2.73) did not differ from that in NT subjects with lower hsCRP levels.

CONCLUSIONS

This study showed that, in a Japanese general population, hsCRP was a marker for relatively short-term risk of ischemic stroke in PreHT subjects.

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.

Gender difference of association between LDL cholesterol concentrations and mortality from coronary heart disease amongst Japanese: the Ibaraki Prefectural Health Study

OBJECTIVE

The aim of this study was to examine whether LDL cholesterol raises the risk of coronary heart disease in a dose-response fashion in a population with low LDL-cholesterol levels.

DESIGN

Population-based prospective cohort study in Japan.

SUBJECTS AND MAIN OUTCOME MEASURES

A total of 30,802 men and 60,417 women, aged 40 to 79 years with no history of stroke or coronary heart disease, completed a baseline risk factor survey in 1993. Systematic mortality surveillance was performed through 2003 and 539 coronary heart disease deaths were identified.

RESULTS

The mean values for LDL-cholesterol were 110.5 mg dL(-1) (2.86 mmol L(-1)) for men and 123.9 mg dL(-1) (3.20 mmol L(-1)) for women. Men with LDL-cholesterol > or =140 mg dL(-1) (> or =3.62 mmol L(-1)) had two-fold higher age-adjusted risk of mortality from coronary heart disease than did those with LDL-cholesterol <80 mg dL(-1) (<2.06 mmol L(-1)), whereas no such association for women was found. The multivariable hazard ratio for the highest versus lowest categories of LDL-cholesterol was 2.06 (95 percent confidence interval: 1.34 to 3.17) for men and 1.16 (0.64 to 2.12) for women.

CONCLUSION

Higher concentrations of LDL-cholesterol were associated with an increased risk of mortality from coronary heart disease for men, but not for women, in a low cholesterol population.

Rosuvastatin for primary prevention in older persons with elevated C-reactive protein and low to average low-density lipoprotein cholesterol levels: exploratory analysis of a randomized trial

BACKGROUND

Randomized data on statins for primary prevention in older persons are limited, and the relative hazard of cardiovascular disease associated with an elevated cholesterol level weakens with advancing age.

OBJECTIVE

To assess the efficacy and safety of rosuvastatin in persons 70 years or older.

DESIGN

Secondary analysis of JUPITER (Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin), a randomized, double-blind, placebo-controlled trial.

SETTING

1315 sites in 26 countries randomly assigned participants in JUPITER.

PARTICIPANTS

Among the 17 802 participants randomly assigned with low-density lipoprotein (LDL) cholesterol levels less than 3.37 mmol/L (<130 mg/dL) and high-sensitivity C-reactive protein levels of 2.0 mg/L or more without cardiovascular disease, 5695 were 70 years or older.

INTERVENTION

Participants were randomly assigned in a 1:1 ratio to receive 20 mg of rosuvastatin daily or placebo.

MEASUREMENTS

The primary end point was the occurrence of a first cardiovascular event (myocardial infarction, stroke, arterial revascularization, hospitalization for unstable angina, or death from cardiovascular causes).

RESULTS

The 32% of trial participants 70 years or older accrued 49% (n = 194) of the 393 confirmed primary end points. The rates of the primary end point in this age group were 1.22 and 1.99 per 100 person-years of follow-up in the rosuvastatin and placebo groups, respectively (hazard ratio, 0.61 [95% CI, 0.46 to 0.82]; P < 0.001). Corresponding rates of all-cause mortality in this age group were 1.63 and 2.04 (hazard ratio, 0.80 [CI, 0.62 to 1.04]; P = 0.090). Although no significant heterogeneity was found in treatment effects by age, absolute reductions in event rates associated with rosuvastatin were greater in older persons. The relative rate of any serious adverse event among older persons in the rosuvastatin versus placebo group was 1.05 (CI, 0.93 to 1.17).

LIMITATION

Effect estimates from this exploratory analysis with age cut-point chosen after trial completion should be viewed in the context of the overall trial results.

CONCLUSION

In apparently healthy older persons without hyperlipidemia but with elevated high-sensitivity C-reactive protein levels, rosuvastatin reduces the incidence of major cardiovascular events.

PRIMARY FUNDING SOURCE

AstraZeneca.

Rosuvastatin for primary prevention in older persons with elevated C-reactive protein and low to average low-density lipoprotein cholesterol levels: exploratory analysis of a randomized trial

BACKGROUND

Randomized data on statins for primary prevention in older persons are limited, and the relative hazard of cardiovascular disease associated with an elevated cholesterol level weakens with advancing age.

OBJECTIVE

To assess the efficacy and safety of rosuvastatin in persons 70 years or older.

DESIGN

Secondary analysis of JUPITER (Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin), a randomized, double-blind, placebo-controlled trial.

SETTING

1315 sites in 26 countries randomly assigned participants in JUPITER.

PARTICIPANTS

Among the 17 802 participants randomly assigned with low-density lipoprotein (LDL) cholesterol levels less than 3.37 mmol/L (<130 mg/dL) and high-sensitivity C-reactive protein levels of 2.0 mg/L or more without cardiovascular disease, 5695 were 70 years or older.

INTERVENTION

Participants were randomly assigned in a 1:1 ratio to receive 20 mg of rosuvastatin daily or placebo.

MEASUREMENTS

The primary end point was the occurrence of a first cardiovascular event (myocardial infarction, stroke, arterial revascularization, hospitalization for unstable angina, or death from cardiovascular causes).

RESULTS

The 32% of trial participants 70 years or older accrued 49% (n = 194) of the 393 confirmed primary end points. The rates of the primary end point in this age group were 1.22 and 1.99 per 100 person-years of follow-up in the rosuvastatin and placebo groups, respectively (hazard ratio, 0.61 [95% CI, 0.46 to 0.82]; P < 0.001). Corresponding rates of all-cause mortality in this age group were 1.63 and 2.04 (hazard ratio, 0.80 [CI, 0.62 to 1.04]; P = 0.090). Although no significant heterogeneity was found in treatment effects by age, absolute reductions in event rates associated with rosuvastatin were greater in older persons. The relative rate of any serious adverse event among older persons in the rosuvastatin versus placebo group was 1.05 (CI, 0.93 to 1.17).

LIMITATION

Effect estimates from this exploratory analysis with age cut-point chosen after trial completion should be viewed in the context of the overall trial results.

CONCLUSION

In apparently healthy older persons without hyperlipidemia but with elevated high-sensitivity C-reactive protein levels, rosuvastatin reduces the incidence of major cardiovascular events.

PRIMARY FUNDING SOURCE

AstraZeneca.

Rosuvastatin for primary prevention in older persons with elevated C-reactive protein and low to average low-density lipoprotein cholesterol levels: exploratory analysis of a randomized trial

BACKGROUND

Randomized data on statins for primary prevention in older persons are limited, and the relative hazard of cardiovascular disease associated with an elevated cholesterol level weakens with advancing age.

OBJECTIVE

To assess the efficacy and safety of rosuvastatin in persons 70 years or older.

DESIGN

Secondary analysis of JUPITER (Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin), a randomized, double-blind, placebo-controlled trial.

SETTING

1315 sites in 26 countries randomly assigned participants in JUPITER.

PARTICIPANTS

Among the 17 802 participants randomly assigned with low-density lipoprotein (LDL) cholesterol levels less than 3.37 mmol/L (<130 mg/dL) and high-sensitivity C-reactive protein levels of 2.0 mg/L or more without cardiovascular disease, 5695 were 70 years or older.

INTERVENTION

Participants were randomly assigned in a 1:1 ratio to receive 20 mg of rosuvastatin daily or placebo.

MEASUREMENTS

The primary end point was the occurrence of a first cardiovascular event (myocardial infarction, stroke, arterial revascularization, hospitalization for unstable angina, or death from cardiovascular causes).

RESULTS

The 32% of trial participants 70 years or older accrued 49% (n = 194) of the 393 confirmed primary end points. The rates of the primary end point in this age group were 1.22 and 1.99 per 100 person-years of follow-up in the rosuvastatin and placebo groups, respectively (hazard ratio, 0.61 [95% CI, 0.46 to 0.82]; P < 0.001). Corresponding rates of all-cause mortality in this age group were 1.63 and 2.04 (hazard ratio, 0.80 [CI, 0.62 to 1.04]; P = 0.090). Although no significant heterogeneity was found in treatment effects by age, absolute reductions in event rates associated with rosuvastatin were greater in older persons. The relative rate of any serious adverse event among older persons in the rosuvastatin versus placebo group was 1.05 (CI, 0.93 to 1.17).

LIMITATION

Effect estimates from this exploratory analysis with age cut-point chosen after trial completion should be viewed in the context of the overall trial results.

CONCLUSION

In apparently healthy older persons without hyperlipidemia but with elevated high-sensitivity C-reactive protein levels, rosuvastatin reduces the incidence of major cardiovascular events.

PRIMARY FUNDING SOURCE

AstraZeneca.

Genetic variation in the estrogen metabolic pathway and mammographic density as an intermediate phenotype of breast cancer

Introduction

Several studies have examined the effect of genetic variants in genes involved in the estrogen metabolic pathway on mammographic density, but the number of loci studied and the sample sizes evaluated have been small and pathways have not been evaluated comprehensively. In this study, we evaluate the association between mammographic density and genetic variants of the estrogen metabolic pathway.

Methods

A total of 239 SNPs in 34 estrogen metabolic genes were studied in 1,731 Swedish women who participated in a breast cancer case-control study, of which 891 were cases and 840 were controls. Film mammograms of the medio-lateral oblique view were digitalized and the software Cumulus was used for computer-assisted semi-automated thresholding of mammographic density. Generalized linear models controlling for possible confounders were used to evaluate the effects of SNPs on mammographic density. Results found to be nominally significant were examined in two independent populations. The admixture maximum likelihood-based global test was performed to evaluate the cumulative effect from multiple SNPs within the whole metabolic pathway and three subpathways for androgen synthesis, androgen-to-estrogen conversion and estrogen removal.

Results

Genetic variants of genes involved in estrogen metabolism exhibited no appreciable effect on mammographic density. None of the nominally significant findings were validated. In addition, global analyses on the overall estrogen metabolic pathway and its subpathways did not yield statistically significant results.

Conclusions

Overall, there is no conclusive evidence that genetic variants in genes involved in the estrogen metabolic pathway are associated with mammographic density in postmenopausal women.

Association between non-high-density lipoprotein cholesterol concentrations and mortality from coronary heart disease among Japanese men and women: the Ibaraki Prefectural Health Study

AIM

The aim of this study was to examine whether non-high-density lipoprotein cholesterol (non-HDL-cholesterol) raises the risk of coronary heart disease in a dose-response fashion in a non-obese population with low total cholesterol levels and high HDL-cholesterol levels, such as Japanese.

METHODS

A total of 30,802 men and 60,417 women, aged 40 to 79 years with no history of stroke or coronary heart disease, completed a baseline risk factor survey in 1993 under the auspices of the Ibaraki Prefectural Health Study. Systematic mortality surveillance through 2003 identified 539 coronary heart disease deaths.

RESULTS

The mean values for non-HDL-cholesterol were 140 mg/dL for men and 151 mg/dL for women. The corresponding mean values were 193 mg/dL and 208 mg/dL total cholesterol and 52 mg/dL and 57 mg/dL HDL-cholesterol, respectively. Men with non-HDL-cholesterol > or = 180 mg/dL had a two-fold higher age-adjusted risk of mortality from coronary heart disease than did those with non-HDL-cholesterol <100 mg/dL, whereas no such association was found for women. The multivariable hazard ratio for > or = 180 mg/dL versus <100 mg/dL of non-HDL-cholesterol was 2.22 (95% confidence interval: 1.37 to 3.62) for men and 0.71 (0.37 to 1.34) for women.

CONCLUSION

Higher concentrations of non-HDL-cholesterol were associated with an increased risk of mortality from coronary heart disease for men, but not for women.

Rosuvastatin in the prevention of stroke among men and women with elevated levels of C-reactive protein: justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER)

BACKGROUND

Prior primary prevention trials of statin therapy that used cholesterol criteria for enrollment have not reported significant decreases in stroke risk. We evaluated whether statin therapy might reduce stroke rates among individuals with low levels of cholesterol but elevated levels of high-sensitivity C-reactive protein.

METHODS AND RESULTS

In Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER), 17 802 apparently healthy men and women with low-density lipoprotein cholesterol levels <130 mg/dL and high-sensitivity C-reactive protein levels > or = 2.0 mg/L were randomly allocated to rosuvastatin 20 mg daily or placebo and then followed up for the occurrence of a first stroke. After a median follow-up of 1.9 years (maximum, 5.0 years), rosuvastatin resulted in a 48% reduction in the hazard of fatal and nonfatal stroke as compared with placebo (incidence rate, 0.18 and 0.34 per 100 person-years of observation, respectively; hazard ratio 0.52; 95% confidence interval, 0.34 to 0.79; P=0.002), a finding that was consistent across all examined subgroups. This finding was due to a 51% reduction in the rate of ischemic stroke (hazard ratio, 0.49; 95% confidence interval, 0.30 to 0.81; P=0.004), with no difference in the rates of hemorrhagic stroke between the active and placebo arms (hazard ratio, 0.67; 95% confidence interval, 0.24 to 1.88; P=0.44).

CONCLUSIONS

Rosuvastatin reduces by more than half the incidence of ischemic stroke among men and women with low levels of low-density lipoprotein cholesterol levels who are at risk because of elevated levels of high-sensitivity C-reactive protein.

CLINICAL TRIAL REGISTRATION

clinicaltrial.gov. Unique identifier: NCT00239681.

High-sensitivity C-reactive protein predicts mortality but not stroke: the Northern Manhattan Study

OBJECTIVE

To determine whether high-sensitivity C-reactive protein (hsCRP) and serum amyloid A (SAA) predict stroke, vascular events, and mortality in a prospective cohort study.

BACKGROUND

Markers of inflammation have been associated with risk of myocardial infarction (MI). Their association with stroke is controversial.

METHODS

The Northern Manhattan Study includes a stroke-free community-based cohort study in participants aged > or =40 years (median follow-up 7.9 years). hsCRP and SAA were measured using nephelometry. Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the association of markers with risk of ischemic stroke and other outcomes after adjusting for demographics and risk factors.

RESULTS

hsCRP measurements were available in 2,240 participants (mean age 68.9 +/- 10.1 years; 64.2% women; 18.8% white, 23.5% black, and 55.1% Hispanic). The median hsCRP was 2.5 mg/L. Compared with those with hsCRP <1 mg/L, those with hsCRP >3 mg/L were at increased risk of ischemic stroke in a model adjusted for demographics (HR = 1.60, 95% CI 1.06-2.41), but the effect was attenuated after adjusting for other risk factors (adjusted HR = 1.20, 95% CI 0.78-1.86). hsCRP >3 mg/L was associated with risk of MI (adjusted HR = 1.70, 95% CI 1.04-2.77) and death (adjusted HR = 1.55, 95% CI 1.23-1.96). SAA was not associated with stroke risk.

CONCLUSION

In this multiethnic cohort, high-sensitivity C-reactive protein (hsCRP) was not associated with ischemic stroke, but was modestly associated with myocardial infarction and mortality. The value of hsCRP and serum amyloid A may depend on population characteristics such as age and other risk factors.

Prospective studies on the relationship between high-density lipoprotein cholesterol and cardiovascular risk: a systematic review

Epidemiological studies have extensively evaluated the association between high-density lipoprotein cholesterol (HDL-C) and cardiovascular disease (CVD) risk. The objective of this systematic review was to enumerate the number of original prospective studies that showed a significant association between HDL-C and CVD risk and provided evidence of the consistency of this association across other lipid risk factors. A systematic MEDLINE literature search identified 53 prospective cohort and five nested case-control studies that provided multivariate assessments of the association between HDL-C and CVD risk. Among these 58 prospective studies, 31 studies found a significant inverse association between HDL-C and CVD risk for all CVD outcomes and subpopulations studied, whereas 17 studies found a significant association for some CVD outcomes and/or subpopulations assessed. The ratio of studies that found a significant association out of the total studies identified was similar across all CVD outcomes, although there was less evidence for stroke and atherosclerotic outcomes. Only seven studies tested for the consistency of this association across other lipid risk factors, of which six studies suggested that the association was consistent across other lipid levels. In conclusion, the association between HDL-C and CVD risk is significant and strong, although further evidence may be needed to establish whether this association is consistent across other lipid risk factors. Furthermore, uncertainties remain regarding the mechanism in which HDL-C exerts its effects, suggesting a need for further research focused on new methods for reliable measurement.

New strategies for the prevention of stroke

1. Stroke is a major cause of disability and death worldwide. It is preferable to prevent stroke rather than to treat it and, for the prevention of stroke, all risk factors relating to stroke need to be understood. The present paper reviews potential new strategies for the prevention of stroke based on findings of new risk factors, as well as classical risk factors. 2. Recently, new risk factors related to stroke were reported, including dysfunction of the arterial baroreflex, pro-inflammatory cytokines, vitamins and hormone deficiency. Correspondingly, therapies targeting these risk factors where shown to significantly reduce the incidence and/or severity of stroke. 3. Because the genesis of stroke is multifactorial, the prevention of stroke should not target one risk factor only. Combination therapies with drugs acting on different risk factors may be more effective in the prevention of stroke.

Serum C-reactive protein and risk of cardiovascular events in middle-aged and older chinese population

The purpose of the present study was to investigate the effect of high-sensitivity C-reactive protein (hs-CRP) on the risk of cardiovascular disease (CVD) in a Chinese population. A total of 2,656 participants (aged 30 to 95 years) with baseline hs-CRP levels available were monitored for the incidence of a composite of CVD events (stroke and coronary heart disease) during a 5.5-year period. With increasing quartiles of hs-CRP (<0.47, 0.47 to 0.97, 0.97 to 2.09, and >or=2.09 mg/L), the incidence of CVD increased progressively (11.7, 16.4, 24.7, and 36.5 per 1,000 person-years, respectively). In a Cox model adjusted for other traditional risk factors (e.g., age, blood pressure, diabetes mellitus, lipids, body mass index, smoking status), elevated hs-CRP (>or=2.0 mg/L) independently predicted the risk of CVD (hazard ratio 1.39; 95% confidence interval 1.04 to 1.87). The effect was especially significant for stroke (hazard ratio 1.58; confidence interval 1.08 to 2.31). In conclusion, the results of our study suggest that elevated hs-CRP (>or=2.0 mg/L) is an effective predictor of CVD in a Chinese population.

Social isolation alters neuroinflammatory response to stroke

Social isolation has dramatic long-term physiological and psychological consequences; however, the mechanisms by which social isolation influences disease outcome are largely unknown. The purpose of the present study was to investigate the effects of social isolation on neuronal damage, neuroinflammation, and functional outcome after focal cerebral ischemia. Male mice were socially isolated (housed individually) or pair housed with an ovariectomized female before induction of stroke, via transient intraluminal middle cerebral artery occlusion (MCAO), or SHAM surgery. In these experiments, peri-ischemic social isolation decreases poststroke survival rate and exacerbates infarct size and edema development. The social influence on ischemic damage is accompanied by an altered neuroinflammatory response; specifically, central interleukin-6 (IL-6) signaling is down-regulated, whereas peripheral IL-6 is up-regulated, in isolated relative to socially housed mice. In addition, intracerebroventricular injection of an IL-6 neutralizing antibody (10 ng) eliminates social housing differences in measures of ischemic outcome. Taken together, these data suggest that central IL-6 is an important mediator of social influences on stroke outcome.

Inflammation and hemostasis biomarkers for predicting stroke in postmenopausal women: the Women's Health Initiative Observational Study

BACKGROUND

Inflammatory and hemostasis-related biomarkers may identify women at risk of stroke.

METHODS

Hormones and Biomarkers Predicting Stroke is a study of ischemic stroke among postmenopausal women participating in the Women's Health Initiative observational study (n = 972 case-control pairs). A Biomarker Risk Score (BRS) was derived from levels of 7 inflammatory and hemostasis-related biomarkers that appeared individually to predict risk of ischemic stroke: C-reactive protein (CRP), interleukin-6, tissue plasminogen activator, D-dimer, white blood cell count, neopterin, and homocysteine. The c index was used to evaluate discrimination.

RESULTS

Of all the individual biomarkers examined, CRP emerged as the only independent single predictor of ischemic stroke (adjusted odds ratio comparing Quartile(4)v Quartile(1) = 1.64, 95% confidence interval: 1.15-2.32, P = .01) after adjustment for other biomarkers and standard stroke risk factors. The BRS identified a gradient of increasing stroke risk with a greater number of elevated inflammatory/hemostasis biomarkers, and improved the c index significantly compared with standard stroke risk factors (P = .02). Among the subset of individuals who met current criteria for high-risk levels of CRP (>3.0 mg/L), the BRS defined an approximately 2-fold gradient of risk. We found no evidence for a relationship between stroke and levels of E-selectin, fibrinogen, tumor necrosis factor-alpha, vascular cell adhesion molecule-1, prothrombin fragment 1+2, Factor VIIC, or plasminogen activator inhibitor-1 antigen (P > .15).

DISCUSSION

The findings support the further exploration of multiple biomarker panels to develop approaches for stratifying an individual's risk of stroke.

Effect of atorvastatin on circulating hsCRP concentrations: a sub-study of the achieve cholesterol targets fast with atorvastatin stratified titration (ACTFAST) study

BACKGROUND

Elevated C-reactive protein (CRP) concentration is a risk factor for cardiovascular events that may add prognostic information. Statin treatment is associated with significant reductions in CRP concentrations, which appear to be unrelated to the magnitude of LDL-cholesterol reduction. We investigated the effect of atorvastatin, across its dose range, on high sensitivity (hs)CRP in subjects at high cardiovascular risk.

METHODS

ACTFAST was a 12 week, prospective, multicenter, open-label trial in which high-risk subjects were assigned a starting dose of atorvastatin (10, 20, 40 or 80 mg/d) based on LDL-C and status of statin use at screening (1345 statin-free [SF] and 772 previously statin-treated [ST]).

RESULTS

At baseline, ST subjects had significantly lower hsCRP levels than SF subjects (ST group 2.31, 95% CI 2.15, 2.48 mg/L vs. SF group 3.16, 95% CI 2.98, 3.34 mg/L, p<0.05). In the SF group, atorvastatin 10 to 80 mg significantly (p<0.01) reduced hsCRP levels in a dose dependent-manner. In ST group, additional hsCRP reductions were observed over the statin used at baseline, which were not dose-dependent. Atorvastatin significantly decreased hsCRP concentrations in subjects with or without diabetes or the metabolic syndrome.

CONCLUSIONS

Atorvastatin treatment at different doses, particularly 80 mg, significantly reduced hsCRP serum concentrations. This reduction was observed in both SF and ST groups and was independent of the presence of metabolic syndrome and/or diabetes. The beneficial effect of atorvastatin was evident at 6 weeks, supporting the practice of early introduction of higher doses of atorvastatin in high-risk patients.

Association between polymorphisms in the beta2-adrenergic receptor gene with myocardial infarction and ischaemic stroke in women

Results from studies investigating the association between polymorphisms in the beta2-adrenergic receptor gene (ADRB2) and cardiovascular disease (CVD) are controversial. Using haplotype-based analysis, we have previously shown a protective effect of the Gly16-Gln27-Ile164 haplotype on myocardial infarction in men. We sought to replicate these findings in women and further investigated whether the gene variants exert differential effects on myocardial infarction and ischaemic stroke. We performed a prospective study among 25,224 women, participating in the Women's Health Study and free of CVD at study entry. We had information on polymorphisms Gly16Arg, Gln27Glu, and Thr164Ile in the ADRB2. Incident CVD was self-reported and confirmed after medical record review. We used proportional hazards models to investigate the association between genotypes and haplotypes with any myocardial infarction, any ischaemic stroke, and CVD death. During a mean of 11.8 years of follow-up, 274 myocardial infarctions, 299 ischaemic strokes, and 159 CVD deaths occurred. Among the whole cohort genotype- and haplotype-based analyses did not show an association for any of the gene variants with any of the CVD outcomes. When we focused on Caucasian women, the haplotype-based analysis, however, suggested an inverse association of the haplotype Gly16-Gln27-Thr164 with incident myocardial infarction (multivariable-adjusted hazard ratio 0.75; 95% confidence interval 0.58-0.97; p = 0.03). We did not find associations in the haplotype-based analyses with incident ischaemic stroke or CVD death. Our results suggest that the haplotype Gly16-Gln27-Thr164 is associated with reduced risk of incident myocardial infarction but not ischaemic stroke in Caucasian women and suggest differential pathophysiologies for myocardial infarction and stroke.

Genetically elevated C-reactive protein and ischemic vascular disease

BACKGROUND

Elevated levels of C-reactive protein (CRP) are associated with increased risks of ischemic heart disease and ischemic cerebrovascular disease. We tested whether this is a causal association.

METHODS

We studied 10,276 persons from a general population cohort, including 1786 in whom ischemic heart disease developed and 741 in whom ischemic cerebrovascular disease developed. We examined another 31,992 persons from a cross-sectional general population study, of whom 2521 had ischemic heart disease and 1483 had ischemic cerebrovascular disease. Finally, we compared 2238 patients with ischemic heart disease with 4474 control subjects and 612 patients with ischemic cerebrovascular disease with 1224 control subjects. We measured levels of high-sensitivity CRP and conducted genotyping for four CRP polymorphisms and two apolipoprotein E polymorphisms.

RESULTS

The risk of ischemic heart disease and ischemic cerebrovascular disease was increased by a factor of 1.6 and 1.3, respectively, in persons who had CRP levels above 3 mg per liter, as compared with persons who had CRP levels below 1 mg per liter. Genotype combinations of the four CRP polymorphisms were associated with an increase in CRP levels of up to 64%, resulting in a theoretically predicted increased risk of up to 32% for ischemic heart disease and up to 25% for ischemic cerebrovascular disease. However, these genotype combinations were not associated with an increased risk of ischemic vascular disease. In contrast, apolipoprotein E genotypes were associated with both elevated cholesterol levels and an increased risk of ischemic heart disease.

CONCLUSIONS

Polymorphisms in the CRP gene are associated with marked increases in CRP levels and thus with a theoretically predicted increase in the risk of ischemic vascular disease. However, these polymorphisms are not in themselves associated with an increased risk of ischemic vascular disease.

Interrelationships among the MTHFR 677C>T polymorphism, migraine, and cardiovascular disease

BACKGROUND

Interrelationships among the MTHFR 677C>T polymorphism (rs1801133), migraine, and cardiovascular disease (CVD) are plausible but remain controversial.

METHODS

Association study among 25,001 white US women, participating in the Women's Health Study, with information on MTHFR 677C>T polymorphism. Migraine and migraine aura status were self-reported. Incident CVD events were confirmed after medical record review. We used logistic regression to investigate the genotype-migraine association and proportional hazards models to evaluate the interrelationships of genotype and migraine on incident CVD.

RESULTS

At baseline, 4,577 (18.3%) women reported history of migraine; 39.5% of the 3,226 women with active migraine indicated aura. During a mean of 11.9 years of follow-up, 625 CVD events occurred. Carriers of the TT genotype were less likely to have migraine with aura. The multivariable-adjusted relative risk (RR) in the recessive model was 0.79 (95% CI = 0.65-0.96; p = 0.02). The TT genotype did not increase the risk for CVD. In contrast, migraine with aura doubled the risk for CVD (multivariable-adjusted RR = 2.06; 95% CI = 1.53-2.78; p < 0.0001). Coexistence of migraine with aura and the TT genotype selectively raised this risk (RR = 3.66; 95% CI = 1.69-7.90; p = 0.001). This pattern was driven by a fourfold increased risk for ischemic stroke (multivariable-adjusted RR = 4.19; 95% CI = 1.38-12.74; p = 0.01) and was not apparent for myocardial infarction.

CONCLUSIONS

Data from this large cohort of women suggest a modest protective effect of the MTHFR 677TT genotype on migraine with aura. The increased risk for cardiovascular disease among migraineurs with aura was magnified for TT genotype carriers, which was driven by a substantially increased risk of ischemic stroke.

Lipids, Apolipoproteins, and Their Ratios in Relation to Cardiovascular Events With Statin Treatment

Background— Low-density lipoprotein (LDL) cholesterol is the principal target of lipid-lowering therapy, but recent evidence has suggested more appropriate targets. We compared the relationships of on-treatment levels of LDL cholesterol, non–high-density lipoprotein (HDL) cholesterol, and apolipoprotein B, as well as ratios of total/HDL cholesterol, LDL/HDL cholesterol, and apolipoprotein B/A-I, with the occurrence of cardiovascular events in patients receiving statin therapy.

Methods and Results— A post hoc analysis was performed that combined data from 2 prospective, randomized clinical trials in which 10 001 (“Treating to New Targets”) and 8888 (“Incremental Decrease in End Points through Aggressive Lipid Lowering”) patients with established coronary heart disease were assigned to usual-dose or high-dose statin treatment. In models with LDL cholesterol, non-HDL cholesterol and apolipoprotein B were positively associated with cardiovascular outcome, whereas a positive relationship with LDL cholesterol was lost. In a model that contained non-HDL cholesterol and apolipoprotein B, neither was significant owing to collinearity. Total/HDL cholesterol ratio and the apolipoprotein B/A-I ratio in particular were each more closely associated with outcome than any of the individual proatherogenic lipoprotein parameters.

Conclusions— In patients receiving statin therapy, on-treatment levels of non-HDL cholesterol and apolipoprotein B were more closely associated with cardiovascular outcome than levels of LDL cholesterol. Inclusion of measurements of the antiatherogenic lipoprotein fraction further strengthened the relationships. These data support the use of non-HDL cholesterol or apolipoprotein B as novel treatment targets for statin therapy. Given the absence of interventions that have been proven to consistently reduce cardiovascular disease risk through raising plasma levels of HDL cholesterol or apolipoprotein A-I, it seems premature to consider the ratio variables as clinically useful.

Ankle-brachial pressure index: a simple tool for assessing cardiovascular risk in patients with systemic vasculitis

OBJECTIVE

Cardiovascular disease may be increased in patients with systemic vasculitides (SV). The Ankle-Brachial Pressure Index (ABPI) is a non-invasive tool for the assessment of cardiovascular risk (CV). Our aim was to determine the prevalence of an abnormal ABPI in patients with SV and healthy controls and to correlate with clinical and serological parameters.

METHODS

We studied 54 consecutive vasculitis patients (20 males) attending the vasculitis clinic and 49 healthy subjects. Patients were classified according to the ACR 1990 criteria and the Chapel Hill Consensus definitions. There were 18 patients with Wegener's granulomatosis, eight with Behcet's disease, seven with Churg-Strauss Syndrome, three with Henoch-Schonlein purpura, three with polyarteritis nodosa, three with Takayasu's disease, three with p-ANCA associated vasculitis, three with urticarial vasculitis, two with cutaneous leucocytoclastic angiitis, one with microscopic polyangiitis, one with primary central nervous system angiitis, one giant cell arteritis and one with cutaneous vasculitis secondary to Sjogren's syndrome. Traditional risk factors as well as glucose, lipid profile, CRP, hsCRP, ANCA and aPL were assessed. ABPI was measured according to a consensus statement on the methodology.

RESULTS

The ABPI was abnormal in 11/54 (20.4%) of SV patients and 2/49 (4%) of the control group (chi(2) with Yates correction = 4.8, P <or= 0.03). CV events were more prevalent in the SV patients with abnormal ABPI (45.5% vs 11.6%, P <or= 0.01).

CONCLUSIONS

There is an increased prevalence of an abnormal ABPI in patients with systemic vasculitides implying an increased risk of cardiovascular disease. This simple tool may be clinically useful in identifying systemic vasculitis patients at risk of accelerated atherosclerosis.

Interleukin-18 and the risk of future cardiovascular disease among initially healthy women

OBJECTIVE

Elevated levels of interleukin (IL)-18 have been implicated in the development of atherosclerosis in animals. Data in humans are less clear, and data in women are particularly scarce.

METHODS AND RESULTS

In a prospective nested case-control study of initially healthy women, we measured baseline plasma IL-18 levels in 253 participants who subsequently developed cardiovascular disease (CVD) and in 253 healthy age- and smoking-matched controls. IL-18 levels were higher at baseline among those who developed CVD (274.1pg/mL versus 233.8pg/mL, P<0.001), and were associated with future CVD (relative risk (RR) for highest versus lowest quartile 2.53; 95% CI, 1.47-4.35, P<0.001). While that risk was attenuated after adjustment for traditional cardiovascular risk factors (RR 1.60; 95% CI, 0.77-3.34, P=0.13), those with IL-18 levels at or above a threshold of the 90th percentile (442pg/mL) remained at elevated risk after adjustment (RR 2.40; 95% CI, 1.05-5.56, P=0.04). Levels of IL-18 above this threshold modify the fully adjusted risk of future CVD conferred by elevated levels of total cholesterol (P(interaction)=0.02).

CONCLUSIONS

In this population of apparently healthy women, IL-18 levels associate with increased risk of cardiovascular disease, but that risk is attenuated in models adjusting for traditional cardiovascular risk factors. Very high levels of IL-18 interact with hypercholesterolemia to alter CVD risk.

Plasma levels of granzyme B are increased in patients with lipid-rich carotid plaques as determined by echogenicity

Increased echolucency of carotid plaques is associated with an increased risk of ischemic stroke. Inflammation and apoptosis of vascular smooth muscle cells in the arterial wall are involved in the atherosclerotic process and destabilization of the plaque. Granzyme B (GrB) is a key mediator of T cell-mediated cytotoxicity, and we therefore hypothesized that this protease could distinguish echolucent from other plaques. Ultrasound-determined echolucency of atherosclerotic plaques was assessed prior to carotid endarterectomy/angioplasty in 57 consecutively recruited patients with high-grade internal carotid stenosis. Plasma levels of GrB were measured by enzyme immunoassay prior to surgery. Patients with carotid atherosclerosis had significantly higher plasma levels of GrB compared to healthy controls (n=16) (p<0.01), with particularly high levels in those with an echolucent lesion. While there were no differences in traditional cardiovascular risk factors or CRP between those with echolucent (n=16) and those with echogenic/heterogeneous (n=41) plaques, the echolucent group had markedly raised plasma levels of GrB (p<0.01). Patients with high levels of circulating granzyme B also had more ischemic lesions on cerebral MRI prior to surgery. Raised plasma levels of GrB in echolucent carotid plaques with increased frequency of cerebrovascular events suggest that GrB may be a marker of plaque instability.

Comparison of relative and attributable risk of myocardial infarction and stroke according to C-reactive protein and low-density lipoprotein cholesterol levels

C-reactive protein (CRP) was proposed as a stronger predictor of cardiovascular events than low-density lipoprotein cholesterol (LDL-C); however, these associations may differ between myocardial infarction (MI) and stroke. We compared statistically the associations of CRP and LDL-C levels with risk of MI versus stroke and examined to what extent consideration of CRP or LDL-C increases the population attributable fractions (PAFs) of MI and stroke beyond traditional risk factors among 27,548 subjects from the European Prospective Investigation into Cancer and Nutrition-Potsdam Study in a case-cohort design. Among subjects without prior MI or stroke, 156 developed MI and 132 stroke during 6.0 years of follow-up. In adjusted competing risk analyses CRP was positively related to MI and stroke (P difference between endpoints = 0.55), whereas LDL-C was related to MI but not stroke (P difference between endpoints = 0.003). The PAF for smoking, diabetes, and hypertension combined was 0.76 for MI, and 0.58 for stroke. With additional consideration of CRP the PAFs were 0.80 and 0.68, while with addition of LDL-C the PAFs were 0.88 and 0.55. We conclude that CRP is equally strongly related to risk of MI and stroke, whereas LDL-C is related to risk of MI but not stroke. Consideration of LDL-C beyond smoking, diabetes and hypertension may increase the PAF of MI slightly more than CRP. In contrast, consideration of CRP but not of LDL-C may increase the PAF of stroke beyond these factors.

Inflammation and ischaemic stroke

PURPOSE OF REVIEW

Inflammation is implicated in ischaemic stroke as a general cardiovascular risk factor, a possible immediate trigger, a component (and possible exacerbating factor) of the response to tissue injury, a marker of future risk, and as a therapeutic target. Each aspect is reviewed.

RECENT FINDINGS

Evidence of epidemiological association of inflammatory markers, particularly C-reactive protein, has accrued, but the independence of inflammation from more conventional risk indicators is under question. Other inflammatory markers are associated with intermediate phenotypes such as hypertension. Tissue inflammation in atherosclerotic plaque is of probable relevance in identifying recently symptomatic carotid disease. Both humoral and cellular inflammation are evident following stroke, with evidence that these responses may exacerbate tissue injury. Blockade of interleukin-1, or of neutrophil chemotaxis, has reduced infarct volume in models of stroke but has yet to show benefit in clinical trials. Other anti-inflammatory strategies are promising.

SUMMARY

Inflammation is implicated in several aspects of acute ischaemic stroke. It remains to be established whether the inflammatory response is a truly independent risk factor in general, or whether specific anti-inflammatory interventions are beneficial either in prevention or acute treatment.

C-reactive protein and the prediction of cardiovascular events among those at intermediate risk: moving an inflammatory hypothesis toward consensus

Over 20 large-scale prospective studies show that the inflammatory biomarker high-sensitivity C-reactive protein (hsCRP) is an independent predictor of future cardiovascular events that additionally predicts risk of incident hypertension and diabetes. In many studies, the relative impact of hsCRP is at least as large as that individually of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, blood pressure, or smoking, and knowledge of hsCRP correctly reclassifies a substantial proportion of "intermediate-risk" individuals into clinically relevant higher- or lower-risk categories. Other studies show the relative benefit of statins to be greater among those with increased hsCRP and that achieved hsCRP levels after statin therapy predict recurrent event rates as much as achieved levels of low-density lipoprotein cholesterol. Nonetheless, it remains controversial whether the time has come to modify traditional algorithms used for global risk detection. As described here, 6 areas of controversy regarding hsCRP are resolvable with a consensus position that focuses in primary prevention on selective use among individuals with 5% to 20% 10-year risk as estimated by Adult Treatment Panel III, and focuses in secondary prevention on high-risk patients being treated with statin therapy. Forthcoming trial data could expand or contract this "screen selectively" policy, and investigators should be open to the possibility that second-generation inflammatory biomarkers may be developed that supplant hsCRP altogether. In the meantime, however, this consensus position on hsCRP should be one to which both advocates and critics of the inflammatory hypothesis of atherosclerosis can adhere because it is one that can immediately improve patient care.

Significance of Determining Levels of Apolipoproteins A-I and B in the Diagnostics and Assessment of Lipid-Related Atherogenic Risk in Hyperalpha-Lipoproteinemia, Hypocholesterolemia and Hypo-Hdl-Cholesterolemia

The significance of determining apolipoproteins apoB and apoA-I and their correlation with lipid status parameters were tested in hyperalpha-lipoproteinemia (30 women), hypocholesterolemia (10 men) and hypo-HDL-cholesterolemia (15 women and 21 men). Control groups were 20 normolipidemic men and women, each. ApoA-I showed positive correlation with HDL-cholesterol in hyperalpha-lipoproteinemia, with total and HDL-cholesterol in hypocholesterolemia, and with total and LDL-cholesterol in females with hypo-HDL-cholesterolemia, and negative correlation with cholesterol ratios only in hypocholesterolemia. ApoB showed a positive correlation with total and LDL-cholesterol in all groups, and with cholesterol ratios in hyperalpha-lipoproteinemia and hypo-HDL-cholesterolemia. The apoB/apoA-I ratio, correlating with the majority of lipid parameters, and with the highest percentage of pathological values in all tested groups, was singled out as the most sensitive parameter for the evaluation of lipid-related atherogenic risks.