Haematological variables and risk of future venous thromboembolism in the British Regional Heart Study on men. Combined D-dimer and APTT as a predictive test for thromboembolism?

We examined the associations between haematological and inflammatory variables with future venous thromboembolism (VTE), in 3494 men aged 60-79 years, with no previous history of VTE or myocardial infarction, who were not receiving oral anticoagulants. After a mean follow-up period of 18 years, there were 149 confirmed cases of fatal or non-fatal VTE (deep vein thrombosis and/or pulmonary embolism). Among classical cardiovascular risk factors, only obesity and cigarette smoking were associated with VTE risk. After adjustment for age, obesity and smoking, VTE risk was associated with coagulation factor VIII, factor IX, von Willebrand factor (VWF), activated partial thromboplastin time (APTT), and fibrin D-dimer. Hazard ratios (95% CI) for top to bottom quarters (bottom to top for APTT), were respectively 2.17 (1.37, 3.44), 2.15 (1.30, 3.53), 2.02 (1.27, 3.22), 2.43 (1.47, 4.02) and 3.62 (2.18, 6.08). The 11% of men with both the shortest APTT and highest D-dimer combined had a 5.02 (2.37, 10.62) higher risk of VTE. VTE risk was not associated with fibrinogen, factor VII or activated protein C resistance; full blood count variables or with inflammatory markers, plasma viscosity, C-reactive protein or interleukin-6. The combination of D-dimer and APTT merits evaluation as an adjunct to VTE risk prediction scores.

Oroxylum indicum (L.) Kurz extract inhibits adipogenesis and lipase activity in vitro.

BACKGROUND: Oroxylum indicum (L.) Kurz (O. indicum) is found in Thailand. It has been used for the treatment of obesity. This study aimed to investigate the effects of an O. indicum extract (OIE) on the adipogenic and biomolecular change in 3T3-L1 adipocytes. METHODS: Initial studies examined the chemical components of OIE. The cell line 3T3-L1 was used to establish potential toxic effects of OIE during the differentiation of pre-adipocytes to adipocytes. The inhibitory effect of OIE on lipid accumulation in 3T3-L1 cells was investigated. Moreover, the impact of OIE on pancreatic lipase activity was determined. In further experiments, Fourier Transform Infrared (FTIR) was used to monitor and discriminate biomolecular changes caused by the potential anti-adipogenic effect of OIE on 3T3-L1 cells. RESULTS: Chemical screening methods indicated that OIE was composed of flavonoids, alkaloids, steroids, glycosides, and tannins. The percentage viability of 3T3-L1 cells was not significantly decreased after exposure to either 200 or 150 µg/mL of OIE for 2 and 10 days, respectively compared to control cells. The OIE exhibited a dose-dependent reduction of lipid accumulation compared to the control (p < 0.05). The extract also demonstrated a dose-dependent inhibitory effect upon lipase activity compared to the control. The inhibitory effect of the OIE on lipid accumulation in 3T3-L1 cells was also confirmed using FTIR microspectroscopy. The signal intensity and the integrated areas relating to lipids, lipid esters, nucleic acids, glycogen and carbohydrates of the OIE-treated 3T3-L1 adipocytes were significantly lower than the non-treated 3T3-L1 adipocytes (p < 0.05). Principal component analysis (PCA) indicated four distinct clusters for the FTIR spectra of 3T3-L1 adipocytes based on biomolecular changes (lipids, proteins, nucleic acids, and carbohydrates). This observation was confirmed using Unsupervised hierarchical cluster analysis (UHCA). CONCLUSIONS: These novel findings provide evidence that the OIE derived from the fruit pods of the plant is capable of inhibiting lipid and carbohydrate accumulation in adipocytes and also has the potential to inhibit an enzyme associated with fat absorption. The initial observations indicate that OIE may have important properties which in the future may be exploited for the management of the overweight or obese.

HMG-coenzyme A reductase inhibition, type 2 diabetes, and bodyweight: evidence from genetic analysis and randomised trials.

BACKGROUND: Statins increase the risk of new-onset type 2 diabetes mellitus. We aimed to assess whether this increase in risk is a consequence of inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the intended drug target. METHODS: We used single nucleotide polymorphisms in the HMGCR gene, rs17238484 (for the main analysis) and rs12916 (for a subsidiary analysis) as proxies for HMGCR inhibition by statins. We examined associations of these variants with plasma lipid, glucose, and insulin concentrations; bodyweight; waist circumference; and prevalent and incident type 2 diabetes. Study-specific effect estimates per copy of each LDL-lowering allele were pooled by meta-analysis. These findings were compared with a meta-analysis of new-onset type 2 diabetes and bodyweight change data from randomised trials of statin drugs. The effects of statins in each randomised trial were assessed using meta-analysis. FINDINGS: Data were available for up to 223 463 individuals from 43 genetic studies. Each additional rs17238484-G allele was associated with a mean 0·06 mmol/L (95% CI 0·05-0·07) lower LDL cholesterol and higher body weight (0·30 kg, 0·18-0·43), waist circumference (0·32 cm, 0·16-0·47), plasma insulin concentration (1·62%, 0·53-2·72), and plasma glucose concentration (0·23%, 0·02-0·44). The rs12916 SNP had similar effects on LDL cholesterol, bodyweight, and waist circumference. The rs17238484-G allele seemed to be associated with higher risk of type 2 diabetes (odds ratio [OR] per allele 1·02, 95% CI 1·00-1·05); the rs12916-T allele association was consistent (1·06, 1·03-1·09). In 129 170 individuals in randomised trials, statins lowered LDL cholesterol by 0·92 mmol/L (95% CI 0·18-1·67) at 1-year of follow-up, increased bodyweight by 0·24 kg (95% CI 0·10-0·38 in all trials; 0·33 kg, 95% CI 0·24-0·42 in placebo or standard care controlled trials and -0·15 kg, 95% CI -0·39 to 0·08 in intensive-dose vs moderate-dose trials) at a mean of 4·2 years (range 1·9-6·7) of follow-up, and increased the odds of new-onset type 2 diabetes (OR 1·12, 95% CI 1·06-1·18 in all trials; 1·11, 95% CI 1·03-1·20 in placebo or standard care controlled trials and 1·12, 95% CI 1·04-1·22 in intensive-dose vs moderate dose trials). INTERPRETATION: The increased risk of type 2 diabetes noted with statins is at least partially explained by HMGCR inhibition. FUNDING: The funding sources are cited at the end of the paper.

Aged Garlic Extract Inhibits Human Platelet Aggregation by Altering Intracellular Signaling and Platelet Shape Change.

BACKGROUND: Increased platelet aggregation plays a pivotal role in the etiology of cardiovascular disease. Upon platelet aggregation, an increase in free cytoplasmic Ca(2+) results in the inhibition of soluble guanylyl cyclase (sGC) and adenylyl cyclase (AC), leading to a decrease in cyclic guaninosine-5'-monophosphate (cGMP) and cAMP, respectively. This leads to the activation of the glycoprotein IIb/IIIa (GPIIb/IIIa) fibrinogen receptor, resulting in platelet shape change. Aged garlic extract (AGE) decreases platelet aggregation; however, the mechanisms involved are not clearly defined. OBJECTIVE: Our objective was to investigate the effects of AGE on intraplatelet cell signaling and platelet shape change. METHODS: Platelets from 14 participants were studied. Platelet aggregation was induced by ADP in the presence of AGE up to a concentration of 6.25% (vol:vol) alone or in combination with 3-morpholinosydnonimine (Sin-1), a nitric oxide donor. The experiments with AGE were repeated in the presence of 3-isobutyl-1-methylxanthine (IBMX), a phosphodiesterase inhibitor. In a series of separate experiments, platelet aggregation was induced in the presence of either 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an sGC inhibitor, or 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ22536), an AC inhibitor, or a combination of both in the presence of IBMX and AGE. Intraplatelet cGMP and cAMP were measured. The platelets were also subjected to scanning electron microscopic analysis, and their binding to fibrinogen was determined. RESULTS: AGE decreased platelet aggregation at all concentrations tested; this decrease was more marked in the presence of Sin-1 and ranged between 15% and 67%.The presence of IBMX also led to a decrease (17-35%) in platelet aggregation at all AGE concentrations and a significant decrease in the amounts of cGMP (24-41%) and cAMP (19-70%), respectively, in the presence of ODQ and SQ22536. The presence of AGE significantly inhibited the binding of activated platelets to fibrinogen, preventing changes in platelet shape. CONCLUSION: These results indicate that AGE inhibits platelet aggregation by increasing cyclic nucleotides and inhibiting fibrinogen binding and platelet shape change.

Lycopene and Its Antioxidant Role in the Prevention of Cardiovascular Diseases-A Critical Review.

The present review is based mainly on papers published between 2000 and 2011 and gives information about the properties of the carotenoid lycopene in chemical and biological systems and its possible role in preventing cardiovascular diseases (CVD). The main aim of this report is to highlight its role as an antioxidant, also reported are bioactive properties that may influence the development of foam cells and protection against endothelial cell damage. The paper will also examine recent observations that lycopene may improve blood flow and reduce inflammatory responses. Lycopene possesses antioxidant properties in vitro, and some epidemiological studies have reported protective effects against the progression of CVD. The oxidation of human low density lipoproteins (LDL) is a fundamental mechanism in the initiation of atherosclerosis. A beneficial role of lycopene as antioxidant in the prevention of CVD is suggested but the data are still controversial. Lycopene is believed to be the most potent carotenoid antioxidant in vitro. Tissue culture experiments and animal studies support potential cardioprotective effects for lycopene and other carotenoids in the blood. Most studies showed beneficial effects of lycopene to individuals who are antioxidant-deficient like elderly patients, or humans exposed to higher levels of oxidative stress like smokers, diabetics, hemodialysis patients and acute myocardial infarction patients. By defining the right population and combining antioxidant potentials of lycopene with vitamins and other bioactive plant compounds, the beneficial role of lycopene in CVD can be clarified in future studies.

Blood Pressure and Fibrinogen Responses to Mental Stress as Predictors of Incident Hypertension over an 8-Year Period.

BACKGROUND: Heightened blood pressure (BP) responses to mental stress predict raised BP levels over subsequent years, but evidence for associations with incident hypertension is limited, and the significance of inflammatory responses is uncertain. PURPOSE: We investigated the relationship between BP and plasma fibrinogen responses to stress and incident hypertension over an average 8-year follow-up. METHOD: Participants were 636 men and women (mean age 59.1 years) from the Whitehall II epidemiological cohort with no history of cardiovascular disease and hypertension. They performed standardized behavioral tasks (color/word conflict and mirror tracing), and hypertension was defined by clinic measures and medication status. RESULTS: Of participants in the highest systolic BP reactivity tertile, 29.3 % became hypertensive over the follow-up period compared with 16.5 % of those in the lowest tertile, with an odds ratio of 2.02 (95 % CI 1.17-3.88, p = 0.012) after adjustment for age, sex, grade of employment, body mass index, smoking, alcohol consumption, physical activity, follow-up time, subjective stress response, perceived task difficulty, perceived task engagement, and baseline BP. Similar associations were observed for diastolic BP reactivity (odds ratio 2.05, 95 % CI 1.23-3.40, p = 0.006) and for impaired systolic BP post-stress recovery (odds ratio 2.06, 95 % CI 1.19-3.57, p = 0.010). Fibrinogen reactions to tasks also predicted future hypertension in women (odds ratio 2.64, 95 % CI 1.11-6.30, p = 0.029) but not men. CONCLUSIONS: These data suggest that heightened cardiovascular and inflammatory reactivity to mental stress is associated with hypertension risk, and may be a mechanism through which psychosocial factors impact on the development of hypertension.

The interaction between systemic inflammation and psychosocial stress in the association with cardiac troponin elevation: A new approach to risk assessment and disease prevention.

We have previously shown that there is a complex and dynamic biological interaction between acute mental stress and acute release of inflammatory factors into the blood stream in relation to heart disease. We now hypothesize that the presence of chronic psychosocial stress may modify the weight of single test results for inflammation as a predictor of heart disease. Using a cross-sectional design, 500 participants free from heart disease drawn from the Whitehall II study in UK in 2006-2008 were tested for plasma fibrinogen as an inflammatory factor, financial strain as a marker of chronic psychosocial stress, coronary calcification measured using computed tomography, and for plasma high-sensitivity cardiac troponin T (HS-CTnT) as a marker of cardiac risk. Fibrinogen concentration levels above the average were associated with a 5-fold increase in the odds of HS-CTnT positivity only among individuals with financial strain (N=208, OR=4.73, 95%CI=1.67 to 13.40, P=0.003). Fibrinogen was in fact not associated with HS-CTnT positivity in people without financial strain despite the larger size of that subsample (n=292, OR=0.84, 95%CI=0.42 to 1.67, P=0.622). A test for interaction on the full sample (N=500) showed a P value of 0.010 after adjusting for a range of demographics, health behaviours, traditional cardiovascular risk factors, psychosocial stressors, inflammatory cytokines, and coronary calcification. In conclusion, elevated fibrinogen seems to be cardio-toxic only when is combined with financial strain. Chronic psychosocial stress may modify the meaning that we should give to single test results for inflammation. Further research is needed to confirm our results.

Endothelial Function, Inflammation, Thrombosis, and Basal Ganglia Perivascular Spaces in Patients with Stroke.

BACKGROUND AND OBJECTIVE: Recent studies suggest perivascular spaces are a marker of small vessel disease, blood-brain barrier permeability, and inflammation, but little is known about their risk factors and associations with peripheral blood markers. MATERIALS AND METHODS: In prospectively recruited patients with recent minor ischemic stroke, we investigated the influence of age, sex, hypertension, diabetes, and smoking on the severity of perivascular spaces in the basal ganglia seen on T2-weighted magnetic resonance imaging. We assessed plasma markers of endothelial function (von Willebrand factor, intracellular adhesion molecule-1), inflammation (interleukin-6, tumor necrosis factor-alpha, C-reactive protein), and thrombosis (fibrinogen, prothrombin fragments 1 + 2, thrombin-antithrombin complex, tissue plasminogen activator, D-dimer). We used a validated semi-automated method to measure basal ganglia perivascular spaces count and volume. We tested uni- and multivariable associations between blood markers and basal ganglia perivascular spaces count and volume. FINDINGS: In 100 patients (median age: 67 years, range: 37-92), on adjusted analysis, basal ganglia perivascular spaces count was associated with age (r = .117, P = .003) and hypertension (r = 2.225, P = .013). On multivariable linear regression, adjusted for age, sex, hypertension, smoking and diabetes, reduced von Willebrand factor was associated with increased basal ganglia perivascular spaces count (r = -.025, P = .032). CONCLUSION: The association of increased basal ganglia perivascular spaces count with reduced von Willebrand factor is novel. As von Willebrand factor may promote cerebral endothelial integrity, insufficient von Willebrand factor is consistent with dysfunctional cerebral endothelium and increased basal ganglia perivascular spaces in cerebral small vessel disease. Quantitative perivascular spaces measurement may increase sensitivity to detect cerebral endothelial dysfunction.

Genetic associations for activated partial thromboplastin time and prothrombin time, their gene expression profiles, and risk of coronary artery disease.

Activated partial thromboplastin time (aPTT) and prothrombin time (PT) are clinical tests commonly used to screen for coagulation-factor deficiencies. One genome-wide association study (GWAS) has been reported previously for aPTT, but no GWAS has been reported for PT. We conducted a GWAS and meta-analysis to identify genetic loci for aPTT and PT. The GWAS for aPTT was conducted in 9,240 individuals of European ancestry from the Atherosclerosis Risk in Communities (ARIC) study, and the GWAS for PT was conducted in 2,583 participants from the Genetic Study of Three Population Microisolates in South Tyrol (MICROS) and the Lothian Birth Cohorts (LBC) of 1921 and 1936. Replication was assessed in 1,041 to 3,467 individuals. For aPTT, previously reported associations with KNG1, HRG, F11, F12, and ABO were confirmed. A second independent association in ABO was identified and replicated (rs8176704, p = 4.26 × 10(-24)). Pooling the ARIC and replication data yielded two additional loci in F5 (rs6028, p = 3.22 × 10(-9)) and AGBL1 (rs2469184, p = 3.61 × 10(-8)). For PT, significant associations were identified and confirmed in F7 (rs561241, p = 3.71 × 10(-56)) and PROCR/EDEM2 (rs2295888, p = 5.25 × 10(-13)). Assessment of existing gene expression and coronary artery disease (CAD) databases identified associations of five of the GWAS loci with altered gene expression and two with CAD. In summary, eight genetic loci that account for ∼29% of the variance in aPTT and two loci that account for ∼14% of the variance in PT were detected and supported by functional data.

Plasma Biomarkers of Inflammation, Endothelial Function and Hemostasis in Cerebral Small Vessel Disease.

BACKGROUND: The cause of lacunar ischemic stroke, a clinical feature of cerebral small vessel disease (SVD), is largely unknown. Inflammation and endothelial dysfunction have been implicated. Plasma biomarkers could provide mechanistic insights but current data are conflicting. White matter hyperintensities (WMHs) are an important imaging biomarker of SVD. It is unknown if plasma biomarkers add predictive capacity beyond age and vascular risk factors in explaining WMH. METHODS: We prospectively recruited patients presenting with non-disabling ischemic stroke, classifying them clinically and with the help of MRI as lacunar or cortical. We measured biomarkers of inflammation, endothelial dysfunction and hemostasis for >1 month after stroke and compared biomarker levels between stroke subtypes. We quantitatively calculated WMH. We used multiple linear regression analysis to model WMH as a function of age, sex, hypertension and smoking (the baseline model). We fitted exploratory models using plasma biomarkers as predictor variables to assess model improvement over baseline. RESULTS: We recruited 125 patients. The lacunar group (n = 65) had lower tissue plasminogen activator (t-PA) levels in unadjusted (7.39 vs. 8.59 ng/ml, p = 0.029) and adjusted (p = 0.035) analyses compared with the cortical group (n = 60). There were no significant differences in the other plasma biomarkers. The results for t-PA were consistent with an updated meta-analysis, although the effect remains non-significant (standardized mean difference -0.08 (95% CI -0.25 to 0.09)). The baseline regression model explained 29% of the variance in quantitative WMH (R2 0.289). Inflammatory biomarkers showed minor improvement over baseline (R2 0.291), but the other plasma biomarkers did not improve the baseline model. CONCLUSION: Plasma t-PA levels appear to differ between lacunar and cortical stroke subtypes, late after stroke, independent of age, sex and vascular risk factors and may reflect endothelial dysfunction. Except for a minor additional predictive effect of inflammatory markers, plasma biomarkers do not relate to WMH severity in this small stroke population.

Inflammatory cytokines and risk of coronary heart disease: new prospective study and updated meta-analysis.

AIMS: Because low-grade inflammation may play a role in the pathogenesis of coronary heart disease (CHD), and pro-inflammatory cytokines govern inflammatory cascades, this study aimed to assess the associations of several pro-inflammatory cytokines and CHD risk in a new prospective study, including meta-analysis of prospective studies. METHODS AND RESULTS: Interleukin-6 (IL-6), IL-18, matrix metalloproteinase-9 (MMP-9), soluble CD40 ligand (sCD40L), and tumour necrosis factor-α (TNF-α) were measured at baseline in a case-cohort study of 1514 participants and 833 incident CHD events within population-based prospective cohorts at the Danish Research Centre for Prevention and Health. Age- and sex-adjusted hazard ratios (HRs) for CHD per 1-SD higher log-transformed baseline levels were: 1.37 (95% CI: 1.21-1.54) for IL-6, 1.26 (1.11-1.44) for IL-18, 1.30 (1.16-1.46) for MMP-9, 1.01 (0.89-1.15) for sCD40L, and 1.13 (1.01-1.27) for TNF-α. Multivariable adjustment for conventional vascular risk factors attenuated the HRs to: 1.26 (1.08-1.46) for IL-6, 1.12 (0.95-1.31) for IL-18, 1.21 (1.05-1.39) for MMP-9, 0.93 (0.78-1.11) for sCD40L, and 1.14 (1.00-1.31) for TNF-α. In meta-analysis of up to 29 population-based prospective studies, adjusted relative risks for non-fatal MI or CHD death per 1-SD higher levels were: 1.25 (1.19-1.32) for IL-6; 1.13 (1.05-1.20) for IL-18; 1.07 (0.97-1.19) for MMP-9; 1.07 (0.95-1.21) for sCD40L; and 1.17 (1.09-1.25) for TNF-α. CONCLUSIONS: Several different pro-inflammatory cytokines are each associated with CHD risk independent of conventional risk factors and in an approximately log-linear manner. The findings lend support to the inflammation hypothesis in vascular disease, but further studies are needed to assess causality.

Common variants of large effect in F12, KNG1, and HRG are associated with activated partial thromboplastin time.

Activated partial thromboplastin time (aPTT) is associated with risk of thrombosis and coagulation disorders. We conducted a genome-wide association study for aPTT and identified significant associations with SNPs in three coagulation cascade genes, F12 (rs2731672, combined p = 2.16 x 10(-30)), KNG1 (rs710446, combined p = 9.52 x 10(-22)), and HRG (rs9898, combined p = 1.34 x 10(-11)). These three SNPs explain approximately 18% of phenotypic variance in aPTT in the Lothian Birth Cohorts.

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.

The interleukin-6 receptor as a target for prevention of coronary heart disease: a mendelian randomisation analysis.

BACKGROUND: A high circulating concentration of interleukin 6 is associated with increased risk of coronary heart disease. Blockade of the interleukin-6 receptor (IL6R) with a monoclonal antibody (tocilizumab) licensed for treatment of rheumatoid arthritis reduces systemic and articular inflammation. However, whether IL6R blockade also reduces risk of coronary heart disease is unknown. METHODS: Applying the mendelian randomisation principle, we used single nucleotide polymorphisms (SNPs) in the gene IL6R to evaluate the likely efficacy and safety of IL6R inhibition for primary prevention of coronary heart disease. We compared genetic findings with the effects of tocilizumab reported in randomised trials in patients with rheumatoid arthritis. FINDINGS: In 40 studies including up to 133,449 individuals, an IL6R SNP (rs7529229) marking a non-synonymous IL6R variant (rs8192284; p.Asp358Ala) was associated with increased circulating log interleukin-6 concentration (increase per allele 9·45%, 95% CI 8·34-10·57) as well as reduced C-reactive protein (decrease per allele 8·35%, 95% CI 7·31-9·38) and fibrinogen concentrations (decrease per allele 0·85%, 95% CI 0·60-1·10). This pattern of effects was consistent with IL6R blockade from infusions of tocilizumab (4-8 mg/kg every 4 weeks) in patients with rheumatoid arthritis studied in randomised trials. In 25,458 coronary heart disease cases and 100,740 controls, the IL6R rs7529229 SNP was associated with a decreased odds of coronary heart disease events (per allele odds ratio 0·95, 95% CI 0·93-0·97, p=1·53×10(-5)). INTERPRETATION: On the basis of genetic evidence in human beings, IL6R signalling seems to have a causal role in development of coronary heart disease. IL6R blockade could provide a novel therapeutic approach to prevention of coronary heart disease that warrants testing in suitably powered randomised trials. Genetic studies in populations could be used more widely to help to validate and prioritise novel drug targets or to repurpose existing agents and targets for new therapeutic uses. FUNDING: UK Medical Research Council; British Heart Foundation; Rosetrees Trust; US National Heart, Lung, and Blood Institute; Du Pont Pharma; Chest, Heart and Stroke Scotland; Wellcome Trust; Coronary Thrombosis Trust; Northwick Park Institute for Medical Research; UCLH/UCL Comprehensive Medical Research Centre; US National Institute on Aging; Academy of Finland; Netherlands Organisation for Health Research and Development; SANCO; Dutch Ministry of Public Health, Welfare and Sports; World Cancer Research Fund; Agentschap NL; European Commission; Swedish Heart-Lung Foundation; Swedish Research Council; Strategic Cardiovascular Programme of the Karolinska Institutet; Stockholm County Council; US National Institute of Neurological Disorders and Stroke; MedStar Health Research Institute; GlaxoSmithKline; Dutch Kidney Foundation; US National Institutes of Health; Netherlands Interuniversity Cardiology Institute of the Netherlands; Diabetes UK; European Union Seventh Framework Programme; National Institute for Healthy Ageing; Cancer Research UK; MacArthur Foundation.

Prospective study of IL-18 and risk of MI and stroke in men and women aged 60-79 years: a nested case-control study.

AIM: IL-18 is hypothesized to destabilise atherosclerotic plaques, leading to thrombotic events and epidemiologic studies suggest that IL-18 may increase risk of CHD or CVD. We examined prospective associations between levels of serum IL-18 and new CHD and stroke events in older men and women from a general population. METHODS: A case-control study was nested within a prospective cohort of men and women aged 60-79 years recruited from general practices in 25 British towns in 1998-2000 and followed-up for 7.5 years for fatal and non-fatal MI and stroke. Baseline IL-18 was measured in stored serum samples of incident cases of MI (n=364) or stroke (n=300) and two controls per case. RESULTS: Geometric mean IL-18 levels were higher among the 364 MI cases than the 706 controls; 417.84 pg/mL (IQR 316.25, 537.44) compared to 386.90 pg/mL (IQR 296.54, 482.33), p(difference)=0.002. IL-18 was positively associated with adverse lipid and inflammatory profiles. Men and women in the top third of baseline IL-18 levels had an age and sex-adjusted odds ratio (OR) for MI of 1.31 (95%CI 0.92, 1.85) compared with those in the lowest third; this attenuated to 1.05 (95%CI 0.72, 1.53) after additional adjustment for established vascular and inflammatory risk factors. Each doubling of IL-18 level was associated with an increased OR for MI 1.34 (95%CI 1.04, 1.72), which was attenuated on adjustment for established vascular and inflammatory risk factors; 1.09 (95%CI 0.83, 1.44). Geometric mean IL-18 levels did not differ between stroke cases and controls. The OR for stroke associated with the highest compared to the lowest tertile of IL-18 was 1.24 (95%CI 0.84, 1.84). Results for MI and stroke did not differ by presence of pre-existing CVD, gender or age. CONCLUSIONS: Circulating IL-18 levels were strongly associated with a range of established and novel risk factors but were not independently associated with risk of MI or stroke in our study.

Inflammation and not cardiovascular risk factors is associated with short leukocyte telomere length in 13- to 16-year-old adolescents.

OBJECTIVE: Short leukocyte telomere length (LTL) is associated with cardiovascular (CV) disease in adulthood. However, the biological basis of this association remains unclear. We sought to define early determinants of the association between CV disease and LTL in an adolescent population. METHODS AND RESULTS: One thousand eighty adolescents, aged 13 to 16 years and participating in the Ten Towns Heart Health Study, provided blood samples for DNA extraction and measurement of a range of CV risk factors. LTL was measured by real-time polymerase chain reaction. LTL was inversely associated with age (P=0.04), longer in females than in males (P=0.03), and longer in South Asians than in white Europeans (P=0.01). No associations were found between LTL and traditional CV risk factors. There was a significant and inverse association between LTL and inflammatory markers, including C-reactive protein (P<0.001) and fibrinogen (P=0.001). The associations between LTL and inflammatory markers were not affected by multiple adjustments for behavioral and metabolic factors. CONCLUSIONS: High levels of inflammation are associated with shorter LTL from early adolescence; traditional CV risk factors have little association with LTL in adolescence. Inflammation in early life may play a causal role in the adult association between short LTL and CV disease.

Chronic inflammation as a determinant of future aging phenotypes.

BACKGROUND: The importance of chronic inflammation as a determinant of aging phenotypes may have been underestimated in previous studies that used a single measurement of inflammatory markers. We assessed inflammatory markers twice over a 5-year exposure period to examine the association between chronic inflammation and future aging phenotypes in a large population of men and women. METHODS: We obtained data for 3044 middle-aged adults (28.2% women) who were participating in the Whitehall II study and had no history of stroke, myocardial infarction or cancer at our study's baseline (1997-1999). Interleukin-6 was measured at baseline and 5 years earlier. Cause-specific mortality, chronic disease and functioning were ascertained from hospital data, register linkage and clinical examinations. We used these data to create 4 aging phenotypes at the 10-year follow-up (2007-2009): successful aging (free of major chronic disease and with optimal physical, mental and cognitive functioning), incident fatal or nonfatal cardiovascular disease, death from noncardiovascular causes and normal aging (all other participants). RESULTS: Of the 3044 participants, 721 (23.7%) met the criteria for successful aging at the 10-year follow-up, 321 (10.6%) had cardiovascular disease events, 147 (4.8%) died from noncardiovascular causes, and the remaining 1855 (60.9%) were included in the normal aging phenotype. After adjustment for potential confounders, having a high interleukin-6 level (> 2.0 ng/L) twice over the 5-year exposure period nearly halved the odds of successful aging at the 10-year follow-up (odds ratio [OR] 0.53, 95% confidence interval [CI] 0.38-0.74) and increased the risk of future cardiovascular events (OR 1.64, 95% CI 1.15-2.33) and noncardiovascular death (OR 2.43, 95% CI 1.58-3.80). INTERPRETATION: Chronic inflammation, as ascertained by repeat measurements, was associated with a range of unhealthy aging phenotypes and a decreased likelihood of successful aging. Our results suggest that assessing long-term chronic inflammation by repeat measurement of interleukin-6 has the potential to guide clinical practice.

Plasma levels of coagulation factors VIII and IX and risk of venous thromboembolism: Systematic review and meta-analysis.

INTRODUCTION: The associations of plasma factor VIII (FVIII) and factor IX (FIX) levels with risk of venous thromboembolism (VTE) are not well defined. We performed a systematic review and meta-analysis of these associations. METHODS: Random effects inverse-variance weighted meta-analysis was used to estimate pooled odds ratios for comparisons across equal quartiles of the distributions and 90 % thresholds (higher versus lower), and for testing linear trends. RESULTS: Among 15 studies (5327 cases) the pooled odds ratio of VTE for the fourth versus first quarter was 3.92 (95 % confidence interval 1.61, 5.29) for FVIII level; and among 7 studies (3498 cases) 1.57 (1.32, 1.87) for FIX level. Comparing factor levels above, versus below, the 90th percentile, the estimated pooled odds ratios were 3.00 (2.10, 4.30) for FVIII; 1.77 (1.22, 2.56) for FIX; and 4.56 (2.73, 7.63) for both FVIII and FIX considered jointly. CONCLUSIONS: We confirm increases in risk of VTE across population distributions of FVIII and FIX levels. Levels above the 90th percentile have almost twice the risk for FIX level compared to levels below; three-fold risk for FVIII level; and almost five-fold risk for both FVIII and FIX levels elevated.

Plasma viscosity, immunoglobulins and risk of cardiovascular disease and mortality: new data and meta-analyses.

AIMS: Associations of plasma viscosity and plasma Ig levels (a determinant of viscosity) with incident coronary heart disease (CHD) events; and with CHD, cardiovascular disease (CVD: CHD and stroke) and all-cause mortalities. METHODS: Meta-analysis of plasma viscosity levels from the MONitoring of trends and determinants of CArdiovascular (MONICA)/Cooperative Health Research in the Region of Augsburg, MONICA Glasgow and Speedwell Studies; and five other published studies. Meta-analysis of IgA, IgG and IgM levels from the Augsburg, Glasgow and Speedwell studies; and one other published study. RESULTS: Over median follow-up periods of 14-26 years, there were 2270 CHD events, and 4220 all cause deaths in 28 605 participants with baseline plasma viscosity measurements. After adjustment for major risk factors, (HRs; 95% CIs) for a 1 SD increase in viscosity were 1.14 (1.09 to 1.20) for CHD events; and 1.21 (1.17 to 1.25) for all-cause mortality. 821 CHD events and 2085 all-cause deaths occurred in 8218 participants with baseline Ig levels. For CHD events, adjusted HRs for 1 SD increases in IgA, IgG and IgM were, respectively, 0.97 (0.89 to 1.05); 0.95(0.76 to 1.17) and 0.90 (0.79 to 1.03). Corresponding adjusted HRs for all-cause mortality were 1.08 (95% CI 1.02 to 1.13), 1.03 (95% CI 0.94 to 1.14) and 1.01 (95% CI 0.96 to 1.06). CONCLUSIONS: After risk factor adjustment, plasma viscosity was significantly associated with risks of CHD events; and with CHD, CVD and all-cause mortalities. We found no significant association of IgA, IgG or IgM levels with incident CHD events or mortality, except for a borderline association of IgA with all-cause mortality.

Fibrin D-dimer, tissue-type plasminogen activator, von Willebrand factor, and risk of incident stroke in older men.

BACKGROUND AND PURPOSE: Abnormalities in blood coagulation and the fibrinolytic system have been associated with increased risk of stroke, but few prospective studies have studied the associations in older adults. We have examined the associations between fibrin D-dimer, tissue-type plasminogen activator, and von Willebrand factor (vWF) and risk of stroke in older men and examined their predictive roles separately in normotensive and hypertensive men. METHODS: Prospective study of 3358 men aged 60 to 79 years with no previous diagnosis of myocardial infarction or stroke and without atrial fibrillation followed-up for an average of 9 years, during which there were 187 incident stroke events. RESULTS: Increased levels of D-dimer and vWF were associated with significantly increased risk of major stroke events after adjustment for potential confounders, including systolic blood pressure (adjusted hazard ratios and 95% confidence interval per standard deviation increase in D-dimer and vWF were 1.24 [95% confidence interval, 1.08-1.44] and 1.25 [95% confidence interval, 1.09-1.45], respectively). No associations were seen with tPA after adjustment. The positive associations between D-dimer and vWF and incident stroke remained after additional adjustment for markers of inflammation (C-reactive protein, IL-6). D-dimer was associated with stroke in both normotensive and hypertensive men; vWF showed stronger associations in normotensive than in hypertensive men (test for interaction: P=0.52 for D-dimer; P<0.01 for vWF). CONCLUSIONS: Fibrin D-dimer and vWF are associated with increased risk of stroke in older men. These associations were not explained by their associations with inflammation. D-dimer may be a useful marker to identify those at high risk for stroke among hypertensive men.