Genetically elevated C-reactive protein and ischemic vascular disease

Association of high-sensitivity C-reactive protein with susceptibility to Schizophrenia in Tunisian population

The pathogenic mechanisms underlying Schizophrenia (SZ), one of the most frequent mental disorders, are complex and poorly understood. Several evidences suggest that inflammatory processes may underpin some of its neurobiological correlates. The aim of this study was: (i) to analyze the potential association between circulating levels of the C-reactive protein (CRP), a crucial inflammatory marker, and Schizophrenia in Tunisian patients and healthy controls (HC) cohorts; (ii) to investigate the genetic diversity of three CRP variants (rs1417938, rs1130864 and rs1205) and; (iii) to analyze a potential relationship between expression and genetic data and clinical and socio demographical characteristics. CRP polymorphisms were exanimated for 155 patients and 203 HC by taqMan5'-nuclease. High-sensitivity CRP (hs-CRP) serum level was measured in 128 clinically stable out-patient SZ patients and 63 HC subjects via an automated biochemical analyzer. We found that hs-CRP levels were significantly higher in SZ patients as compared to HC. No significant differences were found when the proportions of CRP variants were compared in patients and HC. Further analysis according to clinical and socio demographical characteristics revealed a positive association with age and hypertension. Our data on an original Tunisian sample confirm the previous finding in others population groups.

C-Reactive Protein and Its Structural Isoforms: An Evolutionary Conserved Marker and Central Player in Inflammatory Diseases and Beyond

C-reactive protein (CRP) is an evolutionary highly conserved member of the pentraxin superfamily of proteins. CRP is widely used as a marker of inflammation, infection and for risk stratification of cardiovascular events. However, there is now a large body of evidence, that continues to evolve, detailing that CRP directly mediates inflammatory reactions and the innate immune response in the context of localised tissue injury. These data support the concept that the pentameric conformation of CRP dissociates into pro-inflammatory CRP isoforms termed pCRP* and monomeric CRP. These pro-inflammatory CRP isoforms undergo conformational changes that facilitate complement binding and immune cell activation and therefore demonstrate the ability to trigger complement activation, activate platelets, monocytes and endothelial cells. The dissociation of pCRP occurs on the surface of necrotic, apoptotic, and ischaemic cells, regular β-sheet structures such as β-amyloid, the membranes of activated cells (e.g., platelets, monocytes, and endothelial cells), and/or the surface of microparticles, the latter by binding to phosphocholine. Therefore, the deposition and localisation of these pro-inflammatory isoforms of CRP have been demonstrated to amplify inflammation and tissue damage in a broad range of clinical conditions including ischaemia/reperfusion injury, Alzheimer's disease, age-related macular degeneration and immune thrombocytopaenia. Given the potentially broad relevance of CRP to disease pathology, the development of inhibitors of CRP remains an area of active investigation, which may pave the way for novel therapeutics for a diverse range of inflammatory diseases.

Genomic Strategies Toward Identification of Novel Therapeutic Targets

Coronary artery disease, myocardial infarction, and secondary damages of the myocardium in the form of ischemic heart disease remain major causes of death in Western countries. Beyond traditional risk factors such as smoking, hypertension, dyslipidemia, or diabetes, a positive family history is known to increase risk. The genetic factors underlying this observation remained unknown for decades until genetic studies were able to identify multiple genomic loci contributing to the heritability of the trait. Knowledge of the affected genes and the resulting molecular and cellular mechanisms leads to improved understanding of the pathophysiology leading to coronary atherosclerosis. Major goals are also to improve prevention and therapy of coronary artery disease and its sequelae via improved risk prediction tools and pharmacological targets. In this chapter, we recapitulate recent major findings. We focus on established novel targets and discuss possible further targets which are currently explored in translational studies.

Association of plasma C-reactive protein with ischaemic stroke: a Mendelian randomization study

BACKGROUND AND PURPOSE

Elevated C-reactive protein (CRP) is associated with an increased risk of ischaemic stroke (IS). However, the causality of this association is uncertain. The aim is to investigate whether genetically raised plasma CRP concentration levels are associated with IS on the basis of the Mendelian randomization method.

METHODS

Based on the National Center for Biotechnology Information single nucleotide polymorphism (SNP) database, the Chinese online genetic database as well as previously published studies, four CRP-associated SNP alleles (rs1130864, rs1205, rs876537 and rs3093059) with minor allele frequency ≥0.15 were selected and the concentration levels of CRP were measured in 378 first-ever IS patients and 613 healthy controls.

RESULTS

Three SNPs were chosen and used as instrumental variables. The adjusted odds ratios (ORs) [95% confidence interval (95% CI)] of IS per addition of the modelled allele were 1.07 (0.79-1.45) for rs876537, 0.99 (0.73-1.35) for rs1205 and 1.08 (0.71-1.65) for rs3093059. The OR (95% CI) of IS for plasma CRP ≥2.0 mg/l was 2.19 (1.06-4.53) compared with <2.0 mg/l. The adjusted OR (95% CI) of IS per genetically predicted 10% higher CRP concentration, based on the three SNPs as the instruments, was 1.02 (0.94-1.11). Furthermore, similar results were obtained with adjusted ORs (95% CI) of 1.00 (0.88-1.13) and 1.04 (0.93-1.16), respectively, for large-artery atherosclerosis and small-artery occlusion per genetically predicted 10% higher CRP concentration.

CONCLUSIONS

This Mendelian randomization study provides no clear support that elevated CRP concentration is causally associated with the risk of IS.

Association of high sensitive C-reactive protein with coronary heart disease: a Mendelian randomization study

OBJECTIVES

Whether high sensitivity C-reactive protein (hs-CRP) has a causal effect on coronary heart disease (CHD) is unclear. This study investigated the causal effect of hs-CRP on CHD risk using Mendelian Randomization (MR) analysis.

METHODS

A total of 3802 subjects were recruited in the follow-up study. Linear regression model was used to evaluate the relationship between CRP polymorphisms and hs-CRP. Survival receiver operator characteristic curve method was used to explore the cut-off of hs-CRP on CHD incidence. Cox regression model was applied to detect the association of hs-CRP with CHD by calculating the hazard ratio (HR) and 95% confidence interval (CI). Rs1205 and rs876537 in CRP were selected as instrumental variables in MR analysis.

RESULTS

During a median follow-up time of 5.01 years, 98 CHD incidence was identified (47.03/10⁴ person-years). Hs-CRP was significantly increased among rs1205 and rs876537 genotypes with r values of 0.064 and 0.066, respectively. Hs-CRP 1.08 mg/L was identified as the cut-off value with a maximum value of sensitivity and specificity on prediction of CHD. Participants with ≥1.08 mg/L of hs-CRP has a higher risk of CHD incidence than that of participants with < 1.08 mg/L, the adjusted HR (95% CI) was 1.69 (1.11-2.60) with a P value of 0.016. No significant casual association was observed between hs-CRP and CHD with a P value of 0.777.

CONCLUSIONS

The association between hs-CRP and CHD is unlikely to be causal, hs-CRP might be a predictor for incidence of CHD in general population.

Increased CRP: An extended biomarker of microvascular risk in men with type 2 diabetes

BACKGROUND

The usefulness of C-reactive protein (CRP) to predict cardiovascular disease (CVD) in type 2 diabetes (T2DM) remains controversial. As many factors linked to obesity can modulate CRP in T2DM, we comprehensively revisited the cardiometabolic phenotype of patients with normal or raised CRP, taking into account the sexual dimorphism of its serum value.

METHODS

1005 T2DM patients (651 males, 354 females; macroangiopathy 38%; coronary artery disease 26%; microangiopathy 47%) were divided depending on whether CRP level was ≤ or >3 mg/L. Thirty percent of men (n = 195) and 39% of women (n = 137) had raised CRP. Their cardiometabolic phenotype and presence of micro- and macrovascular complications were compared to those with normal CRP.

RESULTS

In both gender, patients with elevated CRP had higher body mass index, waist circumference, fat mass, visceral fat, insulinemia, HbA1c, and lower muscle mass and insulin sensitivity. They had more atherogenic dyslipidemia, higher non-HDL-C and apolipoprotein B₁₀₀, and more lipoprotein(a) (+59% in men and +38% in women). In both sexes, there was no difference between patients with normal or high CRP regarding overall macroangiopathy (42% vs. 45% [men]; 27% vs. 28% [women]), coronary and peripheral artery disease, or stroke. Only in men, microangiopathy was more prevalent when CRP was raised (61% vs 44%; p < 0.0001).

CONCLUSIONS

This study shows major sex-related differences in microangiopathies in T2DM patients with high CRP levels. The latter are unrelated to prevalent CVD despite an unfavorable metabolic phenotype. By contrast, increased CRP may represent an extended biomarker of microvascular risk in men with T2DM.

GlycA, a novel pro-inflammatory glycoprotein biomarker is associated with mortality: results from the PREVEND study and meta-analysis

BACKGROUND

Chronic diseases are associated with an inflammatory response. We determined the association of two inflammatory markers, GlycA and high-sensitivity C-reactive protein (hsCRP), with overall and cause-specific mortality in a cohort of men and women.

METHODS

Cox regression analyses were used to examine associations of GlycA and hsCRP with all-cause, cancer and cardiovascular mortality in 5526 subjects (PREVEND cohort; average follow-up 12.6 years).

RESULTS

GlycA was associated with all-cause mortality (n = 838), independent of clinical risk factors and hsCRP (hazard ratio 1.43 [95% confidence interval (CI): 1.09-1.87] for top versus bottom quartiles). For hsCRP, the association with all-cause mortality was nonsignificant after adjustment for GlycA. GlycA and hsCRP were associated with cancer mortality in men (n = 248), but not in women (n = 132). Neither GlycA nor hsCRP was independently associated with cardiovascular mortality (n = 201). In a meta-analysis of seven population-based studies, including 8153 deaths, the pooled multivariable-adjusted relative risk of GlycA for all-cause mortality was 1.74 (95% CI: 1.40-2.17) for top versus bottom quartiles. The association of GlycA with all-cause mortality was somewhat stronger than that of hsCRP. GlycA and hsCRP were not independently associated with cardiovascular mortality. The associations of GlycA and hsCRP with cancer mortality were present in men, but not in women.

CONCLUSIONS

GlycA is significantly associated with all-cause mortality. GlycA and hsCRP were each not independently associated with cardiovascular mortality. The association of GlycA and hsCRP with cancer mortality appears to be driven by men.

High CRP Levels After Critical Illness are Associated With an Increased Risk of Rehospitalization

PURPOSE

Chronic inflammation, even at subclinical levels, is associated with adverse long-term outcome.

PATIENTS AND METHODS

In this prospective, observational study, 66 critically ill patients surviving to hospital discharge were included. C-reactive protein (CRP) levels were determined at hospital discharge, 1, 2, and 6 weeks after hospital discharge. All the patients were repeatedly screened for adverse events resulting in rehospitalization or death for 1.5 years.

RESULTS

After hospital discharge, over two-thirds of the patients exhibited elevated CRP levels (>2.0 mg/L). During the first week, CRP decreased compared with hospital discharge (P < 0.001) but did not change after week 1 (P = 0.67). Age (P = 0.24), surgical status (P = 0.95), or sepsis (P = 0.77) did not influence the CRP course. The latter differed between patients with (n = 15) and without (n = 51) adverse events (P = 0.003). CRP levels of patients without adverse events persistently decreased after hospital discharge (P = 0.03), whereas those of patients with adverse events did not (P = 0.86) but rebounded early.

CONCLUSIONS

Plasma CRP levels in critically ill patients decreased during the first week after hospital discharge but remained unchanged during the subsequent 5 weeks. Over two-thirds of the patients exhibited elevated CRP levels compatible with chronic sub-clinical inflammation. Persistently elevated CRP levels after hospital discharge are associated with higher risk of rehospitalization.

Brief Report: Prevalence of Peripheral Artery Disease Is Higher in Persons Living With HIV Compared With Uninfected Controls

OBJECTIVE

Ankle-brachial index is an excellent tool for diagnosing peripheral artery disease (PAD). We aimed to determine the prevalence and risk factors for PAD in people living with HIV (PLWH) compared with uninfected controls. We hypothesized that prevalence of PAD would be higher among PLWH than among controls independent of traditional cardiovascular disease (CVD) risk factors.

METHODS

PLWH aged 40 years and older were recruited from the Copenhagen comorbidity in HIV infection (COCOMO) study. Sex- and age-matched uninfected controls were recruited from the Copenhagen General Population Study. We defined PAD as ankle-brachial index ≤0.9 and assessed risk factors for PAD using logistic regression adjusting for age, sex, smoking status, dyslipidemia, diabetes, hypertension, and high-sensitivity C-reactive protein.

RESULTS

Among 908 PLWH and 11,106 controls, PAD was detected in 112 [12% confidence interval: (95% 10 to 14)] and 623 [6% (95% 5 to 6)], respectively (P < 0.001), odds ratio = 2.4 (95% 1.9 to 2.9), and adjusted odds ratio = 1.8 (95% 1.3 to 2.3, P < 0.001). Traditional CVD risk factors, but not HIV-related variables, were associated with PAD. The strength of the association between PAD and HIV tended to be higher with older age (P = 0.052, adjusted test for interaction).

CONCLUSIONS

Prevalence of PAD is higher among PLWH compared with uninfected controls, especially among older persons, and remains so after adjusting for traditional CVD risk factors. Our findings expand the evidence base that PLWH have excess arterial disease to also include PAD. The exact biological mechanisms causing this excess risk remain to be elucidated. Until then, focus on management of modifiable traditional risk factors is important.

2018 George Lyman Duff Memorial Lecture: Genetics and Genomics of Coronary Artery Disease: A Decade of Progress

Recent studies have led to a broader understanding of the genetic architecture of coronary artery disease and demonstrate that it largely derives from the cumulative effect of multiple common risk alleles individually of small effect size rather than rare variants with large effects on coronary artery disease risk. The tools applied include genome-wide association studies encompassing over 200 000 individuals complemented by bioinformatic approaches including imputation from whole-genome data sets, expression quantitative trait loci analyses, and interrogation of ENCODE (Encyclopedia of DNA Elements), Roadmap Epigenetic Project, and other data sets. Over 160 genome-wide significant loci associated with coronary artery disease risk have been identified using the genome-wide association studies approach, 90% of which are situated in intergenic regions. Here, I will describe, in part, our research over the last decade performed in collaboration with a series of bright trainees and an extensive number of groups and individuals around the world as it applies to our understanding of the genetic basis of this complex disease. These studies include computational approaches to better understand missing heritability and identify causal pathways, experimental approaches, and progress in understanding at the molecular level the function of the multiple risk loci identified and potential applications of these genomic data in clinical medicine and drug discovery.

NLRP3 Inflammasome and the IL-1 Pathway in Atherosclerosis

Inflammation is an important driver of atherosclerosis, the underlying pathology of cardiovascular diseases. Therefore, therapeutic targeting of inflammatory pathways is suggested to improve cardiovascular outcomes in patients with cardiovascular diseases. This concept was recently proven by CANTOS (Canakinumab Anti-Inflammatory Thrombosis Outcomes Study), which demonstrated the therapeutic potential of the monoclonal IL (interleukin)-1β-neutralizing antibody canakinumab. IL-1β and other IL-1 family cytokines are important vascular and systemic inflammatory mediators, which contribute to atherogenesis. The NLRP3 (NOD [nucleotide oligomerization domain]-, LRR [leucine-rich repeat]-, and PYD [pyrin domain]-containing protein 3) inflammasome, an innate immune signaling complex, is the key mediator of IL-1 family cytokine production in atherosclerosis. NLRP3 is activated by various endogenous danger signals abundantly present in atherosclerotic lesions, such as oxidized low-density lipoprotein and cholesterol crystals. Consequently, NLRP3 inflammasome activation contributes to the vascular inflammatory response driving atherosclerosis development and progression. Here, we review the mechanisms of NLRP3 inflammasome activation and proinflammatory IL-1 family cytokine production in the context of atherosclerosis and discuss treatment possibilities in light of the positive outcomes of the CANTOS trial.

C-Reactive Protein Gene Variants and Their Serum Levels in Early Adult-onset Type 2 Diabetes Mellitus

BACKGROUND/AIM

C-Reactive protein (CRP) is a common marker of inflammation. Elevated CRP levels have been associated with increased risk of development of type 2 diabetes mellitus (T2DM). This study aimed to evaluate the association of CRP gene polymorphisms with early-onset T2DM and the effect of genetic variants on CRP level.

MATERIALS AND METHODS

In total, 948 individuals with early-onset (n=271) or late-onset (n=677) T2DM were enrolled in the study. Five single-nucleotide polymorphisms (SNPs) in the CRP gene, namely rs3093077, rs2808630, rs1800947, rs11265263, and rs11265265, were selected for genotyping, and CRP levels were measured.

RESULTS

Genotypic, allelic, and haplotype frequencies of these five SNPs were not significantly different between patients with early- and those with late-onset. T2DM Higher serum CRP levels were independently associated with the C-allele of rs3093077 and T-allele of rs11265265 (p<0.001). Furthermore, the C-allele of rs3093077 was associated with higher CRP level in both early- (p=0.016) and late-onset (p<0.001) T2DM.

CONCLUSION

CRP gene variants may contribute to the risk of early-onset T2DM by affecting the serum CRP level.

From genome-wide association studies to Mendelian randomization: novel opportunities for understanding cardiovascular disease causality, pathogenesis, prevention, and treatment

The Mendelian randomization approach is an epidemiological study design incorporating genetic information into traditional epidemiological studies to infer causality of biomarkers, risk factors, or lifestyle factors on disease risk. Mendelian randomization studies often draw on novel information generated in genome-wide association studies on causal associations between genetic variants and a risk factor or lifestyle factor. Such information can then be used in a largely unconfounded study design free of reverse causation to understand if and how risk factors and lifestyle factors cause cardiovascular disease. If causation is demonstrated, an opportunity for prevention of disease is identified; importantly however, before prevention or treatment can be implemented, randomized intervention trials altering risk factor levels or improving deleterious lifestyle factors needs to document reductions in cardiovascular disease in a safe and side-effect sparse manner. Documentation of causality can also inform on potential drug targets, more likely to be successful than prior approaches often relying on animal or cell studies mainly. The present review summarizes the history and background of Mendelian randomization, the study design, assumptions for using the design, and the most common caveats, followed by a discussion on advantages and disadvantages of different types of Mendelian randomization studies using one or more samples and different levels of information on study participants. The review also provides an overview of results on many of the risk factors and lifestyle factors for cardiovascular disease examined to date using the Mendelian randomization study design.

The role of inflammation in the association between overall and visceral adiposity and subclinical atherosclerosis

BACKGROUND AND AIMS

Inflammation may underlie the association between obesity, atherosclerosis and cardiovascular disease. We investigated to what extent markers of inflammation mediate associations between overall and visceral body fat and subclinical atherosclerosis.

METHODS AND RESULTS

In this cross-sectional analysis of the Netherlands Epidemiology of Obesity study we estimated total body fat (TBF) by bio-impedance analysis, carotid artery intima media thickness (cIMT) by ultrasound, C-reactive protein (hs-CRP) and glycoprotein acetyls (GlycA) concentrations in fasting blood samples (n = 5627), and visceral adipose tissue (VAT) by magnetic resonance imaging (n = 2247). We examined associations between TBF and VAT, and cIMT using linear regression, adjusted for potential confounding factors, and for mediators: cardiometabolic risk factors (blood pressure, glucose and low-density lipoprotein cholesterol), and inflammation using CRP and GlycA as proxies. Mean (SD) cIMT was 615 (90) μm. Per SD of TBF (8%), cIMT was 19 μm larger (95% confidence interval, CI: 10, 28). This association was 17 μm (95% CI: 8, 27) after adjustment for cardiometabolic risk factors, and did not change after adjustment for markers of inflammation. Per SD (56 cm²) VAT, cIMT was 9 μm larger (95% CI: 2, 16) which changed to 5 μm (95% CI: -3, 12) after adjustment for cardiometabolic risk factors, and did not change after adjustment for inflammatory markers.

CONCLUSION

Our results suggest that associations between measures of overall and visceral body fat and subclinical atherosclerosis are not mediated by inflammation as measured by CRP and GlycA. Obesity may exert cardiovascular risk via other markers of systemic inflammation.

The Multiple Faces of C-Reactive Protein-Physiological and Pathophysiological Implications in Cardiovascular Disease

C-reactive protein (CRP) is an intriguing protein which plays a variety of roles in either physiological or pathophysiological states. For years it has been regarded merely as a useful biomarker of infection, tissue injury and inflammation, and it was only in the early 80s that the modified isoforms (mCRP) of native CRP (nCRP) appeared. It soon became clear that the roles of native CRP should be clearly discriminated from those of the modified form and so the impacts of both isoforms were divided to a certain degree between physiological and pathophysiological states. For decades, CRP has been regarded only as a hallmark of inflammation; however, it has since been recognised as a significant predictor of future episodes of cardiovascular disease, independent of other risk factors. The existence of modified CRP isoforms and their possible relevance to various pathophysiological conditions, suggested over thirty years ago, has prompted the search for structural and functional dissimilarities between the pentameric nCRP and monomeric mCRP isoforms. New attempts to identify the possible relevance between the diversity of structures and their opposing functions have initiated a new era of research on C-reactive protein. This review discusses the biochemical aspects of CRP physiology, emphasizing the supposed relevance between the structural biology of CRP isoforms and their differentiated physiological and pathophysiological roles.

Lipid profile and statin use in critical care setting: implications for kidney outcome

Objective:

To determine whether pre-hospital statin use is associated with lower renal replacement therapy requirement and/or death during intensive care unit stay.

Methods:

Prospective cohort analysis. We analyzed 670 patients consecutively admitted to the intensive care unit of an academic tertiary-care hospital. Patients with ages ranging from 18 to 80 years admitted to the intensive care unit within the last 48 hours were included in the study.

Results:

Mean age was 66±16.1 years old, mean body mass index 26.6±4/9kg/m² and mean abdominal circumference was of 97±22cm. The statin group comprised 18.2% of patients and had lower renal replacement therapy requirement and/or mortality (OR: 0.41; 95%CI: 0.18-0.93; p=0.03). The statin group also had lower risk of developing sepsis during intensive care unit stay (OR: 0.42; 95%CI: 0.22-0.77; p=0.006) and had a reduction in hospital length-of-stay (14.7±17.5 days versus 22.3±48 days; p=0.006). Statin therapy was associated with a protective role in critical care setting independently of confounding variables, such as gender, age, C-reactive protein, need of mechanical ventilation, use of pressor agents and presence of diabetes and/or coronary disease.

Conclusion:

Statin therapy prior to hospital admission was associated with lower mortality, lower renal replacement therapy requirement and sepsis rates.

A redox sensitivity-based method to quantify both pentameric and monomeric C-reactive protein in a single assay

C-reactive protein (CRP) can exist in both pentameric (pCRP) and monomeric conformation (mCRP). Though serum pCRP is an established marker of inflammation, the diagnostic significance of mCRP remains unknown largely due to the lack of a reliable assay. The power and specificity of antibody-based assays are limited by the antibody reagents used and by the degree of cross-reactivity that may exist in detecting each antigen, as mCRP is known to be formed from the pentameric and both conformations usually coexist in clinical samples. Here, we describe an assay that measures both CRP conformations in simple samples in a single assay. This assay depends on the rationale that the intra-molecular disulfide bonds in pCRP resist reduction, while those in mCRP can be readily reduced. The distinct sensitivity of pCRP and mCRP to reduction can be easily detected and separated by electrophoresis. This assay may provide a means to study clinical correlation between pCRP and mCRP in clinical samples in the future and to evaluate their respective significance as disease markers.

IL-10-specific autoantibodies predict major adverse cardiovascular events in kidney transplanted patients - a retrospective cohort study

End-stage renal failure is associated with persistent systemic inflammation. The aim of this study was to investigate if systemic inflammation at the time of kidney transplantation is linked to poor graft survival, major adverse cardiovascular events (MACE), and increased mortality, and if these processes are modulated by naturally occurring cytokine-specific autoantibodies (c-aAbs), which have been shown to regulate cytokine activity in vitro. Serum levels of cytokines, high-sensitivity C-reactive protein (hsCRP) and c-aAbs specific for interleukin (IL)-1α, tumor necrosis factor (TNF)-α, IL-6, and IL-10 were measured at the time of transplantation in a retrospective cohort study of 619 kidney transplanted patients with a median follow-up of 4.9 years (range 1.2-8.2 years). Systemic inflammation was associated with all-cause mortality in simple and multiple Cox regression analyses. IL-10-specific c-aAbs were associated with MACE after transplantation, suggesting that IL-10 may be a protective factor. Similarly, patients with a history of MACE before transplantation had lower levels of TNF-α-specific c-aAbs, hence we hypothesized that TNF may be a risk factor of MACE. These findings support that pro-inflammatory activity before transplantation is a pathological driver of MACE and all-cause mortality after transplantation. This information adds to pretransplantation risk estimation in renal transplant candidates.

Increased Serum C-reactive Protein and Corpus Callosum Alterations in Older Adults

Chronic systemic low-grade inflammation is associated with aging, but little is known on whether age-related inflammation affects brain structure, particularly white matter. The current study tested the hypothesis that in older adults without dementia, higher serum levels of high-sensitivity C-reactive protein (hs-CRP) are associated with reduced corpus callosum (CC) areas. French community-dwelling subjects (ESPRIT study) aged 65 and older (N=101) underwent hs-CRP testing and structural magnetic resonance imaging (MRI). Multiple linear regression models were carried out. In the unadjusted model, higher hs-CRP level was significantly associated with smaller anterior, mid, and total midsagittal CC areas, but not with the posterior CC area. These associations were independent of demographic characteristics and intracranial volume. After adjustment for body mass index, diabetes, inflammation-related chronic pathologies and white matter lesions (WML), only the associations between hs-CRP level and smaller anterior and total midsagittal CC areas were still significant, although weaker. These findings suggest that low-grade inflammation is associated with CC structural integrity alterations in older adults independently of physical or neuropsychiatric pathologies.

Oxidative Stress, Inflammation, and Neuroprogression in Chronic PTSD

Posttraumatic stress disorder is a serious and often disabling syndrome that develops in response to a traumatic event. Many individuals who initially develop the disorder go on to experience a chronic form of the condition that in some cases can last for many years. Among these patients, psychiatric and medical comorbidities are common, including early onset of age-related conditions such as chronic pain, cardiometabolic disease, neurocognitive disorders, and dementia. The hallmark symptoms of posttraumatic stress-recurrent sensory-memory reexperiencing of the trauma(s)-are associated with concomitant activations of threat- and stress-related neurobiological pathways that occur against a tonic backdrop of sleep disturbance and heightened physiological arousal. Emerging evidence suggests that the molecular consequences of this stress-perpetuating syndrome include elevated systemic levels of oxidative stress and inflammation. In this article we review evidence for the involvement of oxidative stress and inflammation in chronic PTSD and the neurobiological consequences of these processes, including accelerated cellular aging and neuroprogression. Our aim is to update and expand upon previous reviews of this rapidly developing literature and to discuss magnetic resonance spectroscopy as an imaging technology uniquely suited to measuring oxidative stress and inflammatory markers in vivo. Finally, we highlight future directions for research and avenues for the development of novel therapeutics targeting oxidative stress and inflammation in patients with PTSD.

Targeting Residual Inflammatory Risk: A Shifting Paradigm for Atherosclerotic Disease

As biologic, epidemiologic, and clinical trial data have demonstrated, inflammation is a key driver of atherosclerosis. Circulating biomarkers of inflammation, including high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6), are associated with increased risk of cardiovascular events independent of cholesterol and other traditional risk factors. Randomized trials have shown that statins reduce hsCRP, and the magnitude of hsCRP reduction is proportional to the reduction in cardiovascular risk. Additionally, these trials have demonstrated that many individuals remain at increased risk due to persistent elevations in hsCRP despite significant reductions in low-density lipoprotein cholesterol (LDL-C) levels. This "residual inflammatory risk" has increasingly become a viable pharmacologic target. In this review, we summarize the data linking inflammation to atherosclerosis with a particular focus on residual inflammatory risk. Additionally, we detail the results of Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS), which showed that directly reducing inflammation with an IL-1β antagonist reduces cardiovascular event rates independent of LDL-C. These positive data are contrasted with neutral evidence from CIRT in which low-dose methotrexate neither reduced the critical IL-1β to IL-6 to CRP pathway of innate immunity, nor reduced cardiovascular event rates.

Evaluation of plasma levels of neopterin and soluble CD40 ligand in patients with acute ischemic stroke in upper Egypt: can they surrogate the severity and functional outcome?

BACKGROUND

Inflammation constitutes a major component of ischemic stroke pathology. The prognostic value of "neopterin" and soluble CD40 ligand (sCD40L), as a potential biomarker of ischemic stroke, has been less extensively studied.

OBJECTIVES OF THE STUDY

This study aims at assessing the serum levels of neopterin and sCD40L in acute ischemic stroke (AIS), to clarify its association with the severity, etiology, and risk factors of stroke, and to evaluate their relationship with the stroke functional outcome in our study sample within 90 days of follow-up.

STUDY SAMPLE

This case-control study was conducted on 100 patients with first-ever acute onset ischemic stroke and 25 control subjects.

METHODS

Participants were subjected to full history taking and detailed clinical and neurological examination. Brain imaging was performed after hospital admission. Blood tests were drawn for assessment of neopterin and sCD40L on the first day of admission.

RESULTS

High levels of neopterin and sCD40L was reported. Their levels were significantly higher in relation with survival status. There was a relationship between AIS and sCD40L levels and the severity of the stroke. Within 3 months of follow-up, these biomarkers were associated significantly with poor functional outcome, within a 90-day follow-up period, and mortality. These biomarkers were highly associated in patients with small vessel occlusion as an etiology for AIS.

CONCLUSION

Neopterin and sCD40L levels increased after AIS. Both biomarkers were strong and independent predictors of 90-day unfavorable clinical outcome and death in patients after AIS.

Evaluation of carotid intima media thickness and hematologic inflammatory markers in patients with chronic spontaneous urticaria

Introduction

Low grade inflammation is associated with chronic spontaneous urticaria (CSU) and atherosclerosis. There are little data on the relationship between urticarial inflammation and atherosclerosis. The neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR) and mean platelet volume (MPV) have recently been studied in many diseases as a biomarker of inflammation.

Aim

To evaluate hematologic inflammatory parameters and subclinical atherosclerosis in CSU patients.

Material and methods

C-reactive protein (CRP), NLR, PLR, MPV and carotid intima media thickness (CIMT) in CSU patients were compared with healthy controls. Thirty CSU patients and 30 healthy controls participated in the study.

Results

Thirty CSU patients and 30 healthy controls participated in the study. 53.3% of the patient group were females, 46.7% were males and the mean age was 37.7 ±7.7. 53.3% of the healthy control group were females, 46.7% were males and the mean age was 37.1 ±7.2. Body mass index was 24.63 ±2.7 kg/m² in the patient group and 24.83 ±2.5 kg/m² in the control group. Left and right CIMT and CRP values were higher in CSU patients and high-density lipoproteins (HDL) values were lower in the CSU patients. There was a positive correlation between the right and left CIMT and urticaria activity severity 4 (UAS4), disease severity, and triglycerides in the patient group, also a negative correlation was found between the right and left CIMT and the HDL values. C-reactive protein was also correlated with UAS4 and disease severity.

Conclusions

This is the first study to evaluate subclinical atherosclerosis in CSU patients. Chronic spontaneous urticaria may be associated with an increased atherosclerotic risk. Serum CRP concentration can also be used as an objective parameter to evaluate disease severity.

No evidence of increased risk of thyroid dysfunction in well treated people living with HIV

OBJECTIVES

Possible effects of HIV on thyroid function in the modern combination antiretroviral therapy (cART) era are largely unknown. We aimed to investigate the prevalence and associated risk factors of thyroid dysfunction in well treated people living with HIV (PLWH) and matched uninfected controls and to examine whether HIV is independently associated with thyroid dysfunction.

DESIGN AND METHODS

Thyroid-stimulating hormone (TSH), free thyroxine, total thyroxine, and free triiodothyronine were measured in 826 PLWH from the Copenhagen co-morbidity in HIV infection (COCOMO) Study and in 2503 matched uninfected controls, and medical treatment for hypothyroidism or hyperthyroidism was recorded. Multinomial logistic regression adjusting for known risk factor was used to examine the association between HIV and thyroid dysfunction and multivariate linear regression to study the association between HIV and serum TSH concentrations.

RESULTS

The PLWH were generally well treated, with 95% having undetectable viral replication. Among PLWH and controls 31 (3.8%) and 114 (4.6%) had hypothyroidism, and 7 (0.8%) and 21 (0.8%) had hyperthyroidism, respectively. In adjusted analyses, we found no significant associations between HIV and hypothyroidism OR 0.8 [95% confidence interval (CI) 0.6-1.3], P = 0.40 or between HIV and hyperthyroidism OR 1.1 (95% CI 0.5-2.5), P = 0.91. Furthermore, serum TSH concentration was unrelated to HIV status (P = 0.6).

CONCLUSION

There was no difference in the prevalence of hyperthyroidism or hypothyroidism in well treated PLWH compared with uninfected controls. HIV status was not associated with thyroid dysfunction or serum TSH concentration.

An updated Alzheimer hypothesis: Complement C3 and risk of Alzheimer's disease-A cohort study of 95,442 individuals

INTRODUCTION

We tested the hypothesis that low plasma complement C3 is observationally and genetically associated with high risk of Alzheimer's disease (AD).

METHODS

We studied 95,442 individuals enrolled in the Copenhagen General Population Study. In genetic analyses, we further included 8367 individuals from the Copenhagen City Heart Study. In the two studies, 1189 and 35 developed AD during median 8 years follow-up.

RESULTS

The multifactorially adjusted hazard ratio for risk of AD for a one standard deviation lower levels of complement C3 was 1.11 (95% confidence interval: 1.04-1.19) in all individuals and 1.66 (1.33-2.07) in APOE ε44 carriers. In Mendelian randomization, the corresponding genetic estimates were 1.66 (1.05-2.63) overall and 1.99 (0.52-7.65) in APOE ε44 carriers.

DISCUSSION

Low baseline levels of complement C3 were associated with high risk of AD. The risk was amplified in APOE ε44 highly susceptible individuals, and these findings were substantiated by a Mendelian randomization approach, potentially implying causality. Based on these findings, we present and thoroughly discuss an updated Alzheimer hypothesis incorporating low complement C3 levels.

Lipid lowering drugs and inflammatory changes: an impact on cardiovascular outcomes?

Inflammatory changes are responsible for maintenance of the atherosclerotic process and may underlie some of the most feared vascular complications. Among the multiple mechanisms of inflammation, the arterial deposition of lipids and particularly of cholesterol crystals is the one responsible for the activation of inflammasome NLRP3, followed by the rise of circulating markers, mainly C-reactive protein (CRP). Elevation of lipoproteins, LDL but also VLDL and remnants, associates with increased inflammatory changes and coronary risk. Lipid lowering medications can reduce cholesterolemia and CRP: patients with elevations of both are at greatest cardiovascular (CV) risk and receive maximum benefit from therapy. Evaluation of the major drug series indicates that statins exert the largest LDL and CRP reduction, accompanied by reduced CV events. Other drugs, mainly active on the triglyceride/HDL axis, for example, PPAR agonists, may improve CRP and the lipid pattern, especially in patients with metabolic syndrome. PCSK9 antagonists, the newest most potent medications, do not induce significant changes in inflammatory markers, but patients with the highest baseline CRP levels show the best CV risk reduction. Parallel evaluation of lipids and inflammatory changes clearly indicates a significant link, both guiding to patients at highest risk, and to the best pharmacological approach. Key messages Lipid lowering agents with "pleiotropic" effects provide a more effective approach to CV prevention In CANTOS study, patients achieving on-treatment hsCRP concentrations ≤2 mg/L had a higher benefit in terms of reduction in major CV events The anti-inflammatory activity of PCSK9 antagonists appears to be of a minimal extent.

Effect of Serum C-Reactive Protein Level on Admission to Predict Mortality After Transcatheter Aortic Valve Implantation

The relation between C-reactive protein (CRP) level on admission and mortality after transcatheter aortic valve implantation (TAVI) remains unclear. To evaluate the impact of serum CRP level on mortality after TAVI, we assessed 1,016 patients with CRP who underwent TAVI and 538 patients with high-sensitive CRP (hs-CRP) level who underwent TAVI on admission in the OCEAN (Optimized Transcatheter Valvular Intervention)-TAVI registry. Study population was stratified into 2 groups (high/low), according to the median of CRP and hs-CRP on admission. We assessed the impact of high CRP and hs-CRP level on all-cause death after TAVI. During 2-year follow-up, all-cause death after TAVI was 9.4% in patients with CRP and 11.9% in patients with hs-CRP. Median value of serum CRP was 0.10 mg/dl in both CRP and hs-CRP. Patients with high CRP (>0.10 mg/dl) had significantly higher incidence of all-cause death compared with those with low CRP (11.5% vs 7.6%, log-rank p = 0.015). Multivariate Cox regression analysis with a time-varying covariate demonstrated that high CRP was an independent predictor of all-cause death within the first 3 months (hazard ratio 2.78, 95% CI 1.30 to 5.95) compared with from 3 months to 2 years (hazard ratio 0.80, 95% CI 0.47 to 1.36) (P for interaction = 0.008). Inversely, these results were not observed in the stratification using hs-CRP on admission. In conclusion, high CRP on admission was significantly associated with an increased risk of all-cause death after TAVI, particularly within the first 3 months after TAVI. Risk stratification using CRP may be a simple and useful strategy to identify high-risk patients who undergo TAVI.

Complement C3 and Risk of Diabetic Microvascular Disease: A Cohort Study of 95202 Individuals from the General Population

BACKGROUND

Whether the complement system is involved in the development of diabetic microvascular disease is unknown. We tested the hypothesis that high concentrations of complement C3 are associated with increased risk of diabetic retinopathy, nephropathy, and neuropathy in individuals from the general population.

METHODS

We studied 95202 individuals from the general population with baseline measurements of complement C3, genotyped for rs1065489, rs429608, and rs448260 determining concentrations of complement C3, and enrolled in the Copenhagen General Population Study from 2003 through 2013, following them until April 10, 2013. Rs1065489, rs429608, and rs448260 were identified with genome-wide association scans in 3752 individuals from the Copenhagen City Heart Study.

RESULTS

The cumulative incidence was increased from the lowest tertile to the highest tertile of complement C3 for diabetic retinopathy (log-rank trend, P = 1 × 10^-20), nephropathy (P = 7 × 10^-15), and neuropathy (P = 5 × 10^-10). Multifactorially adjusted hazard ratios for a 1 SD higher concentration of complement C3 were 1.87 (95% CI, 1.61-2.18) for diabetic retinopathy, 1.90 (1.62-2.23) for diabetic nephropathy, and 1.56 (1.29-1.89) for diabetic neuropathy. The multifactorially adjusted hazard ratio for individuals with the highest vs lowest tertile of complement C3 was 3.29 (1.78-6.07) for retinopathy, 2.71 (1.42-5.16) for nephropathy, and 2.40 (1.26-4.54) for neuropathy.

CONCLUSIONS

High baseline concentrations of complement C3 were associated with increased risk of diabetic retinopathy, nephropathy, and neuropathy in individuals from the general population. These epidemiological findings were substantiated by a Mendelian randomization approach, potentially indicating causality.

Scientific Contributions of Population-Based Studies to Cardiovascular Epidemiology in the GWAS Era

Longitudinal, well phenotyped, population-based cohort studies offer unique research opportunities in the context of genome-wide association studies (GWAS), including GWAS for new-onset (incident) cardiovascular disease (CVD) events, the assessment of gene x lifestyle interactions, and evaluating the incremental predictive utility of genetic information in apparently healthy individuals. Furthermore, comprehensively phenotyped community-dwelling samples have contributed to GWAS of numerous traits that reflect normal organ function (e.g., cardiac structure and systolic and diastolic function) and for many traits along the CVD continuum (e.g., risk factors, circulating biomarkers, and subclinical disease traits). These GWAS have heretofore identified many genetic loci implicated in normal organ function and different stages of the CVD continuum. Finally, population-based cohort studies have made important contributions to Mendelian Randomization analyses, a statistical approach that uses genetic information to assess observed associations between cardiovascular traits and clinical CVD outcomes for potential causality.

Mendelian randomization: Its impact on cardiovascular disease

Cardiovascular diseases and their risk factors are inheritable. Single nucleotide polymorphisms in the human genome are found in around 1 in 1000 base pairs, and this may affect the genetic variety of individuals. During meiosis, any genetic information is randomized and is independent of other characteristics. In a Mendelian randomization study (MRS), a genetic variant associated with biomarker is used as a proxy for the biomarker, and the outcomes are compared between the groups harboring the effect alleles and a group with the reference allele. An MRS using variants of both rare and modest effect sizes and variants of common and lower effect sizes provides an understanding of risk factors and their causality of cardiovascular disease; for example, an individual possessing an allele associated with lower low-density lipoprotein cholesterol (LDL-C) exhibits lower risk of coronary artery disease (CAD). Moreover, the log-transformed reduction rates of CAD are linearly correlated with the reduction value of LDL-C. High-density lipoprotein (HDL) removes cholesteryl esters from peripheral tissues, including atherosclerotic plaque to the liver. Numerous epidemiological studies have shown that HDL-cholesterol (HDL-C) levels are inversely associated with the frequency of the occurrence of CAD. However, genetic variants, which are only associated with higher HDL-C levels, do not decrease the frequency of myocardial infarction. This fact shows that HDL-C level is not a cause but a biomarker of CAD. Discoveries of rare variants in Mendelian disorders resulted in the successful development of drugs for the general population. An MRS may also predict the pharmacological effectiveness and adverse side effects of novel drugs targeting specific molecules. An MRS could become a standard process to be performed before the development of novel drugs. Furthermore, future guidelines for the prevention of CAD should consider the genetic information of individuals, which will result in precision medicine for cardiovascular diseases.

Joint Effect of Carotid Plaque and C-Reactive Protein on First-Ever Ischemic Stroke and Myocardial Infarction?

Background

The joint effect of atherosclerosis and CRP (C‐reactive protein) on risk of ischemic stroke (IS) and myocardial infarction (MI) has been sparsely studied. The aim of this study was to explore whether CRP mediates the risk of events in subjects with prevalent carotid plaque, examine synergism, and test whether CRP and carotid plaque add to risk prediction beyond traditional risk factors.

Methods and Results

CRP and carotid total plaque area (TPA) were measured in 10 109 participants in the Tromsø Study from 1994 to 2008. Incident IS (n=671) and MI (n=1079) were registered until December 31, 2013. We calculated hazard ratios (HRs) of MI and IS according to categories of CRP (<1, 1–3, and >3 mg/L) and plaque status (no plaque and TPA below and above median) in Cox proportional hazard models with time‐varying covariates. Multivariable‐adjusted CRP >3 versus <1 mg/L was associated with risk of IS (HR, 1.84; 95% confidence interval, 1.49–2.26) and MI (HR, 1.46; 95% confidence interval, 1.23–1.73). TPA above median versus no plaque was associated with risk for IS (HR, 1.65; 95% confidence interval, 1.36–2.01) and MI (HR, 1.64; 95% confidence interval, 1.41–1.92). In participants with plaque, adjustment for CRP minimally attenuated the risk estimates. The highest incidence rates for MI and IS were seen in the group with both CRP >3 mg/L and TPA is above the median. TPA and CRP combined added to risk prediction beyond traditional risk factors.

Conclusions

The simultaneous presence of subclinical atherosclerosis and elevated CRP was associated with increased risk of IS and MI. The combined assessment of subclinical atherosclerosis and inflammatory biomarkers may improve cardiovascular disease risk stratification.

Circulating Interleukin-6 is a biomarker for coronary atherosclerosis in nonalcoholic fatty liver disease: Results from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Biomarkers to predict the presence and severity of subclinical cardiovascular disease (CVD) in nonalcoholic fatty liver disease (NAFLD) are lacking.

METHODS

3876 participants from the Multi-Ethnic Study of Atherosclerosis (MESA), without known chronic liver disease underwent baseline non-contrast cardiac CT, with NAFLD defined by validated liver:spleen ratio (L:S) < 1.0, and subclinical CVD defined by coronary artery calcium (CAC) score > 0. Randomly-selected subgroups underwent detailed inflammatory marker testing, including LpPLA2 mass (N = 2951), activity (N = 3020), high-sensitivity C-reactive protein (hsCRP; N = 3849), and interleukin-6 (IL-6; N = 3764). Among those with NAFLD, we estimated the prevalence of CAC > 0 and CAC > 100 for each SD biomarker increase, using multivariable log-binomial regression models adjusted for cardiometabolic risk factors.

RESULTS

Seventeen percent (N = 668) of participants met the criteria for NAFLD. NAFLD participants were younger (mean age 61 ± 10 vs. 63 ± 10 years, p < .0001) but more likely to have an elevated BMI (mean 31.1 ± 5.5 vs. 28.0 ± 5.2 kg/m2, p < .0001), diabetes (22% vs. 11%, p < .0001), and increased inflammatory biomarkers, including LpPLA2 activity, hsCRP and IL-6 (all p < .0001). Among NAFLD participants, IL-6 was the only biomarker independently associated with prevalent CAC > 0 (PR = 1.06 [1.00-1.11]), or CAC > 100 (PR = 1.09 [1.02-1.17]). In contrast, circulating LpPLA2 mass/activity and hsCRP were not associated with either the prevalence or severity of subclinical CVD (all p > .05).

CONCLUSION

In a large, multi-ethnic population with NAFLD, IL-6 is independently associated with the prevalence and severity of subclinical atherosclerosis. Further research into the longitudinal effects of NAFLD on progressive CVD will determine whether IL-6 is a marker or mediator of NAFLD-related atherosclerosis.

Relative Prognostic Value of Cardiac Troponin I and C-Reactive Protein in the General Population (from the Nord-Trøndelag Health [HUNT] Study)

C-reactive protein and cardiac troponin I measured with high-sensitivity assays (high-sensitivity C-reactive protein [hs-CRP] and high-sensitivity troponin I [hs-TnI]) have been associated with risk of fatal and nonfatal cardiovascular events in the general population. The relative prognostic merits of hs-CRP and hs-TnI, and whether these markers of inflammation and subclinical myocardial injury provide incremental information to established cardiovascular risk prediction models, remain unclear. hs-CRP and hs-TnI were measured in 9,005 participants from the prospective observational Nord-Trøndelag Health (HUNT) study. All study subjects were free from known cardiovascular disease at baseline. During a median follow-up period of 13.9 years, 733 participants reached the composite end point of hospitalization for acute myocardial infarction or heart failure, or cardiovascular death. In adjusted models, increased hs-TnI concentrations (>10 ng/L for women and >12 ng/L for men) were associated with the incidence of the composite end point (hazard ratio 3.61, 95% confidence interval [CI] 2.89 to 4.51]), whereas the risk associated with increased hs-CRP concentrations (>3 mg/L for both genders) appeared to be weaker (HR 1.71, 95% CI 1.40 to 2.10). The addition of hs-TnI to established cardiovascular risk prediction models led to a net reclassification improvement of 0.35 (95% CI 0.27 to 0.42), superior to that of hs-CRP (0.21, 95% CI 0.13 to 0.28). The prognostic accuracy of hs-TnI, assessed by C-statistics, was significantly greater than that of hs-CRP (0.753, 95% CI 0.735 to 0.772, vs 0.644, 95% CI 0.625 to 0.663). In conclusion, in subjects from the general population without a history of cardiovascular disease, hs-TnI provides prognostic information superior to that provided by hs-CRP and may therefore be a preferred marker for targeted prevention.

Cardiorespiratory fitness and the metabolic syndrome: Roles of inflammation and abdominal obesity

OBJECTIVE

Individuals with metabolic syndrome have increased risk of type 2 diabetes and cardiovascular disease. We aimed to test the hypothesis that a high level of cardiorespiratory fitness (CR-fitness), counteracts accumulation of visceral fat, decreases inflammation and lowers risk factors of the metabolic syndrome.

METHOD

The study sample included 1,293 Danes (age 49-52 years) who from 2009 to 2011 participated in the Copenhagen Aging and Midlife Biobank, including a questionnaire, physical tests, and blood samples. Multiple linear regression models were performed with CR-fitness as exposure and plasma levels of cytokines and high sensitive C-reactive protein as outcomes and measures of abdominal obesity were added to test if they explained the potential association. Similarly, multiple linear regression models were performed with CR-fitness as exposure and factors of the metabolic syndrome as outcomes and the potential explanation by inflammatory biomarkers were tested. All models were adjusted for the effect of age, sex, smoking, alcohol consumption, socio-economic status, and acute inflammatory events within the preceding two weeks.

RESULTS

CR-fitness was inversely associated with high sensitive C-reactive protein, Interleukin (IL)-6, and IL-18, and directly associated with the anti-inflammatory cytokine IL-10, but not associated with tumor necrosis factor alpha, interferon gamma or IL-1β. Abdominal obesity could partly explain the significant associations. Moreover, CR-fitness was inversely associated with an overall metabolic syndrome score, as well as triglycerides, glycated haemoglobin A1c, systolic blood pressure, diastolic blood pressure and directly associated with high-density lipoprotein. Single inflammatory biomarkers and a combined inflammatory score partly explained these associations.

CONCLUSION

Data suggest that CR-fitness has anti-inflammatory effects that are partly explained by a reduction in abdominal obesity and a decrease in the metabolic syndrome risk profile. The overall inflammatory load was mainly driven by high sensitive C-reactive protein and IL-6.

Genetic variation in clusterin and risk of dementia and ischemic vascular disease in the general population: cohort studies and meta-analyses of 362,338 individuals

BACKGROUND

Clusterin, also known as apolipoprotein J (apoJ), is one of the most abundantly expressed apolipoproteins in the brain after apolipoprotein E (apoE). Like the ε4 allele of the apolipoprotein E gene (APOE), the clusterin gene (CLU) is a risk locus for Alzheimer's disease, and may play additional roles in atherosclerosis pathogenesis. We tested whether genetic variation in CLU was associated with either Alzheimer's disease or atherosclerosis-related diseases.

METHODS

We studied individual data on 103,987 participants from the Copenhagen General Population Study (CGPS) and the Copenhagen City Heart Study (CCHS). We genotyped a common CLU variant (rs9331896) and two common APOE variants (rs7412 and rs429358), defining the ε2, ε3, and ε4, alleles in CGPS and CCHS. All individuals in the CGPS and CCHS cohorts were followed from study inclusion to occurrence of event, death, emigration, or until 10 November 2014, whichever came first. Summary consortia data on 258,351 individuals from the International Genomics of Alzheimer's Project (IGAP) and the Coronary Artery Disease Genome-wide Replication and Meta-analysis plus the Coronary Artery Disease (C4D) Genetics and 1000-Genomes-based genome-wide association studies (CARDIoGRAMplusC4D) were used in meta-analyses.

RESULTS

In CGPS and CCHS, multifactorially adjusted hazard ratios for Alzheimer's disease, all dementia, vascular dementia, ischemic cerebrovascular disease, and ischemic heart disease were 1.18 (1.07-1.30), 1.09 (1.02-1.17), 0.96 (0.80-1.17), 1.02 (0.97-1.07), and 0.97 (0.93-1.01) per T allele, respectively. Multifactorially adjusted hazard ratios for Alzheimer's disease and all dementia were 2.72 (2.45-3.01) and 2.21 (2.05-2.38) for the APOE ɛ4 allele. There was no interaction between rs9331896 in CLU and rs429358 (defining the ɛ4 allele) in APOE in predicting Alzheimer's disease or all dementia (P = 0.39 and P = 0.21). In a meta-analysis including consortium data, the overall fixed- and random-effects odds ratios for Alzheimer's disease per T allele were 1.16 (1.13-1.18) (I 2 = 0.0%; P for heterogeneity = 0.89).

CONCLUSIONS

A common variant in CLU was associated with a high risk of Alzheimer's disease and all dementia in the general population but not with vascular dementia or ischemic vascular disease. Important novel aspects compared to previous studies are the incorporation of individual risk factor data, the exact causative ε4 allele, and several subtypes of dementia and atherosclerosis-related endpoints.

An ELISA Assay for Quantifying Monomeric C-Reactive Protein in Plasma

Native C-reactive protein (nCRP) is a non-specific marker of inflammation being claimed as a bystander in several chronic disorders. Accumulating evidence indicates that nCRP dissociates to and acts primarily as the monomeric conformation (mCRP) at inflammatory loci. This suggests that mCRP may be a superior disease marker with improved specificity and clear causality to the underlying pathogenesis. However, the lack of a feasible assay to quantify mCRP in clinical samples precludes the assessment of that suggestion. Here we report the development of a sandwich ELISA assay for quantification of plasma mCRP using commercially available reagents. Our assay is reproducible and highly conformation-specific showing a reliable detection limit of 1 ng/mL. We further show that mCRP appears to be a better marker than nCRP in several skin-related autoimmune disorders. This assay thus provides a useful tool to examine the clinical significance and utility of mCRP.

Impact of C-reactive protein on long-term mortality in acute myocardial infarction patients with diabetes and those without

BACKGROUND

Little is known about the relationship between C-reactive protein (CRP) and long-term mortality after acute myocardial infarction (AMI) in diabetic patients. The current study aimed to examine whether CRP levels are associated with for long-term all-cause, cardiovascular, and cardiac mortality in AMI patients with diabetes and those without separately.

METHODS

The cohort study included 663 diabetic and 1853 non-diabetic patients with AMI. The median follow-up time was 1045 days (2.9 years).

RESULTS

According to the median concentration of serum CRP (8.95 mg/l), the patients were divided into two groups. The low CRP level group (<8.95 mg/l) served as a reference. In diabetic patients with AMI, the adjusted hazard ratios (HRs) for long-term all-cause, cardiovascular, and cardiac mortality were 1.62 (P = 0.027), 1.91 (P = 0.008), and 2.08 (P = 0.007), respectively. In non-diabetic patients with AMI, the adjusted hazard ratios (HRs) for long-term all-cause, cardiovascular, and cardiac mortality were 1.72 (P < 0.001), 1.8 (P < 0.001), and 1.78 (P = 0.001), respectively.

CONCLUSIONS

Regardless of whether patients had diabetes or not, CRP value is an independent predictor of long-term, all-cause, cardiovascular, and cardiac mortality after AMI.

The Interplay of Lipids, Lipoproteins, and Immunity in Atherosclerosis

PURPOSE OF REVIEW

Atherosclerosis is an inflammatory disorder of the arterial wall, in which several players contribute to the onset and progression of the disease. Besides the well-established role of lipids, specifically cholesterol, and immune cell activation, new insights on the molecular mechanisms underlying the atherogenic process have emerged.

RECENT FINDINGS

Meta-inflammation, a condition of low-grade immune response caused by metabolic dysregulation, immunological memory of innate immune cells (referred to as "trained immunity"), cholesterol homeostasis in dendritic cells, and immunometabolism, i.e., the interplay between immunological and metabolic processes, have all emerged as new actors during atherogenesis. These observations reinforced the interest in directly targeting inflammation to reduce cardiovascular disease. The novel acquisitions in pathophysiology of atherosclerosis reinforce the tight link between lipids, inflammation, and immune response, and support the benefit of targeting LDL-C as well as inflammation to decrease the CVD burden. How this will translate into the clinic will depend on the balance between costs (monoclonal antibodies either to PCSK9 or to IL-1ß), side effects (increased incidence of death due to infections for anti-IL-1ß antibody), and the benefits for patients at high CVD risk.

Coffee intake, cardiovascular disease and all-cause mortality: observational and Mendelian randomization analyses in 95 000-223 000 individuals

Background

Coffee has been associated with modestly lower risk of cardiovascular disease and all-cause mortality in meta-analyses; however, it is unclear whether these are causal associations. We tested first whether coffee intake is associated with cardiovascular disease and all-cause mortality observationally; second, whether genetic variations previously associated with caffeine intake are associated with coffee intake; and third, whether the genetic variations are associated with cardiovascular disease and all-cause mortality.

Methods

First, we used multivariable adjusted Cox proportional hazard regression models evaluated with restricted cubic splines to examine observational associations in 95 366 White Danes. Second, we estimated mean coffee intake according to five genetic variations near the AHR (rs4410790; rs6968865) and CYP1A1/2 genes (rs2470893; rs2472297; rs2472299). Third, we used sex- and age adjusted Cox proportional hazard regression models to examine genetic associations with cardiovascular disease and all-cause mortality in 112 509 Danes. Finally, we used sex and age-adjusted logistic regression models to examine genetic associations with ischaemic heart disease including the Cardiogram and C4D consortia in a total of up to 223 414 individuals. We applied similar analyses to ApoE genotypes associated with plasma cholesterol levels, as a positive control.

Results

In observational analyses, we observed U-shaped associations between coffee intake and cardiovascular disease and all-cause mortality; lowest risks were observed in individuals with medium coffee intake. Caffeine intake allele score (rs4410790 + rs2470893) was associated with a 42% higher coffee intake. Hazard ratios per caffeine intake allele were 1.02 (95% confidence interval: 1.00-1.03) for ischaemic heart disease, 1.02 (0.99-1.02) for ischaemic stroke, 1.02 (1.00-1.03) for ischaemic vascular disease, 1.02 (0.99-1.06) for cardiovascular mortality and 1.01 (0.99-1.03) for all-cause mortality. Including international consortia, odds ratios per caffeine intake allele for ischaemic heart disease were 1.00 (0.98-1.02) for rs4410790, 1.01 (0.99-1.03) for rs6968865, 1.02 (1.00-1.04) for rs2470893, 1.02 (1.00-1.04) for rs2472297 and 1.03 (0.99-1.06) for rs2472299. Conversely, 5% lower cholesterol level caused by ApoE genotype had a corresponding odds ratio for ischaemic heart disease of 0.93 (0.89-0.97).

Conclusions

Observationally, coffee intake was associated with U-shaped lower risk of cardiovascular disease and all-cause mortality; however, genetically caffeine intake was not associated with risk of cardiovascular disease or all-cause mortality.

Association between CRP genetic diversity and bipolar disorder comorbid complications

Background

Chronic low-grade inflammation is believed to contribute, at least in a subset of patients, to the development of bipolar disorder (BD). In this context, the most investigated biological marker is the acute phase response molecule, C-reactive protein (CRP). While the genetic diversity of CRP was amply studied in various pathological settings, little is known in BD.

Methods

568 BD patients along with 163 healthy controls (HC) were genotyped for the following single-nucleotide polymorphisms (SNPs) on the CRP gene: intron rs1417938 (+ 29) T/A, 3′-UTR rs1130864 (+ 1444) G/A, and downstream rs1205 (+ 1846) (C/T). The statistical analysis was performed using Chi-square testing and consisted of comparisons of allele/genotype frequencies between patients and controls and within patient sub-groups according to BD clinical phenotypes and the presence of thyroid disorders.

Results

We found that the frequencies of the studied SNPs were similar in BD and HC groups. However, the CRP rs1130864 A allele carrier state was significantly more frequent: (i) in BD patients with thyroid disorders than in those without (pc = 0.046), especially among females (pc = 0.01) and independently of lithium treatment, (ii) in BD patients with rapid cycling than in those without (pc = 0.004).

Conclusions

Overall, our findings suggest the possibility that CRP genetic diversity may contribute to the development of auto-immune comorbid disorders and rapid cycling, both proxy of BD severity. Such findings, if replicated, may allow to predict complex clinical presentations of the disease, a possible step towards precision medicine in psychiatry.

CRP polymorphisms and DNA methylation of the AIM2 gene influence associations between trauma exposure, PTSD, and C-reactive protein

BACKGROUND

Recent studies have implicated inflammatory processes in the pathophysiology of posttraumatic stress disorder (PTSD). C-reactive protein (CRP) is a widely-used measure of peripheral inflammation, but little is known about the genetic and epigenetic factors that influence blood levels of C-reactive protein (CRP) in individuals with PTSD.

METHODS

Participants were 286 U.S. military veterans of post-9/11 conflicts (57% with current PTSD). Analyses focused on single nucleotide polymorphisms (SNPs) in the CRP gene and DNA methylation at cg10636246 in AIM2-a locus recently linked to CRP levels through results from a large-scale epigenome-wide association study.

RESULTS

PTSD was positively correlated with serum CRP levels with PTSD cases more likely to have CRP levels in the clinically-elevated range compared to those without a PTSD diagnosis. Multivariate analyses that controlled for white blood cell proportions, genetic principal components, age and sex, showed this association to be mediated by methylation at the AIM2 locus. rs3091244, a functional SNP in the CRP promoter region, moderated the association between lifetime trauma exposure and current PTSD severity. Analyses also revealed that the top SNPs from the largest genome-wide association study of CRP conducted to date (rs1205 and rs2794520) significantly interacted with PTSD to influence CRP levels.

CONCLUSIONS

These findings provide new insights into genetic and epigenetic mechanisms of inflammatory processes in the pathophysiology of PTSD and point to new directions for biomarker identification and treatment development for patients with PTSD.

Metabolically healthy obese individuals present similar chronic inflammation level but less insulin-resistance than obese individuals with metabolic syndrome

The Metabolic Syndrome (MetS) is a cluster of cardiometabolic risk factors, usually accompanied by the presence of insulin resistance (IR) and a systemic subclinical inflammation state. Metabolically healthy obese (MHO) individuals seem to be protected against cardiometabolic complications. The aim of this work was to characterize phenotypically the low-grade inflammation and the IR in MHO individuals in comparison to obese individuals with MetS and control non obese. We studied two different populations: 940 individuals from the general population of Buenos Aires and 518 individuals from the general population of Venado Tuerto; grouped in three groups: metabolically healthy non-obese individuals (MHNO), MHO and obese individuals with MetS (MSO). Inflammation was measured by the levels of hs-CRP (high-sensitivity C reactive protein), and we found that MHO presented an increase in inflammation when compared with MHNO (Buenos Aires: p<0.001; Venado Tuerto: p<0.001), but they did not differ from MSO. To evaluate IR we analyzed the HOMA (Homoeostatic Model Assessment) values, and we found differences between MHO and MSO (Buenos Aires: p<0.001; Venado Tuerto: p<0.001), but not between MHNO and MHO. In conclusion, MHO group would be defined as a subgroup of obese individuals with an intermediate phenotype between MHNO and MSO individuals considering HOMA, hs-CRP and central obesity.