The role of C-reactive protein in cardiovascular disease risk

Exposure to different fractions of diesel exhaust PM2.5 induces different levels of pulmonary inflammation and acute phase response

AIM

Ambient fine particulate matter (PM2.5) consists of various components, and their respective contributions to the toxicity of PM2.5 remains to be determined. To provide specific recommendations for preventing adverse effects due to PM2.5 pollution, we determined whether the induction of pulmonary inflammation, the putative pathogenesis for the morbidity and mortality due to PM2.5 exposure, was fractioned through solubility-dependent fractioning.

METHODS

In the present study, the water and heptane solubilities-dependent serial fractioning of diesel exhaust particulate matter (DEP), a prominent source of urban PM2.5 pollution, was performed. The pro-inflammatory actions of these resultant fractions were then determined using both an intratracheal instillation mouse model and cultured BEAS-2B cells, a human bronchial epithelial cell line.

RESULTS

Instillation of the water-insoluble, but not -soluble fraction elicited significant pulmonary inflammatory and acute phase responses, comparable to those induced by instillation of DEP. The water-insoluble fraction was further fractioned using heptane, a polar organic solvent, and instillation of heptane-insoluble, but not -soluble fraction elicited significant pulmonary inflammation and acute phase responses. Furthermore, we showed that DEP and water-insoluble DEP, but not water-soluble DEP, activated pro-inflammatory signaling in cultured BEAS-2B cells, ruling out the possibility that the solubility impacts the in vivo distribution and thus the pulmonary inflammatory response.

C-reactive protein as a novel biomarker

C-reactive protein (CRP) is a relatively nonspecific marker of inflammation. However, it can be used to monitor the severity and progression of some well-defined cardiovascular diseases. For example, it can predict serious events in patients with coronary artery disease (CAD) who are hospitalized with acute coronary syndrome, myocardial infarction (MI), or advanced peripheral vascular disease. In this article, the authors review the role of CRP in the diagnosis, monitoring, and treatment of various forms of ischemic and inflammatory cardiovascular disease.

Circadian influences on myocardial infarction

Components of circadian rhythm maintenance, or "clock genes," are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations.

Haem catabolism: a novel modulator of inflammation in Gilbert's syndrome

BACKGROUND

Moderately elevated unconjugated bilirubin concentrations protect against inflammatory diseases and are present in individuals with Gilbert's syndrome. This study examined the relationship between circulating haem oxygenase catabolites, unconjugated bilirubin, carboxy haemoglobin, iron and inflammatory parameters.

MATERIALS AND METHODS

Seventy-six matched individuals were allocated to Gilbert's syndrome (GS) or control group (unconjugated bilirubin ≥ or < 17.1 μM). Iron, carboxy haemoglobin and high-sensitivity C-reactive protein were analysed using routine diagnostic tests. Unconjugated bilirubin and haem were analysed using high-performance liquid chromatography. The cytokines IL-1β, TNF-α and IL-6 were assessed using high-sensitivity enzyme-linked immunosorbent assays.

RESULTS

Gilbert's syndrome subjects had significantly greater levels of unconjugated bilirubin (P < 0.05), carboxy haemoglobin (P < 0.05), iron (P < 0.05), IL-1β (P < 0.05), a significantly lower body mass index (P < 0.05) and IL-6 concentrations (P < 0.05) vs. controls. Regression analysis revealed that unconjugated bilirubin mainly explained IL-1β results (16%), and body mass index+IL-6 predicted 26% of the variance in C-reactive protein concentrations.

CONCLUSIONS

A positive relationship between unconjugated bilirubin and free plasma haem, iron and carboxy haemoglobin indicated a positive feedback loop of haem oxygenase induction possibly mediated by unconjugated bilirubin. Furthermore, reduced body mass index in Gilbert's syndrome individuals was linked to reduced inflammation status, which could be influenced by circulating haem oxygenase catabolites and contribute to reduced risk of noncommunicable diseases in this population.

All-cause in-hospital mortality and comorbidity in diabetic and non-diabetic patients with stroke

INTRODUCTION

The aim of this study was to compare diabetic and non-diabetic patients with stroke with regard to their all-cause in-hospital mortality and possible differences regarding their comorbidities.

METHODS

All patients of the Munich Stroke Registry (2003-2004, n=537) were assessed. Hospital mortality in diabetic (n=160, 29.8%) and non-diabetic (n=377, 70.2%) patients was compared. Pre-existing comorbidities such as hypertension, coronary artery disease (CAD), peripheral arterial disease (PAD), albuminuria and impaired renal function (IRF) were noted.

RESULTS

Regarding all-cause in-hospital mortality, no significant differences were found between diabetic and non-diabetic patients. Overall 71 patients (13.2%) died of whom 27 (16.9%) where diabetic and 44 (11.7%) non-diabetic patients (n.s.). Hypertension, CAD, PAD, albuminuria and IRF were more frequent in diabetic patients (p<0.05).

CONCLUSION

Despite multiple comorbidities and risk factors no significant difference in all-cause in-hospital mortality was seen in diabetic patients as compared to non-diabetic patients. Improved treatment strategies and early intervention may compensate for their poorer prognosis.

Myocardial ischemia, reperfusion, and infarction in chronically instrumented, intact, conscious, and unrestrained mice

In the United States alone, the National Heart, Lung, and Blood Institute (NHLBI) has invested several hundred million dollars in pursuit of myocardial infarct-sparing therapies. However, due largely to methodological limitations, this investment has not produced any notable clinical application or cardioprotective therapy. Among the major methodological limitations is the reliance on animal models that do not mimic the clinical situation. In this context, the limited use of conscious animal models is of major concern. In fact, whenever possible, studies of cardiovascular physiology and pathophysiology should be conducted in conscious, complex models to avoid the complications associated with the use of anesthesia and surgical trauma. The mouse has significant advantages over other experimental models for the investigation of infarct-sparing therapies. The mouse is inexpensive, has a high throughput, and presents the ability of one to create genetically modified models. However, successful infarct-sparing therapies in anesthetized mice or isolated mouse hearts may not be successful in more complex models, including conscious mice. Accordingly, a conscious mouse model of myocardial ischemia and reperfusion has the potential to be of major importance for advancing the concepts and methods that drive the development of infarct-sparing therapies. Therefore, we describe, for the first time, the use of an intact, conscious, and unrestrained mouse model of myocardial ischemia-reperfusion and infarction. The conscious mouse model permits occlusion and reperfusion of the left anterior descending coronary artery in an intact, complex model free of the confounding influences of anesthetics and surgical trauma. This methodology may be adopted for advancing the concepts and ideas that drive cardiovascular research.

Intraoperative device closure of atrial septal defects in the older population

Objective

This study sought to prove the safety and feasibility of intraoperative device closure of atrial septal defect (ASD) with transthoracic minimal invasion in the older patients.

Methods

From January 2006 to December 2009, 47 patients aged 50 years or more and suffered from atrial septal defect were enrolled in our institution. Patients were divided into two groups, 27 of which in group I with intraoperative device closure and the other 20 in group II with surgical closure. In group I, the method involved a minimal intercostal incision, which was performed after full evaluation of the atrial septal defect by transthoracic echocardiography, and the insertion of the device through the delivery sheath to occlude the atrial septal defect.

Results

In group I, implantation was ultimately successful in all patients. The complete closure rate at 24 hours and 1 year were 81.5% and 100% respectively. In 6 of 27 patients, minor complications occurred: transient arrhythmia (n = 5) and blood transfusion (n = 3). In group II, all patients were closured successfully; almost all of them needed blood transfusion and suffered from various minor complications though. During a follow-up period of 1 to 5 years, no residual shunt, noticeable mitral regurgitation, significant arrhythmias, thrombosis, or device failure were found. In our comparative studies, group II had significantly longer ICU stay and hospital stay than group I (p < 0.05). The cost of group I was less than that of group II(p < 0.05).

Conclusions

Minimally invasive transthoracic device closure of the atrial septal defect at advanced age with a domestically made device without cardiopulmonary bypass is safe and feasible under transthoracic echocardiographic guidance. It was cost-savings, yielding better cosmetic results and leaving fewer traumas than surgical closure. Early and mid-term results are encouraging. However, it is necessary to evaluate the long-term results.

Relationship between bilirubin and C-reactive protein

BACKGROUND

Epidemiologic studies have shown that serum total bilirubin is inversely related to an increased risk of coronary artery disease. However, the number of studies which have focused on the relationship between bilirubin and C-reactive protein (CRP), which is a marker reflecting chronic vascular inflammation, are limited.

METHOD

This cross-sectional study consisted of 2307 Korean adults who visited the Center for Health Promotion for a routine health check-up from January 2009 to December 2009.

RESULT

CRP level showed a declining tendency as total bilirubin increased according to total bilirubin quartiles. Negative relations of CRP with both total and direct bilirubin were found after adjustment of age, body mass index, hypertension, diabetes, hypercholesterolemia, cardiovascular disease, taking aspirin, smoking, alcohol drinking and regular exercise and total bilirubin or direct bilirubin.

CONCLUSIONS

This study found that elevation of the two types of bilirubin (total and direct) have a relationship with a low serum CRP level among apparently healthy Korean adults. It is hypothesized that a low serum CRP level may be due to the antioxidant and anti-inflammatory effects of bilirubin metabolism.

Transcatheter closure of large atrial septal defects in 18 patients

PURPOSE

This study was designed to evaluate the efficacy and safety of transcatheter closure of large atrial septal defects (ASD).

METHODS

Eighteen patients diagnosed as ostium secundum defect with a diameter of 30-40 mm were enrolled in this study. With the guidance of echocardiography and fluoroscopy, the Amplazter occlusion devices were implanted percutaneously through the femoral vein.

RESULTS

A small residual left-to-right shunt was detected with echocardiography immediately postprocedure but resolved after 1 week. The occlusion devices remained in proper position, and there was no residual shunt at 1- and 29-month follow-ups. Cardiac function and atrial sizes improved significantly as compared with the preclosure states.

CONCLUSIONS

Transcatheter closure of large atrial septal defects with the Amplazter occlusion device is feasible, safe and effective.

Plasma free fatty acid level patterns according to cardiovascular risk status in postmenopausal women

BACKGROUND

The present study examines changes in the pattern of plasma free polyunsaturated fatty acids (PUFA) according to menopausal status and the existence of diabetes mellitus (DM) or coronary heart disease (CHD) in Korean women.

METHODS

The participants were as follows; premenopausal women (PRE, n=20) and postmenopausal women without any known chronic disease (POST, n=35), with DM (DM, n=35), or with angiographically proven CHD (CHD, n=30). Plasma free fatty acids were measured in all participants.

RESULTS

Healthy premenopausal women had a higher ratio of omega-3/omega-6 PUFA than postmenopausal women (p=0.001). As expected, the PRE group had higher docsapentaenoic acid (DPA) and docosahexaenoic acid (DHA) levels (p<0.05) and lower arachidonic acid levels (p<0.05) than the POST group. In turn, the healthy POST group had higher levels of DPA and DHA compared to the DM or CHD groups (p<0.05). There were significant shifts of increased omega-6 and decreased omega-3 among the women, according to each disease.

CONCLUSIONS

There was a significant relationship between omega-3 and omega-6 PUFA profiles and risk for CHD in women. This metabolic profile of PUFA might be an important surrogate marker in postmenopausal women.

Well-being, health-related quality of life and cardiovascular disease risk profile in women with subclinical thyroid disease - a community-based study

OBJECTIVES

The aim of this study was to evaluate whether subclinical thyroid disease is associated with impaired health-related quality of life and a more adverse cardiovascular disease risk profile.

DESIGN

A community-based cross-sectional study.

SETTING AND PARTICIPANTS

A total of 1423 non-healthcare-seeking women, aged 18-75 years were randomly recruited from the community via the electoral roll from April 2002 to August 2003.

MAIN OUTCOME MEASURES

These were the scores for the Short-Form 36 (SF-36), the Psychological General Well-being Index (PGWI), thyroid hormone levels, serum lipids and high sensitivity C-reactive protein (hsCRP). Subclinical hypothyroidism (SCH) and subclinical hyperthyroidism (SCHyper) were defined as serum TSH > 4.0 mIU/l and < 0.5 mIU/l, respectively, with a normal free thyroxine (free T4) level.

RESULTS

Evaluable data were available for all participants. 10.7% of all women had an abnormal TSH value. The prevalence of a low TSH level by age group ranged from 1.2% to 6.4%, whereas the prevalence of an elevated TSH level ranged from 2.8% to 9.2% and increased with age (P = 0.002). There were no significant differences between women with SCH or SCHyper and age-matched controls for the total PGWI score or the Mental and Physical Component Scores of the SF-36. Women with SCH were no different from controls for serum lipids or hsCRP. Using linear regression, SCH vs. euthyroidism did not make an independent contribution to variation in either total cholesterol or triglycerides, with or without adjustment for age +/- age(2) +/- BMI.

CONCLUSIONS

Our data indicate that subclinical thyroid disease in women in the community is not associated with lower well-being or impaired health-related quality of life and SCH is not associated with increased serum markers of CVD risk.

Severity of myocardial injury following ischemia-reperfusion is increased in a mouse model of allergic asthma

Cardiovascular disease is common in asthmatic patients but often is attributed to respiratory drug therapy. With mounting evidence for an inflammatory role in the development of cardiovascular disease, we hypothesized that the inflammation associated with asthma adversely affects the cardiovascular system independent of therapeutic interventions. The hypothesis was tested in a murine model of myocardial ischemia-reperfusion injury. BALB/C mice were sensitized by intraperitoneal injection of ragweed (RW) or normal saline (NS) and challenged by intratracheal instillation of RW or NS. Effective allergic sensitization and challenge were confirmed by hyperresponsiveness to aerosolized methacholine and bronchoalveolar lavage. In vivo myocardial ischemia-reperfusion injury was induced by ligation of the left anterior descending artery for 20 min, followed by reperfusion for 2 h. The infarct size (% risk area) and neutrophil density in the myocardial area at risk were significantly higher in the RW/RW group than in the control groups. The tissue neutrophil count correlated with the infarct size but did not correlate with blood neutrophil counts. Furthermore, in the RW/RW group, circulating granulocytes showed an enhanced expression of CD11b and P-selectin glycoprotein ligand-1, enhanced stimulated release of myeloperoxidase, and enhanced expression of P-selectin in the coronary vasculature. These results indicate that allergic responses in the airways enhance expression of attachment molecules in coronary vasculature and activate circulating neutrophils, resulting in recruitment of highly activated neutrophils to the infarct zone during an acute ischemia-reperfusion event, thereby enhancing tissue destruction.

Chronic Obstructive Pulmonary Disease, inflammation and co-morbidity--a common inflammatory phenotype?

Chronic Obstructive Pulmonary Disease (COPD) is and will remain a major cause of morbidity and mortality worldwide. The severity of airflow obstruction is known to relate to overall health status and mortality. However, even allowing for common aetiological factors, a link has been identified between COPD and other systemic diseases such as cardiovascular disease, diabetes and osteoporosis.

COPD is known to be an inflammatory condition and neutrophil elastase has long been considered a significant mediator of the disease. Pro-inflammatory cytokines, in particular TNF-α (Tumour Necrosis Factor alpha), may be the driving force behind the disease process. However, the roles of inflammation and these pro-inflammatory cytokines may extend beyond the lungs and play a part in the systemic effects of the disease and associated co-morbidities. This article describes the mechanisms involved and proposes a common inflammatory TNF-α phenotype that may, in part, account for the associations.

Assessing the economic impact of chronic conditions in postmenopausal women

The ageing of the US population and the recognised importance of preventative care has led to a growing body of research regarding the morbidity and mortality associated with chronic diseases in postmenopausal women. According to the National Institute of Health, postmenopausal women have a significant increase in risk for a number of debilitating diseases, including osteoporosis, breast cancer and cardiovascular disease. In addition, recently published studies prompted patients, clinicians and payers to re-examine the risks and benefits of a well-accepted therapy to treat postmenopausal symptoms. The objective of this paper is to provide a framework for assessing the economic impact of disorders affecting postmenopausal women, with a particular focus on osteoporosis, breast cancer and cardiovascular disease. This framework considers the prevalence of these conditions, the profiles of women suffering from each of them and prevailing patterns of treatment for these disorders. Taken together, these factors are used to analyse the overall economic impact of postmenopausal disorders and to provide an expert opinion in this context.

Hormone replacement therapy and cardiovascular risk

Hormone replacement therapy (HRT) is effective in suppressing postmenopausal symptoms and, in the past, many have claimed that it is cardioprotective. It was thought that the lower incidence of cardiovascular disease in premenopausal women was related to the cardioprotective effect of estrogen. Many of these studies were, however, observational studies. HRT alters many cardiovascular parameters, most beneficially. The mixed effect on these parameters make the overall result on cardiovascular risk difficult to predict. However, recent randomized, placebo-controlled trials have shown not only that HRT does not confer cardioprotection, but that it actually increases one's cardiovascular risk in the short term. Based on the current evidence, HRT should not be recommended in the hope that it will protect postmenopausal women against coronary heart disease.

Direct modulatory effect of C-reactive protein on primary human monocyte adhesion to human endothelial cells

C-reactive protein (CRP) is the prototypic acute phase serum protein in humans. The effects of CRP on primary human monocyte adhesion molecule expression and interaction with the endothelium have not been studied. Herein, we describe an investigation into the phenotypic and functional consequences of CRP binding to peripheral blood monocytes ex vivo. Peripheral whole blood was collected from healthy, non-smoking males. Mononuclear cells (MNC) and monocytes were isolated by differential centrifugation using lymphoprep and Dynal negative isolation kit, respectively. Cells were exposed to CRP from 0 to 250 micro g/ml for 0-60 min at 37 degrees C and analysed for (a) CD11b, PECAM-1 (CD31) and CD32 expression by flow cytometry and (b) adhesion to LPS (1 micro g/ml; 0-24 h) treated human umbilical vein endothelial cells (HUVEC). CD14+ monocyte expression of CD11b increased significantly up to twofold when exposed to CRP, compared to controls. There was no significant difference in CD32 expression, whereas CD31 expression decreased after exposure to CRP. CRP treatment of monocytes inhibited their adhesion to early LPS-activated HUVEC (0-5 h). However, the adhesion of CRP-treated monocytes to HUVEC was significantly greater to late activation antigens on HUVEC (24 h, LPS) compared to controls. We have shown that CRP can affect monocyte activation ex vivo and induce phenotypic changes that result in an altered recruitment to endothelial cells. This study provides the first evidence for a further role for C-reactive protein in both monocyte activation and adhesion, which may be of importance during an inflammatory event.