Critical appraisal of C-reactive protein throughout the spectrum of cardiovascular disease

Inflammation and echocardiographic parameters of ventricular hypertrophy in a cohort with preserved cardiac function

OBJECTIVE

To investigate the association between inflammation and selective echocardiographic parameters (EP) characteristic for ventricular hypertrophy in cross-sectional and longitudinal population-based analyses.

METHODS

Baseline (711 men, 659 women: 45-83 years) and 4-year follow-up data (622 men, 540 women) of the prospective, population-based CARdio-vascular disease, Living and Ageing in Halle (CARLA)study after exclusion of participants with cardiacvascular diseases were analysed. Inflammation parameters: soluble tumour necrosis factor receptor 1 (sTNF-R1), high-sensitivity C reactive protein (hsCRP) and interleukin 6 (IL-6). EPs: left ventricular mass (LVM), left atrial systolic dimension (LADS), interventricular septum diameter (IVSD), posterior wall dimension (PWD), left ventricular diastolic diameter (LVDD), ejection fraction according to Teichholz (EF). For the longitudinal analyses baseline to follow-up differences were considered. Effect sizes were determined by using multiple linear regression and mixed models. Missing values were replaced by means of multiple imputations.

RESULTS

Men had higher sTNF-R1 levels; means of hsCRP and IL-6 were similar in men and women. In multiple regression models, sTNF-R1 was associated with LADS (1.4 mm/1000 pg/mL sTNF-R1, 95% CI 0.6 to 2.1) in men. Respecting confounder hsCRP was associated with LVM (5.2 g/10 mg/L hsCRP, 95% CI 1.6 to 8.8), IVSD (0.2 mm/10 mg/L hsCRP, 95% CI 0 to 0.3) and PWD (0.2 mm/10 mg/L hsCRP, 95% CI 0.1 to 0.3) in women, while there were no relevant effects in analysis of IL-6 in both sexes. The baseline to follow-up change in EPs was not relevantly associated with sTNF-R1, hsCRP or IL-6.

CONCLUSIONS

STNF-R1, hsCRP and IL-6 were inadequate predictors for structural changes of the heart at follow-up, while weak cross-sectional associations are restricted to certain EPs and depend on sex.

Is there any association of anxiety-depressive symptoms with vascular endothelial function or systemic inflammation?

BACKGROUND

Studies have shown the association of mood disorders and endothelial dysfunction, and increased risk of cardiovascular disease; however, mediatory mechanisms are not entirely clarified in this regard. We investigated the relationship between depression/anxiety symptoms with systemic inflammation and endothelial function.

MATERIALS AND METHODS

This cross-sectional study was performed in 2011 on employees of an oil company located in the Isfahan city (central Iran). Participants were selected with clustered random sampling. Anxiety and depression were evaluated by Hospital Anxiety Depression Scale (HADS). Systemic inflammatory status was evaluated by measuring sensitive C-reactive protein (high sensitive-CRP). To evaluate the endothelial function flow-mediated dilation (FMD) was measured.

RESULTS

During the study period, 254 participants (mean age = 51.4 ± 6.1 years) were evaluated. No significant relationship was found between high sensitive-CRP or FMD and any of the variables of anxiety or depression. In multivariate analysis, by controlling the possible confounding factors, no association was found between anxiety score, depression, or the overall score of HADS with high sensitive-CRP or FMD. After the separate analysis of patients with and without diabetes, depression score was correlated inversely with FMD among patients with diabetes (r = 0.525, P = 0.021).

CONCLUSION

According to the results, in the studied population, there was no relationship between anxiety/depression with systemic inflammation or endothelial dysfunction, while in individuals with diabetes, depression was associated with endothelial dysfunction. In this regard more cohort studies are recommended.

Inflammation does not influence arterial stiffness and pulse-wave velocity in patients with coronary artery disease

Vascular function is an important pathophysiological factor in cardiovascular disease, and is influenced by many factors, one of the principles being hypertension. Developing evidence suggests that inflammation may be another risk factor. Vascular function and blood pressure haemodynamics can be assessed by arterial stiffness, pulse pressure and plasma markers. Testing the hypothesis of a relationship between inflammatory markers, hypertension and vascular function, we recruited 222 stable coronary artery disease outpatients, assessing inflammation with levels of high sensitivity CRP and interleukin-6 (IL-6), vascular function/arterial stiffness by pulse-wave velocity (PWV), augmentation (SphygmoCor system Artcor, Sidney, Australia), aortic and brachial artery pulse pressure, Von Willebrand factor (vWf) and soluble E-selectin (both enzyme-linked immunosorbent assay). In multivariate regression analysis, PWVs, augmentation indices and pulse pressures were linked with age, blood pressure and (some) with heart rate (all P<0.01), while vWf was associated with age (P=0.01). We conclude that, in patients with stable coronary artery disease, arterial stiffness and pulse pressure are related strongly and independently with age, blood pressure and heart rate, and that any effect of inflammation is minimal.

Erectile dysfunction in heart failure patients: a critical reappraisal

Heart failure (HF) is a complex clinical syndrome with a constantly increasing incidence and prevalence in western countries. Total absence of sexual activity is registered in 30% of HF patients. Moreover, HF-induced reduction in exercise tolerance, side effects of HF medications and the coexistence of shared risk factors between HF and sexual dysfunction may further aggravate the sexual health of HF patients. The purpose of this review is to examine the pathophysiological mechanisms behind the association of erectile dysfunction (ED) and HF, the potential therapeutic approaches and the eventual indications for sexual activity in HF patients. Medline and Cochrane Library search was performed from January 1970 through October 2012 to retrieve relevant papers outlining the association between ED and HF. Many evidences have outlined a tight association between ED and HF pathophysiological standpoint. Shared risk factors, common pathogenic traits and epidemiologic association represent some of the links between these conditions. Erectile dysfunction has been recognized as an earlier predictor of cardiovascular events; moreover, HF itself may cause and/or worsen ED because of its particular feature and co-morbidities. Furthermore, some cardiovascular drugs may contribute to impaired erectile function. In stable patients with stable HF, sexual activity is generally not contraindicated but it should be encouraged, as a form of moderate-intensity physical exertion. An effective treatment of ED in HF patients should be founded on the correction of reversible risk factors, on the choice of cardiovascular drugs with the lowest effect upon patient's erectile function, and on the use of phosphodiesterase-5-inhibitors. Physicians should be aware of the close relation between HF and ED and of the related clinical and therapeutic implications, in order to improve patients quality of life and clinical outcome.

C-reactive protein is elevated in schizophrenia

BACKGROUND

Increased levels of inflammatory markers have been reported in schizophrenia, but few studies have examined levels of high sensitivity C-reactive protein (CRP), a non-specific inflammatory marker.

METHODS

Levels of high sensitivity CRP were measured in individuals with schizophrenia, bipolar disorder, and non-psychiatric controls. Linear regression analyses were used to compare the CRP levels among the three groups adjusting for demographic and clinical variables. Logistic regression analyses were used to determine the odds ratios associated with elevated levels of CRP, defined as >=75th and 90th percentile in the controls.

RESULTS

The sample consisted of 715 individuals: 295 with schizophrenia, 192 with bipolar disorder, and 228 without a psychiatric disorder. The levels of CRP in the schizophrenia group, but not in the bipolar disorder group, were significantly increased compared to controls adjusting for age, gender, race, maternal education, smoking status, and Body Mass Index (BMI) (t=3.78, p=<.001). The individuals with schizophrenia had significantly increased odds of having elevated levels of CRP relative to both the 75th and 90th percentile levels of the controls adjusting for the same covariates (OR 1.79, 95% CI 1.14, 2.82; p=.012; OR 2.76, 95% CI 1.58, 4.83, p=<.001). In the multivariate linear and logistic regression analyses, levels of CRP were also associated with BMI and female gender.

CONCLUSIONS

Individuals with schizophrenia may be at risk for the adverse health consequences associated with elevated CRP in the overall population. Trials of interventions directed at lowering the level of CRP and other inflammatory markers are indicated.

Effects of fish oil supplementation on inflammatory markers in chronic heart failure: a meta-analysis of randomized controlled trials

Background

Effects of fish oil on systematic inflammation in chronic heart failure remain unclear. In this meta-analysis, we aimed to evaluate the influence of fish oil supplementation on circulating levels of inflammatory markers in patients with chronic heart failure.

Methods

Human randomized controlled trials, which compared the effects of fish oil supplementation with placebo in patients with chronic heart failure, were identified by systematic search of Medline, Embase, Cochrane’s library and references cited in related reviews and studies up to November 2011. Outcome measures comprised the changes of circulating inflammatory markers. Meta-analysis was performed with the fixed-effect model or random-effect model according to the heterogeneity.

Results

A total of seven trials with eight study arms were included. The pooled results indicated circulating levels of tumor necrosis factor α (SMD = -0.62, 95% CI -1.08 to -0.16, p = 0.009), interleukin 1 (SMD = -1.24, 95% CI -1.56 to -0.91, p < 0.001) and interleukin 6 (SMD = -0.81, 95% CI -1.48 to -0.14, p = 0.02) were significantly decreased after fish oil supplementation; however, high sensitivity C reactive protein, soluble intracellular adhesion molecular 1 and vascular cell adhesion molecular 1 were not significantly affected. Meta-regression and subgroup analysis results suggested the difference in dose of fish oil and follow-up duration might influence the effects of fish oil on tumor necrosis factor α and interleukin 6. Greater reduction of these two markers might be achieved in patients taking fish oil of a higher dose (over 1000 mg/day) or for a longer duration (over 4 months).

Conclusions

Limited evidence suggests anti-inflammation may be a potential mechanism underlying the beneficial effects of fish oil for chronic heart failure. Further large-scale and adequately powered clinical trials are needed to confirm these effects.

Biochemical markers in acute coronary syndrome

Owing to their higher risk for cardiac death or ischemic complications, patients with acute coronary syndrome (ACS) must be identified from other causes of chest pain. Patients with acute coronary syndrome are divided into categories based on their electrocardiogram; those with new ST-segment elevation and those who present with ST-segment depression. The subgroups of patients with ST-segment elevation are candidates for immediate reperfusion, while fibrinolysis appears harmful for those with non-ST elevation myocardial infarction. There is increasing evidence to encourage appropriate risk stratification before deciding on a management strategy (invasive or conservative) for each patient. The TIMI, GRACE or PURSUIT risk models are recommended as useful for decisions regarding therapeutic options. Cardiac biomarkers are useful additions to these clinical tools to correctly risk stratify ACS patients. Cardiac troponin is the biomarker of choice to detect myocardial necrosis and is central to the universal definition of myocardial infarction. The introduction of troponin assays with a lower limit of detection will allow for earlier diagnosis of patients who present with chest pain. Analytical and clinical validations of these new assays are currently in progress. The question is whether the lower detection limit of the troponin assays will be able to indicate myocardial ischemia in the absence of myocardial necrosis. Previous to the development of ultrasensitive cardiac troponin assays free fatty acids unbound to albumin and ischemia modified albumin were proposed as biochemical markers of ischemia. Advances in our knowledge of the pathogenesis of acute coronary thrombosis have stimulated the development of new biomarkers. Markers of left ventricular performance (N-terminal pro-brain natriuretic peptide) and inflammation (e.g. C-reactive protein) are generally recognized as risk indicators. Studies suggest that using a number of biomarkers clinicians can risk stratify patients over a broad range of short and long term cardiac events. Nevertheless, it is still under debate as to which biomarker combination is best preferred for risk prediction. This review will focus on recent practice guidelines for the management of patients with ACS as well as current advances in cardiac biomarkers, their integration into clinical care and their diagnostic, prognostic and therapeutic utility.

Association of High Sensitivity C-Reactive Protein Concentrations and Metabolic Syndrome among Thai Adults

OBJECTIVE: To investigate the association of high sensitivity C-reactive protein (hsCRP) concentrations and metabolic syndrome among Thai adults. METHODS: This cross-sectional study is comprised of 467 Thai participants (209 men and 258 women) receiving annual health check-up. Spearman's rank correlation coefficients were used to assess associations of metabolic parameters (age, waist circumference, blood pressure, triglycerides, HDL-C, fasting plasma glucose, fasting insulin and uric acid) with hsCRP concentrations for men and women, respectively. Multivariable logistic regression procedures were used to estimate the risk (odds ratios [OR] and 95% confidence intervals [95% CI]) of metabolic syndrome according to low, moderate and high hsCRP concentrations (<1.0, 1.0-3.0 and >3.0 mg/l, respectively). RESULTS: Measures of adiposity and fasting insulin were positively and significantly correlated with hsCRP concentrations among women with and without metabolic syndrome. Similar associations were observed among men without metabolic syndrome. After controlling for confounders, moderately elevated hsCRP concentrations were associated with a 2.38-fold increased risk of metabolic syndrome (OR=2.38, 95% CI: 1.20-4.72) among men. Men with high hsCRP concentrations had a 5.45-fold increased risk of metabolic syndrome (OR=5.45, 95% CI: 2.24-13.27) when compared with those who had low hsCRP concentrations. The corresponding odds ratios for women with moderately elevated and high hsCRP concentrations were 4.92 (OR=4.92, 95% CI: 2.34-10.35) and 11.93 (OR=11.93, 95% CI: 5.54-25.72), respectively. CONCLUSIONS: These findings are consistent with the literature suggesting a role of hsCRP as a biomarker for metabolic syndrome.

C-Reactive Protein and The Risk of Atrial Fibrillation: A Systematic Review and Meta-Analysis

There is increasing evidence linking C-reactive protein (CRP) and atrial fibrillation (AF). Despite the abundance of literature, confusion exists regarding this association because of inconsistent results. MEDLINE and Cochrane Controlled Trials Register databases were carefully searched through July, 2009 combining the following terms "C-reactive protein" and "atrial fibrillation". Reference lists of selected articles and reviews were also screened to identify additional relevant studies. Of the 129 studies initially identified, 8 studies with 7507 subjects (719 with AF) were included in the meta-analysis. Analysis yielded a relative risk of 1.63 (1.43, 1.86) for occurrence of AF when CRP level was above a cut off of 3-3.5 mg/l. When 3 studies with data on a higher cut off of 4.5-5.0 mg/l were analyzed separately, the relative risk was 4.03 (3.1, 5.25). Our study suggests that elevated CRP is associated with increased risk for AF. The risk appears incremental with higher CRP levels conferring proportionately increased risk. There is an urgent need for further large scale, well designed prospective studies to assess the relationship between CRP and AF.

Assessment of cardiac troponin I and C-reactive protein concentrations associated with anesthetic protocols using sevoflurane or a combination of fentanyl, midazolam, and sevoflurane in dogs

OBJECTIVE

To report serum cardiac troponin I (cTnI) and C-reactive protein (CRP) concentrations in dogs anesthetized for elective surgery using two anesthetic protocols.

STUDY DESIGN

Prospective, randomized clinical study.

ANIMALS

Twenty client-owned dogs presenting for elective ovariohysterectomy or castration.

METHODS

The dogs were randomized into two groups. All dogs were premedicated with glycopyrrolate (0.011 mg kg(-1)) and hydromorphone (0.1 mg kg(-1)) i.m. approximately 30 minutes prior to induction of anesthesia. Anesthesia in dogs in group 1 was induced with propofol (6 mg kg(-1)) i.v. to effect and in dogs in group 2 with diazepam (0.2 mg kg(-1)) i.v. followed by etomidate (2 mg kg(-1)) i.v. to effect. For maintenance of anesthesia, group 1 received sevoflurane (adjustable vaporizer setting 0.5-4%) and group 2 received a combination of fentanyl (0.8 microg kg(-1) minute(-1)) and midazolam (8.0 microg kg(-1) minute(-1)) i.v. plus sevoflurane (adjustable vaporizer setting 0.5-4%) to maintain anesthesia. Serum cTnI and CRP concentrations were measured at baseline and 6, 18, and 24 hours post-anesthetic induction. Biochemical analysis was performed at baseline. Lactate was obtained at baseline and 6 hours post-anesthetic induction. Heart rate and mean arterial blood pressure were measured intra-operatively.

RESULTS

Baseline serum cTnI and CRP concentrations were comparable between groups. A significant difference in serum cTnI or CRP concentrations was not detected post-operatively between groups at any time point. Serum CRP concentrations were significantly increased post-anesthetic induction in both groups, which was attributed to surgical trauma.

CONCLUSIONS AND CLINICAL RELEVANCE

There was no significant difference in serum cTnI and CRP concentrations between anesthetic protocols. Further investigation in a larger number of dogs is necessary to confirm the current findings.

Atorvastatin decreases high-sensitivity C-reactive protein in multiple sclerosis

The anti-inflammatory potential of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, as reflected by modulation of C-reactive protein (CRP), might be beneficial in the treatment of patients with multiple sclerosis (MS). We evaluated serum levels of high-sensitivity (hs)-CRP in relapsing–remitting MS patients receiving interferon-β 1b and atorvastatin as add-on therapy. This study shows that interferon-β treatment is associated with increased serum levels of hs-CRP in MS patients ( P < 0.01). In contrast, when atorvastatin is added to interferon-β, hs-CRP serum levels decrease to the normal range ( P < 0.05), indicating an anti-inflammatory action of atorvastatin in MS. However, whether add-on treatment with atorvastatin modifies the course of MS remains to be investigated.

C-reactive protein (CRP): more than just an innocent bystander?

This editorial discusses whether measuring C-reactive protein (CRP) levels can be used as a predictor of vascular risk. The agents that reduce CRP levels and the evidence for a possible causative role of CRP in the pathogenesis of coronary events and atherosclerosis are also considered. There is a need to further elucidate the role of CRP, as well as the clinical relevance, if any, of CRP-lowering agents.

Longitudinal follow-up of systemic inflammation after acute exacerbations of COPD

BACKGROUND

Acute exacerbations are important in the clinical course of COPD, yet the underlying mechanisms are poorly understood. Systemic inflammation is now considered as an important component in the disease process. In this study we evaluated longitudinally the systemic inflammation during hospital treatment for acute exacerbation and after clinical recovery.

METHODS

Blood was collected on day 0, 1, 4 and 8 in 21 patients admitted for an acute exacerbation of COPD and at 1 month, 3 months and 6 months after discharge. Systemic inflammation was determined by measurement of the pro-inflammatory markers interleukin (IL)-6, soluble tumor necrosis factor (TNF) receptors sTNFR55 and sTNFR75, the anti-inflammatory mediator sIL-1RII, and bactericidal permeability increasing protein (BPI) as a marker of neutrophil activation. In addition, plasma level of Trolox antioxidant capacity (TEAC) was determined. Healthy age-matched controls were measured for the same markers at one time-point.

RESULTS

All inflammatory markers analyzed were elevated on first day of admission for exacerbation of COPD, as compared to healthy controls. During treatment, levels of IL-6, and sTNFR75 rapidly decreased, whereas sTNFR55 and BPI remained elevated. Moreover, sIL-1RII and TEAC increased during first 8 days of treatment. In the stable condition all inflammatory markers returned to values comparable to healthy controls, with the exception of BPI, which remained persistently elevated compared to healthy controls.

CONCLUSION

This study clearly demonstrates upregulation of systemic inflammation in acute exacerbations of COPD. Attenuation of systemic inflammation may offer new perspectives in the management of COPD patients to reduce the burden of exacerbations.