Role of inflammation in the pathogenesis of unstable coronary artery diseases

Hospitalization for acute coronary syndrome increases the long-term risk of pneumonia: a population-based cohort study

It is well established that the risk of acute coronary syndrome (ACS) increases after respiratory infection. However, the reverse association has not been evaluated. We tested the hypothesis that the long-term risk of pneumonia is increased after a new ACS event. A matched-cohort study was conducted using a nationally representative dataset. We identified patients with admission for ACS between 2004 and 2014, without a previous history of ACS or pneumonia. Incidence density sampling was used to match patients, on the basis of age and sex, to 3 controls who were also free from both ACS and pneumonia. We examined the incidence of pneumonia after ACS until the end of the cohort observation (Dec 31, 2014). The analysis cohort consisted of 5469 ACS cases and 16,392 controls (median age, 64 years; 68.3% men). The incidence rate ratios of the first and the total pneumonia episodes in the ACS group relative to the control group was 1.25 (95% confidence interval [CI], 1.11–1.41) and 1.23(95% CI 1.11–1.36), respectively. A significant ACS-related increase in the incidence of pneumonia was observed in the Cox-regression, shared frailty, and joint frailty model analyses, with hazard ratios of 1.25 (95% CI 1.09–1.42), 1.35 (95% CI 1.15–1.58), and 1.24 (95% CI 1.10–1.39), respectively. In this population-based cohort of patients who were initially free from both ACS and pneumonia, we found that hospitalization for ACS substantially increased the long term risk of pneumonia. This should be considered when formulating post-discharge care plans and preventive vaccination strategies in patients with ACS.

Body mass index and musculoskeletal pain: is there a connection?

Background

Back pain is one of the most common complaints that patients report to physicians and two-thirds of the population has an elevated body mass index (BMI), indicating they are either overweight or obese. It was once assumed that extra body weight would stress the low back and lead to pain, however, researchers have reported inconsistencies association between body weight and back pain. In contrast, more recent studies do indicate that an elevated BMI is associated with back pain and other musculoskeletal pain syndromes due to the presence of a chronic systemic inflammatory state, suggesting that the relationship between BMI and musculoskeletal pains be considered in more detail.

Objective

To describe how an elevated BMI can be associated with chronic systemic inflammation and pain expression. To outline measurable risk factors for chronic inflammation that can be used in clinical practice and discuss basic treatment considerations.

Discussion

Adiposopathy, or “sick fat” syndrome, is a term that refers to an elevated BMI that is associated with a chronic systemic inflammatory state most commonly referred to as the metabolic syndrome. The best available evidence suggests that the presence of adiposopathy determines if an elevated BMI will contribute to musculoskeletal pain expression. It is not uncommon for physicians to fail to identify the presence of adiposopathy/metabolic syndrome.

Conclusion

Patients with an elevated BMI should be further examined to identify inflammatory factors associated with adiposopathy, such as the metabolic syndrome, which may be promoting back pain and other musculoskeletal pain syndromes.

Changes in the vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and c-reactive protein following administration of aqueous extract of piper sarmentosum on experimental rabbits fed with cholesterol diet

BACKGROUND

Inflammation process plays an important role in the development of atherosclerosis. Hypercholesterolemia is one of the major risk factors for atherosclerosis. The present study aimed to evaluate the effect of aqueous extract of Piper sarmentosum (P.s) on inflammatory markers like vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and C-reactive protein (CRP).

METHODS

Forty two male New Zealand white rabbits were divided equally into seven groups; (i) C- control group fed normal rabbit chow (ii) CH- cholesterol diet (1%cholesterol) (iii) X1- 1% cholesterol with water extract of P.s (62.5 mg/kg) (iv) X2- 1% cholesterol with water extract of P.s (125 mg/kg (v) X3- 1% cholesterol with water extract of P.s (250 mg/kg) (vi) X4- 1% cholesterol with water extract of P.s (500 mg/kg) and (vii) SMV group fed with 1% cholesterol supplemented with simvistatin drug (1.2 mg/kg). All animals were treated for 10 weeks. Blood serum was taken for observing the inflammatory markers at the beginning and end of the experiment.

RESULTS

Rabbits fed with 1% cholesterol diet (CH) showed significant increase in the level of VCAM-1, ICAM-1 and CRP compared to the C group. The levels of VCAM-1, ICAM-1 and CRP in the 1% cholesterol group and supplemented with P.s (500 mg/kg) were significantly reduced compared to the cholesterol group. Similar results were also reported with simvistatin group.

CONCLUSION

These results suggest that the supplementation of Piper sarmentosum extract could inhibit inflammatory markers which in turn could prevent atherosclerosis.

Chronic periodontitis and C-reactive protein levels

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The paradox of the neutrophil's role in tissue injury

The neutrophil is an essential component of the innate immune system, and its function is vital to human life. Its production increases in response to virtually all forms of inflammation, and subsequently, it can accumulate in blood and tissue to varying degrees. Although its participation in the inflammatory response is often salutary by nature of its normal interaction with vascular endothelium and its capability to enter tissues and respond to chemotactic gradients and to phagocytize and kill microrganisms, it can contribute to processes that impair vascular integrity and blood flow. The mechanisms that the neutrophil uses to kill microorganisms also have the potential to injure normal tissue under special circumstances. Its paradoxical role in the pathophysiology of disease is particularly, but not exclusively, notable in seven circumstances: 1) diabetic retinopathy, 2) sickle cell disease, 3) TRALI, 4) ARDS, 5) renal microvasculopathy, 6) stroke, and 7) acute coronary artery syndrome. The activated neutrophil's capability to become adhesive to endothelium, to generate highly ROS, and to secrete proteases gives it the potential to induce local vascular and tissue injury. In this review, we summarize the evidence for its role as a mediator of tissue injury in these seven conditions, making it or its products potential therapeutic targets.

Adiponectin levels in coronary artery ectasia

Etiopathogenesis of coronary artery ectasia (CAE), which is defined as abnormal dilatation of a segment of the coronary artery to 1.5 times of an adjacent normal coronary artery segment, is unclear. However, it is speculated that CAE develops in the atherosclerosis process through degeneration of coronary artery media layer. Our objective in this study is to compare levels of adiponectin between cases with CAE and normal coronary anatomy, and to examine whether adiponectin plays a role in CAE etiopathogenesis. The study registered a total of 66 cases, consisting of CAE cases (group 1, n = 36) and cases with normal coronary anatomy (group 2, n = 30). Taking coronary artery diameters of the control group cases as the reference, patients with abnormal segments 1.5 times larger than the adjacent segments were accepted as CAE. Serum adiponectin levels were 4.31 +/- 2.02 microg/ml in group 1 and 6.73 +/- 4.0 microg/ml in group 2 (P = 0.02). High-sensitivity C-reactive protein was 4.8 +/- 3.8 mg/l in group 1 and 3.6 +/- 3.4 mg/l in group 2 (P > 0.05). There was a negative correlation between ectatic coronary artery diameter and plasma adiponectin level (P = 0.03; r = -0.339). It was known that adiponectin levels dropped in atherosclerotic heart disease. In this study we found low plasma adiponectin levels in acquired CAE, attributed to atherosclerosis. Therefore, we think that adiponectin might be playing a role in etiopathogenesis and progression of CAE. This in turn may indicate that hypo-adiponectinemia may be useful in revealing a realized risk in CAE. However, larger, randomized, multicenter studies are required to examine the role of adiponectin in the development of CAE.

Comparison of C-reactive protein levels in patients with coronary artery ectasia versus patients with obstructive coronary artery disease

This study evaluated plasma C-reactive protein (CRP) levels, a specific marker of inflammation, in 32 patients with isolated coronary artery ectasia (CAE) and compared the results with those of 32 patients with obstructive coronary artery disease without coronary artery ectasia and 30 subjects with angiographically normal coronary arteries. CRP levels were found to be significantly higher in patients with isolated CAE (p <0.001), suggesting that more severe inflammation may be involved in the pathogenesis of CAE.

The associations between physical activity and inflammatory markers in high-functioning older persons: MacArthur Studies of Successful Aging

OBJECTIVES

To determine the relationships between recreational activity, house/yard work activity, work activity, and total physical activity and high levels of two peripheral blood markers of inflammation: interleukin-6 (IL-6) and C-reactive protein (CRP).

DESIGN

Cross-sectional study.

SETTING

Three communities (Durham, NC; New Haven, CT; and East Boston, MA).

PARTICIPANTS

Eight hundred seventy persons aged 70 to 79 who were in the top third of community-dwelling older persons with respect to physical and cognitive functioning.

MEASUREMENTS

Blood levels of IL-6 and CRP and self-reported recreational activity, house/yard work activity, work activity, and total physical activity.

RESULTS

The adjusted odds ratios (AORs) for individuals with high levels of recreational activity to have values in the top tertiles of IL-6 and CRP were 0.65 (95% confidence interval (CI) = 0.48-0.87) and 0.70 (95% CI = 0.51-0.95), respectively. The AORs for those with a high level of house/yard work activity to have values in the top tertile of IL-6 and CRP were 0.90 (95% CI = 0.67-1.20) and 0.70 (95% CI = 0.50-0.96), respectively. High levels of house/yard work and recreational activity were independently associated with lower risk of high CRP.

CONCLUSION

The association between high levels of recreational activity and lower levels of the inflammatory markers IL-6 and CRP suggests a mechanism for its protective effect and supports interventions that increase physical activity in older persons. Such potential benefits of increased physical activity on inflammatory markers will need to be confirmed in clinical trials.

High sensitivity C-reactive protein: an emerging role in cardiovascular risk assessment

Coronary heart disease (CHD) is the major cause of death in the developed world and screening for conventional cardiovascular risk factors fails to identify more than 50% of the individuals who will present with acute coronary syndromes. Chronic inflammation appears to play a significant role in the initiation and development of atherosclerosis. Recent investigations have shown an association between inflammatory markers such as C-reactive protein (CRP) and CHD. These markers have proven useful as prognostic indicators in acute coronary syndromes and in predicting future coronary events in apparently healthy men and women. The availability of high sensitivity CRP (hs-CRP) assays has been crucial in exploring the role of this acute phase reactant in primary prevention settings. In this review, we discuss the evidence associating these inflammatory markers, especially CRP, with the pathogenesis of atherosclerosis and acute coronary syndromes, and we address the mechanism of risk as well as the clinical utility of this marker.

Generation of C-reactive protein and complement components in atherosclerotic plaques

C-reactive protein (CRP) and complement are hypothesized to be major mediators of inflammation in atherosclerotic plaques. We used the reverse transcriptase-polymerase chain reaction technique to detect the mRNAs for CRP and the classical complement components C1 to C9 in both normal arterial and plaque tissue, establishing that they can be endogenously generated by arteries. When the CRP mRNA levels of plaque tissue, normal artery, and liver were compared in the same cases, plaque levels were 10.2-fold higher than normal artery and 7.2-fold higher than liver. By Western blotting, we showed that the protein levels of CRP and complement proteins were also up-regulated in plaque tissue and that there was full activation of the classical complement pathway. By in situ hybridization, we detected intense signals for CRP and C4 mRNAs in smooth muscle-like cells and macrophages in the thickened intima of plaques. By immunohistochemistry we showed co-localization of CRP and the membrane attack complex of complement. We also detected up-regulation in plaque tissue of the mRNAs for the macrophage markers CD11b and HLA-DR, as well as their protein products. We showed by immunohistochemistry macrophage infiltration of plaque tissue. Because CRP is a complement activator, and activated complement attacks cells in plaque tissue, these data provide evidence of a self-sustaining autotoxic mechanism operating within the plaques as a precursor to thrombotic events.