Effect of short-term aspirin use on C-reactive protein

Firefighting Induces Acute Inflammatory Responses that are not Relieved by Aspirin in Older Firefighters

OBJECTIVE

Sudden cardiac events account for 40% to 50% of firefighter line-of-duty deaths. Inflammatory proteins are strong biomarkers of cardiovascular inflammation. The present study investigated the effects of aspirin supplementation on inflammatory biomarkers following firefighting.

METHODS

Using a randomized, placebo-controlled, double-blind crossover design, 24 male firefighters (48.2 ± 5.9 years) were allocated into four conditions: acute (81 mg; single-dose) aspirin and placebo supplementation, and chronic (81 mg; 14 days) aspirin and placebo supplementation. Inflammatory proteins [interleukin (IL)-6, C-reactive protein (CRP), intracellular adhesion molecule (ICAM)-1, P-selectin, matrix metalloproteinase-9 (MMP-9)] and antioxidant potential [total antioxidant capacity (TAC)] were measured pre- and post-structural firefighting drills.

RESULTS

Firefighting activities significantly increased IL-6, MMP-9, and P-Selectin; however, no changes in TAC and ICAM-1 were detected. Neither acute nor chronic aspirin supplementation attenuated this inflammatory response.

CONCLUSION

Firefighting significantly increases inflammatory biomarkers and neither acute nor chronic low-dose aspirin mitigates this response.

Use of Aspirin and Statins in Relation to Inflammation in Benign Prostate Tissue in the Placebo Arm of the Prostate Cancer Prevention Trial

Aspirin and statin use may lower the risk of advanced/fatal prostate cancer, possibly by reducing intraprostatic inflammation. To test this hypothesis, we investigated the association of aspirin and statin use with the presence and extent of intraprostatic inflammation, and the abundance of specific immune cell types, in benign prostate tissue from a subset of men from the placebo arm of the Prostate Cancer Prevention Trial. Men were classified as aspirin or statin users if they reported use at baseline or during the 7-year trial. Presence and extent of inflammation were assessed, and markers of specific immune cell types (CD4, CD8, FoxP3, CD68, and c-KIT) were scored, in slides from end-of-study prostate biopsies taken irrespective of clinical indication, per trial protocol. Logistic regression was used to estimate associations between medication use and inflammation measures, adjusted for potential confounders. Of 357 men included, 61% reported aspirin use and 32% reported statin use. Prevalence and extent of inflammation were not associated with medication use. However, aspirin users were more likely to have low FoxP3, a T regulatory cell marker [OR, 5.60; 95% confidence interval (CI), 1.16-27.07], and statin users were more likely to have low CD68, a macrophage marker (OR, 1.63; 95% CI, 0.81-3.27). If confirmed, these results suggest that these medications may alter the immune milieu of the prostate, which could potentially mediate effects of these medications on advanced/fatal prostate cancer risk.

Antiinflammatory effects of aspirin in ACS: relevant to its cardio coronary actions?

Vascular injury in acute coronary syndromes (ACS) involves a complex cross-talk between inflammatory mediators, platelets and thrombosis, where the interaction between platelets and coagulation factors (e. g. thrombin) is a central link between thrombosis and inflammation. In ACS, aspirin at antiplatelet doses exhibits anti-inflammatory effects as seen from the decrease in inflammation markers such as CRP, M-CSF, MCP-1 and others. These actions probably occur subsequent to inhibition of platelet COX-1-dependent thromboxane formation and its action as a multipotent autocrine and paracrine agent. This likely involves inhibition of thrombin formation as well as inhibition of secondary pro-inflammatory mediators, such as sphingosine-1-phosphate. Experimental and limited clinical data additionally suggest antiinflammatory effects of aspirin independent of its antiplatelet action. For example, aspirin at antiplatelet doses might acetylate COX-2 in vascular cells, directing the activity of the enzyme into a 15-lipoxygenase which by transcellular metabolism results in the formation of 15-epi-lipoxin (‘aspirin-triggered lipoxin’), an antiinflammatory mediator. Furthermore, aspirin stimulates eNOS via lysine-acetylation, eventually resulting in induction of heme oxygenase (HO-1), which improves the antioxidative potential of vascular cells. All of these effects have been seen at antiplatelet doses of 100–300 mg/day, equivalent to peak plasma levels of 10–30 μM. Many more potentially antiinflammatory mechanisms of aspirin have been described, mostly salicy-late-related, at low to medium millimolar concentrations and, therefore, are of minor clinical interest. Altogether, there is a wealth of data supporting antiiflammatory effects of aspirin in ACS, but studies generating direct evidence for antiinflammatory effects in ACS remain to be done.

Current and future therapies for addressing the effects of inflammation on HDL cholesterol metabolism

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Inflammatory processes arising from metabolic abnormalities are known to precipitate the development of CVD. Several metabolic and inflammatory markers have been proposed for predicting the progression of CVD, including high density lipoprotein cholesterol (HDL-C). For ~50 years, HDL-C has been considered as the atheroprotective 'good' cholesterol because of its strong inverse association with the progression of CVD. Thus, interventions to increase the concentration of HDL-C have been successfully tested in animals; however, clinical trials were unable to confirm the cardiovascular benefits of pharmaceutical interventions aimed at increasing HDL-C levels. Based on these data, the significance of HDL-C in the prevention of CVD has been called into question. Fundamental in vitro and animal studies suggest that HDL-C functionality, rather than HDL-C concentration, is important for the CVD-preventive qualities of HDL-C. Our current review of the literature positively demonstrates the negative impact of systemic and tissue (i.e. adipose tissue) inflammation in the healthy metabolism and function of HDL-C. Our survey indicates that HDL-C may be a good marker of adipose tissue health, independently of its atheroprotective associations. We summarize the current findings on the use of anti-inflammatory drugs to either prevent HDL-C clearance or improve the function and production of HDL-C particles. It is evident that the therapeutic agents currently available may not provide the optimal strategy for altering HDL-C metabolism and function, and thus, further research is required to supplement this mechanistic approach for preventing the progression of CVD.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Association between Regular Aspirin Use and Circulating Markers of Inflammation: A Study within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

BACKGROUND

Regular aspirin use may decrease cancer risk by reducing chronic inflammation. However, associations between aspirin use and circulating markers of inflammation have not been well studied.

METHODS

Serum levels of 78 inflammatory markers were measured in 1,819 55- to 74-year-old men and women in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Data were combined from three completed case-control studies and reweighted to the PLCO screening arm. Self-reported aspirin and ibuprofen use (number of tablets taken per day/week/month) over the previous 12 months was collected at baseline. Associations between (i) nonregular (<4 tablets/month), (ii) low (1-4 tablets/week), (iii) moderate (1 tablet/day), or (iv) high (2+ tablets/day) regular aspirin or ibuprofen use and marker levels were assessed with weighted logistic regression.

RESULTS

Aspirin use was nominally associated with (Ptrend across categories ≤ 0.05) decreased levels of chemokine C-C motif ligand 15 [CCL15; OR, 0.5; 95% confidence intervals (CI), 0.3-0.8; moderate versus nonregular use]; soluble vascular endothelial growth factor receptor 2 (sVEGFR2; OR, 0.7; 95% CI, 0.4-1.0); soluble tumor necrosis factor receptor 1 (sTNFR1; OR, 0.6; 95% CI, 0.4-0.9) and increased levels of CCL13 (OR, 1.3; 95% CI, 0.8-2.1); CCL17 (OR, 1.1; 95% CI, 0.7-1.9) and interleukin 4 (IL4; OR, 1.6; 95% CI, 0.9-2.8). Trends were not statistically significant following correction for multiple comparisons. Likewise, no statistically significant associations were observed between ibuprofen use and marker levels.

CONCLUSIONS

No significant associations were observed between regular aspirin use and the inflammatory markers assessed.

IMPACT

Additional studies are needed to better understand the relationship between aspirin use, chronic inflammation, and cancer risk.

Cytokines and hs-CRP levels in individuals treated with low-dose aspirin for cardiovascular prevention: a population-based study (CoLaus Study)

Pro-inflammatory cytokines and high-sensitive C-reactive protein (hs-CRP) are associated with increased risk for cardiovascular disease. Low-dose aspirin for CV prevention is reported to have anti-inflammatory effects. The aim of this study was to determine the association between pro-inflammatory cytokines and hs-CRP levels and low-dose aspirin use for cardiovascular prevention in a population-based cohort (CoLaus Study). We assessed blood samples in 6085 participants (3201 women) aged 35-75years. Medications' use and indications were recorded. Among aspirin users (n=1'034; 17%), overall low-dose users (351; 5.8%) and low-dose for cardiovascular prevention users (324; 5.3%) were selected for analysis. Pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α were assessed by a multiplex particle-based flow cytometric assay and hs-CRP by an immunometric assay. Cytokines and hs-CRP were presented in quartiles. Multivariate analysis adjusting for sex, age, smoking status, body mass index, diabetes mellitus and immunomodulatory drugs showed no association between cytokines and hs-CRP levels and low-dose aspirin use for cardiovascular prevention, either comparing the topmost vs. the three other quartiles (OR 95% CI, 0.84 (0.59-1.18), 1.03 (0.78-1.32), 1.10 (0.83-1.46), 1.00 (0.67-1.69) for IL-1β, IL-6, TNF-α and hs-CRP, respectively), or comparing the topmost quartile vs. the first one (OR 95% CI, 0.87 (0.60-1.26), 1.19 (0.79-1.79), 1.26 (0.86-1.84), 1.06 (0.67-1.69)). Low-dose aspirin use for cardiovascular prevention does not impact plasma pro-inflammatory cytokine and hs-CRP levels in a population-based cohort.

Acidosis, magnesium and acetylsalicylic acid: effects on thrombin

Thrombin, an enzyme from the hydrolase family, is the main component of the blood coagulation system. In ischemic stroke it acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin forming blood clots in the brain. It has been found to phosphoresce at room temperature in the millisecond and microsecond ranges. The phosphorescence of thrombin was studied under physiological conditions, in acidosis (decrease of pH from 8.0 to 5.0) and on the addition of salts (magnesium sulfate and sodium chloride) and of acetylsalicylic acid, and its connection with thrombin function is discussed. Acidosis significantly increased the internal dynamics of thrombin. We propose that lactate-acidosis plays a protective role in stroke, preventing the formation of clots. The addition of NaCl and MgSO(4) in different concentrations increased the internal dynamics of thrombin. Also, the addition of MgSO(4) decreased thrombin-induced platelet aggregation. However, magnesium sulfate and acetylsalicylic acid in the therapeutic concentrations used for treatment of ischemic stroke had no effect on thrombin internal dynamics. The data obtained will help to elucidate the conformational stability of thrombin under conditions modulating lactate-acidosis and in the presence of magnesium sulfate.

Association between use of specialty dietary supplements and C-reactive protein concentrations

Laboratory evidence suggests that certain specialty dietary supplements have antiinflammatory properties, though evidence in humans remains limited. Data on a nationally representative sample of 9,947 adults from the 1999-2004 cycles of the National Health and Nutrition Examination Survey were used to assess the associations between specialty supplement use and inflammation, as measured by serum high-sensitivity C-reactive protein (hs-CRP) concentration. Using survey-weighted multivariate linear regression, significant reductions in hs-CRP concentrations were associated with regular use of glucosamine (17%, 95% confidence interval (CI): 7, 26), chondroitin (22%, 95% CI: 8, 33), and fish oil (16%, 95% CI: 0.3, 29). No associations were observed between hs-CRP concentration and regular use of supplements containing methylsulfonylmethane, garlic, ginkgo biloba, saw palmetto, or pycnogenol. These results suggest that glucosamine and chondroitin supplements are associated with reduced inflammation in humans and provide further evidence to support an inverse association between use of fish oil supplements and inflammation. It is important to further investigate the potential antiinflammatory role of these supplements, as there is a need to identify safe and effective ways to reduce inflammation and the burden of inflammation-related diseases such as cancer and cardiovascular disease.

Aspirin and platelet adenosine diphosphate receptor antagonists in acute coronary syndromes and percutaneous coronary intervention: role in therapy and strategies to overcome resistance

Platelet activation and aggregation are key components in the cascade of events causing thrombosis following plaque rupture. Antiplatelet therapy is essential in the treatment of patients with acute coronary syndromes (ACS) and for those requiring percutaneous coronary intervention (PCI). Aspirin (acetylsalicylic acid) is a well established antiplatelet therapy and is mandated for secondary prevention of cardiovascular events following ACS. In patients with ACS, the addition of clopidogrel to aspirin is more effective than aspirin alone. For patients undergoing PCI, dual antiplatelet therapy with aspirin and clopidogrel is warranted. Aspirin should be continued indefinitely after PCI. Pretreatment of patients with clopidogrel prior to PCI lowers the incidence of cardiovascular events, yet the optimum timing of drug administration and dose are still being investigated, as is the duration of therapy following PCI. Late-stent thrombosis with drug-eluting stents has pushed the recommendation for duration of clopidogrel therapy up to 1 year and perhaps beyond, in patients without risks for bleeding. The concepts of aspirin and clopidogrel resistance are important clinical questions. No uniform definition exists for aspirin or clopidogrel resistance. Measurements of resistance are often highly variable and do not necessarily correlate with clinical resistance. Noncompliance remains the most prominent mode of resistance. Screening of selected patient populations for resistance or pharmacologic intervention of those patients termed 'resistant' warrants further study.

Factors associated with inflammation markers, a cross-sectional analysis

Epidemiological studies have reported associations between circulating inflammation markers and risk of chronic diseases. It is of interest to examine whether risk factors for these diseases are associated with inflammation. We conducted a cross-sectional analysis to evaluate whether reproductive and lifestyle factors and circulating vitamin D were associated with inflammation markers, including C-reactive protein, cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p40, IL-12p70, IL-13, TNFα), and cytokine modulators (IL-1RA, sIL-1RII, sIL-2Ra, sIL-4R, sIL-6R, sTNF-R1/R2), among 616 healthy women. We confirmed associations of several inflammation markers with age and BMI. We also observed significantly higher levels of certain inflammation markers in postmenopausal vs. premenopausal women (TNFα, sIL-1RII, sIL-2Ra), with increasing parity (IL-12p40), and with higher circulating 25(OH) vitamin D (IL-13) and lower levels among current users of non-steroidal anti-inflammatory drugs (NSAIDs) (IL-1β, IL-2, IL-10, IL-12p70, and IL-12p40), current smokers (IL-4, IL-13, IL-12p40), and women with a family history of breast or ovarian cancer (IL-4, IL-10, IL-13). Our findings suggest that risk factors for chronic diseases (age, BMI, menopausal status, parity, NSAID use, family history of breast and ovarian cancer, and smoking) are associated with inflammation markers in healthy women.

Cardiovascular disease, SCI and exercise: unique risks and focused countermeasures

PURPOSE

To summarise the spinal cord injury (SCI) specific profile of three cardiovascular disease risk factors (CVD): fasting dyslipidaemia, postprandial lipidaemia and vascular inflammation and to summarise exercise prescriptions that may attenuate each.

METHOD

NA.

RESULTS

NA.

CONCLUSIONS

At least three CVD risk factors have unique profiles in the SCI population. Fasting dyslipidaemia is characterised in the SCI population by depressed HDL cholesterol and normal or low total cholesterol. In the post-prandial state, persons with SCI exhibit an exaggerated triglyceride rise and delayed clearance compared to non-disabled persons. Finally, vascular inflammation, as indexed by C-reactive protein, is markedly elevated in SCI. Exercise may improve each, although the specific prescriptions differs. Fasting dyslipidaemia responds to 8 weeks of moderate intensity aerobic exercise performed 5 days weekly for 30 min daily. Post-prandial lipaemia treatment requires daily moderate or vigorous aerobic exercise, as the effect dissipates day by day. The daily exercise duration is proportional to fitness level, with total caloric expenditure emphasised rather than time. Finally, attenuating vascular inflammation in non-disabled persons requires moderate or vigorous exercise performed for ≥12 months, 5 days weekly for ≥45 min; with aerobic exercise plus resistance training more effective than aerobic exercise alone.

Clopidogrel discontinuation and platelet reactivity following coronary stenting

AIMS

Antiplatelet therapy with aspirin and clopidogrel is recommended for 1 year after drug-eluting stent (DES) implantation or myocardial infarction. However, the discontinuation of antiplatelet therapy has become an important issue as recent studies have suggested a clustering of ischemic events within 90 days of clopidogrel withdrawal. The objective of this investigation was to explore the hypothesis that there is a transient 'rebound' increase in platelet reactivity within 3 months of clopidogrel discontinuation.

METHODS AND RESULTS

In this prospective study, platelet function was assessed in patients taking aspirin and clopidogrel for at least 1 year following DES implantation. Platelet aggregation was measured using a modification of light transmission aggregometry in response to multiple concentrations of adenosine diphosphate (ADP), epinephrine, arachidonic acid, thrombin receptor activating peptide and collagen. Clopidogrel was stopped and platelet function was reassessed 1 week, 1 month and 3 months later. Thirty-two patients on dual antiplatelet therapy were recruited. Discontinuation of clopidogrel increased platelet aggregation to all agonists, except arachidonic acid. Platelet aggregation in response to ADP (2.5, 5, 10, and 20 μm) and epinephrine (5 and 20 μm) was significantly increased at 1 month compared with 3 months following clopidogrel withdrawal. Thus, a transient period of increased platelet reactivity to both ADP and epinephrine was observed 1 month after clopidogrel discontinuation.

CONCLUSIONS

This study demonstrates a transient increase in platelet reactivity 1 month after clopidogrel withdrawal. This phenomenon may, in part, explain the known clustering of thrombotic events observed after clopidogrel discontinuation. This observation requires confirmation in larger populations.

The effect of aspirin on C-reactive protein in hypertensive patients

High level of C-reactive protein (CRP), most popular inflammatory marker, increases the risk of thrombotic cardiovascular events. Aspirin, which has both anti-inflammatory and anti-thrombotic effects, has the potential to influence CRP release. Several studies have been reported investigating clinical effects of aspirin on CRP levels. Some studies have reported aspirin reduced CRP levels, but other studies did not. This study was designed to assess the effect of low-dose aspirin on CRP levels in controlled hypertensive patients who had low inflammatory burden. Two hundred twenty-five patients with controlled hypertension were randomly divided into two groups; aspirin group (n = 122, 100 mg of aspirin) and the control group (n = 134). Patients with a CRP level >1 mg/dL (10 mg/L) were excluded because these high levels suggest infection. C-reactive protein level and lipid profiles were measured before therapy and 3 months after therapy. There were no differences in baseline clinical characteristics between the two groups. Low-dose aspirin showed no significant influence on CRP levels over 3 months (from 0.10 ± 0.0099 to 0.12 ± 0.0097 mg/dL, p = 0.12). Statin therapy did not influence CRP levels. Aspirin-resistance also had no influence on CRP levels. We conclude that low-dose aspirin has no significant effect on decreasing CRP levels in the patients with controlled hypertension which had low inflammatory burden. The anti-inflammatory mechanism may not play an important role in the cardioprotective effect of aspirin in the population with low inflammatory burden such as controlled hypertensive patients.

Aspirin adherence, aspirin dosage, and C-reactive protein in the first 3 months after acute coronary syndrome

Persistent elevation of inflammatory markers such as C-reactive protein (CRP) has been associated with an increased risk of recurrent cardiac events after acute coronary syndromes (ACS). Conflicting evidence is available regarding whether aspirin can reduce CRP after ACS. We investigated whether the dosage and adherence to aspirin was associated with the CRP level 3 months after ACS. Adherence to aspirin was monitored for 3 months in a cohort of 105 patients enrolled within 1 week of an ACS using an electronic chip stored in the pill bottle cap. The CRP level was measured at baseline and 3 months. Logistic regression analysis was used to test whether poor adherence to aspirin and a lower aspirin dosage were associated with increased CRP levels, controlling for age, ACS type, disease co-morbidity, baseline CRP level, use of clopidogrel and statins, depressive symptoms, smoking, and adherence to other medications. Aspirin adherence was inversely correlated with the CRP level at 3 months (Spearman's r = -0.36, p < 0.001). In the adjusted model, every 10% decrease in aspirin adherence was associated with a 1.7 increased risk (95% confidence interval 1.2 to 2.4) of a CRP level of ≥ 3.0 mg/L at 3 months. Low-dose aspirin was associated with a 7.1 increased risk (95% confidence interval 1.5 to 33.3) of a CRP level of ≥ 3.0 mg/L. The Charlson co-morbidity index, depressive symptoms, and baseline CRP level were also predictive of a CRP level of ≥ 3.0 mg/L at 3 months. The association between aspirin adherence and CRP level was not attenuated by controlling for other risk-reducing behaviors. In conclusion, a strong association was found between aspirin adherence and the CRP level after an ACS.

Aspirin resistance following pediatric cardiac surgery

INTRODUCTION

Aspirin is often used to prevent thrombosis in pediatric cardiac surgery. The primary study aim was to assess aspirin resistance in this context. Secondary aims were to evaluate (1) the relationship between elevated inflammatory markers and thrombosis and (2) aspirin's effect on these levels.

MATERIALS AND METHODS

This was a prospective observational study of children undergoing cardiac surgery managed with and without aspirin. Aspirin response was assessed using the VerifyNow system and urinary 11-dehydrothromboxane B2 (uTxB2) measurements. Laboratory studies of inflammation were also obtained.

RESULTS

101 subjects were studied; 50 received aspirin. Six subjects (5.9%), 5 aspirin-treated, experienced symptomatic thrombosis. When measured by VerifyNow resistance was 43% after aspirin suppositories and 14% after additional days of oral aspirin. There was no correlation with thrombosis. Upper quartile post-operative day (POD) #5 uTxB2 was correlated with thrombosis in aspirin treated subjects (p<0.01). High risk aspirin-treated subjects who experienced thrombosis had higher POD#5 uTxB2. This finding did not reach statistical significance (p=0.07). Elevated pre-operative C-reactive protein (CRP) was independently associated with thrombosis (p<0.02) in all subjects and in high risk subjects (p=0.01). Inflammatory markers were not affected by aspirin.

CONCLUSIONS

Aspirin inhibited ex-vivo platelet function with a low incidence of resistance. Elevated POD#5 uTxB2 and pre-operative CRP were correlated with thrombosis in aspirin treated subjects. Further studies are needed to determine whether children with high levels of uTxB2 despite aspirin therapy and/or those with elevated preoperative CRP are at increased risk for thrombosis.

Antagonistic effects of aspirin and folic acid on inflammation markers and subsequent risk of recurrent colorectal adenomas

The Aspirin/Folate Polyp Prevention Trial found that aspirin, but not folic acid, reduced recurrence of colorectal adenomas. This study examined whether treatment effects on inflammation markers explained the trial results. The trial had a factorial design with three aspirin (placebo, 81, and 325 mg/d) and two folic acid (placebo and 1 mg/d) groups. There were 884 subjects who had colonoscopic evaluation for adenomas at year 3 and plasma levels of C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), soluble TNF receptor type II (sTNF-R2), and IL-1 receptor antagonist (IL-1Ra) measured at baseline and year 3. Among individuals not receiving folic acid, there was a 4% decrease (mean ratio of year 3 to baseline levels = 0.96, 95% confidence interval [CI] = 0.82 to 1.14) in CRP for a period of 3 years in the 325 mg of aspirin group vs a 20% increase (mean ratio = 1.20, 95% CI = 1.03 to 1.41) in the placebo group (P = .027). By contrast, the reverse was observed among individuals who also received folic acid (P(interaction) = .013). Changes in inflammation markers were not associated with adenoma recurrence. Low-dose aspirin (325 mg/d) is beneficial in stabilizing CRP levels, which may be abrogated by folate. Nevertheless, inflammation markers do not mediate the chemopreventive effect of aspirin on colorectal adenomas.

Effect of aspirin, clopidogrel and dipyridamole on soluble markers of vascular function in normal volunteers and patients with prior ischaemic stroke

Although the mechanisms of action by which aspirin, clopidogrel and dipyridamole inhibit platelets are well characterised, their effects on soluble modulators of thrombosis, inflammation, and endothelial function have yet to assessed systematically. In this investigation aspirin (A), clopidogrel (C), and dipyridamole (D) were administered singly and in combination (A, C, D, AC, AD, CD, ACD) in random order for 2 weeks (without washout) to 11 healthy subjects and 11 patients with previous ischaemic stroke. At the end of each treatment period plasma cyclic guanosine monophosphate (cGMP), monocyte chemoattractant pertide-1 (MCP-1), nitric oxide metabolites (NO(x)), plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor (vWf); and serum C-reactive protein (CRP) and platelet derived growth factor (PDGF); were measured blinded to treatment. Dipyridamole reduced plasma vWf levels (%) in both volunteers, -10.0 (4.95), and patients, -10.11 (4.34) (p < 0.05). Dipyridamole also lowered CRP (mg/l) in patients, -0.96 (0.47), but not volunteers. Clopidogrel reduced PAI-1 (ng/ml) in volunteers, -5.30 (2.20) (p < 0.05), and patients, -3.61 (2.75) (non-significant trend). Aspirin lowered PDGF (ng/ml) in volunteers, -3.46 (1.55), but not patients. Triple antiplatelet therapy was superior to dual and mono therapy in reducing vWf levels. In conclusion, antiplatelet agents have non-platelet-related effects on soluble modulators of thrombosis, inflammation, and endothelial function. In particular, dipyridamole reduces plasma vWf and clopidogrel lowers plasma PAI-1 levels. These effects may explain, in part, their roles in preventing atherothrombogenesis.

High-sensitivity C-reactive protein measurements in patients with non-arteritic anterior ischaemic optic neuropathy: a clue to the presence of a microinflammatory response

PURPOSE

To explore the possibility that individuals with non-arteritic anterior ischaemic optic neuropathy (NA-AION) harbour a heightened microinflammatory response compared to carefully matched controls.

METHODS

Diagnosis and follow-up were performed by a senior neuro-ophthalmologist (A.K.). The inflammatory biomarkers included white blood cell count, Westergren erythrocyte sedimentation rate (ESR), quantitative fibrinogen as well as high-sensitivity C-reactive protein (hs-CRP). The values of the inflammatory biomarkers of four and five matched controls were compared to patients with NA-AION.

RESULTS

We examined 33 NA-AION patients and 151 controls matched for age, gender, body mass index, oral temperature, smoking status and atherothrombotic risk factors. A significantly elevated concentration was noted for hs-CRP (P = 0.021): 3.3 mg/l for NA-AION patients and 2.1 mg/l for controls. Accelerated ESR (18.8 versus 13.5 mm/hr, P = 0.025) was noted in the NA-AION patients.

CONCLUSION

Following appropriate matching to apparently healthy controls, patients with NA-AION presented a microinflammatory response, revealed by the presence of increased hs-CRP concentrations and accelerated ESR. The finding, if confirmed in future studies, might shed more light on the eventual pathophysiological processes involved in the disease and pave the way for new therapeutic approaches.

Inflammatory markers and negative mood symptoms following exercise withdrawal

OBJECTIVE

Physical inactivity is associated with elevated inflammatory markers, but little is known about the time trajectories of reduced physical activity and inflammatory markers. Changes in inflammatory markers in response to withholding regular aerobic exercise were prospectively examined and correlated with increased negative mood symptoms and fatigue that accompany exercise withdrawal.

METHODS

Participants with regular exercise habits (N=40, mean age of 31.3+/-7.5 years, 55% women) were randomized to aerobic exercise withdrawal or to continue regular exercise for 2 weeks. Protocol adherence was documented using ambulatory actigraphy. Inflammatory markers (interleukin-6, C-reactive protein, fibrinogen and soluble intercellular adhesion molecule-1) were assessed at weekly intervals. Negative mood was measured with the Profile of Mood States (POMS) and the Beck Depression Inventory (BDI), and fatigue with the Multidimensional Fatigue Inventory (MFI). Autonomic nervous system activity was examined using heart rate variability-based indices.

RESULTS

Changes in inflammatory markers did not differ between exercise withdrawal and control groups (multivariate p interaction=0.25). Exercise withdrawal resulted in increased negative mood symptoms and fatigue from baseline to day 14 compared to controls (p DeltaPOMS=0.008, p DeltaBDI=0.002; p DeltaMFI=0.003), but these responses were not associated with changes in inflammatory markers (p-values >0.10). Inflammatory markers were also not correlated with autonomic nervous system dysregulation (p-values >0.10).

CONCLUSION

Inflammatory markers were not increased following 2 weeks of exercise withdrawal. Negative mood symptoms and fatigue were not accounted for by changes in inflammatory markers. Compensatory feedback mechanisms may operate among healthy individuals to promote resilience from the effects of reduced exercise.

Effects of aspirin on serum C-reactive protein and interleukin-6 levels in patients with type 2 diabetes without cardiovascular disease: a randomized placebo-controlled crossover trial

AIM

Low-grade inflammation plays a pivotal role in atherogenesis in type 2 diabetes. Next to its antithrombotic effects, several lines of evidence demonstrate anti-inflammatory properties of aspirin. We determined the effects of aspirin on inflammation - represented by C-reactive protein (CRP) and interleukin-6 (IL-6) - in type 2 diabetic subjects without cardiovascular disease and assessed differential effects of aspirin 300 mg compared with 100 mg.

METHODS

A randomized, placebo-controlled, double-blind, crossover trial was performed in 40 type 2 diabetic patients. In two periods of 6 weeks, patients used 100 or 300 mg aspirin and placebo. Plasma CRP and IL-6 levels were measured before and after both periods.

RESULTS

Use of aspirin resulted in a CRP reduction of 1.23 +/- 1.02 mg/l (mean +/- s.e.m.), whereas use of placebo resulted in a mean increase of 0.04 +/- 1.32 mg/l (P = 0.366). Aspirin reduced IL-6 with 0.7 +/- 0.5 pg/ml, whereas use of placebo resulted in a mean increase of 0.2 +/- 0.8 pg/ml (P = 0.302). There were no significant differences in effects on CRP and IL-6 between 100 and 300 mg aspirin.

CONCLUSIONS

Our results indicate that a 6-week course of aspirin does not improve low-grade inflammation in patients with type 2 diabetes without cardiovascular disease, although a modest effect could not be excluded. No significant differential effects between aspirin 100 and 300 mg were found.

An assessment of the joint associations of aspirin and statin use with C-reactive protein concentration

BACKGROUND

The use of aspirin alone and statins alone has been shown to reduce markers of inflammation, including C-reactive protein (CRP); however, their combination has been poorly studied.

METHODS

In a cross-sectional analysis of black and white adults > or =45 years old from the REGARDS cohort, the associations of aspirin and statin use with CRP were examined. Individuals requiring nonsteroidal anti-inflammatory drug therapy or those taking aspirin for reasons other than cardioprotection were excluded from analysis. Participants were classified into 1 of 4 groups: aspirin only (n = 3,673), statin only (n = 1,898), both agents (n = 3,008), or neither agent (n = 7,718).

RESULTS

Estimated mean CRP was 2.78 mg/L for subjects taking neither drug, 2.73 mg/L with aspirin only, 2.29 mg/L with statins only, and 2.03 mg/L for subjects taking both agents. The combined use of both agents was associated with an apparent synergistically lower CRP; the mean CRP level among these combined users was 0.21 mg/L lower than that anticipated from additive association related to aspirin and statins alone (P for interaction = .01). Associations were larger among participants reporting a history of cardiovascular disease. In addition, among statin users, the use of aspirin for >5 years compared with < or =5 years was associated with apparent significantly lower CRP concentrations (P = .01).

CONCLUSIONS

The combined use of aspirin and statins was associated with a synergistically lower CRP concentration, especially among participants taking aspirin for >5 years. Given the limitations of this study and the modest associations, randomized controlled trial evidence is needed to confirm the findings.

C-reactive protein levels increase after exercise testing in patients with increased platelet reactivity

Aspirin has the potential to influence C-reactive protein (CRP) levels, an inflammatory marker, by its anti-inflammatory activity. Persistently increased platelet reactivity, however, can be detected with different laboratory methods despite aspirin therapy in some patients. The aim of this study was to investigate the effects of increased platelet reactivity on CRP levels at rest and after exercise in patients with documented or suspected coronary artery disease. Blood samples were collected from 100 patients (age, 58.1+/-8.5 years; 63.0% men) who were treated with 100 or 300 mg/day enteric-coated aspirin for at least 7 days, before and immediately after treadmill test for CRP analyses. Platelet reactivity was measured by the standardized platelet function analyzer-100, and increased platelet reactivity was defined as a normal collagen/epinephrine closure time (<165 s). Of the 100 patients, 82 had normal platelet reactivity (group A) and 18 had increased platelet reactivity (group B). The CRP levels increase was statistically significant after exercise in patients with increased platelet reactivity [group A: 2.3 (1.4-4.3) to 2.8 (1.6-4.9) mg/l, P=0.09; group B: 3.3 (2.0-4.5) to 4.7 (2.9-8.5) mg/l, P=0.02]. Detecting increased platelet reactivity is associated with an increase in CRP levels. The clinical significance of this finding needs to be further investigated.

Clinical evidence for anti-inflammatory effects of antiplatelet therapy in patients with atherothrombotic disease

Recent advances in our understanding of cardiovascular disease have revealed that atherothrombotic events, such as myocardial infarction and ischemic stroke, are the end result of a complex inflammatory response to multifaceted vascular pathology. As well as initiating thrombus formation at the site of a ruptured atherosclerotic plaque, platelets play a key role in vascular inflammation, through release of their own pro-inflammatory mediators and interactions with other relevant cell types (endothelial cells, leukocytes, and smooth muscle cells). An increasing body of literature shows that inflammatory biomarkers can be used to predict atherothrombotic risk and that antiplatelet therapy may reduce the levels of these markers. Acetylsalicylic acid (ASA) has been attributed with reducing levels of the transcription factor nuclear factor kappaB (NF-kappaB), C-reactive protein, and soluble CD40 ligand, although the evidence relating to the latter two markers is conflicting. There is also substantial evidence that therapy with clopidogrel, a specific antagonist of the platelet P2Y12 ADP-receptor, also leads to reductions in serum levels of CD40 ligand, C-reactive protein, P-selectin, and platelet-leukocyte aggregate formation. Beneficial effects of clopidogrel on inflammatory markers have been demonstrated across the spectrum of atherothrombotic disease (acute coronary syndrome patients, patients undergoing percutaneous coronary intervention (PCI), acute ischemic stroke patients, and those with peripheral arterial disease). Oral glycoprotein (GP) IIb/IIIa receptor antagonists, at doses that achieve moderate levels of receptor blockade, may paradoxically be associated with platelet-mediated pro-inflammatory effects. A similar phenomenon has been observed with intravenous GP IIb/IIIa antagonists in vitro, but most often at low doses, and data from clinical studies suggest that these agents may actually attenuate release of inflammatory mediators when administered at doses producing more complete receptor blockade.

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

Clinicians involved in the care of patients with cardiovascular conditions have recently been confronted with an important body of literature linking inflammation and cardiovascular disease. Indeed, the level of systemic inflammation as measured by circulating levels of C-reactive protein (CRP) has been linked to prognosis in patients with atherosclerotic disease, congestive heart failure, atrial fibrillation, myocarditis, aortic valve disease and heart transplantation. In addition, a number of basic science reports suggest an active role for CRP in the pathophysiology of cardiovascular diseases. This article explores the potential role of CRP in disease initiation, progression, and clinical manifestations and reviews its role in the prediction of future events in clinical practice. Therapeutic interventions to decrease circulating levels of CRP are also reviewed.

Aspirin may be more effective in preventing colorectal adenomas in patients with higher BMI (United States)

Obesity is a risk factor for colon cancer, possibly due to elevated levels of circulating cytokines derived from adipose tissue. Aspirin, which may affect the levels of these cytokines, has been shown in randomized controlled trials to decrease the risk of colorectal adenomas. We hypothesized that the chemopreventive effect of aspirin might be greater in individuals with higher body mass index (BMI). Data were available from the Aspirin/Folate Polyp Prevention Study, a randomized controlled trial of aspirin and folic acid to prevent recurrent colorectal adenomas. Obesity was defined as BMI > or = 30 (kg/m2), overweight as BMI of 25-29 (kg/m2) and normal weight as BMI <25 (kg/m2). For the analysis of the effect of aspirin on the recurrence of colorectal adenoma by BMI, we computed risk ratios for aspirin versus placebo within the three BMI strata using a modified Poisson model. Overall the risk reduction of adenomas with a daily dose of 325 mg aspirin was greater among subjects with higher BMI. Among obese subjects the risk ratio (RR) for advanced adenomas compared with placebo was 0.44 (95% CI 0.17-1.10), versus RR = 1.23 (95% CI 0.55-2.77) among those with normal weight. However, 81 mg aspirin daily did not interact with BMI to modify the risk of adenomas in such a fashion. The more pronounced effect of 325 mg aspirin in individuals with higher BMI suggests a possible protective role of anti-inflammatory aspirin against increased adipose-driven cytokines among obese subjects.

C-Reactive Protein Distribution and Correlates among Men and Women with Chronic Coronary Heart Disease

BACKGROUND

C-reactive protein (CRP) elevated in inflammation is associated with atherosclerotic disease. We describe the distribution of CRP and its association with coronary heart disease (CHD) risk factors in a large CHD patient group.

METHODS

This analysis comprises 2,723 male and 256 female CHD patients, included in the Bezafibrate Infarction Prevention (BIP) study. High sensitive CRP levels were determined in frozen plasma samples.

RESULTS

CRP distribution, was normalized upon log transformation. Levels among women were higher than in men in the entire group (4.4 vs. 3.5 mg/l) and in each age group. Co-morbidities, smoking, lower education level, and use of cardiovascular drugs, were associated with elevated CRP levels in both sexes. The correlation between CRP and body mass index (BMI), insulin and glucose was stronger among women. The explained variability in CRP level was larger in women (20%) compared to men (13%). Among women, BMI explained 10% of CRP variability, whereas the contribution of each variable among men was significantly smaller.

CONCLUSIONS

Among men and women with CHD, CRP level was correlated with traditional risk factors and to a lesser degree to manifestation of CHD. BMI is the main contributor to CRP variability, explained by these factors among women.

Platelets as Mediators of Inflammation

An expanding body of evidence continues to build on the central role of inflammation in the progression and clinical manifestations of atherosclerosis. Platelets, long thought to play only a reactionary role at the time of endothelial disruption, are now recognized as important mediators of the inflammatory process. Platelet activation, which is modulated by both inflammatory and hemostatic factors, can lead to the release of hundreds of proteins--many with known proinflammatory functions. Although compelling evidence is lacking that antiplatelet therapies directly lower markers of inflammation, there are intriguing, although preliminary, data suggesting that markers of inflammation predict the clinical benefit of antiplatelet therapies.

Relation between soluble intercellular adhesion molecule-1, statin therapy, and long-term risk of clinical cardiovascular events in patients with previous acute coronary syndrome (from PROVE IT-TIMI 22)

High levels of adhesion molecules, such as soluble intercellular adhesion molecule-1 (sICAM-1), are associated with long-term risk of cardiac events in patients with and without stable coronary artery disease. The relation between sICAM-1 and long-term risk after acute coronary syndromes (ACSs) and the influence of statin treatment has not been explored. Using a nested case-control design, patients with ACS who were enrolled in the PROVE IT-TIMI 22 trial were matched for age, gender, smoking, diabetes, type of ACS presentation, and revascularization for index event (583 patients with recurrent events vs 581 controls). Patients with recurrent events were identified as such by death, myocardial infarction, or hospitalization for recurrent ACS. Soluble ICAM-1 was measured at study entry (approximately 7 days after ACS). After adjusting for statin regimen and other risk factors, patients in quartiles 2 to 4 were at a higher risk of clinical events compared with those in quartile 1 (odds ratio 1.6 for quartile 4 vs 1, 95% confidence interval 1.1 to 2.3, p = 0.02). The risk of adverse events in patients with sICAM-1 levels in quartiles 2 to 4 was most marked in subjects who were allocated to standard dose statin therapy, even after adjusting for low-density lipoprotein cholesterol and C-reactive protein at day 30. The risk in quartiles 2 to 4 was somewhat attenuated in the intensive therapy group. In conclusion, in this large study of patients with ACS, we provide evidence that increased endothelial activation after ACS is independently associated with increased long-term risk of death, myocardial infarction, or recurrent ACS.

Clopidogrel withdrawal is associated with proinflammatory and prothrombotic effects in patients with diabetes and coronary artery disease

Inhibition of the P2Y12 pathway by the platelet antagonist clopidogrel is associated with a marked reduction in platelet reactivity. Recent reports have shown that P2Y12 inhibition has anti-inflammatory effects as well. However, whether clopidogrel withdrawal is associated with proaggregatory and proinflammatory effects has not yet been explored. Since diabetic subjects are characterized by a prothrombotic and proinflammatory status, we hypothesize that these patients may be more vulnerable to these effects. A total 54 patients with diabetes on long-term (12 months) dual antiplatelet therapy (aspirin plus clopidogrel) were studied. Platelet aggregation (following 6 and 20 micromol/l ADP stimuli) and inflammatory markers (C-reactive protein and P-selectin expression) were assessed before and 1 month following clopidogrel withdrawal. Following clopidogrel withdrawal, aspirin responsiveness using platelet function analyzer-100 was determined as well. A significant increase in all the assessed platelet (P < 0.0001 for 6 and 20 micromol/l ADP-induced aggregation) and inflammatory (P < 0.05 for C-reactive protein, P < 0.001 for P-selectin expression in resting platelets, and P < 0.0001 for P-selectin expression in ADP-stimulated platelets) biomarkers was observed following clopidogrel withdrawal. Low responders to aspirin had increased platelet aggregation profiles (P < 0.05 for 6 and 20 micromol/l ADP-induced aggregation) but no differences in inflammatory markers. In conclusion, clopidogrel withdrawal is associated with an increase in platelet and inflammatory biomarkers in diabetic patients, supporting pleiotropic effects coupled with P2Y12 receptor antagonism.

Lack of significant effect of low doses of aspirin on the concentrations of C-reactive protein in a group of individuals with atherothrombotic risk factors and vascular events

Atherothrombosis is associated with the presence of a microinflammatory response, usually monitored by the use of C-reactive protein (CRP) measurements. In the Physician Health Study it was suggested that individuals who benefit most from the treatment are those who have enhanced concentrations of this biomarker. The possibility was suggested that one of the mechanisms of action of aspirin in thrombotic prevention is through its anti-inflammatory properties in terms of reducing the concentration of CRP. We conducted a regression analysis in a cohort of 3888 apparently healthy individuals and those with atherothrombotic risk factors and vascular events, 370 of whom were under the treatment of low doses (<or= 325 mg/day) of aspirin. The significant determinants of CRP concentrations included body mass index, oral contraceptives, hormonal replacement therapy, gender, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, physical activity, age, smoking status and the presence of diabetes mellitus but not the use of low dose of aspirin. We conclude that the use of low doses (<or= 325 mg/day) of aspirin does not have a significant role in the modulation of CRP concentrations in apparently healthy individuals and those with atherothrombotic risk factors and vascular events. The anti-atherothrombotic activity of this drug is probably not mediated through a significant reduction of the concentration of this protein.

Response of Serum C-Reactive Protein to Percutaneous Coronary Intervention Has Prognostic Value

Background: Data are sparse regarding the association between C-reactive protein (CRP) and percutaneous coronary intervention (PCI) in long-term prognosis. Previous studies have shown that PCI evokes an inflammatory response. We tested the hypothesis that the CRP response to PCI has a prognostic value.

Methods: We investigated 891 consecutive patients presenting with stable or unstable angina pectoris, with serum concentrations of cardiac troponin T ≤0.03 μg/L, who were undergoing a variety of PCIs. Serum concentrations of CRP and cardiac troponin T were determined before and the day after PCI. The mean follow-up time after PCI was 2.6 years, and the endpoint was death or nonfatal myocardial infarction.

Results: Seventy-six patients reached the endpoint (4.6% death, 3.9% nonfatal myocardial infarction), whereas 21% developed myocardial infarction during the procedure. CRP increased more than 2-fold after the procedure. Patients in the third tertile of the CRP response to PCI had an increased risk for death or nonfatal myocardial infarction in multivariate analysis.

Conclusions: Increased serum CRP in response to PCI is an independent predictor of death or nonfatal myocardial infarction independent of myocardial injury during the procedure. CRP determinations might be of value in risk stratification after PCI.

Increased titres of anti-human heat shock protein 60 predict an adverse one year prognosis in patients with acute cardiac chest pain

OBJECTIVE

To assess whether antibodies to human heat shock protein 60 (anti-huhsp60) or to mycobacterial heat shock protein 65 (anti-mhsp65) predict an adverse one year prognosis in patients admitted with acute cardiac chest pain.

DESIGN

Prospective observational study.

SETTING

Teaching hospital.

PATIENTS

588 consecutive emergency admissions of patients with acute chest pain of suspected cardiac origin.

MAIN OUTCOME MEASURES

Anti-huhsp60 and anti-mhsp65 titres were assayed on samples drawn on the morning after admission. The end points after discharge were coronary heart disease death, non-fatal myocardial infarction, coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, angiogram, or readmission with further cardiac ischaemic chest pain.

RESULTS

During follow up after discharge (mean of 304 days, range 1-788 days), 277 patients had at least one of the study outcomes. Patients with increased titres of anti-huhsp60 had an adverse prognosis (hazard ratio 1.56 (95% confidence interval 1.09 to 2.23) comparing highest versus lowest quartiles, p = 0.015). Anti-mhsp65 titres were not predictive.

CONCLUSIONS

Patients admitted with acute cardiac chest pain and increased titres of anti-huhsp60 had an adverse one year prognosis.

Place of drug therapy in the treatment of carotid stenosis

Carotid stenosis is an important cause of transient ischaemic attacks and stroke. The cause of carotid stenosis is most often atherosclerosis; contributing to the pathogenesis of the lesion are endothelial injury, inflammation, lipid deposition, plaque formation, fibrin, platelets and thrombin. Carotid stenosis accounts for 10-20% of cases of brain infarction, depending on the population studied. Despite successful treatment of selected patients who have had an acute ischaemic stroke with tissue plasminogen activator and the promise of other experimental therapies, prevention remains the best approach to reducing the impact of ischaemic stroke. High-risk or stroke-prone patients can be identified and targeted for specific interventions. At this juncture, treatment of carotid stenosis is a well established therapeutic target and a pillar of stroke prevention. There are two main strategies for the treatment of carotid stenosis. The first approach is to stabilise or halt the progression of the carotid plaque through risk factor modification and medication. Hypertension, diabetes mellitus, smoking, obesity and high cholesterol levels are closely associated with carotid stenosis and stroke; control of these factors may decrease the risk of plaque formation and progression. The second approach is to eliminate or reduce carotid stenosis through carotid endarterectomy or carotid angioplasty and stenting. Carotid endarterectomy, which is the mainstay of therapy for severe carotid stenosis, is beyond the scope of this review. Anticoagulants seem to play little role (if any) in the medical (i.e. non-surgical) treatment of carotid stenosis. Adoption of a healthy lifestyle combined with the reduction of risk factors has been shown to lead to a reduction in the extent of carotid stenosis. The medical treatment of carotid stenosis should be based on the triad of the reduction of risk factors, patient education, and use of antiplatelet agents.

Aspirin Resistance and Atherothrombotic Disease

Acute coronary syndromes and other manifestations of atherothrombotic disease are primarily caused by atherosclerotic plaque rupture or fissuring and subsequent occlusive or subocclusive thrombus formation. Platelets play a critical role in the pathophysiology of atherothrombotic disease, and aspirin is the most commonly used antiplatelet agent. Clinical trials have demonstrated the efficacy of aspirin in both primary and secondary prevention of myocardial infarction, stroke, and cardiovascular death. Despite its proven benefit, the absolute risk of recurrent vascular events among patients taking aspirin remains relatively high, an estimated 8% to 18% after two years. Therapeutic resistance to aspirin might explain a portion of this risk. Although formal diagnostic criteria and a validated method of measurement are lacking, aspirin resistance may affect between 5% and 45% of the population. Given the prevalence of cardiovascular disease, the potential impact of aspirin resistance is large. Currently, however, there are many unanswered questions regarding the biological mechanism, diagnosis, population prevalence, clinical relevance, and optimal therapeutic intervention for aspirin resistance.

Cyclooxygenase-mediated prostaglandin F2alpha is decreased in an elderly population treated with low-dose aspirin

Low-dose aspirin (acetylsalicylic acid) is used as prophylaxis against cardiovascular diseases. The effect of aspirin on inflammation and oxidative stress, processes known to be involved in cardiovascular diseases, are not fully known. The cyclooxygenase(COX)-mediated inflammatory indicator prostaglandin F2alpha (PGF2alpha) (15-keto-dihydro-PGF2alpha), cytokine-mediated inflammatory indicators (interleukin-6, high-sensitivity C-reactive protein, serum amyloid A protein), and oxidative stress indicators (8-iso-PGF2alpha, tocopherols) were quantified in men with daily 75 mg of aspirin (n=175) and control men (n=464), all of age 77, in a cross-sectional study. Men treated with aspirin had decreased levels of urinary 15-keto-dihydro-PGF2alpha than controls (P<0.01), independent of possible cardiovascular risk factors. Aspirin-treated men had increased levels of alpha-tocopherol than controls (P<0.05). This is the first study to indicate that low-dose aspirin treatment is associated with decreased levels of PGF2alpha. This observation suggests a possible COX-mediated anti-inflammatory effect of low-dose aspirin, which should be further confirmed by intervention studies.

Lifelong aspirin supplementation as a means to extending life span

Arising from an initiative by the National Institute of Aging (NIA) requesting novel proposals challenged with increasing lifespan and longevity, our laboratory has generated a hypothesis to test the efficacy of lifelong, low-dosage aspirin administration as a means to achieving this goal. The intervention testing program (currently underway) proposing aspirin as an anti-aging agent evolved from the multitude of properties encompassed in aspirin and the potential of these attributes to prevent the cellular and functional declines, particularly from inflammatory and oxidative sources, evidenced to contribute to aging. Aspirin is a widely administered, cheap, anti-inflammatory, and antioxidant compound that has a variety of positive effects on the immune system and cardiovascular health. Notably, aspirin may affect oxidant production, cytokine responses, and block glycooxidation reactions, thus posing it as a triple threat against the symptoms of aging. Whether aging is molded by interplay between oxidative stress and inflammatory mediators has received little attention; however, we and other laboratories have explored this notion and have observed an elevated inflammatory status with age. Stemming from these observations and in view of the limited success of antioxidant therapies in improving lifespan in long-lived species, in this article we propose a protocol to examine life-long use of a very low dose anti-inflammatory compound such as aspirin to engage the inflammatory and endogenous oxidative insults accompanying aging and, in so doing, attempt to increase maximum and mean life span.

Aspirin in cardiovascular disorders. What is the optimum dose?

Clinical trials of aspirin (acetylsalicylic acid) for cardiovascular disorders have employed doses defined for other pharmacological effects of the drug (such as analgesic effects). Antioxidant and anti-inflammatory mechanisms with different dose-response relationships may contribute to the clinical effect of aspirin in cardiovascular disease. The optimal aspirin dose remains uncertain. Although the difference between 325 mg/day and 81 mg/day of aspirin sounds trivial, finding an optimal aspirin dose has enormous potential to reduce ischemic events. Large aspirin doses have not been associated with proportionally greater benefit. For patients with ischemic heart disease, overall consensus defines a range between 75 and 160 mg/day for the secondary prevention of myocardial infarction, stroke, and vascular death. Any benefit of aspirin must be measured against its adverse effects, principally gastrointestinal hemorrhage. The potential for adverse bleeding events may be lower with a 81mg dose, while maintaining clinical benefit. Although current aggregate data is reassuring about aspirin administration, it is increasingly clear that existing aspirin studies are insufficient to conclusively determine an optimal aspirin dose. Platelets can be activated by pathways that are not blocked by aspirin, and the dose of aspirin needed to fully suppress platelet aggregation may be higher in some patients as a result. Higher doses of aspirin than are currently used (75-325 mg/day) may be required in these patients to achieve desired antithrombotic effects. Better understanding of aspirin-resistant populations will facilitate identification of patients who require higher aspirin doses or alternative forms of antiplatelet therapy.

Role of C-reactive protein in cardiovascular disease

OBJECTIVE

To discuss the role of C-reactive protein (CRP) in cardiovascular disease as a predictor of vascular events and identify key factors that increase or decrease this inflammatory marker.

DATA SOURCES

Articles were identified through searches of MEDLINE (1966-July 2003), International Pharmaceutical Abstracts (1970-June 2003), and bibliographies of selected articles. Search terms included C-reactive protein, HMG-CoA reductase inhibitors, fenofibrate, niacin, aspirin, estrogen, thiazolidinediones, and raloxifene. data selection and data extraction: All studies relevant to CRP and cardiovascular disease or the effects of pharmacologic and nonpharmacologic interventions on CRP levels were evaluated. All information deemed relevant to this review was included.

DATA SYNTHESIS

Numerous studies have shown a strong association between CRP levels and future vascular events (i.e., coronary, cerebrovascular, peripheral vascular disease), with minimal correlation to low-density-lipoprotein cholesterol. Clinical guidelines have recently been published indicating that CRP levels of <1, 1-3, and >3 mg/L correspond to low, moderate, and high risk, respectively, for future vascular events. Drugs including statins, fibrates, niacin, thiazolidinediones, and antiplatelet agents, as well as weight loss and exercise, have demonstrated efficacy in lowering CRP levels.

CONCLUSIONS

CRP appears to be a valuable tool for predicting future vascular events in patients striving for primary or secondary prevention of cardiovascular disease. While several pharmacologic and nonpharmacologic interventions have been shown to lower CRP levels, the impact on clinical outcomes requires further study.

Type 2 diabetes mellitus: a disease of the innate immune system? An update

A few years ago a hypothesis was proposed suggesting that elements of the innate immune system, such as acute phase reactants, contribute to the development of Type 2 diabetes mellitus. Acute phase reactants such as C-reactive protein and sialic acid may thus predict risk of developing Type 2 diabetes mellitus, as well as being markers of diabetes microvascular and macrovascular complications. This article discusses these issues.

Role of inflammation in cardiovascular disease: how to use C-reactive protein in clinical practice

Acute coronary syndromes, stroke, and sudden death are common complications of a disrupted atherosclerotic plaque. Unstable plaque is a result of multiple factors but is commonly characterized by an infiltrate of inflammatory cells. Medical research strongly supports a role for inflammation in the pathogenesis, progression, and disruption of atherosclerotic plaque. Medical science also has improved our understanding of the complex interactions between our environment and our immune, coagulation, and cardiovascular systems. Clinical studies have demonstrated systemic markers of inflammation to be strong predictors of clinical events, and specific treatments of atherosclerosis and its risk factors have been associated with reductions in inflammatory markers. The authors review the current understanding of the role of inflammation in the pathogenesis of atherosclerosis, the common inflammatory markers, and potential anti-inflammatory therapy. Among several potential circulating markers of vascular inflammation, high sensitivity C-reactive protein is best validated and standardized as a marker for cardiovascular risk assessment. Nevertheless, there remain many uncertainties in utilizing C-reactive protein in clinical practice. Here, the authors describe the central role of C-reactive protein in atherosclerosis, review the studies demonstrating predictive value of C-reactive protein, describe the factors requiring consideration when utilizing C-reactive protein, discuss clinical scenarios in which measurement of C-reactive protein may be helpful, and suggest ways to interpret and treat elevated C-reactive protein levels. Finally, the authors summarize future expectations for assessing and modulating the vascular inflammation to inhibit initiation and progression of the atherosclerotic process.