C-reactive protein, fibrinogen, and cardiovascular disease prediction

Increased arterial stiffness in resistant hypertension is associated with inflammatory biomarkers

BACKGROUND

Increased levels of inflammatory biomarkers such as interleukin-6 (IL-6), 10 (IL-10), 1β (IL-1β), tumor necrosis factor-α (TNF-α) high-sensitivity C-reactive protein (hs-CRP) are associated with arterial stiffness in hypertension. Indeed, resistant hypertension (RHTN) leads to unfavorable prognosis attributed to poor blood pressure (BP) control and target organ damage. This study evaluated the potential impact of inflammatory biomarkers on arterial stiffness in RHTN.

METHODS

In this cross-sectional study, 32 RHTN, 20 mild hypertensive (HTN) and 20 normotensive (NT) patients were subjected to office BP and arterial stiffness measurements assessed by pulse wave velocity (PWV). Inflammatory biomarkers were measured in plasma samples.

RESULTS

PWV was increased in RHTN compared with HTN and NT (p < 0.05). TNF-α levels were significantly higher in RHTN and HTN than NT patients. No differences in IL-6 levels were observed. RHTN patients had a higher frequency of subjects with increased levels of IL-10 and IL-1β compared with HTN and NT patients. Finally, IL-1β was independently associated with PWV (p < 0.001; R(2) = 0.5; β = 0.077).

CONCLUSION

RHTN subjects have higher levels of inflammatory cytokines (TNF-α, IL-1β and IL-10) as well as increased arterial stiffness, and detectable IL-1β levels are associated arterial stiffness. These findings suggest that inflammation plays a possible role in the pathophysiology of RHTN.

High-Sensitivity C-Reactive Protein and Statin Initiation

The assessment of cardiovascular risk and treatment of cardiovascular diseases are major public health issues worldwide. Inflammation is now recognized as a key regulatory process that links multiple risk factors for atherosclerosis. The substantial number of patients having cardiovascular events lack commonly established risk factors. The utility of high-sensitivity C-reactive protein (hsCRP), a circulating biomarker related to inflammation, may provide additional information in risk prediction. This review will consider the impact of hsCRP level on initiation of statin therapy.

C-reactive protein and risk of cardiovascular and all-cause mortality in 268 803 East Asians

AIMS

C-reactive protein concentrations are decreased in Asians compared with people of white European ethnicity. It is uncertain whether C-reactive protein is a robust biomarker of cardiovascular disease (CVD) in Asians. This study aimed to determine the association between C-reactive protein and CVD and all-cause mortality in a large population of Koreans.

METHODS AND RESULTS

Mortality outcomes for 268 803 Koreans enrolled in a health screening programme with measurements of C-reactive protein at baseline and median follow-up of 4.49 years (1 155 930 person-years) were analysed. A subset (48%) of subjects had a repeat C-reactive protein measurement during follow-up. The median (interquartile) baseline C-reactive protein values were higher in men than in women [0.6 (0.3-1.3) vs. 0.4 (0.1-1.1), P < 0.001]. Only 8.6% of men and 6.2% of women met the standard cut point for C-reactive protein >3 mg/L, which represents the top tertile in white populations. During a median follow-up of 4.49 years (1 155 930 person-years), 1047 died; 187 died of CVD causes. In men but not women, baseline C-reactive protein quartiles were linearly associated with both CVD and all-cause mortality (P < 0.001), even after adjustment for known CVD risk factors. Regardless of baseline C-reactive protein concentration, any increase or decrease in C-reactive protein over time did not affect the HR for all-cause, or CVD mortality. Models with C-reactive protein yielded a net reclassification improvement for CVD mortality of 24.9% (P = 0.04) for individuals with intermediate risk.

CONCLUSIONS

C-reactive protein concentrations are substantially lower in Koreans than reported for whites populations. Nonetheless, C-reactive protein levels are associated with CVD and all-cause mortality in Korean men. Standard cut points for C-reactive protein may under-represent Asians at risk for CVD.

HELP LDL apheresis reduces plasma pentraxin 3 in familial hypercholesterolemia

BACKGROUND

Pentraxin 3 (PTX3), a key component of the humoral arm of innate immunity, is secreted by vascular cells in response to injury, possibly aiming at tuning arterial activation associated with vascular damage. Severe hypercholesterolemia as in familial hypercholesterolemia (FH) promotes vascular inflammation and atherosclerosis; low-density lipoprotein (LDL) apheresis is currently the treatment of choice to reduce plasma lipids in FH. HELP LDL apheresis affects pro- and antiinflammatory biomarkers, however its effects on PTX3 levels are unknown. We assessed the impact of FH and of LDL removal by HELP apheresis on PTX3.

METHODS

Plasma lipids, PTX3, and CRP were measured in 19 patients with FH undergoing chronic HELP LDL apheresis before and after treatment and in 20 control subjects. In the patients assessment of inflammation and oxidative stress markers included also plasma TNFα, fibrinogen and TBARS.

RESULTS

At baseline, FH patients had higher (p = 0.0002) plasma PTX3 than matched control subjects. In FH PTX3 correlated positively (p≤0.05) with age, gender and CRP and negatively (p = 0.01) with HELP LDL apheresis vintage. The latter association was confirmed after correction for age, gender and CRP. HELP LDL apheresis acutely reduced (p≤0.04) plasma PTX3, CRP, fibrinogen, TBARS and lipids, but not TNFα. No association was observed between mean decrease in PTX3 and in LDL cholesterol. PTX3 paralleled lipids, oxidative stress and inflammation markers in time-course study.

CONCLUSION

FH is associated with increased plasma PTX3, which is acutely reduced by HELP LDL apheresis independently of LDL cholesterol, as reflected by the lack of association between change in PTX3 and in LDL levels. These results, together with the finding of a negative relationship between PTX3 and duration of treatment suggest that HELP LDL apheresis may influence both acutely and chronically cardiovascular outcomes in FH by modulating PTX3.

Leg length is associated with lower values of inflammatory markers in older Chinese: The Guangzhou Biobank Cohort Study

BACKGROUND

In developed western populations, longer legs are a biomarker of better childhood conditions and negatively associated with cardiovascular disease risk factors. These associations are less obvious in non-western settings. However, early life is also a key immune system development phase.

AIM

To examine the associations of height, leg length, sitting height and leg length/sitting height ratio with inflammatory markers (white blood, lymphocyte and granulocyte cell counts and C-reactive protein (CRP)) in a developing population of southern China.

SUBJECTS AND METHODS

This study used multivariable linear regression to examine the adjusted associations in 30,499 Chinese (50+ years).

RESULTS

Height z-score was associated with lower white blood, lymphocyte and granulocyte cell counts. Leg length z-score was associated with lower white blood, lymphocyte and granulocyte cell counts and CRP. Sitting height z-score was associated with lower white blood and granulocyte cell counts, but not with lymphocyte cell count or CRP. Leg length/sitting height ratio z-score was associated with lower white blood, lymphocyte and granulocyte cell counts and CRP.

CONCLUSION

Factors enabling more early growth may also lead to changes in immunity that are associated with reduced CVD risk.

Dietary inflammatory index as a potential determinant of a length of hospitalization among surgical patients treated for colorectal cancer

Background/objectives:

Inflammation is a central process responsible for health outcomes among surgical patients. Immunonutrition has been investigated as a promising modifying factor; however, inflammatory properties of habitual diet have not yet been investigated. The purpose of this study was to describe inflammatory properties of diet measured by the dietary inflammatory index (DII) among surgical patients treated for colorectal cancer and to link inflammatory properties of habitual diet with a duration of hospitalization.

Subjects/methods:

A follow-up study among colorectal cancer patients treated surgically was performed in Krakow, Poland. In total, 689 patients were recruited for the study. Habitual diet was assessed using a standardized semiquantitative food frequency questionnaire. Overall, 23 dietary items (including macro-and micronutrients) were used to calculate individuals' DII. Gender, age, marital status, body mass index, smoking status, lifetime physical activity, taking vitamin supplements, number of chronic diseases, cancer site, Duke's staging and surgery type were considered as potential covariates.

Results:

Participants were aged 58 years, with the average hospitalization time of 11 days. Higher DII (meaning diet with higher anti-inflammatory properties) was negatively associated with the duration of hospitalization (univariable linear regression: b=−0.59; P=0.005). Multivariable logistic regression has shown the decrease of the risk of longer stays (>7 days) among patients with the DII >−4.25, but only among younger (⩽60 years) patients, irrespective of Duke's staging.

Conclusions:

The DII might be used as a potential predictor of longer hospitalization among colorectal cancer patients treated surgically. The study provides evidence for the role of dietary-related low-grade inflammation among surgical patients.

An assessment of the relationship between clinical utility and predictive ability measures and the impact of mean risk in the population

BACKGROUND

Measures of clinical utility (net benefit and event free life years) have been recommended in the assessment of a new predictor in a risk prediction model. However, it is not clear how they relate to the measures of predictive ability and reclassification, such as the c-statistic and Net Reclassification Improvement (NRI), or how these measures are affected by differences in mean risk between populations when a fixed cutpoint to define high risk is assumed.

METHODS

We examined the relationship between measures of clinical utility (net benefit, event free life years) and predictive ability (c-statistic, binary c-statistic, continuous NRI(0), NRI with two cutpoints, binary NRI) using simulated data and the Framingham dataset.

RESULTS

In the analysis of simulated data, the addition of a new predictor tended to result in more people being treated when the mean risk was less than the cutpoint, and fewer people being treated for mean risks beyond the cutpoint. The reclassification and clinical utility measures showed similar relationships with mean risk when the mean risk was less than the cutpoint and the baseline model was not strong. However, when the mean risk was greater than the cutpoint, or the baseline model was strong, the reclassification and clinical utility measures diverged in their relationship with mean risk.Although the risk of CVD was lower for women compared to men in the Framingham dataset, the measures of predictive ability, reclassification and clinical utility were both larger for women. The difference in these results was, in part, due to the larger hazard ratio associated with the additional risk predictor (systolic blood pressure) for women.

CONCLUSION

Measures such as the c-statistic and the measures of reclassification do not capture the consequences of implementing different prediction models. We do not recommend their use in evaluating which new predictors may be clinically useful in a particular population. We recommend that a measure such as net benefit or EFLY is calculated and, where appropriate, the measure is weighted to account for differences in the distribution of risks between the study population and the population in which the new predictors will be implemented.

Improving long-term prediction of first cardiovascular event: the contribution of family history of coronary heart disease and social status

OBJECTIVE

The aim of this study is to assess whether family history of coronary heart disease (CHD) and education as proxy of social status improve long-term cardiovascular disease risk prediction in a low-incidence European population.

METHODS

The 20-year risk of first coronary or ischemic stroke events was estimated using sex-specific Cox models in 3956 participants of three population-based surveys in northern Italy, aged 35-69 years and free of cardiovascular disease at enrollment. The additional contribution of education and positive family history of CHD was defined as change in discrimination and Net Reclassification Improvement (NRI) over the model including 7 traditional risk factors.

RESULTS

Kaplan-Meier 20-year risk was 16.8% in men (254 events) and 6.4% in women (102 events). Low education (hazard ratio=1.35, 95%CI 0.98-1.85) and family history of CHD (1.55; 1.19-2.03) were associated with the endpoint in men, but not in women. In men, the addition of education and family history significantly improved discrimination by 1%; NRI was 6% (95%CI: 0.2%-15.2%), raising to 20% (0.5%-44%) in those at intermediate risk. NRI in women at intermediate risk was 7%.

CONCLUSION

In low-incidence populations, family history of CHD and education, easily assessed in clinical practice, should be included in long-term cardiovascular disease risk scores, at least in men.

Haemostatic factors, lipoproteins and long-term mortality in a multi-ethnic population of Gujarati, African-Caribbean and European origin

OBJECTIVES

To examine the relations between haemostatic factors and lipoproteins with mortality in British Europeans, African-Caribbeans (AfC) and Gujarati Indians.

METHODS

A prospective cohort study of 331 subjects (40-79 years), followed-up over 26 years for mortality. Apolipoprotein-A1 (Apo-A1), apolipoprotein-B (Apo-B), factor VII coagulant activity (FVIIc), fibrinogen and von Willebrand Factor (vWF) were measured at baseline in 118 Europeans, 100 AfC and 113 Gujaratis. Aortic pulse wave velocity (aPWV) was measured in 174 participants.

RESULTS

147 (44.4%) subjects died during a median of 24 years follow-up with 69 cardiovascular deaths. Women at baseline had higher, and AfC males the lowest FVIIc and Apo-A1 levels. Baseline age-sex and ethnicity adjusted FVIIc levels were higher in those who died (131.0 vs. 117.4%; P = 0.048). In similarly adjusted partial correlations, Apo-A1 was inversely related to arterial stiffness (ρ = -0.23, P = 0.04). Over the 26 years follow-up, participants below the median (i.e. with lower concentration) of FVIIc, Fibrinogen, Apo-B and vWF had better survival rates than those with higher concentrations; those with higher concentrations of Apo-A1 had better survival. In Cox multivariable regression analyses including sex, ethnicity and aPWV, independently increased risk of all-cause mortality came only from SBP (per 5 mmHg); P = 0.011), age (per year); P < 0.0001 and FVIIc at 7% (per 10-unit; HR 1.07 (1.02, 1.12); P = 0.008. Separately, Apo-A1 (HR 0.12 (0.02, 0.75; P = 0.029) was independently associated with a very significant 88% reduction in all-cause mortality.

CONCLUSIONS

Despite a relatively small sample size, long-term follow-up suggests an independent effect of the prothrombotic state (via FVIIc) and apo-A1 (a constituent of HDL) on mortality.

Evidence for the healthy immigrant effect in older Chinese immigrants: a cross-sectional study

BACKGROUND

Previous work has found that first-generation immigrants to developed nations tend to have better health than individuals born in the host country. We examined the evidence for the healthy immigrant effect and convergence of health status between Chinese immigrants (n = 147) and U.S. born whites (n = 167) participating in the cross-sectional Community Assessment of Freeway Exposure and Health study and residing in the same neighborhoods.

METHODS

We used bivariate and multivariate models to compare disease prevalence and clinical biomarkers.

RESULTS

Despite an older average age and lower socioeconomic status, Chinese immigrants were less likely to have asthma (OR = 0.20, 95% CI = 0.09-0.48) or cardiovascular disease (OR = 0.44, 95% CI = 0.20-0.94), had lower body mass index (BMI), lower inflammation biomarker levels, lower average sex-adjusted low-density lipoprotein (LDL) cholesterol, and higher average sex-adjusted high-density lipoprotein (HDL) cholesterol. However, there was no significant difference in the prevalence of diabetes or hypertension. Duration of time in the U.S. was related to cardiovascular disease and asthma but was not associated with diabetes, hypertension, BMI, HDL cholesterol, LDL cholesterol, socioeconomic status, or health behaviors.

CONCLUSIONS

The lower CVD and asthma prevalence among the Chinese immigrants may be partially attributed to healthier diets, more physical activity, lower BMI, and less exposure to cigarette smoke. First generation immigrant status may be protective even after about two decades.

Serum tryptase: a new biomarker in patients with acute coronary syndrome?

BACKGROUND

Mast cell tryptase has recently been reported to be involved in atherosclerotic plaque destabilization. However, the results of these reports are conflicting.

METHODS

The aim of this study was to characterize the role of tryptase as a prognostic marker of patient cardiovascular complexity in acute coronary syndrome (ACS). Furthermore, its association with an angiographic scoring system [defined by the SYNergy between percutaneous coronary intervention (PCI) with the TAXUS drug-eluting stent and the cardiac surgery (SYNTAX) score] was examined. The serum tryptase was measured at admission in 65 consecutive ACS patients and in 35 healthy controls. In the patients with ACS, a composite measure of clinical and angiographic patient cardiovascular complexity was indicated by two of the following: clinical adverse events at hospitalization, at least 2 epicardial coronary arteries involved in the atherosclerotic disease, more than 1 stent implanted or more than 2 coronary artery disease risk factors.

RESULTS

The tryptase measurements were lower in patients without the composite measure (p < 0.0005). Linear regression showed a significant relationship between tryptase levels and the SYNTAX score (SX-score). Conversely, high-sensitivity troponin values did not correlate with either the composite outcome or the SX-score. The predictive accuracy of serum tryptase for the composite outcome was set at the cut-off point of 5.22 ng/ml (sensitivity 81% and specificity 95.7%).

CONCLUSION

In ACS patients, serum tryptase levels at admission may predict patient cardiovascular complexity more reliably than currently known biomarkers. Further studies are needed to demonstrate the long-term prognostic role of this biomarker in ACS.

Particle-induced pulmonary acute phase response may be the causal link between particle inhalation and cardiovascular disease

Inhalation of ambient and workplace particulate air pollution is associated with increased risk of cardiovascular disease. One proposed mechanism for this association is that pulmonary inflammation induces a hepatic acute phase response, which increases risk of cardiovascular disease. Induction of the acute phase response is intimately linked to risk of cardiovascular disease as shown in both epidemiological and animal studies. Indeed, blood levels of acute phase proteins, such as C-reactive protein and serum amyloid A, are independent predictors of risk of cardiovascular disease in prospective epidemiological studies. In this review, we present and review emerging evidence that inhalation of particles (e.g., air diesel exhaust particles and nanoparticles) induces a pulmonary acute phase response, and propose that this induction constitutes the causal link between particle inhalation and risk of cardiovascular disease. Increased levels of acute phase mRNA and proteins in lung tissues, bronchoalveolar lavage fluid and plasma clearly indicate pulmonary acute phase response following pulmonary deposition of different kinds of particles including diesel exhaust particles, nanoparticles, and carbon nanotubes. The pulmonary acute phase response is dose-dependent and long lasting. Conversely, the hepatic acute phase response is reduced relative to lung or entirely absent. We also provide evidence that pulmonary inflammation, as measured by neutrophil influx, is a predictor of the acute phase response and that the total surface area of deposited particles correlates with the pulmonary acute phase response. We discuss the implications of these findings in relation to occupational exposure to nanoparticles.

How to cite this article: WIREs Nanomed Nanobiotechnol 2014, 6:517–531. doi: 10.1002/wnan.1279

Prognostic utility of biochemical markers of cardiovascular risk: impact of biological variability

BACKGROUND

Although a variety of biochemical markers are used to help predict the risk of cardiovascular disease, the prognostic utility of any marker used as a risk assessment tool is dependent on the long- and short-term biological variability that the marker shows in different individuals.

METHODS

We measured total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol; triglycerides; high-sensitivity C-reactive protein (hsCRP); total fibrinogen; and γ' fibrinogen in blood samples collected from 15 apparently healthy individuals over the course of 1 year. Repeated measures variation estimates were used to calculate short- and long-term intraclass correlation coefficients (ICC), within- and between-subject coefficients of variation (CVI and CVG, respectively), validity coefficients, and indices of individuality for each marker.

RESULTS

HDL cholesterol demonstrated the lowest variability profile, with an ICC of 0.84 and CVI of 11.1 (95% CI: 8.3, 17.0). hsCRP showed the highest levels of short- and long-term within-subject variability [CVI (95% CI): 54.8 (32.8, 196.3) and 77.1 (53.3, 141.3), respectively]. Stated differently, it would require five separate measurements of hsCRP, performed on samples collected over multiple days, to provide the risk assessment information provided by a single measurement of HDL cholesterol. γ' Fibrinogen demonstrated an ICC of 0.79 and CVI of 14.3 (95% CI: 10.6, 21.9).

CONCLUSIONS

hsCRP showed very high biological variability, such that a single measurement of hsCRP lacks sufficient clinical utility to justify routine measurement. The variability profile of γ' fibrinogen was not markedly different than HDL cholesterol, necessitating only a limited number of measurements to establish an individual's risk of cardiovascular disease.

Effect of vitamin D supplementation on the level of circulating high-sensitivity C-reactive protein: a meta-analysis of randomized controlled trials

Vitamin D might elicit protective effects against cardiovascular disease by decreasing the level of circulating high-sensitivity C-reactive protein (hs-CRP), an inflammatory marker. Thus, we conducted a meta-analysis of randomized controlled trials to evaluate the association of vitamin D supplementation with circulating hs-CRP level. A systematic literature search was conducted in September 2013 (updated in February 2014) via PubMed, Web of Science, and Cochrane library to identify eligible studies. Either a fixed-effects or a random-effects model was used to calculate pooled effects. The results of the meta-analysis of 10 trials involving a total of 924 participants showed that vitamin D supplementation significantly decreased the circulating hs-CRP level by 1.08 mg/L (95% CI, -2.13, -0.03), with the evidence of heterogeneity. Subgroup analysis suggested a higher reduction of 2.21 mg/L (95% CI, -3.50, -0.92) among participants with baseline hs-CRP level ≥5 mg/L. Meta-regression analysis further revealed that baseline hs-CRP level, supplemental dose of vitamin D and intervention duration together may be attributed to the heterogeneity across studies. In summary, vitamin D supplementation is beneficial for the reduction of circulating hs-CRP. However, the result should be interpreted with caution because of the evidence of heterogeneity.

Strategies for vascular disease prevention: the role of lipids and related markers including apolipoproteins, low-density lipoproteins (LDL)-particle size, high sensitivity C-reactive protein (hs-CRP), lipoprotein-associated phospholipase A2 (Lp-PLA₂) and lipoprotein(a) (Lp(a))

Considerable progress has been achieved in the treatment of dyslipidemias. However, half of cardiovascular events occur in individuals with average or low cholesterol levels and there is still a considerable residual risk with 70% of patients having an event despite statin treatment. In the era of personalized medicine there is increased interest in the incorporation of individual biomarkers in risk score algorithms in order to improve cardiovascular risk stratification followed by the prompt initiation of preventive measures. Since the 2001 third report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment on High Blood Cholesterol in Adults (ATP III) several studies have evaluated the prognostic value of lipid related biomarkers such as non-HDL-cholesterol, apolipoprotein B, apolipoprotein B/apolipoprotein A1 ratio, lipoprotein(a), lipoprotein-associated phospholipase A2, and C-reactive protein. This article tries to summarize the most recent results in this area.

Therapeutic potential of p38 MAP kinase inhibition in the management of cardiovascular disease

p38 mitogen-activated protein kinases (p38 MAPKs) are key signalling molecules that regulate cellular behavior in response to environmental stresses. They regulate pro-inflammatory cytokines and therefore p38 MAPKs are implicated in the pathogenesis of many inflammatory-driven conditions, including atherosclerosis. Therapeutic inhibition of p38 MAPKs to attenuate inflammation has been the focus of comprehensive research in the last 2 decades, following the discovery of p38α as the molecular target of pyrindinyl imidazole compounds, which suppress the cytokines tumor necrosis factor-α and interleukin-1. The potential of p38 MAPK inhibitors was initially explored within archetypal inflammatory conditions such as rheumatoid arthritis and Crohn's disease, but early studies demonstrated poor clinical efficacy and unacceptable side effects. Subsequent clinical trials evaluating different p38 MAPK inhibitor compounds in disease models such as chronic obstructive pulmonary disease (COPD) and atherosclerosis have shown potential clinical efficacy. This review aims to provide succinct background information regarding the p38 MAPK signaling pathway, a focus of p38 MAPKs in disease, and a brief summary of relevant pre-clinical studies. An update of human clinical trial experience encompassing a clinically orientated approach, dedicated to cardiovascular disease follows. It provides a current perspective of the therapeutic potential of p38 MAPK inhibitors in the cardiovascular domain, including safety, tolerability, and pharmacokinetics.

Associations of the Baltic Sea diet with cardiometabolic risk factors – a meta-analysis of three Finnish studies

Dyslipidaemia, hypertension and low-grade inflammation increase the risk of CVD. In the present meta-analysis, we examined whether adherence to a healthy Nordic diet, also called the Baltic Sea diet, may associate with a lower risk of these cardiometabolic risk factors. In 2001–2007, three cross-sectional Finnish studies were conducted: the Dietary, Lifestyle and Genetic Determinants of Obesity and Metabolic Syndrome study (n4776); Health 2000 Survey (n5180); Helsinki Birth Cohort Study (n1972). The following parameters were assessed in these three studies: blood pressure, total, HDL- and LDL-cholesterol, TAG and high-sensitivity C-reactive protein (hs-CRP); a validated FFQ was used to assess the participants' dietary intakes. The Baltic Sea Diet Score (BSDS) was developed based on the healthy Nordic diet. All studies assessed confounding variables, such as physical activity and BMI, based on standardised questionnaires and measurements. The random-effects meta-analysis provided summary estimates for OR and 95 % CI by the BSDS quintiles. In the meta-analysis, the risk of elevated hs-CRP concentration was lower among men (OR 0·58, 95 % CI 0·43, 0·78) and women (OR 0·73, 95 % CI 0·58, 0·91) in the highest BSDS quintile than among those in the lowest BSDS quintile. In contrast, the risk of lowered HDL-cholesterol concentration was higher among women (OR 1·67, 95 % CI 1·12, 2·48) in the highest BSDS quintile than among those in the lowest BSDS quintile. However, no other associations were found. In conclusion, the associations between the adherence to the healthy Nordic diet and cardiometabolic risk factors are equivocal. Longitudinal studies are needed to further examine this hypothesis.

A pro-atherogenic HDL profile in coronary heart disease patients: an iTRAQ labelling-based proteomic approach

Objectives

This study aims to compare the protein composition of high-density lipoprotein (HDL) particles in coronary heart disease (CHD) patients and controls by proteomic methods.

Background

HDL has been reported to exert pro-atherogenic properties in CHD patients. Accumulating evidence indicates that HDL composition, rather than the HDL-C level, determines its functions. The changes in HDL composition involved in the conversion of anti-atherogenic to pro-atherogenic properties in CHD patients are currently unknown.

Methods and Results

iTRAQ combined with nanoLC-MS/MS was performed to obtain a differential expression profile of the HDL pooled samples of the male age-matched CHD patients and controls (n = 10/group). Of the 196 proteins identified in the examined HDL, 12 were differentially expressed between the CHD patients and the controls, including five up-regulated proteins and seven down-regulated proteins. Using GO analysis, we determined that the up-regulated proteins were mostly involved in inflammatory reactions, displaying a potential pro-atherogenic profile. In contrast, the down-regulated proteins were mostly involved in lipid metabolism processes, displaying anti-atherogenic properties. To confirm the proteomic results, serum amyloid A (SAA) and apoC-I were selected and quantified by ELISA, in the same population as the proteomic analysis, as well as another independent population (n = 120/group). Consistent with the proteomic results, the amount of SAA was significantly increased, and apoC-I was significantly decreased in the HDL particles of CHD patients compared with those of controls (P<0.05).

Conclusions

Our study shows that the HDL proteome changes to a pro-atherogenic profile in CHD patients, which might compromise the protective effects of HDL. Proteomic analysis of HDL composition may provide more relevant information regarding their functional properties than steady-state HDL-C levels.

Intraindividual variability over time in plasma biomarkers of inflammation and effects of long-term storage

PURPOSE

Systemic measures of chronic inflammation, often based on a single blood draw, are frequently used to study the associations between inflammation and chronic diseases such as cancer. However, more information is needed on the measurement error in these markers due to laboratory error, within-person variation over time, and long-term storage.

METHODS

We investigated the intraindividual variability of inflammation markers C-reactive protein (CRP), interleukin-6 (IL-6), and soluble tumor necrosis factor receptors I and II (sTNFRI and II) in a subsample of the Seattle Barrett's esophagus study cohort. Two fasting blood samples were collected between 1995 and 2009 from 360 participants on average 1.8 years apart. CRP, IL-6, and sTNF receptor levels were measured by immunonephelometry, ELISA, and multiplex assays, respectively. Intra- and inter-batch coefficients of variation (CV) were estimated using blinded pooled samples within each batch. Intraclass correlations (ICCs) were computed using random effects ANOVA.

RESULTS

Intra- and inter-batch CVs for the pooled plasma aliquots were low (2.4-8.9 %), suggesting little laboratory variability. Reliability over time was excellent for sTNF receptors (ICCsTNF-RI = 0.89, ICCsTNF-RII = 0.85) and fair-to-good for CRP and IL-6 (ICCCRP = 0.55, ICCIL-6 = 0.57). For samples stored for over 13 years, the ICCs for CRP and IL-6 were decreased but those for sTNF receptors were unaffected.

CONCLUSION

sTNF receptor levels are more stable within person over time than CRP or IL-6. Long-term storage of samples appears to increase the variability of CRP and IL-6 measures, while the reliability of soluble TNF receptor measures was not affected by storage time.

Evaluating the role of inflammation in chronic airways disease: the ERICA study

Extrapulmonary manifestations are recognized to be of increasing clinical importance in Chronic Obstructive Pulmonary disease. To investigate cardiovascular and skeletal muscle manifestations of COPD, we developed a unique UK consortium funded by the Technology Strategy Board and Medical Research Council comprising industry in partnership with 5 academic centres. ERICA (Evaluating the Role of Inflammation in Chronic Airways disease) is a prospective, longitudinal, observational study investigating the prevalence and significance of cardiovascular and skeletal muscle manifestations of COPD in 800 subjects. Six monthly follow up will assess the predictive value of plasma fibrinogen, cardiovascular abnormalities and skeletal muscle weakness for death or hospitalization. As ERICA is a multicentre study, to ensure data quality we sought to minimise systematic observer error due to variations in investigator skill, or adherence to operating procedures, by staff training followed by assessment of inter- and intra-observer reliability of the four key measurements used in the study: pulse wave velocity (PWV), carotid intima media thickness (CIMT), quadriceps maximal voluntary contraction force (QMVC) and 6-minute walk distance (6MWT). This report describes the objectives and methods of the ERICA trial, as well as the inter- and intra-observer reliability of these measurements.

Changes in inflammatory markers after sleeve gastrectomy in patients with impaired glucose homeostasis and type 2 diabetes

BACKGROUND

Bariatric surgery is an effective treatment for morbid obesity. Obesity and type 2 diabetes are associated with chronic inflammation. There is lack of data examining the effects of sleeve gastrectomy (SG) on inflammatory biomarkers. Our aim was to study the effects of SG on specific cytokines associated with obesity including interleukin-6 (IL-6), interleukin-10 (IL-10), leptin, adiponectin, and C-reactive protein (CRP) preoperatively, 1 and 6 months after surgery.

METHODS

A nonrandomized prospective study comprising of 22 participants with impaired glucose homeostasis and type 2 diabetes undergoing SG (body mass index 50.1 kg/m(2), glycated hemoglobin [HbA1c] 53 mmol/mol). Serial measurements of IL-6, IL-10, leptin, adiponectin, and CRP were performed during oral glucose tolerance testing preoperatively, 1 and 6 months postoperatively.

RESULTS

We observed significant improvements at 1 and 6 months in leptin (P≤.001) and CRP (P = .003) after SG. We also observed a significant reduction in IL-6 at 6 months (P = .001). No statistically significant differences were observed for adiponectin and IL-10.

CONCLUSION

This study is the first to examine the detailed changes in the inflammatory cytokines after SG. Our study shows significant improvements in the inflammatory biomarkers after SG in patients with impaired glucose homeostasis and type 2 diabetes.

Fibrinogen plasma concentration is an independent marker of haemodynamic impairment in chronic thromboembolic pulmonary hypertension

Fibrinogen has a crucial role in both inflammation and coagulation, two processes pivotal for the pathogenesis of pulmonary hypertension. We therefore aimed to investigate whether fibrinogen plasma concentrations a) are elevated in pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) and b) may serve as a novel biomarker for haemodynamic impairment. In a dual-centre, retrospective analysis including 112 patients with PAH (n = 52), CTEPH (n = 49) and a control cohort of patients with suspected PAH ruled out by right heart catheterisation (n = 11), we found fibrinogen plasma concentrations to be increased in patients with PAH (4.1 ± 1.4 g/l) and CTEPH (4.3 ± 1.2 g/l) compared to control patients (3.4 ± 0.5 g/l, p = 0.0035 and p = 0.0004, respectively). In CTEPH patients but not in PAH patients fibrinogen was associated with haemodynamics (p < 0.036) and functional parameters (p < 0.041). Furthermore, fibrinogen was linked to disease severity (WHO functional class, p = 0.017) and independently predicted haemodynamic impairment specifically in CTEPH (p < 0.016). Therefore, fibrinogen seems to represent an important factor in CTEPH pathophysiology and may have the potential to guide clinical diagnosis and therapy.

Animal models of C-reactive protein

As the main theme of this special issue, CRP not only is an inflammatory marker but also has diverse biological functions associated with different diseases. To investigate CRP's physiologies and their relationship with human pathological significance, it is essential to use appropriate animal models for translational research. The most popular models for the study of CRP are transgenic mice. However, researchers should be careful when extrapolating the findings derived from these animal models. This review will discuss the current concerns on CRP transgenic mice and rabbits.

Glycated hemoglobin measurement and prediction of cardiovascular disease

IMPORTANCE

The value of measuring levels of glycated hemoglobin (HbA1c) for the prediction of first cardiovascular events is uncertain.

OBJECTIVE

To determine whether adding information on HbA1c values to conventional cardiovascular risk factors is associated with improvement in prediction of cardiovascular disease (CVD) risk.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of individual-participant data available from 73 prospective studies involving 294,998 participants without a known history of diabetes mellitus or CVD at the baseline assessment.

MAIN OUTCOMES AND MEASURES

Measures of risk discrimination for CVD outcomes (eg, C-index) and reclassification (eg, net reclassification improvement) of participants across predicted 10-year risk categories of low (<5%), intermediate (5% to <7.5%), and high (≥ 7.5%) risk.

RESULTS

During a median follow-up of 9.9 (interquartile range, 7.6-13.2) years, 20,840 incident fatal and nonfatal CVD outcomes (13,237 coronary heart disease and 7603 stroke outcomes) were recorded. In analyses adjusted for several conventional cardiovascular risk factors, there was an approximately J-shaped association between HbA1c values and CVD risk. The association between HbA1c values and CVD risk changed only slightly after adjustment for total cholesterol and triglyceride concentrations or estimated glomerular filtration rate, but this association attenuated somewhat after adjustment for concentrations of high-density lipoprotein cholesterol and C-reactive protein. The C-index for a CVD risk prediction model containing conventional cardiovascular risk factors alone was 0.7434 (95% CI, 0.7350 to 0.7517). The addition of information on HbA1c was associated with a C-index change of 0.0018 (0.0003 to 0.0033) and a net reclassification improvement of 0.42 (-0.63 to 1.48) for the categories of predicted 10-year CVD risk. The improvement provided by HbA1c assessment in prediction of CVD risk was equal to or better than estimated improvements for measurement of fasting, random, or postload plasma glucose levels.

CONCLUSIONS AND RELEVANCE

In a study of individuals without known CVD or diabetes, additional assessment of HbA1c values in the context of CVD risk assessment provided little incremental benefit for prediction of CVD risk.

Epidemiological studies of CHD and the evolution of preventive cardiology

Cardiovascular diseases (CVDs) cause nearly one-third of all deaths worldwide. Coronary heart disease (CHD) accounts for the greatest proportion of CVDs, and risk factors such as hypertension, cigarette smoking, diabetes mellitus or elevated glucose level, elevated cholesterol levels, and obesity or being overweight are the top six causes of death globally. Ecological and population-based longitudinal studies, conducted globally or within individual countries, have established the role of traditional and novel risk factors and measures of subclinical disease in the prediction of CHD. Risk assessment with short-term or long-term risk prediction algorithms can help to identify individuals who would benefit most from risk-factor interventions. Evaluation of novel risk factors and screening for subclinical atherosclerosis can also help to identify individuals at highest cardiovascular risk. Prevention of CHD focuses on identifying and managing risk factors at both the population and individual levels through primordial, primary, and secondary prevention. Epidemiological studies have provided the hypotheses for subsequent clinical trials that have documented the efficacy of risk-factor interventions, which are the basis of preventive cardiology. Future research efforts will determine the screening and intervention strategies that have the greatest effect on CHD prevention.

Targeting the unstable plaque in acute coronary syndromes

BACKGROUND

Rupture or erosion of an unstable atherosclerotic plaque is the typical pathology and usual cause of acute coronary syndromes. Despite detailed understanding of the processes of lipid accumulation, thinning of the fibrous cap, and inflammation leading to plaque instability, there are no strategies in clinical use that uniquely target the unstable plaque.

OBJECTIVE

A critical review of recent publications on potential therapies that could be used to stabilize unstable plaque.

METHODS

We searched PubMed, other literature databases, drug development sites, and clinical trial registries to retrieve clinical studies on anti-inflammatory and lipid-modulating therapies that could be used to stabilize unstable atherosclerotic plaque.

RESULTS

Multiple experimental targets involving lipid and inflammatory pathways have the potential to stabilize the plaque and expand the armamentarium against coronary artery disease. Randomized clinical trials of darapladib, methotrexate, canakinumab, and colchicine are well advanced to establish if plaque stabilization is feasible and effective in patients with acute coronary syndromes.

CONCLUSIONS

Although there are still no agents in clinical use for plaque stabilization, there are important advances in understanding plaque instability and several encouraging approaches are being evaluated in Phase III clinical trials.

Iron-induced fibrin in cardiovascular disease

Accumulating evidence within the last two decades indicates the association between cardiovascular disease (CVD) and chronic inflammatory state. Under normal conditions fibrin clots are gradually degraded by the fibrinolytic enzyme system, so no permanent insoluble deposits remain in the circulation. However, fibrinolytic therapy in coronary and cerebral thrombosis is ineffective unless it is installed within 3-5 hours of the onset. We have shown that trivalent iron (FeIII) initiates a hydroxyl radical-catalyzed conversion of fibrinogen into a fibrin-like polymer (parafibrin) that is remarkably resistant to the proteolytic dissolution and thus promotes its intravascular deposition. Here we suggest that the persistent presence of proteolysis-resistant fibrin clots causes chronic inflammation. We study the effects of certain amphiphilic substances on the iron- and thrombin-induced fibrinogen polymerization visualized using scanning electron microscopy. We argue that the culprit is an excessive accumulation of free iron in blood, known to be associated with CVD. The only way to prevent iron overload is by supplementation with iron chelating agents. However, administration of free radical scavengers as effective protection against persistent presence of fibrin-like deposits should also be investigated to contribute to the prevention of cardiovascular and other degenerative diseases.

Prospective coronary heart disease screening in asymptomatic Hodgkin lymphoma patients using coronary computed tomography angiography: results and risk factor analysis

PURPOSE

To prospectively investigate the coronary artery status using coronary CT angiography (CCTA) in patients with Hodgkin lymphoma treated with combined modalities and mediastinal irradiation.

METHODS AND MATERIALS

All consecutive asymptomatic patients with Hodgkin lymphoma entered the study during follow-up, from August 2007 to May 2012. Coronary CT angiography was performed, and risk factors were recorded along with leukocyte telomere length (LTL) measurements.

RESULTS

One hundred seventy-nine patients entered the 5-year study. The median follow-up was 11.6 years (range, 2.1-40.2 years), and the median interval between treatment and the CCTA was 9.5 years (range, 0.5-40 years). Coronary artery abnormalities were demonstrated in 46 patients (26%). Coronary CT angiography abnormalities were detected in nearly 15% of the patients within the first 5 years after treatment. A significant increase (34%) occurred 10 years after treatment (P=.05). Stenoses were mostly nonostial. Severe stenoses were observed in 12 (6.7%) of the patients, entailing surgery with either angioplasty with stent placement or bypass grafting in 10 of them (5.5%). A multivariate analysis demonstrated that age at treatment, hypertension, and hypercholesterolemia, as well as radiation dose to the coronary artery origins, were prognostic factors. In the group of patients with LTL measurements, hypertension and LTL were the only independent risk factors.

CONCLUSIONS

The findings suggest that CCTA can identify asymptomatic individuals at risk of acute coronary artery disease who might require either preventive or curative measures. Conventional risk factors and the radiation dose to coronary artery origins were independent prognostic factors. The prognostic value of LTL needs further investigation.

C-reactive protein concentration predicts change in body mass index during childhood

OBJECTIVE

Inflammation may constitute an underlying mechanism for increased risk of developing chronic diseases in later years, but few prospective studies have assessed the influence of low-grade inflammation on body weight gain, particularly among children in low- to middle-income settings with lower prevalence of overweight and obesity. We aimed to investigate whether C-reactive protein (CRP), as a biomarker of low-grade inflammation, predicts changes in body mass index-for-age z scores (BAZ) during childhood.

METHODS

A population-based longitudinal study was conducted in the Brazilian Amazon among children aged ≤10 years in 2007, with follow-up visits in 2009 and 2012. Outcome was annual change in BAZ. As the main exposure of interest, CRP concentrations were divided into four categories, with values <1 mg/L divided in tertiles plus a fourth category with values ranging from 1 to 10 mg/L. Children were simultaneously screened for iron and vitamin A deficiencies, diarrhea, and wheezing. We used mixed-effect linear regression models to measure the effect of CRP concentrations on annual BAZ change and linear regression models to explore CRP predictors at baseline.

RESULTS

At baseline, 1007 children had CRP and anthropometric data [mean (SD) age: 5.3 (2.9) years; 50.9% male, 84.5% mulatto/mixed-race, 14.0% at risk for overweight or obesity, 4.8% stunted]; 737 were successfully followed up. Morbidities and nutritional deficiencies were widespread. Among participants aged >5 years, children in the highest tertile of CRP <1 mg/L at baseline, regarded as an indicator of low-grade inflammation, had a 0.04 z/y higher gain in BAZ (95% CI: 0.01, 0.09 z/y) during follow-up. CRP was positively associated with household poverty and worse nutritional indicators.

CONCLUSIONS

We found evidence of a role for low-grade inflammation in predicting annual BAZ gain among children aged >5 years.

Comparison of three troponins as predictors of future cardiovascular events--prospective results from the FINRISK and BiomaCaRE studies

IMPORTANCE AND OBJECTIVE

Besides their role in diagnosis of acute myocardial infarction (MI), troponins may be powerful biomarkers for risk stratification in the general population. The objective of our study was to compare the performance of three troponin assays in cardiovascular disease (CVD) risk prediction in a population-based cohort without a history of CVD events.

DESIGN, SETTING AND PARTICIPANTS

Troponin I concentrations were measured using a contemporary-sensitivity, high-sensitivity, and super-sensitivity assay in 7,899 participants of the general-population based FINRISK 1997 cohort. We used Cox proportional hazards regression to determine relative risks, followed by measures of discrimination and reclassification using 10-fold cross-validation to control for over-optimism.

MAIN OUTCOME

As outcome measures we used CVD, MI, ischemic stroke, heart failure (HF), and major adverse cardiac events (MACE). During the follow-up of 14 years 1,074 incident MACE were observed.

RESULTS

Values above the lower limit of detection were observed in 26.4%, 81.5% and 93.9% for the contemporary-sensitivity, high-sensitivity and super-sensitivity assay, respectively. We observed significant associations of troponin concentrations with the risk of future CVD events and the results tended to become stronger with increasing assay sensitivity. For the super-sensitivity assay the multivariate adjusted hazard ratios (per one standard deviation increase) for different outcomes were: MI 1.24 [95% CI 1.11-1.39], stroke 1.14 [1.01-1.28], CVD 1.15 [1.07-1.24], HF 1.28 [1.18-1.39], and MACE 1.18 [1.11-1.25]. In subjects with intermediate risk, we found an improvement of net reclassification for HF (10.2%, p<0.001), and MACE (5.1%, p<0.001).

CONCLUSION

Using a super-sensitivity assay, cardiac troponin was detectable in almost all healthy individuals. Its concentration improved risk prediction and reclassification for cardiovascular endpoints.

A significant correlation between C - reactive protein levels in blood monocytes derived macrophages versus content in carotid atherosclerotic lesions

Background

Atherosclerosis is a complex disease involving different cell types, including macrophages that play a major role in the inflammatory events occurring in atherogenesis. C-Reactive Protein (CRP) is a sensitive systemic marker of inflammation and was identified as a biomarker of cardiovascular diseases. Histological studies demonstrate CRP presence in human atherosclerotic lesions, and we have previously shown that macrophages express CRP mRNA. CRP could be locally secreted in the atherosclerotic lesion by arterial macrophages and local regulation of CRP could affect its pro-atherogenic effects. Moreover, human blood derived macrophages (HMDM) expression of CRP could reflect atherosclerotic lesion secretion of CRP.

Methods

Ten type 2 diabetic patients and ten non-diabetic patients scheduled to undergo carotid endarterectomy were enrolled in this study, and their blood samples were used for serum CRP, lipid determination, and for preparation of HMDM further analyzed for their CRP mRNA expression and CRP content. Carotid lesions obtained from the patients were analyzed for their CRP and interleukin 6 (IL-6) content by immunohistochemistry.

Results

Lesions from diabetic patients showed substantially higher CRP levels by 62% (p = 0.05) than lesions from non diabetic patients, and CRP staining that co-localized with arterial macrophages. CRP carotid lesion levels positively correlated with CRP mRNA expression (r² = 0.661) and with CRP content (r² = 0.611) in the patient’s HMDM.

Conclusions

Diabetes up-regulated carotid plaques CRP levels and CRP measurements in HMDM could reflect atherosclerotic lesion macrophages secretion of CRP. Understanding the regulation of locally produced macrophage CRP in the arterial wall during atherogenesis could be of major importance in identifying the underlying mechanisms of inflammatory response pathways during atherogenesis.

Circulating inflammatory markers and the risk of vascular complications and mortality in people with type 2 diabetes and cardiovascular disease or risk factors: the ADVANCE study

C-reactive protein (CRP), fibrinogen, and interleukin-6 (IL-6) are associated with cardiovascular disease (CVD) and death in general populations. However, studies of these factors in type 2 diabetes are limited. We studied their associations with the risk of major macrovascular events, microvascular complications, and mortality in patients with type 2 diabetes who participated in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) Study. Plasma CRP, fibrinogen, and IL-6 levels were determined in a case-cohort study (n = 3,865) nested within the 11,140 men and women with type 2 diabetes and baseline CVD or risk factors in the ADVANCE Study. All three biomarkers of inflammation were associated with an increased risk of macrovascular events and death in analyses adjusted for age, sex, and treatment groups. After further adjustment, only IL-6 was an independent predictor of macrovascular events (hazard ratio per SD increase 1.37 [95% CI 1.24-1.51]) and death (1.35 [1.23-1.49]). IL-6 significantly improved the prediction of macrovascular events and death. After adjustment, none of the markers predicted microvascular complications. We conclude that IL-6 levels, but not CRP or fibrinogen levels, add significantly to the prediction of macrovascular events and mortality in individuals with type 2 diabetes who have baseline CVD or risk factors.

Assessing risk prediction models using individual participant data from multiple studies

Individual participant time-to-event data from multiple prospective epidemiologic studies enable detailed investigation into the predictive ability of risk models. Here we address the challenges in appropriately combining such information across studies. Methods are exemplified by analyses of log C-reactive protein and conventional risk factors for coronary heart disease in the Emerging Risk Factors Collaboration, a collation of individual data from multiple prospective studies with an average follow-up duration of 9.8 years (dates varied). We derive risk prediction models using Cox proportional hazards regression analysis stratified by study and obtain estimates of risk discrimination, Harrell's concordance index, and Royston's discrimination measure within each study; we then combine the estimates across studies using a weighted meta-analysis. Various weighting approaches are compared and lead us to recommend using the number of events in each study. We also discuss the calculation of measures of reclassification for multiple studies. We further show that comparison of differences in predictive ability across subgroups should be based only on within-study information and that combining measures of risk discrimination from case-control studies and prospective studies is problematic. The concordance index and discrimination measure gave qualitatively similar results throughout. While the concordance index was very heterogeneous between studies, principally because of differing age ranges, the increments in the concordance index from adding log C-reactive protein to conventional risk factors were more homogeneous.

Gender and the active smoking and high-sensitivity C-reactive protein relation in late adolescence

C-reactive protein (CRP), smoking, and oral contraceptive (OC) use are associated with CVD risk in adults. This study examines the effect of smoking on high-sensitivity CRP (hs-CRP) levels, and the interactive effects of sex and OC use on this relationship in an adolescent cohort. A total of 1,050 adolescents (mean age 17 ± 0.25 years) from the Western Australian Pregnancy Cohort (Raine) Study had anthropometric, lifestyle, and metabolic measures recorded. The association between smoking status and log-transformed hs-CRP was analyzed using multivariable Tobit linear regression models, with adjustment for adiposity, lifestyle, and early-life confounders. A three-level variable (girls not using OCs, girls using OCs, and boys) was employed to assess the interactive effects of sex, OC use, and smoking. Smoking associated with higher hs-CRP levels in girls not using OCs (b = 0.571; P = 0.001), but not in girls using OCs (b = -0.117; P = 0.598) or in boys (b = 0.183; P = 0.2). OC use in nonsmoking girls was the strongest factor associated with higher hs-CRP levels (b = 1.189; P < 0.001). This study has demonstrated a more robust effect of smoking on hs-CRP levels in girls not using OCs compared with boys. The findings may explain why CVD risk conferred by smoking is higher in women than in men.

Periodic limb movements during sleep and their effect on the cardiovascular system: is there a final answer?

Periodic limb movements during sleep (PLMS) is a sleep-related movement disorder characterized by repetitive limb movements during sleep, seen predominantly in the legs but also occasionally involving the arms. These movements may be associated with arousals that can lead to increases in sympathetic tone, resulting in tachycardia and elevated systolic blood pressure. Chronic sustained tachycardia and elevated systolic blood pressure are known to be associated with the development of arrhythmias, hypertension, left ventricular hypertrophy, and congestive heart failure. However, the data are not entirely clear on whether untreated PLMS is associated with these cardiovascular risks. This review examines the current evidence on whether PLMS has any effect on the cardiovascular system.

Perioperative cardiac biomarkers: the utility and timing

PURPOSE OF REVIEW

We presume that biomarkers will improve identification of patients at risk, leading to interventions and treatments that reduce perioperative adverse events. Risk stratification is multifactorial, and a biomarker must add information to this process, thereby redistributing patients to either higher or lower risk categories, to improve the allocation of expensive and risky interventions. This review focuses on the utility of three cardiac biomarkers in perioperative management.

RECENT FINDINGS

Using newly defined epidemiologic criteria, three distinct molecules, brain natriuretic peptide (BNP), troponin (cTn), and glycosylated hemoglobin (HbA1c) emerge as potentially useful in perioperative medicine. A meta-analysis shows, in vascular surgery, BNP improves risk stratification. Four articles highlight the utility of postoperative cTn measurements in cases of myocardial injury. These articles show that most injury is not infarction, and they present preliminary evidence of the populations that will benefit from structured surveillance protocols. HbA1c is shown to improve the prediction of mortality, but there are questions whether this risk is modifiable.

SUMMARY

The findings here suggest an expanded role for postoperative cTn surveillance; however, the precise populations that benefit, or the interventions required, are not yet defined. The encouraging data for the other two biomarkers need more investigations before adopting them into routine clinical use.

The long-term effects of postoperative complications

PURPOSE OF REVIEW

This review examines the long-term influence of postoperative complications on survival. Although it is intuitive that complications after surgery worsen short-term outcomes, it is not clear to what extent and why a longer-term relationship may exist.

RECENT FINDINGS

Most studies have focused on outcomes after cancer surgery. Despite mixed results in smaller cohorts, large multicentre analyses consistently identify an association between postoperative complications and long-term mortality. In part, this phenomenon may be due to unmeasured confounding factors or insufficient separation of short and long-term consequences. Nevertheless, functional and biological imprints established during postoperative complications are likely to be relevant, and are the subject of ongoing research.

SUMMARY

Patients that develop postoperative complications and survive the immediate risk period, demonstrate worsened long-term mortality. The field of perioperative medicine is increasingly mandated to identify vulnerable individuals, develop and implement strategies to prevent and treat complications, and provide better care pathways after hospital discharge.

C-reactive protein levels in patients at cardiovascular risk: EURIKA study

Background

Elevated C-reactive protein (CRP) levels are associated with high cardiovascular risk, and might identify patients who could benefit from more carefully adapted risk factor management. We have assessed the prevalence of elevated CRP levels in patients with one or more traditional cardiovascular risk factors.

Methods

Data were analysed from the European Study on Cardiovascular Risk Prevention and Management in Usual Daily Practice (EURIKA, ClinicalTrials.gov Identifier: NCT00882336), which included patients (aged ≥50 years) from 12 European countries with at least one traditional cardiovascular risk factor but no history of cardiovascular disease. Analysis was also carried out on the subset of patients without diabetes mellitus who were not receiving statin therapy.

Results

In the overall population, CRP levels were positively correlated with body mass index and glycated haemoglobin levels, and were negatively correlated with high-density lipoprotein cholesterol levels. CRP levels were also higher in women, those at higher traditionally estimated cardiovascular risk and those with greater numbers of metabolic syndrome markers. Among patients without diabetes mellitus who were not receiving statin therapy, approximately 30% had CRP levels ≥3 mg/L, and approximately 50% had CRP levels ≥2 mg/L, including those at intermediate levels of traditionally estimated cardiovascular risk.

Conclusions

CRP levels are elevated in a large proportion of patients with at least one cardiovascular risk factor, without diabetes mellitus who are not receiving statin therapy, suggesting a higher level of cardiovascular risk than predicted according to conventional risk estimation systems.

Trial registration

ClinicalTrials.gov Identifier: NCT00882336

Predictive value of updating Framingham risk scores with novel risk markers in the U.S. general population

Background

According to population-based cohort studies CT coronary calcium score (CTCS), carotid intima-media thickness (cIMT), high-sensitivity C- reactive protein (CRP), and ankle-brachial index (ABI) are promising novel risk markers for improving cardiovascular risk assessment. Their impact in the U.S. general population is however uncertain. Our aim was to estimate the predictive value of four novel cardiovascular risk markers for the U.S. general population.

Methods and Findings

Risk profiles, CRP and ABI data of 3,736 asymptomatic subjects aged 40 or older from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 exam were used along with predicted CTCS and cIMT values. For each subject, we calculated 10-year cardiovascular risks with and without each risk marker. Event rates adjusted for competing risks were obtained by microsimulation. We assessed the impact of updated 10-year risk scores by reclassification and C-statistics. In the study population (mean age 56±11 years, 48% male), 70% (80%) were at low (<10%), 19% (14%) at intermediate (≥10–<20%), and 11% (6%) at high (≥20%) 10-year CVD (CHD) risk. Net reclassification improvement was highest after updating 10-year CVD risk with CTCS: 0.10 (95%CI 0.02–0.19). The C-statistic for 10-year CVD risk increased from 0.82 by 0.02 (95%CI 0.01–0.03) with CTCS. Reclassification occurred most often in those at intermediate risk: with CTCS, 36% (38%) moved to low and 22% (30%) to high CVD (CHD) risk. Improvements with other novel risk markers were limited.

Conclusions

Only CTCS appeared to have significant incremental predictive value in the U.S. general population, especially in those at intermediate risk. In future research, cost-effectiveness analyses should be considered for evaluating novel cardiovascular risk assessment strategies.

Severity of obstructive sleep apnea is associated with elevated plasma fibrinogen in otherwise healthy patients

PURPOSE

Obstructive sleep apnea (OSA) has been implicated in both cardiovascular and cerebrovascular diseases. Systemic inflammation and coagulation may be related to cardiovascular pathophysiology in patients with OSA. Fibrinogen is a major coagulation protein associated with inflammation, and long-term elevated plasma fibrinogen is associated with an increased risk of major cardiovascular diseases. We assessed whether severity of OSA is associated with levels of fibrinogen in newly diagnosed, untreated, and otherwise healthy OSA patients.

METHODS

We studied 36 men with OSA and 18 male control subjects (apnea-hypopnea index [AHI]<5 events/h). OSA patients were divided into mild (AHI≥5<15 events/h) and severe (AHI≥15 events/h) OSA groups. Morning fibrinogen levels in OSA patients were compared to those in control subjects of similar age, body mass index, blood pressure, smoking habits, and alcohol consumption.

RESULTS

Fibrinogen levels were significantly elevated in patients with severe OSA compared to both control (P=0.003) and mild OSA (P=0.02) subjects after adjustment for covariates. However, there were no significant differences in fibrinogen levels between mild OSA and control subjects. Fibrinogen levels were directly related to AHI and arousal index and inversely related to mean and lowest oxygen saturation during sleep.

CONCLUSIONS

Severity of OSA was associated with increased fibrinogen level independent of other factors, suggesting that apneic events and oxygen desaturation during sleep are mechanisms for increased fibrinogen levels in patients with OSA.

Combined oral contraception and obesity are strong predictors of low-grade inflammation in healthy individuals: results from the Danish Blood Donor Study (DBDS)

BACKGROUND

C-reactive protein (CRP) is a well-established marker of inflammation. The level of CRP is affected by several lifestyle factors. A slightly increased CRP level, also known as low-grade inflammation (LGI), is associated with increased risk of several diseases, especially cardiovascular disease. The aim of this study was to identify predictors of increased CRP levels in healthy individuals. We therefore assessed CRP in a large cohort of blood donors.

METHODS

We measured plasma CRP levels in 15,684 participants from the Danish Blood Donor Study. CRP was measured by a commercial assay. Furthermore, all participants completed a standard questionnaire on smoking status, alcohol consumption, physical activity, diet, and various body measurements. Female participants also reported the use of contraception, childbirth, and menopausal status. The relationship between LGI (defined here as a plasma CRP level between 3 mg/L and 10 mg/L) and predictors was explored by multivariable logistic regression analysis. Results were presented as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

We found LGI in a total of 1,561 (10.0%) participants. LGI was more frequent in women using combined oral contraception (OC) (29.9%) than in men (6.1%) and women not using OC (7.9%). Among premenopausal women, OC was the strongest predictor of LGI (odds ratio = 8.98, p<0.001). Additionally, body mass index (BMI) and waist circumference were positively associated with LGI.

CONCLUSION

High BMI and abdominal obesity strongly predicted LGI among healthy individuals. However, the most striking finding was the high prevalence of LGI among premenopausal women who used combined oral contraception. Although the significance of CRP as a marker of inflammation is well known, the role of CRP in pathogenesis is still uncertain. The impact of oral contraception on CRP levels should nevertheless be considered when CRP is used in risk assessment.