The relationship between blood pressure and C-reactive protein in the Multi-Ethnic Study of Atherosclerosis (MESA)

Metabolic syndrome, C-reactive protein and increased arterial stiffness in Japanese subjects

The aim of this study was to investigate whether the metabolic syndrome (MS) was associated with an elevated level of C-reactive protein (CRP) and increased arterial stiffness, and to clarify whether combined MS and CRP data had a stronger relation to arterial stiffness than did MS data alone. Brachial-ankle pulse wave velocity (baPWV), CRP, and conventional risk factors were evaluated in 3,412 men and 854 women. Adjusted mean values of baPWV in men with 0, 1, 2, and > or = 3 components were 1,309, 1,372, 1,422, and 1,462 cm/s, respectively (p for trend <0.001). Adjusted mean values of baPWV in women with 0, 1, 2, and > or =3 components were 1,212, 1,292, 1,357, and 1,391 cm/s, respectively (p for trend <0.001). Adjusted geometric mean concentrations of CRP in men with 0, 1, 2, and > or = 3 components were 0.036, 0.049, 0.059, and 0.076 mg/dI, respectively (p for trend <0.001). Adjusted geometric mean concentrations of CRP in women with 0, 1, 2, and > or = 3 components were 0.023, 0.030, 0.057, and 0.077 mg/dI, respectively (p for trend <0.001). In analyses of adjusted mean values of baPWV according to the number of MS components and according to CRP levels within or without top quartile levels, the p value for the trend was significant (<0.001) in both men and women but, in post hoc analyses, comparing high and low CRP levels in each MS component-number group, no significant difference was found. These results suggest that, for prediction of increased arterial stiffness, combining MS and CRP data has little additive effect compared to the use of MS data alone.

Comparison of interleukin-6 and C-reactive protein for the risk of developing hypertension in women

Although markers of systemic inflammation may have a role in the development of hypertension, supportive clinical data remain limited. We, therefore, examined interleukin (IL)-6 and C-reactive protein (CRP) in a nested case-control study of 400 women developing hypertension and an equal number of age-matched normotensive control subjects during 10 years of follow-up as part of the Women's Health Study. All of the women initially had nonhypertensive blood pressure values and no history of diagnosis or treatment. Subjects provided self-reported risk factors, and IL-6 and CRP were measured from baseline bloods. Case subjects reported elevated systolic (>or=140 mm Hg) or diastolic (>or=90 mm Hg) blood pressure, newly diagnosed hypertension, or initiating antihypertensive treatment during follow-up. In crude-matched models, IL-6 and CRP quartiles were each strongly associated with hypertension risk (both Ps for trend <0.0001). In multivariate models, the linear trends became nonsignificant, and the relative risks (95% CIs) of hypertension for IL-6 reduced to 1.00 (ref), 1.29 (0.76 to 2.19), 2.14 (1.23 to 3.73), and 1.70 (0.92 to 3.13) and for CRP were 1.00 (ref), 2.09 (1.16 to 3.76), 2.51 (1.42 to 4.44), and 2.44 (1.29 to 4.64), primarily because of confounding by body mass index. Simultaneous adjustment for IL-6 and CRP modestly attenuated both sets of relative risks, although more for IL-6. Finally, there was no effect modification by baseline blood pressure or other risk factors (all Ps for interaction >0.05). Therefore, after multivariate adjustment and strong confounding by body mass index, IL-6 was weakly associated and CRP strongly associated with hypertension risk. In models simultaneously examining IL-6 and CRP, only CRP remained strongly associated with an increased risk of hypertension.

Are intramural suction-squeezing effects generated by the variations in radial wall stress during each heart beat the motor of atherosclerosis? A new concept

In the early sixties, the existence of predilection sites for atherosclerotic lesions inside the arterial circulation led to the concept that low wall shear stress (WSS) was responsible, together with systemic factors like high blood pressure, hypercholesterolemia, or diabetes, for the genesis and progression of atherosclerosis. It was found later that oscillating WSS and high WSS gradients could also be incriminated. Yet, this concept, which is broadly accepted today, fails to explains several facts, for instance that some arteries (e.g. epicardial coronary arteries) are more prone to become atherosclerotic than other ones exposed to the same systemic factors (e.g. hepatic and brain arteries). In this paper, we present a quite different concept. It is based on the fact that the increase in intravascular pressure and flow that occur in the arteries during systole generates, at the predilection sites of atherosclerotic lesions (bends, bifurcations, and branchings), an increase of radial wall stress in the outer layers of the arterial wall so that this stress becomes momentarily tensile. These cyclic stress increases have a suction effect that is likely to facilitate the diffusion of atherogenic cells and substances inside the wall. Furthermore, since arteries are not primarily structured to resist inversions of radial stress, they may also create damages (e.g. disruptions of cell membranes and elastic lamellae) followed by inflammations and micro-haemorrhages in the wall. This new concept may provide a complementary (or possibly alternative) explanation of atherosclerosis.

C-reactive protein in hypertension: clinical significance and predictive value

Mild elevations in C-reactive protein concentration predict myocardial infarction, stroke, and vascular death in a variety of clinical settings. Despite the lack of specific evidence that C-reactive protein levels are independently associated with cardiovascular risk in patients with hypertension, the prognostic value of C-reactive protein has proven to be complementary to that of blood pressure values. Recent epidemiological evidence has indicated a link between hypertension and increased C-reactive protein levels, and there are some indications that C-reactive protein may predict the future development of hypertension. Vessel wall inflammation is part of the vascular changes observed in animal models of hypertension. C-reactive protein is involved in the complex pathways leading to endothelial dysfunction, increased peripheral vascular resistance, and large artery stiffness in hypertension. In this regard, the role of C-reactive protein as a marker or a causal factor in promoting hypertension and its complications remains, however, to be elucidated. In this review, various aspects of the pathogenesis of inflammation in hypertension are summarized and connected with clinical studies that address the role of C-reactive protein in hypertensive disease.

Early and late determinants of C-reactive protein release in patients with acute coronary syndrome

Increased levels of C-reactive protein (CRP) could be detected in subjects with acute coronary syndrome (ACS). Several factors, atherosclerosis, coronary flow impairment, myocardial necrosis, each one acting during a different, earlier or later, phase of ACS, are supposed to be involved in CRP release in case of ACS. Role and relevance of each factor, not mutually exclusive, still need to be comparatively evaluated but a cooperative synergism could be presumably hypothesized.

Systemic Inflammation in Patients With COPD and Pulmonary Hypertension

STUDY OBJECTIVES

COPD is a systemic disorder that is associated with increases of inflammatory proteins in systemic circulation. However, no data on the potential role of systemic inflammation in pulmonary hypertension secondary to COPD are available. Therefore, our aim was to investigate the degree of systemic inflammation reflected by circulatory levels of C-reactive protein (CRP), tumor-necrosis factor (TNF)-alpha, and interleukin (IL)-6 in COPD patients with and without pulmonary hypertension.

DESIGN

Cross-sectional study.

SETTING

University hospital, tertiary referral setting.

PATIENTS AND MEASUREMENTS

In 43 consecutive patients with COPD (mean [+/- SD] age, 65.0 +/- 10.5 years; mean FEV(1), 46.2 +/- 18.1% predicted), lung function was assessed using body plethysmography; pulmonary artery pressure (Ppa) levels were measured by echocardiography. Serum TNF-alpha and IL-6 levels were assessed by enzyme-linked immunosorbent assay, and high-sensitivity serum CRP levels were measured by chemiluminescent immunoassay.

RESULTS

Pulmonary hypertension was present in 19 patients and was absent in 24 patients. In patients with pulmonary hypertension, serum CRP and TNF-alpha levels were significantly higher than in those patients without hypertension (median, 3.6 mg/L [25th to 75th percentile, 1.4 to 13.0 mg/L] vs 1.8 mg/L [25th to 75th percentile, 0.8 to 2.8 mg/L; p = 0.034]; and median, 4.2 pg/mL [25th to 75th percentile, 3.4 to 10.9 pg/mL] vs 3.1 pg/mL [25th to 75th percentile, 2.1 to 4.2 pg/mL]; p = 0.042, respectively). No differences were seen in serum IL-6 (median, 10.4 pg/mL [25th to 75th percentile, 8.8 to 12.2 pg/mL] vs 10.5 pg/mL [25th to 75th percentile, 9.4 to 39.1 pg/mL]; p = 0.651) between the groups. In multiple linear regression analysis, the following two variables were independent predictors of systolic Ppa (R(2) = 0.373): Pao(2) (p = 0.011); and log-transformed serum CRP level (p = 0.044).

CONCLUSION

We conclude that increases in Ppa in patients with COPD are associated with higher serum levels of CRP and TNF-alpha, raising the possibility of a pathogenetic role for low-grade systemic inflammation in the pathogenesis of pulmonary hypertension in COPD patients.

C-reactive protein and echocardiography have little impact on risk stratification in never-treated hypertensive patients

The aim of this study was to assess the contribution of increased concentrations of high-sensitivity C-reactive protein (hsCRP) and echocardiography to risk stratification according to the 2003 European guidelines for the management of arterial hypertension in patients with untreated hypertension. A total of 207 consecutive medical outpatients with untreated hypertension were included. History and clinical examination, electrocardiography, laboratory analyses including the measurement of hsCRP and echocardiography were performed in all patients. Patients were classified into four risk groups with and without using echocardiography and hsCRP concentrations of at least 10 mg/l according to the 2003 guidelines for the management of hypertension. The majority of the 207 patients (81%) were at moderate or high cardiovascular risk before adding echocardiography and/or hsCRP to the risk stratification process. When echocardiography was included, only three patients were reclassified from the moderate added risk to the high added risk group. Adding hsCRP concentrations of at least 10 mg/l had no impact on risk stratification. Using an hsCRP cutoff level of 3 mg/l, one patient was at moderate instead of low added risk, eight patients were at high instead of moderate added risk and one patient was at very high instead of high added risk. We conclude that hsCRP at the proposed cutoff level of 10 mg/l has no impact on risk stratification in outpatients with untreated hypertension. An hsCRP cutoff level of 3 mg/l may be more suitable for risk stratification. Finally, our data suggest that depending on the population studied, there is minimal impact of echocardiography on risk stratification.