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

Inflammatory markers are elevated in Eisenmenger syndrome

Inflammation may be an important contributing factor to the progression of Eisenmenger syndrome (ES). Markers of systemic inflammation in ES have not been systematically studied. Inflammatory markers including high-sensitivity C-reactive protein (hs-CRP), interleukin-2 (IL-2), IL-6, and interferon-γ (IFN-γ) were measured in 42 consecutive ES patients (mean age, 24.3 ± 10.6 years) compared with their levels in 22 healthy control subjects. The patients were followed up for a mean duration of 16.3 ± 13.7 months. The levels of inflammatory markers were correlated with clinical and hemodynamic variables at baseline and the outcomes of death, hospitalization, and worsening World Health Organization (WHO) functional class at follow-up evaluation. Compared with the control subjects, ES patients showed a significant elevation in hs-CRP (2.99 ± 3.5 vs 1.1 ± 0.9 mg/dl; p = 0.002) and IFN-γ (41.3 ± 43.6 vs 10.4 ± 6.9 pg/ml; p < 0.001) levels. The levels of IL-2 and IL-6 also were elevated but did not differ significantly from those in the control subjects. The patients with hs-CRP levels higher than 3 mg/dl were significantly older (28.9 ± 10.6 vs 21.5 ± 9.8 years) and had a significantly shorter 6-min walk distance (421.5 ± 133.2 vs 493.3 ± 74.8 m). The levels of inflammatory markers did not correlate with baseline parameters or clinical outcomes. To conclude, the levels of hs-CRP and IFN-γ are significantly elevated in ES. Elevated hs-CRP in ES was associated with older age and shorter 6-min walk distance, but the levels of inflammatory markers were not predictive of clinical events.

The association between smoking quantity and hypertension mediated by inflammation in Chinese current smokers

OBJECTIVES

Previous studies indicated that cigarette smokers were more likely to develop hypertension, and both smoking and hypertension were associated with inflammation. Whether inflammation mediates the relationship of them is unclear. This study aims to examine whether inflammation mediates the association between smoking and hypertension.

METHODS

Nine hundred and eighty-four Chinese current smokers from a community-based chronic diseases survey in Guangzhou and Zhuhai were interviewed about sociodemographics, smoking, chronic conditions, and other health-related variables. Hypertension was defined according to 2007 European Society of Hypertension and European Society of Cardiology (ESH-ESC) Practice Guidelines. Inflammatory markers including C-reactive protein (CRP), interleukin (IL)-6, IL-1β, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), and vascular cell adhesion molecule-1 (VCAM-1) were measured by flow cytometry. Logistic regressions were performed to assess the mediation of inflammation on the relationship between smoking quantity and hypertension.

RESULTS

We observed a positive association between smoking quantity and hypertension (P<0.05). After controlling for potential confounders, daily cigarette consumption was significantly associated with higher level of CRP and VCAM-1 and lower level of TNF-α among six measured inflammatory markers, and the current smokers with hypertension had significantly higher level of MCP-1 and CRP than those smokers who were normotensive. Furthermore, the association between smoking quantity and hypertension was mediated by CRP, which accounted for 58.59% of the estimated causal effect of smoking on hypertension.

CONCLUSION

We have confirmed previous observations that smoking quantity was positively associated with hypertension, and the results of our study suggested that the association between smoking and hypertension was probably mediated by CRP.

Impact of inflammation on vascular disease in hypertension

Low grade inflammation exerts a crucial pathogenic role in hypertension and cardiovascular disease. A large body of evidence indicates that innate and adaptive immune systems, and in particular T cells, are involved. A balance between T-effector lymphocytes and Treg lymphocytes represents a crucial regulatory mechanism that, when altered, favours blood pressure elevation and organ damage development. Of note, Treg lymphocytes exert important anti-inflammatory properties, whose activities guarantees vascular homeostasis and protects the vessel wall from the development of atherosclerosis. In humans, most of evidence ascertaining essential hypertension as a condition of chronic low-grade inflammatory status revealed a strict and independent association between CRP, TNF-α, IL-6 or adhesion molecules and vascular changes in essential hypertensive patients. Evidence of involvement of the immune system in vasculature from patients with hypertension or cardiovascular disease starts to appear in literature. Further investigation on immunity, including the role of T-lymphocytes, will help develop of new therapeutic targets that may improve outcomes in hypertension and cardiovascular disease and discover novel approaches in the treatment of hypertension and vascular disease.

Multiancestral analysis of inflammation-related genetic variants and C-reactive protein in the population architecture using genomics and epidemiology study

BACKGROUND

C-reactive protein (CRP) is a biomarker of inflammation. Genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) associated with CRP concentrations and inflammation-related traits such as cardiovascular disease, type 2 diabetes mellitus, and obesity. We aimed to replicate previous CRP-SNP associations, assess whether these associations generalize to additional race/ethnicity groups, and evaluate inflammation-related SNPs for a potentially pleiotropic association with CRP.

METHODS AND RESULTS

We selected and analyzed 16 CRP-associated and 250 inflammation-related GWAS SNPs among 40 473 African American, American Indian, Asian/Pacific Islander, European American, and Hispanic participants from 7 studies collaborating in the Population Architecture using Genomics and Epidemiology (PAGE) study. Fixed-effect meta-analyses combined study-specific race/ethnicity-stratified linear regression estimates to evaluate the association between each SNP and high-sensitivity CRP. Overall, 18 SNPs in 8 loci were significantly associated with CRP (Bonferroni-corrected P<3.1×10(-3) for replication, P<2.0×10(-4) for pleiotropy): Seven of these were specific to European Americans, while 9 additionally generalized to African Americans (1), Hispanics (5), or both (3); 1 SNP was seen only in African Americans and Hispanics. Two SNPs in the CELSR2/PSRC1/SORT1 locus showed a potentially novel association with CRP: rs599839 (P=2.0×10(-6)) and rs646776 (P=3.1×10(-5)).

CONCLUSIONS

We replicated 16 SNP-CRP associations, 10 of which generalized to African Americans and/or Hispanics. We also identified potentially novel pleiotropic associations with CRP for two SNPs previously associated with coronary artery disease and/or low-density lipoprotein-cholesterol. These findings demonstrate the benefit of evaluating genotype-phenotype associations in multiple race/ethnicity groups and looking for pleiotropic relationships among SNPs previously associated with related phenotypes.

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

Inflammation in high blood pressure: a clinician perspective

Hypertension is one of the most important contributors to atherosclerosis. A possible link between inflammation and elevated blood pressure has been suggested by several cross-sectional and longitudinal studies. Possible mechanisms include an imbalance between vasoconstrictors and vasodilators, amplified thrombogenesis and platelet activation, and perhaps a direct effect of inflammatory mediators. C-reactive protein (CRP), an inflammatory cytokine, may play an essential role in vascular inflammation and can directly decrease the production of nitric oxide, a vasocodilator. Angiotensin II (Ang II) up-regulates several inflammatory cytokines, leukocyte adhesion molecules, and chemokines through the activation of the nuclear factor-kappa B leading to a decrease in the bioavailability of vasodilators. The increase in oxidative stress and endothelin-1 production through Ang II may further contribute to vasoconstriction. Adipose tissue can add to the production of CRP and creates a prothrombotic state. The presence of low-grade inflammation, especially elevations of CRP, can help predict the risk of future cardiovascular events and is associated with target organ damage in hypertensive individuals. Angiotensin converting enzyme inhibitors, angiotensin receptor blockers, beta-adrenoreceptor antagonists, and, to a lesser degree calcium channel antagonists, have shown efficacy in reducing CRP. Lifestyle changes such as exercise, weight loss, and tobacco cessation have also shown a similar efficacy. Whether targeting inflammation in the treatment of uncomplicated hypertension can alter the natural history of the disease or lead to improved outcome has yet to be determined.

Association between C-reactive protein and blood pressure in a cohort of elderly Muscovites: epidemiological study data

Background. The elevation of blood pressure (BP) affects the development of vascular inflammation. At the same time, it has been suggested that inflammation itself could be an independent risk factor (RF) of arterial hypertension (AH) development. Aim. To investigate whether the association between increased levels of C-reactive protein (CRP) and AH is independent from classical RFs. Material and methods. The data were obtained during a crosssectional survey of 1876 Muscovites (47,9% men) aged ≥55 years, who participated in the prospective study “Stress, Ageing, and Health in Russia”. In all participants, socio-demographic characteristics, health behaviours, parameters of anthropometry and rest electrocardiography (ECG) were assessed. The levels of BP and blood lipids were also measured. The outcome variable was an increase in CRP levels (>3 mg/l). Statistical methods included logistic regression; the risk estimates were presented as odds ratios (OR) and 95% confidence intervals (CI). Results. There was a positive link between AH and CRP levels of >3 mg/l. After adjustment for age and sex, OR of increased CRP levels in hypertensive participants vs. their AH-free peers was 1,688 (95% CI 1,323-2,154; p=0,0001). In the final model (adjustment for age, sex, educational level, smoking, alcohol consumption, abdominal obesity, high atherogenicity index, and coronary heart disease, CHD), this effect remained statistically significant (OR 1,450; 95% CI 1,127-1,864; p=0,004). Conclusion. In elderly Muscovites, a positive association between increased CRP levels and the elevation of BP was independent from RFs and CHD.

Inflammatory markers and blood pressure: sex differences and the effect of fat mass in the CoLaus Study

Several studies have reported high levels of inflammatory biomarkers in hypertension, but data coming from the general population are sparse, and sex differences have been little explored. The CoLaus Study is a cross-sectional examination survey in a random sample of 6067 Caucasians aged 35-75 years in Lausanne, Switzerland. Blood pressure (BP) was assessed using a validated oscillometric device. Anthropometric parameters were also measured, including body composition, using electrical bioimpedance. Crude serum levels of interleukin-6 (IL-6), tumor necrosis factor α (TNF-α) and ultrasensitive C-reactive protein (hsCRP) were positively and IL-1β (IL-1β) negatively (P<0.001 for all values), associated with BP. For IL-6, IL-1β and TNF-α, the association disappeared in multivariable analysis, largely explained by differences in age and body mass index, in particular fat mass. On the contrary, hsCRP remained independently and positively associated with systolic (β (95% confidence interval): 1.15 (0.64; 1.65); P<0.001) and diastolic (0.75 (0.42; 1.08); P<0.001) BP. Relationships of hsCRP, IL-6 and TNF-α with BP tended to be stronger in women than in men, partly related to the difference in fat mass, yet the interaction between sex and IL-6 persisted after correction for all tested confounders. In the general population, the associations between inflammatory biomarkers and rising levels of BP are mainly driven by age and fat mass. The stronger associations in women suggest that sex differences might exist in the complex interplay between BP and inflammation.

Relationship between inflammation and microalbuminuria in prehypertension

Inflammation is a pathogenic factor for target-organ damage (TOD) in hypertension. This study examined the relationship between inflammatory parameters and urinary albumin excretion (UAE) in prehypertension. A total of 65 prehypertensive subjects (blood pressure (BP) 120-139/80-89 mm Hg) and 26 healthy volunteers with BP <120/80 mm Hg were included. High-sensitivity C-reactive protein (hs-CRP), and serum and urinary tumor necrosis factor-α (TNF-α) were measured as inflammatory markers. Prehypertensive individuals had higher levels of inflammatory parameters and UAE than healthy subjects. Analyses carried out in prehypertensive participants showed that BP was similar between individuals with normoalbuminuria or microalbuminuria (MAB) (UAE between 30 and 299 mg per day). However, serum hs-CRP and urinary TNF-α excretion were higher in prehypertensives with MAB. Multiple regression analysis showed that systolic blood pressure (r=0.29, P<0.01), hs-CRP (r=0.20, P<0.001), and urinary TNF-α (r=0.69, P<0.001) were independently correlated with UAE (adjusted R(2)=0.73, P<0.001). Finally, logistic regression analysis performed in the prehypertensive group with the absence or presence of MAB as the dependent variable demonstrated that hs-CRP (3.92 (1.45-10.58), P=0.007) and urinary TNF-α (1.69 (1.20-2.37), P=0.002) were independent risk factors for the presence of MAB. Inflammatory parameters are significantly and independently associated with UAE in prehypertensive subjects, suggesting that inflammation may be a pathogenic factor for the early vascular or TOD in these individuals.

Inflammation and hypertension: the interplay of interleukin-6, dietary sodium, and the renin-angiotensin system in humans

BACKGROUND

Prior evidence suggests a link between inflammation and hypertension. Interleukin-6 (IL-6) has been implicated in animal studies to play an important role in angiotensin II (ANGII)-mediated hypertension. The aim of this study was to examine the relationship of IL-6 and renin-angiotensin system (RAS) activity in human hypertension.

METHODS

Data from 385 hypertensives and 196 normotensives are included in this report. Blood pressure and laboratory evaluation were performed on liberal and low sodium diets. IL-6 response to an ANGII infusion was evaluated to assess the effect of acute RAS activation.

RESULTS

Hypertensives had higher baseline IL-6 and C-reactive protein (CRP) compared with normotensives on both diets. IL-6 increased in response to ANGII in hypertensives and normotensives (28% in hypertensives, 31% in normotensives, P ≤ 0.001 for change from baseline). In the setting of RAS activation by a low salt diet, multivariate regression analysis adjusted for age, body mass index (BMI), gender, race, and hypertension status demonstrated an independent positive association of plasma renin activity (PRA) with CRP (β = 0.199, P < 0.001). There was no significant difference in IL-6 or CRP levels between liberal and low sodium diets.

CONCLUSION

These findings confirm an association between hypertension and inflammation and provide human data supporting previous evidence from animal studies that IL-6 plays a role in ANGII-mediated hypertension. Notably, compared to levels on a liberal sodium diet, neither IL-6 nor CRP were higher with activation of the RAS by a low salt diet indicating that a low sodium diet is not inflammatory despite increased RAS activity.

Inflammation in psychotic disorders: a population-based study

We investigated inflammatory markers in psychotic disorders and their association with metabolic comorbidity, antipsychotic medication, smoking, alcohol use, physical condition, and mood. From the population-based Finnish Health 2000 study, we identified all persons with schizophrenia (n=45), other nonaffective psychosis (ONAP) (n=57), affective psychosis (n=37) and chose controls matched by age, sex, and region of residence. We found that persons with schizophrenia had significantly higher sIL-2Rα, IL-1RA and C-reactive protein (CRP), persons with ONAP significantly higher IL-1RA and CRP and persons with affective psychosis almost significantly higher TNF-α compared to their matched controls. Current antipsychotic use was associated with elevated IL-1RA and CRP. After taking metabolic and lifestyle-related variables that associated with inflammatory markers into account, only antipsychotic medication remained associated with elevated IL-1RA and TNF-α which are markers related to the activation of innate immune system. CRP was influenced by both antipsychotic medication and nonaffective psychosis. sIL-2Rα, a marker of T-cell activation, was associated with depressive symptoms, schizophrenia, and affective psychosis. We conclude that in persons with psychotic disorders, activation of mononuclear phagocyte system was mostly related to metabolic comorbidity and antipsychotic medication use, whereas T-cell activation had a more direct relationship with both psychotic disorders and depressive symptoms.

Rosuvastatin attenuates the elevation in blood pressure induced by overexpression of human C-reactive protein

C-reactive protein (CRP) has been shown to function as an inflammatory factor to induce endothelial dysfunction and hypertension in rats. The anti-inflammatory effects of statins suggest that they may attenuate CRP-induced endothelial dysfunction and hypertension in Sprague-Dawley rats. Male Sprague-Dawley rats were injected with an adeno-associated virus (AAV) to induce overexpression of human CRP (AAV-hCRP) or green fluorescent protein (GFP) control (AAV-GFP). At 2 months after injection, rats were administered rosuvastatin by daily oral gavage (10 mg kg(-1)) for 2 additional months. Rosuvastatin administration attenuated the increased blood pressure and loss of vascular endothelial nitric oxide synthase expression in AAV-hCRP-treated rats, and N-nitro-L-arginine methyl ester blocked its hypotensive effect. Rosuvastatin also activated phosphoinositide 3-kinases/Akt, and inhibited Rho kinase activity in aorta. Rosuvastatin reduced the production of reactive oxygen species through downregulation of nicotinamide adenine dinucleotide phosphate oxidase subunits, p22 phox and gp91 phox, and upregulation of superoxide dismutase 1 expression. Rosuvastatin attenuated the increase in blood pressure in AAV-hCRP-treated rats through endothelial protection and antioxidant effects. Our data reveals a novel mechanism through which statins may lower blood pressure.

Inflammatory cytokines imbalance in the very early phase of acute coronary syndrome: correlations with angiographic findings and in-hospital events

The aim of this study is to investigate the release of some inflammatory cytokines (Cks) during the very early phase (first 24 h) of acute coronary syndrome (ACS). Twenty-six consecutive subjects admitted to coronary care unit with ACS underwent serial blood sampling in order to evaluate concentrations of interleukin (IL)-2, IL-10, IL-18, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ. Blood samples were taken within 6 h after onset of chest pain (T₀), at 12 h (T₁), and at 24 h (T₂). Patients were thus divided into four groups comparing pro-inflammatory Ck release (IL-2, TNF-α, and IFN-γ) and anti-inflammatory activity (IL-10). Clinical features, risk factors, incidence of adverse events, and coronary angiography findings were compared with Ck activation. Ck levels were significantly increased if compared with baseline. Subjects with marked inflammatory response showed a higher incidence of left anterior descending coronary disease (IL-2, p < 0.001; TNF-α and IFN-γ, p < 0.05) and more often incurred early complications (IL-2, p < 0.05; IFN-γ, p < 0.001). A correlation was detectable between IL-18 levels and myocardial enzyme release (creatine kinase, r = 0.47; lactate dehydrogenase, r = 0.54; troponin I, r = 0.58; p < 0.05). TNF-α levels were associated with a worse prognosis at follow-up (Log rank, p < 0.05). A Ck activation characterizes the early phase of ACS. Early inflammatory reaction seems to correlate with coronary disease and adverse events.

Interactions among gender, age, hypertension and C-reactive protein in coronary vasospasm

BACKGROUND

Coronary vasospasm (CVsp) has been reported to be an inflammatory disease, reflected by elevated high-sensitivity C-reactive protein (hs-CRP). We investigated the interactions among gender, age, hypertension and hs-CRP in patients with CVsp.

MATERIALS AND METHODS

We retrospectively examined 722 Taiwanese patients with or without CVsp during an 8-year period. None of the patients had obstructive coronary artery disease. Serum hs-CRP levels were examined in a subset of 375 patients to evaluate the interactions of hs-CRP with gender, age, smoking and hypertension in the development of CVsp.

RESULTS

In women, only the highest hs-CRP tertile (> 3 mg L⁻¹) was independently associated with CVsp. In men, age > 58 years and the highest hs-CRP tertile were independently associated with CVsp. In women, elevated risk was only demonstrated in patients ≤ 58 years of age with hs-CRP levels in the highest tertile. In men, a positively monotonic trend was demonstrated between hs-CRP levels and CVsp in those > 58 years of age. The odds ratios of CVsp in both women and men with hs-CRP in the highest tertile reduced from 6·01 to 1·48 and 6·35-2·69 respectively, if they had hypertension.

CONCLUSION

The relationship between hs-CRP and CVsp differed between men and women. Our findings that there is a non-threshold model in men and a threshold model in women provide evidence that more smokers in men (life-style) and age (induction time) contribute to the natural history of CVsp development. The negative effect of hypertension on CVsp suggests that the pathogenesis of CVsp differs from that of coronary atherosclerosis.

The relationship between inflammation, obesity and risk for hypertension in the Multi-Ethnic Study of Atherosclerosis (MESA)

It has been suggested that inflammation is important in the aetiology of hypertension and that this may be most relevant among obese persons. To study this, we examined the independent relationships between obesity, inflammation-related proteins (interleukin-6 (IL-6), C-reactive protein (CRP) and fibrinogen) and risk for hypertension in the Multi-Ethnic Study of Atherosclerosis (MESA). Hypertension status, defined as a blood pressure ≥140/90 mm Hg or a history of hypertension and use of blood pressure medications, was determined at baseline and two subsequent exams over 5 years. Among 3543 non-hypertensives at baseline, 714 individuals developed incident hypertension by Exam 3. Cox proportional hazard models were used to determine the relationship between baseline levels of IL-6, CRP and fibrinogen and future risk of hypertension. One s.d. difference in baseline concentration of IL-6, CRP or fibrinogen was associated with 20-40% greater risk of incident hypertension. This risk was attenuated after accounting for other hypertension risk factors (hazard ratio (HR) IL-6: 1.13 (95% CI: 1.04-1.23); CRP: 1.11 (95% CI: 1.02-1.21); fibrinogen 1.0 (95% CI: 0.92-1.08)). Conversely, obesity was an independent risk factor for hypertension risk, minimally impacted by other covariates, including IL-6 and CRP (HR 1.72 (95% CI: 1.36-2.16)). IL-6 and CRP did not modify the relationship between obesity and hypertension, though an adjusted twofold greater risk was observed for obese individuals with a CRP >3 mg l⁻¹ compared with CRP <1 mg l⁻¹. The relationship between inflammation-related proteins and hypertension risk was predominantly explained by other hypertension risk factors. Obesity, independent of inflammation, remained a potent risk factor for future hypertension.

Ancestry as a determinant of mean population C-reactive protein values: implications for cardiovascular risk prediction

BACKGROUND

Eligibility for rosuvastatin treatment for cardiovascular disease prevention includes a C-reactive protein (CRP) concentration >2 mg/L. Most observational studies of CRP and cardiovascular disease have been in Europeans. We evaluated the influence of ancestry on population CRP concentration to assess the implications for statin targeting in non-Europeans.

METHODS AND RESULTS

In a systematic review and meta-analysis among 221 287 people from 89 studies, geometric mean CRP was 2.6 mg/L (95% credible interval, 2.27 to 2.96) in blacks resident in the United States (n=18 585); 2.51 mg/L (95% CI, 1.18 to 2.86) in Hispanics (n=5049); 2.34 mg/L (95% CI, 1.99 to 2.8) in South Asians (n=1053); 2.03 mg/L (95% CI, 1.77 to 2.3) in whites (n=104 949); and 1.01 mg/L (95% CI, 0.88 to 1.18) in East Asians (n=39 521). Differences were not explained by study design or CRP assay and were preserved after adjustment for age and body mass index. At age 60 years, fewer than half of East Asians but more than two thirds of Hispanics were estimated to have CRP values exceeding 2 mg/L. HapMap frequencies of CRP polymorphisms known to associate with CRP concentration but not coronary heart disease events differed by ancestry. In participant data from the Wandsworth Heart and Stroke Study including European, South Asian and African, and Caribbean-descent subjects, body mass index, systolic blood pressure, and smoking contributed to between-group differences in CRP, but the majority of the difference in CRP was unexplained.

CONCLUSIONS

Differences in CRP concentration in populations of diverse ancestry are sufficiently large to affect statin eligibility, based on a single CRP threshold of 2 mg/L, and only partially influenced by differences in variables related to cardiovascular risk. A single threshold value of CRP for cardiovascular risk prediction could lead to inequalities in statin eligibility that may not accurately reflect underlying levels of cardiovascular risk.

Enhanced blood pressure variability in a high cardiovascular risk group of African Americans: FIT4Life Study

High blood pressure (BP) levels in African Americans elicit vascular inflammation resulting in vascular remodeling. BP variability (BPV) correlates with target organ damage. We aimed to investigate the relationship between inflammatory markers and BPV in African Americans. Thirty-six African Americans underwent 24-hour ambulatory BP monitoring (ABPM). BPV was calculated using the average real variability index. Fasting blood samples were assayed for high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-alpha), and white blood cell (WBC) count. Significant associations between hs-CRP and 24-hour systolic variability (r=0.50; P=.012) and awake systolic variability (r=0.45; P=.02) were identified after adjusting for age, body mass index, and 24-hour mean BP. ABPM variables were compared between the hs-CRP tertile groups. In post-hoc analysis, there was a significant difference in 24-hour and awake periods for both systolic and diastolic variability among the groups. TNF-alpha and WBC count showed no associations with ABPM variables. hs-CRP was associated with systolic variability, and higher levels of hs-CRP were related with greater BPV. Higher inflammatory status influences wider fluctuations in systolic BP, which in turn could facilitate early progression to target organ damage independent of absolute BP levels in African Americans.

The association of age, gender, body fatness and lifestyle factors with plasma C-reactive protein concentrations in older Taiwanese

OBJECTIVE

This study determined the population distribution of plasma C-reactive protein (CRP) and evaluated its association with age, body fatness status and lifestyle factors in elderly Taiwanese.

DESIGN

A crosssectional-study.

SETTING

A population-representative sample. The "1999-2000 Elderly Nutrition and Health Survey in Taiwan".

PARTICIPANTS

2432 non-institutionalized population-representative Taiwanese, 65 y or older.

MEASUREMENTS

Plasma CRP-concentrations and factors that impact plasma CRP concentrations.

RESULTS

Results showed that weighting-adjusted plasma CRP concentration (mean +/- SE) was 2.50 +/- 0.10 mg/L for men and 2.70 +/- 0.10 mg/L for women. Cigarette smoking was positively associated with plasma CRP concentrations in both men and women. Age was positively (P < 0.05) but physical activity was negatively (P <0.05) associated with plasma CRP concentrations in men. These associations were not significant in women. Waist circumference but not BMI was significantly (P < 0.05) associated with plasma CRP in women. Both associations were not significant in men. Alcohol drinking and betel nut-chewing were not significantly associated with CRP concentrations.

CONCLUSION

Results suggest that there are gender-related differences in the degree of association of CRP concentrations with age, waist circumference, BMI and physical activity in older Taiwanese. Results also suggest population-related differences in the strength of many associations when compared to observations made in Western countries. These findings may help delineate the differences in cardiovascular risk among various populations.

hs-CRP: A potential marker for hypertension in Kashmiri population

Hypertension is the most important public health problem in developing countries and one of the major risk factors for cardiovascular diseases, and it has been reported that hypertension is in part an inflammatory disorder and several workers have reported elevated levels of CRP in hypertensive individuals. The main aim of the present study was to evaluate the association between blood pressure and serum CRP levels across the range of blood pressure categories including prehypertension. A total of 104 patients and 63 control subjects were included in the present study. The level of CRP in the serum samples was estimated by a high sensitivity immunoturbidometric assay. Standard unpaired student's 't' test was used for comparison of hs-CRP levels between hypertensive patients and normotensive control subjects and between patient groups with different grades of hypertension and different durations of hypertensive histories. The mean serum hs-CRP level in hypertensive patients was 3.26 mg/L compared with 1.36 mg/L among normotensive control subjects (P<0.001). On comparison with normotensive control subjects, the hs-CRP levels vary significantly both with grades and duration of hypertension, with most significant difference found in patients with prehypertension (P<0.001), followed by Stage-I (P=0.01) and Stage-II(P=0.02) hypertensives. Significant difference in hs-CRP levels was also found in patients with shorter duration of hypertensive history (≤ 1year) when compared with those with ≥5 years of hypertensive history (P<0.01). Our study reveals a graded association between blood pressure and CRP elevation in people with hypertension. Individuals with prehypertension or with shorter duration of hypertension (≤1 Year) had significantly a greater likelihood of CRP elevation in comparison to chronic stage-I or stage-II hypertensives.

Hyperglycemia and oxidative stress strengthen the association between myeloperoxidase and blood pressure

Scavenging of the vasodilator nitric oxide by myeloperoxidase activity in the vasculature may contribute to hypertension. Because hydrogen peroxide is a cosubstrate of myeloperoxidase, hyperglycemia-induced oxidative stress may strengthen the relationship between myeloperoxidase and blood pressure. We investigated this relationship and its modification by hyperglycemia and oxidative stress in a population-based cohort of elderly subjects with normal glucose metabolism (n=267), impaired glucose metabolism (n=189), and type 2 diabetes (n=290). In an age- and sex-adjusted linear regression model, plasma myeloperoxidase was positively associated with systolic blood pressure (2.10 mm Hg per 1 SD increment of myeloperoxidase [95% CI: 0.66 to 3.54]), and this association was stronger at higher levels of fasting glucose (0.61 [-1.70 to 2.93], 1.33 [-1.43 to 4.10], and 3.42 [1.01 to 5.82] for increasing tertiles of glucose) and higher plasma levels of oxidized low-density lipoprotein (0.92 [-1.31 to 3.14], 2.00 [-0.71 to 4.70], and 3.58 [0.98 to 6.19] for increasing tertiles of oxidized low-density lipoprotein). Likewise, the relationship between myeloperoxidase and blood pressure was strongest under conditions associated with oxidative stress, like obesity, low high-density lipoprotein cholesterol, metabolic syndrome, and type 2 diabetes. The strength of these associations was only marginally attenuated by adjustment for other cardiovascular risk factors. Our data demonstrate that myeloperoxidase is positively and independently associated with blood pressure, and this association is strongest in subjects with (hyperglycemia-induced) oxidative stress. These observations, together with emerging evidence that myeloperoxidase-derived oxidants contribute to the initiation and propagation of cardiovascular disease, identify myeloperoxidase as a promising target for drug development.

CRP polymorphisms and progression of chronic kidney disease in African Americans

BACKGROUND AND OBJECTIVES

Chronic inflammation may play a role in chronic kidney disease (CKD) progression. CRP gene polymorphisms are associated with serum C-reactive protein (CRP) concentrations. It is unknown if CRP polymorphisms are associated with CKD progression or modify the effectiveness of anti-hypertensive therapy in delaying CKD progression.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We genotyped 642 participants with CKD from the African American Study of Kidney Disease and Hypertension (AASK), selecting five tag polymorphisms: rs2808630, rs1205, rs3093066, rs1417938, and rs3093058. We compared the minor allele frequencies (MAF) of single nucleotide polymorphisms (SNPs) in AASK to MAFs of African Americans from NHANES III. Among AASK participants, we evaluated the association of SNPs with CRP levels and prospectively with a composite: halving the GFR, ESRD, or death.

RESULTS

The MAF was higher for the rs2808630_G allele (P = 0.03) and lower for the rs1205_A allele (P = 0.03) in the AASK compared with NHANES III. Among AASK participants, the rs3093058_T allele predicted higher CRP concentrations (P < 0.0001) but not CKD progression. The rs2808630_GG genotype was associated with higher risk of the composite endpoint compared with the AA genotype (P = 0.002). Participants with the rs2808630_GG genotype on angiotensin converting enzyme inhibitors (ACEIs) versus beta blockers had increased risk of progression (P = 0.03).

CONCLUSION

CRP SNPs that were associated with higher levels of CRP did not predict CKD progression. The rs2808630_GG genotype was associated with higher risk of CKD progression, and in patients with this genotype, ACEIs did not slow progression.

Periodontal therapy reduces plasma levels of interleukin-6, C-reactive protein, and fibrinogen in patients with severe periodontitis and refractory arterial hypertension

BACKGROUND

Recent epidemiologic studies suggest that inflammation is the link between periodontal diseases and cardiovascular complications. This study aimed to evaluate the effects of non-surgical periodontal treatment on plasma levels of inflammatory markers (interleukin [IL]-6, C-reactive protein [CRP], and fibrinogen) in patients with severe periodontitis and refractory arterial hypertension.

METHODS

Twenty-two patients were examined and randomly divided into two groups. The test group was composed of 11 patients (mean age, 48.9 +/- 3.9 years) who received periodontal treatment, whereas the control group had 11 patients (mean age, 49.7 +/- 6.0 years) whose treatment was delayed for 3 months. Demographic and clinical periodontal data were collected, and blood tests were performed to measure the levels of IL-6, CRP, and fibrinogen at baseline and 3 months later.

RESULTS

The clinical results showed that the mean percentages of sites with bleeding on probing, probing depth (PD) 4 to 5 mm, PD > or =6 mm, clinical attachment loss (CAL) 4 to 5 mm, and CAL > or =6 mm were significantly reduced in the test group 3 months after periodontal treatment. There were no significant differences between the data at baseline and 3 months in the control group. Periodontal treatment significantly reduced the blood levels of fibrinogen, CRP, and IL-6 in the test group.

CONCLUSION

Non-surgical periodontal therapy was effective in improving periodontal clinical data and in reducing the plasma levels of IL-6, CRP, and fibrinogen in hypertensive patients with severe periodontitis.

Effects of acute exercise on atherogenic lipids in untreated mild hypertensive patients

BACKGROUND/AIM

Exercise can positively influence risk factors associated with cardiovascular disease. The mechanisms by which exercise reduces atherogenic risk remain unknown. The aim of the present study was to investigate the effect of acute exercise (cardiopulmonary exercise cycle ergometer test) on atherogenic lipids in untreated mild hypertensive patients with or without hypercholesterolemia. This testing allows determination of exercise capacity, peak heart rate, and ventilation per minute (VE), peak oxygen uptake (pVO2) and exercise time (ET).

METHODS

The study group included 85 untreated mild hypertensive patients (according to VII Joint National Committee--JNC 7) divided into two subgroups: hypertensive hypercholesterolemic and hypertensive normocholesterolemic. The control grouip included 35 normotensive subjects divided into two subgroups: normotensive hypercholesterolemic and normotensive normocholesterolemic. Lipid profiles to determine were oxidized LDL (OxLDL)--a marker of oxidative stress, triglycerides, total cholesterol, LDL cholesterol, and HDL cholesterol, which were measured at rest and 30 minutes after the acute bout of cardiopulmonary exercise cycle ergometer test. Lipids profiles were measured by enzymatic methods. Oxidized LDL was determined by a commercially available sandwich ELISA (Mercodia AB, Uppsala, Sweden). C-reactive protein (CRP) was measured using chemiluminiscent methods (Immulite-DPC).

RESULTS

In our study OxLDL was significantly higher in hypertensive patients with atherogenic lipid profiles in basal condition, compared to the hypertensive patients without atherogenic lipid profiles and controls. There was a significant difference in CRP (p < 0.001) between hypercholesterolemics (hypertensive and normotensive) and normocholesterolemics (hypertensive and normotensive). We found increased OxLDL after exercise in both groups (hypertensive patients and normotensive), but only in the hypertensive hypercholesterolemic patients the difference was statistically significant (90.47 +/- 15.31 vs. 105.94 +/- 14.17 IU/L, p < 0.001). Systolic and diastolic blood pressures were significantly higher during exercise only in the hypertensive patients. There were significantly lower values of pVO2 only in hypertensive hypercholesterolemic patients. There were no significant differences between hypertensive and normotensive ones for ET and VE. In hypertensive ones we found after exercise a negative correlation between pVO2 and OxLDL (r = -0.473; p < 0.05), and pVO2 and CRP (r = -0.478; p < 0.05). We also found in normotensive normocholesterolemic patients a positive correlation between VE and systolic blood pressure (r = 0.420; p < 0.05), a negative correlation between VE and OxLDL (r= -0.421; p < 0.05), and VE and CRP (r = -0.561; p < 0.05).

CONCLUSION

This study showed that acute exercise induces and increases oxidative stress only in untreated mild hypertensive patients with atherogenic lipid profiles. These results imply the need to normalize atherogenic lipid profile in untreated patients with mild hypertension in order to prevent an increased lipid peroxidation under acute exercise.

Free Leptin Is Associated With Masked Hypertension in Nonobese Subjects

The aim of the study was to investigate whether diverse clinical blood pressure phenotypes are associated with free leptin surrogates, as reflected by plasma leptin, human soluble leptin receptor, and their ratio (ie, free leptin index) in nonobese normoglycemic subjects. Three separate clinic blood pressure measurements and ambulatory blood pressure monitoring were implemented to divide 494 subjects (aged 44±5 years; 272 men; body mass index: <30 kg/m 2 ) into hypertensives (n=166), white-coat hypertensives (n=82), masked hypertensives (n=66), and normotensives (n=180). Participants underwent echocardiography, while, from fasting venous blood samples, metabolic profile, plasma leptin, and its receptor levels were assessed. Hypertensives and masked hypertensives demonstrated higher levels of log (10)(leptin) and log (10)(free leptin index), as well as lower levels of log (10)(human soluble leptin receptor) with respect to normotensives. White-coat hypertensives had similar free leptin surrogates compared with normotensives. Younger age, 24-hour systolic and diastolic blood pressures, 24-hour heart rate, and left ventricle mass index were common correlates of free leptin surrogates. After adjustment for confounders, masked hypertensive and hypertensive with respect to normotensive phenotype were associated with log (10)(leptin) with odds ratios (95% CIs) of 1.31 (1.12 to 3.80) and 1.26 (1.09 to 2.24), respectively, log (10)(human soluble leptin receptor) with 0.65 (0.53 to 0.78) and 0.69 (0.57 to 0.84), respectively, and log (10)(free leptin index) with 2.46 (1.32 to 7.23) and 1.84 (1.26 to 3.73), respectively ( P <0.05 for all of the cases). Free leptin surrogates are associated with masked hypertension in nonobese normoglycemic subjects. Free leptin is almost equally increased in masked and sustained hypertension, suggesting a similar leptin-related vascular impairment.

Markers of inflammation and hemodynamic measurements in obesity: Copenhagen City Heart Study

BACKGROUND

Low-grade chronic inflammation has been proposed to play a major role in the pathogenesis of hypertension. Low-grade chronic inflammation is also closely associated with obesity, an established causative factor in the development of hypertension. The purpose of this study was to investigate the relationship between two markers of inflammation, C-reactive protein (CRP) and fibrinogen, and blood pressure (BP) and other hemodynamic variables in obese subjects.

METHODS

From a large cardiovascular study based in the general population, we selected subjects with a body mass index (BMI) > or =30 kg/m2, free of major cardiovascular diseases, not taking BP-lowering or lipid-lowering drugs (n = 487; women = 51.1%; median (5th to 95th percentile) age = 62 years (36-80)). The cardiovascular study included measurements of traditional and new risk factors, including ankle brachial BP index, a measure of subclinical atherosclerosis. CRP was determined by a high-sensitive assay.

RESULTS

In partial Spearman rank correlation analysis, adjusted for age and sex, we found no significant relationships between either CRP or fibrinogen and systolic BP, diastolic BP, pulse pressure, or ankle brachial index (rho: -0.057 to 0.068; P > 0.13). However, fibrinogen and CRP were found to be significantly related to heart rate (rho: 0.127-0.169; P < 0.01).

CONCLUSIONS

In this study of generally healthy obese subjects from the general population, we found no significant relationships between markers of inflammation and systolic BP or diastolic BP, showing that obese subjects with higher levels of inflammatory markers do not have higher BP levels than their obese counterparts with lower levels of inflammatory markers.

Physical activity and high-sensitivity C-reactive protein: the multi-ethnic study of atherosclerosis

BACKGROUND

Previous studies have suggested an inverse relationship between physical activity and markers of inflammation such as high-sensitivity C-reactive protein (hs-CRP). However, these were inconsistent, and few examined whether race and gender influenced the relationship. This study determined a cross-sectional association between physical activity and hs-CRP level in 6142 middle-aged white, Chinese, black, and Hispanic participants enrolled in the Multi-Ethnic Study of Atherosclerosis in 2000-2002.

METHODS

Combined moderate and vigorous physical activity was measured by self-reported leisure, conditioning, occupational, and household activities. ANCOVA was used to assess the association between moderate/vigorous physical activity and hs-CRP by gender and race.

RESULTS

Hs-CRP was higher in women. Blacks had the highest hs-CRP, and Chinese participants had the lowest. Hs-CRP decreased across tertiles of moderate/vigorous physical activity in Hispanic men in models adjusted for age, education, study site, and physical activity questionnaire mode of administration (p=0.005) and further adjusted for smoking, infection, and aspirin use (p=0.020). The trend remained significant after further adjustment for BMI; blood pressure; low-density lipoprotein cholesterol; high-density lipoprotein cholesterol; diabetes; and the use of antihypertensive, statin, and diabetes medication (p=0.044). There was a downward trend in hs-CRP across tertiles of physical activity in black and white men, but the association was weaker. No clear trend was observed in any female racial/ethnic groups.

CONCLUSIONS

These findings suggest that the association between moderate/vigorous physical activity and hs-CRP differs by race and gender. Further studies are needed to confirm this and to examine the mechanisms for these race and gender differences.

C-reactive protein and coronary heart disease: predictive test or therapeutic target?

BACKGROUND

The hepatocyte-derived acute-phase reactant C-reactive protein (CRP) has been the subject of intense research over the last 2 decades for its possible role in the pathogenesis of cardiovascular diseases. This research has spawned interest in the use of the blood concentration of CRP for predicting a first coronary heart disease (CHD) event, which has been made possible with the development of high-sensitivity CRP (hsCRP) assays that can measure the typically low concentrations of CRP that circulate in the absence of an overt infective or inflammatory episode, and as a potential causal factor that might be targeted therapeutically. The research has encompassed observational and genetic epidemiology, basic science studies with cells and tissues, experiments with animal models and humans, and randomized trials (although not of specific CRP-lowering therapies as yet).

CONTENT

We focus on investigations of the potential role of small differences in basal hsCRP concentration seen in healthy individuals and the relationship of such differences to the long-term risk of a first CHD event, rather than on research devoted to the high acute-phase CRP concentrations, which occur after acute atherothrombotic events and can influence the severity of ischemic tissue damage and the subsequent prognosis. We concentrate mainly on research findings at the translational interface and draw on evidence from human observational and genetic epidemiology, as well as from randomized trials.

CONCLUSIONS

As the field matures from one of discovery to an evaluative science, the development of possible clinical applications requires a sharpening of focus on and a critical appraisal of the strengths and deficiencies of the accumulated evidence. Such assessments require attention to both the current state of affairs and the design of future research, so that the existing uncertainties about the utility of CRP in predicting CHD and its role in causing this disease can be resolved.

Adeno-associated virus-mediated human C-reactive protein gene delivery causes endothelial dysfunction and hypertension in rats

BACKGROUND

Prospective studies have shown that C-reactive protein (CRP) is a predictor of hypertension. Because of confounding variables, a causal linkage between CRP and hypertension has not been clearly shown. We investigated whether high circulating concentrations of human CRP can induce hypertension in rats.

METHODS

We administered a single intravenous injection of adeno-associated virus-green fluorescent protein (AAV-GFP) or AAV-hCRP and measured blood pressure. Using ELISA, we measured serum hCRP, serum endothelin 1 (ET-1), and urine cGMP, and we measured serum nitric oxide (NO) using the Griess method. We recorded heart rate, maximum pressure, arterial elastance, mean aortic pressure, cardiac output, and maximum rate of rise in left ventricular pressure (dP/dt max).

RESULTS

A single injection of AAV-hCRP resulted in efficient and sustained hCRP expression and led to increased blood pressure 2 months after gene transfer that persisted for another 2 months. This effect was associated with decreased NO production, as demonstrated by decreased serum NO concentration and urinary cGMP excretion, and impairment of endothelial-dependent vascular relaxation. CRP transduction also increased expression of angiotensin type 1 receptor, ET-1, and endothelin type A receptor, decreased expression of angiotensin type 2 receptor and endothelial NO synthase in thoracic aortas, and increased arterial stiffness. Ex vivo studies indicated a similar detrimental effect of CRP that was reversed by the NO donor.

CONCLUSION

AAV vector-mediated CRP expression resulted in hypertension mediated through reduced NO production and subsequent alteration in ET-1 and renin-angiotensin system activation. Impaired arterial elasticity may also contribute to CRP-induced hypertension. These results support a causal role for CRP in the pathogenesis of hypertension.

C-reactive protein and coronary heart disease: a critical review

Modestly elevated baseline concentrations of C-reactive protein (CRP), the classical acute phase protein, are associated with the long-term risk of coronary heart disease in general populations, whilst the major acute phase response of CRP following myocardial infarction is associated with death and cardiac complications. The pathogenic and clinical significance of these associations is controversial. Here we critically review the evidence and describe large-scale epidemiological studies, novel experiments and possible specific therapies which will rigorously inform the debate. We distinguish between the potential pathogenicity of high acute phase circulating CRP concentrations in individuals with substantial tissue damage and modest but persistent increases in baseline values in generally healthy subjects.

Metabolic syndrome, inflammation, and incident heart failure in the elderly: the cardiovascular health study

BACKGROUND

Inflammation markers and metabolic syndrome (MetS) are associated with risk of congestive heart failure (CHF). We evaluated whether combining inflammation markers and MetS provided additive information for incident CHF and if incorporating inflammation markers to the MetS definition added prognostic information.

METHODS AND RESULTS

We studied 4017 men and women > or =65 years old, without baseline CHF or diabetes, participating in the Cardiovascular Health Study, an observational study with 12.2 years follow-up and 966 cases of incident CHF. Baseline "C-reactive protein (CRP)-MetS" or "interleukin (IL)-6-MetS" were defined as presence of 3 out of 6 components, with elevated CRP (> or =3 mg/L) or IL-6 (> or =2.21 pg/mL) as a sixth component added to ATPIII criteria. Cox models adjusted for CHF risk factors and incident coronary disease were used to calculate hazard ratios for CHF. MetS and elevated inflammation markers were independently associated with CHF risk (hazard ratios, 95% CI: 1.32, 1.16 to 1.51 for MetS; 1.53, 1.34 to 1.75 for CRP; 1.37, 1.19 to 1.55 for IL-6). There was a 20% relative excess risk attributed to the combination of MetS and CRP (95% CI, -44% to 88%). CRP-MetS and IL-6-MetS definitions reclassified 18% and 13%, respectively of participants as MetS. Both CRP-MetS and IL-6-MetS increased risk of CHF by 60% compared with those without MetS.

CONCLUSIONS

MetS and inflammation markers provided additive information on CHF risk in this elderly cohort. Inflammation-incorporated MetS definitions identified more participants with the same risk level as ATPIII MetS. Considering inflammation markers and MetS together may be useful in clinical and research settings.

Sex differences in circulating and renal angiotensins of hypertensive mRen(2). Lewis but not normotensive Lewis rats

Sex differences in blood pressure are evident in experimental models and human subjects, yet the mechanisms underlying this disparity remain equivocal. The current study sought to define the extent of male-female differences in the circulating and tissue renin-angiotensin aldosterone systems (RAASs) of congenic mRen(2). Lewis and control Lewis rats. Male congenics exhibited higher systolic blood pressure than females [200 +/- 4 vs. 146 +/- 7 mmHg, P < 0.01] or Lewis males and females [113 +/- 2 vs. 112 +/- 2 mmHg, P > 0.05]. Plasma ANG II levels were twofold higher in male congenics [47 +/- 3 vs. 19 +/- 3 pM, P < 0.01] and fivefold higher than in male or female Lewis rats [6 +/- 1 vs. 6 +/- 1 pM]. ANG I levels were also highest in the males; however, plasma ANG-(1-7) was higher in female congenics. Male congenics exhibited greater circulating renin and angiotensin-converting enzyme (ACE) activities, as well as angiotensinogen, than female littermates. Renal cortical and medullary ANG II levels were also higher in the male congenics versus all the other groups; ANG I was lower in the males. Cortical ACE2 activity was higher in male congenics, yet neprilysin activity and protein were greater in the females, which may contribute to reduced renal levels of ANG II. These data reveal that sex differences in both the circulating and renal RAAS are apparent primarily in the hypertensive group. The enhanced activity of the RAAS in male congenics may contribute to the higher pressure and tissue injury evident in the strain.

Long-term N-acetylcysteine and L-arginine administration reduces endothelial activation and systolic blood pressure in hypertensive patients with type 2 diabetes

OBJECTIVE

Reactive oxygen and nitric oxide (NO) have recently been considered to be involved in the cardiovascular complications of patients with type 2 diabetes, as NO is thought to lose its beneficial physiological effects in the presence of oxygen radicals. For this reason, we tested the effects of l-arginine (ARG) and N-acetylcysteine (NAC) administration in increasing NO bioavailability by reducing free radical formation.

RESEARCH DESIGN AND METHODS

A double-blind study was performed on 24 male patients with type 2 diabetes and hypertension divided into two groups of 12 patients that randomly received either an oral supplementation of placebo or NAC + ARG for 6 months.

RESULTS

The NAC + ARG treatment caused a reduction of both systolic (P < 0.05) and diastolic (P < 0.05) mean arterial blood pressure, total cholesterol (P < 0.01), LDL cholesterol (P < 0.005), oxidized LDL (P < 0.05), high-sensitive C-reactive protein (P < 0.05), intracellular adhesion molecule (P < 0.05), vascular cell adhesion molecule (P < 0.01), nitrotyrosine (P < 0.01), fibrinogen (P < 0.01), and plasminogen activator inhibitor-1 (P < 0.05), and an improvement of the intima-media thickness during endothelial postischemic vasodilation (P < 0.02). HDL cholesterol increased (P < 0.05). No changes in other parameters studied were observed.

CONCLUSIONS

NAC + ARG administration seems to be a potential well-tolerated antiatherogenic therapy because it improves endothelial function in hypertensive patients with type 2 diabetes by improving NO bioavailability via reduction of oxidative stress and increase of NO production. Our study's results give prominence to its potential use in primary and secondary cardiovascular prevention in these patients.

Associations between recent exposure to ambient fine particulate matter and blood pressure in the Multi-ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Blood pressure (BP) may be implicated in associations observed between ambient particulate matter and cardiovascular morbidity and mortality. This study examined cross-sectional associations between short-term ambient fine particles (particulate matter <or= 2.5 microm in aerodynamic diameter; PM(2.5)) and BP: systolic (SBP), diastolic (DBP), mean arterial (MAP), and pulse pressure (PP).

METHODS

The study sample included 5,112 persons 45-84 years of age, free of cardiovascular disease at the Multi-Ethnic Study of Atherosclerosis baseline examination (2000-2002). Data from U.S. Environmental Protection Agency monitors were used to estimate ambient PM(2.5) exposures for the preceding 1, 2, 7, 30, and 60 days. Roadway data were used to estimate local exposures to traffic-related particles.

RESULTS

Results from linear regression found PP and SBP positively associated with PM(2.5). For example, a 10-microg/m(3) increase in PM(2.5) 30-day mean was associated with 1.12 mmHg higher pulse pressure [95% confidence interval (CI), 0.28-1.97] and 0.99 mmHg higher systolic BP (95% CI, -0.15 to 2.13), adjusted for age, sex, race/ethnicity, income, education, body mass index, diabetes, cigarette smoking and environmental tobacco smoke, alcohol use, physical activity, medications, atmospheric pressure, and temperature. Results were much weaker and not statistically significant for MAP and DBP. Although traffic-related variables were not themselves associated with BP, the association between PM(2.5) and BP was stronger in the presence of higher traffic exposure.

CONCLUSIONS

Higher SBP and PP were associated with ambient levels of PM(2.5) and the association was stronger in the presence of roadway traffic, suggesting that impairment of blood pressure regulation may play a role in response to air pollution.

Inflammation and descending thoracic aortic calcification as detected by computed tomography: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Inflammation is related to many stages of atherosclerosis, and inflammatory markers have been associated with both atherosclerosis and future cardiovascular events. Descending thoracic aortic calcification (DTAC) is a manifestation of atherosclerosis, however, no previous study has examined the relationship of inflammatory markers and DTAC as detected by computed tomography (CT) in a large study. We examined whether C-reactive protein (CRP) and interleukin-6 (IL-6) are independently associated with DTAC.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective cohort study that includes 6814 women and men ages 45-84 years old, all free of baseline cardiovascular disease. The inflammation markers CRP and IL-6, and DTAC by CT, quantified by Agatston score, were measured at baseline in all participants.

RESULTS

We studied 6613 participants with complete data (3112 men, 3501 women, mean age 62+/-10 years). The prevalence of DTAC was 27%. Participants with DTAC had significantly higher levels of both CRP and IL-6. After adjustment for baseline risk factors, CRP was not correlated with presence or severity of DTAC (Adjusted RR per S.D., 1.01; 95% confidence intervals 0.97; 1.05) while IL-6 associations remained significant (adjusted RR per S.D., 1.07; 95% confidence intervals 1.02; 1.14).

CONCLUSIONS

IL-6, a systemic inflammatory marker, is related to the presence and extent of DTAC. Further studies are needed to evaluate the interaction between DTAC and inflammation markers as predictors of future cardiovascular events.

Does elevated high-sensitivity serum C-reactive protein associate with hypertension in non-obese Japanese males?

The object of this study is to assess whether elevated hsCRP levels are independently related to hypertension in non-obese Japanese males. This cross-sectional study comprised 86 hypertensive and 109 normotensive subjects. We defined hypertension as a systolic blood pressure >/=140 mmHg and/or a diastolic blood pressure >/=90 mmHg and/or taking antihypertensive therapy. Log-hsCRP levels were significantly higher in hypertensive than normotensive subjects. In logistic regression analysis, subjects in the highest tertile had a two-fold higher risk than those in the lowest tertile. The association between hypertension and hsCRP levels was marginally significant. In addition, there was a significant tendency for hypertension to increase with an increase in CRP level (p < .05). These findings suggest that elevated hsCRP level is an independent risk factor for hypertension in non-obese Japanese males.

A low level of C-reactive protein in Japanese adults and its association with cardiovascular risk factors: The Japan NCVC-Collaborative Inflammation Cohort (JNIC) Study

High-sensitivity C-reactive protein (hs-CRP) levels vary remarkably by race and ethnic group. We examined hs-CRP levels and their association with cardiovascular risk factors in the Japanese general population. The Japan National Cardiovascular Center (NCVC)-collaborative Inflammation Cohort (JNIC) Study recruited 5213 men and 7071 women aged > or = 40 years from seven communities in Japan during 2002-2004. hs-CRP was measured using nephelometry calibrated with CRM 470, the international plasma protein reference material. Traditional cardiovascular risk factors and their aggregation were studied in multivariate logistic models, stratified by overweight status. Median hs-CRP levels in men and women were 0.60 and 0.45 mg/L, respectively. The percentage of subjects with hs-CRP levels < 1.0, 1.0-3.0, and > 3.0 mg/L was 67.4%, 22.0%, and 10.6% in men, respectively, and 76.3%, 16.7%, and 7.0% in women. hs-CRP levels showed significant linear associations with traditional risk factors. Overweight, hypertension, dyslipidemia (men only), smoking (men only), and diabetes (women only) contributed significantly to elevated hs-CRP levels. Overweight individuals with hypertension, dyslipidemia, and diabetes had a high prevalence of elevated hs-CRP levels in both sexes. Japanese adults have very low hs-CRP levels. An aggregation of metabolic risk factors is associated with elevated hs-CRP levels among overweight individuals, particularly in women.

Serum C-reactive protein levels correlates better to metabolic syndrome defined by International Diabetes Federation than by NCEP ATP III in men

The International Diabetes Federation (IDF) proposed a new definition for metabolic syndrome (MS) in 2005. We conducted this study to compare the association of MS by IDF and ATP III definition to various metabolic variables. In 2005, we enrolled 654 Chinese people in a screening program in Taiwan. Anthropometric and biochemical profiles, including high-sensitivity C-reactive protein (hsCRP), were measured. Serum hsCRP levels were higher in those with MS by IDF definition (2.4+/-1.9mg/l versus 1.3+/-1.4mg/l, p<0.0001). Serum hsCRP levels increase with the number of components of MS they met (p for trend<0.001). Serum LDL levels were higher in those with MS by IDF definition (131+/-39 versus 125+/-32, p<0.05) but not in those with MS by ATP III definition (p=0.2). Serum hsCRP levels correlate significantly to MS by ATP III definition, after adjusting for age, sex, smoking, body mass index, serum apolipoprotein A1 and LDL levels. Adding MS status by IDF definition in this model significantly increased model fitness in men (MS by IDF definition, partial r=0.18, p<0.05, MS by ATP III definition, partial r=0.12, p=0.071). In conclusion, IDF definition of MS has a stronger relationship with serum hsCRP than ATP III definition in men.

Inflammatory Cytokine Imbalance after Coronary Angioplasty: Links with Coronary Atherosclerosis

AIM

To investigate release of some inflammatory cytokines (Cys) after coronary angioplasty and its links with coronary atherosclerosis.

METHODS

Twenty-seven consecutive subjects with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI) were enrolled in the study: serial blood samples were taken in order to evaluate plasma concentrations of Interleukin (IL)-2, IL-10, IL-18, TNFalpha, and IFNgamma just before PCI at 12 and 24 hours. Patients were then divided, considering balance between each inflammatory Cy and IL-10, an antiinflammatory Cy, into four groups, ranging from a prevalent antiinflammatory response (stable inflammatory Cy-increasing IL-10 values) to a marked inflammatory imbalance (increasing inflammatory Cy-stable IL-10 values).

RESULTS

All Cys showed significant increases in plasma concentrations if compared with baseline values. Release curves were not significantly different when comparing subjects with ST-elevation myocardial infarction (STEMI) versus unstable angina-non-STEMI (UA-NSTEMI), diabetics versus controls. Subjects with marked inflammatory response showed a higher incidence of stenosis on left anterior descending (LAD) coronary artery (IL-2 chi(2) and IFNgamma P < 0.05); Cy release was higher in patients with multivessel coronary disease (IL-2 and IFNgamma, ANOVA P < 0.01). Correlations were also referable between Cys and myocardial enzyme release. Subjects treated with sirolimus-eluting stents (SES) showed significantly lower Cy periprocedure ratio if compared with those treated with bare metal stents.

CONCLUSIONS

A significant Cy release is detectable after PCI: inflammatory response seems to correlate with both PCI due to plaque instabilization and coronary atherosclerosis. A blunted inflammatory response is detectable in subjects treated with SES.

C-reactive protein causes downregulation of vascular angiotensin subtype 2 receptors and systolic hypertension in mice

BACKGROUND

Chronic elevations in circulating C-reactive protein (CRP) are associated with a greater risk of hypertension. Whether elevations in CRP cause hypertension is unknown.

METHODS AND RESULTS

Chronic, conscious blood pressure (BP) measurements were performed by radiotelemetry in wild-type CF1 control and CF1 transgenic mice expressing rabbit CRP (CF1-CRP) under the regulation of the phosphoenolpyruvate carboxykinase promoter. Compared with controls, CF1-CRP mice had hypertension that was predominantly systolic, and the severity of hypertension varied in parallel with changes in CRP levels modulated by dietary manipulation. Mice that were hemizygous for the transgene with CRP levels of 9 microg/mL were also hypertensive, indicating that modest elevations in CRP are sufficient to alter BP. CRP transgenic mice had exaggerated BP elevation in response to angiotensin II and a reduction in vascular angiotensin receptor subtype 2 (AT2) expression. In contrast, the decline in BP with angiotensin receptor subtype 1 (AT1) antagonism and vascular AT1 abundance were unaltered, which indicates a selective effect of CRP on AT2. Ex vivo experiments further showed that the CRP-induced decrease in AT2 is a direct effect on the vascular wall, not requiring systemic responses, and that it is reversed by an NO donor, which indicates a role for NO deficiency in the process. In parallel, the chronic inhibition of NO synthase in wild-type mice attenuated vascular AT2 expression without affecting AT1.

CONCLUSIONS

These findings provide direct evidence for CRP-induced hypertension, and they further identify a novel underlying mechanism involving downregulation of AT2 related to NO deficiency.