White blood cell count: an independent predictor of coronary heart disease mortality among a national cohort

Carotid artery stiffness, high-density lipoprotein cholesterol and inflammation in men with pre-hypertension

Low circulating levels of high-density lipoprotein cholesterol (HDL-C) are associated with increased risk for cardiovascular events. HDL-C has a variety of poorly understood atheroprotective effects, including altering lipid metabolism and reducing inflammation. Increased arterial stiffness is an important predictor of subsequent cardiovascular risk. Therefore, in this study, we sought to determine whether HDL-C levels are associated with carotid arterial stiffness. In addition, we examined potential correlates of this association, such as inflammatory factors, cardiorespiratory fitness and body fat percentage. Carotid artery beta-stiffness was measured by ultrasound in 47 (23 years old) healthy pre-hypertensive men. Low HDL-C was defined as <1.0 mmol l(-1). Body fat was measured by air displacement plethysmography. Cardiorespiratory fitness was measured using a maximal exercise test, with metabolic gas analysis and inflammatory markers consisting of C-reactive protein (CRP), white blood cell (WBC) count and absolute neutrophil count. Men with a low HDL-C had significantly higher carotid artery stiffness, CRP, WBC count, neutrophil count, body fat, fasting glucose and lower cardiorespiratory fitness (P<0.05). Co-varying for cardiorespiratory fitness, % body fat and glucose had no effect on group differences in carotid artery stiffness. Co-varying for inflammatory markers resulted in groups having similar carotid artery stiffness. Pre-hypertensive men with low HDL-C have a higher carotid artery stiffness when compared with those with higher HDL-C. The detrimental effects of low HDL-C on large artery stiffness in pre-hypertensive men may be mediated by inflammation and not by cardiorespiratory fitness or body fat levels.

Exercise training improves autonomic function and inflammatory pattern in women with polycystic ovary syndrome (PCOS)

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common female reproductive-age endocrine disease predominantly characterized by chronic anovulation, hyperandrogenism, insulin-resistance and low-grade inflammatory status. Exercise training (ET) favourably modulates cardiopulmonary function and insulin-sensitivity markers in PCOS women. The present study investigated the effects of ET on autonomic function and inflammatory pattern in PCOS women.

STUDY DESIGN

Prospective baseline uncontrolled clinical study.

METHODS

One-hundred and eighty five PCOS women referred to our department were screened for the inclusion into the study protocol from March 2004 to July 2007. One-hundred and twenty four PCOS women met the criteria for the inclusion into the study protocol and were subdivided into two groups each composed of 62 patients: PCOS-T (trained) group underwent 3-month ET program, whereas PCOS-UnT (untrained) group did not. At baseline and at 3-month follow-up, hormonal and metabolic profile, cardiopulmonary parameters, autonomic function (as expressed by heart rate recovery, HRR) and inflammatory pattern [as expressed by C-reactive protein (CRP) and white blood cells (WBCs) count] were evaluated.

RESULTS

PCOS-T showed a significant (P < 0.05) improvement in maximal oxygen consumption (VO(2max)) and in post-exercise HRR, and a significant (P < 0.001) decrease in CRP and WBCs; whereas no statistically significant changes of the same parameters were observed in PCOS-UnT. Multiple linear regression analysis showed that 3-month HRR is linearly related to the inclusion in training group (beta = 0.316, P < 0.001), VO(2max) (beta = 0.151, P = 0.032) and the ratio between glucose and insulin area under curve (AUC) (beta = 0.207, P = 0.003), and inversely related to body mass index (beta = -0.146, P = 0.046), insulin AUC (beta = -0.152, P = 0.032), CRP (beta = -0.165, P < 0.021), and WBCs count (beta = -0.175, P = 0.039).

CONCLUSIONS

Exercise training improves autonomic function and inflammatory pattern in PCOS women.

Association of WBC count and glucose metabolism among Chinese population aged 40 years and over

Chronic subclinical inflammation may be involved in the pathogenesis of Type 2 diabetes. We examined whether elevated WBC count, a marker of inflammation, was associated with worsening of glucose tolerance among Chinese population aged 40 years and over. Based on the 75g OGTT, 1016 subjects aged from 40 to 88 years were classified into four groups: NFG/NGT (n=299), isolated IFG (n=213), IGT (n=213) and Type 2 diabetes (n=291). We compared the WBC count among the four groups and investigated relevant variables associated significantly with the WBC count. The IGT and Type 2 diabetes groups had a significantly higher WBC count than the NFG/NGT and isolated IFG groups. By stepwise regression analyses, we found that waist circumference, DBP, total cholesterol, HDL cholesterol and 2-h PG showed an independent association with the WBC count. In the analysis stratified by sex and smoking status, WBC count was independently associated with age and triglycerides in males, whereas it was associated with BMI, SBP, triglycerides and 2-h PG in females. BMI, SBP, triglycerides and 2-h PG showed an independent association with WBC count in subjects who never smoked. We concluded that an increase in WBC count was associated with the deterioration of glucose tolerance. WBC count was associated with lipid metabolism in males and with various components of the metabolic syndrome in females and subjects who never smoked.

Association between low birth weight and elevated white blood cell count in adulthood within a Japanese population

BACKGROUND

Epidemiological studies have demonstrated the association between low birth weight and increased adulthood risk for cardiovascular and metabolic diseases. However, the precise mechanism underlying the association remains poorly understood. We investigated the association between birth weight and adult white blood cell (WBC) count in a Japanese population.

METHODS AND RESULTS

The subjects were 779 men and 209 women aged 35-64 years. The mean WBC count was 5,283 /microl (SD: 1,326). Birth weight was divided to 6 categories: <2,500, 2,500-<2,800, 2,800-<3,000, 3,000-<3,200, 3,200-<3,500, and >3,500 g. Estimated WBC counts were 5,729, 5,341, 5,301, 5,212, 5,013 and 5,372 for the subjects with birth weights of the above respective categories (p=0.015, trend p=0.016) by one-way analysis of covariance after adjustments for sex, age, height, body mass index (BMI), lifestyles, and chronic diseases. This association was pronounced among the subjects with a BMI <25.0 kg/m2 rather than those with a higher BMI.

CONCLUSIONS

These findings support the idea that part of the association of low birth weight with elevated risk for vascular and metabolic diseases in later life could be mediated by an inflammatory pathway.

Having more healthy practice was associated with low white blood cell counts in middle-aged Japanese male and female workers

White blood cell (WBC) count is well known to be an independent risk marker for cardiovascular disease. The aim of this study is to examine the relationships of WBC counts to seven health practices including obesity, eating habits, smoking, alcohol intake, sleeping, physical activity, and perceived mental stress, and then clustering the relevant healthy practices. The subjects were 1,492 male and 316 female Japanese workers aged 40 yr and over in 2002. Each of seven health practices from a self-administered questionnaire was categorized as a 'healthy' or 'unhealthy' practice, and WBC counts from fasting blood samples were determined by automated particle counters. The means of age and WBC counts were 49.5 yr and 5,375 cells/microl in men, and 48.6 yr and 4,890 cells/microl in women, respectively. After multivariate adjustments for all health practices and age, the estimated WBC counts were significantly lower in normal weight subjects and never or former smokers (p<0.01). Age-adjusted WBC counts decreased significantly by 204.9+/-23.7 cells/microl (means+/-SE) and 117.6+/-53.2 cells/microl for each increase in one healthy practice (p<0.05), respectively, suggesting that cultivating healthier practices would lead to lower WBC counts. This study recommends modifying unhealthy practice one by one and maintaining healthy practices as an effective strategy for the prevention of atherosclerotic diseases, in addition, to quit smoking or abstain from heavy smoking especially in men is important to prevent the low-grade inflammation.

The associations of total and differential white blood cell counts with obesity, hypertension, dyslipidemia and glucose intolerance in a Korean population

Although many studies have reported an association between total white blood cell count and metabolic syndrome, relatively few reports are available on the association between differential white blood cell counts and metabolic syndrome. The medical records of 15,654 subjects (age, median 46, range 14-90 yr; 8,380 men and 7,274 women) who visited the Center for Health Promotion were investigated. It was found that as total white blood cell (WBC) and differential WBC counts increased the frequencies of diabetes, hypertension, obesity, dyslipidemia, and metabolic syndrome also increased. Moreover, these significant relationships persisted after adjusting for age, gender, smoking, alcohol intake, educational background, and household income. The odds ratios (95% CI) for metabolic syndrome was 2.64 (2.30- 3.04) in the highest quartile of total WBC count, with corresponding figures of 2.14 (1.88-2.44) for neutrophils, 2.32 (2.03-2.64) for lymphocytes, 1.56 (1.37-1.78) for monocytes, 1.36 (1.20-1.54) for basophils, and 1.82 (1.59-2.08) for eosinophils versus the lowest quartiles of the appropriate total and differential counts, respectively, after adjusting for the variables mentioned above. These independent associations were also observed by subgroup analyses according to the smoking status. Our data suggest that even within normal ranges, total WBC count and the differential WBC counts are associated with the presence of metabolic syndrome.

Role of atherosclerosis assessment and other novel markers in the metabolic syndrome

The metabolic syndrome is a constellation of cardiovascular disease risk factors predisposing to future cardiovascular disease events as well as the development of type 2 diabetes mellitus. This syndrome is closely linked to both subclinical atherosclerosis and vascular inflammation. The extent of vascular inflammation can be estimated by a number of biomarkers, such as high-sensitivity C-reactive protein, that are associated with the presence of the metabolic syndrome. Evaluating for the presence of subclinical atherosclerosis and inflammatory biomarkers may help to risk stratify patients with the metabolic syndrome.

A diet rich in conjugated linoleic acid and butter increases lipid peroxidation but does not affect atherosclerotic, inflammatory, or diabetic risk markers in healthy young men

Intake of conjugated linoleic acid (CLA) has been demonstrated to beneficially affect risk markers of atherosclerosis and diabetes in rats. CLA is naturally found in milk fat, especially from cows fed a diet high in oleic acid, and increased CLA intake can occur concomitantly with increased milk fat intake. Our objective was to investigate the effect of CLA as part of a diet rich in butter as a source of milk fat on risk markers of atherosclerosis, inflammation, diabetes type II, and lipid peroxidation. A total of 38 healthy young men were given a diet with 115 g/d of CLA-rich fat (5.5 g/d CLA oil, a mixture of 39.4% cis9, trans11 and 38.5% trans10, cis12) or of control fat with a low content of CLA in a 5-wk double-blind, randomized, parallel intervention study. We collected blood and urine before and after the intervention. The fatty acid composition of plasma triacylglycerol, cholesterol esters, and phospholipids reflected that of the intervention diets. The CLA diet resulted in increased lipid peroxidation measured as an 83% higher 8-iso-prostaglandin F2alpha concentration compared with the control, P < 0.0001. We observed no other significant differences in the effect of the interventions diets. In conclusion, when given as part of a diet rich in butter, a mixture of CLA isomers increased lipid peroxidation but did not affect risk markers of cardiovascular disease, inflammation, or fasting insulin and glucose concentrations.

Does smoking status affect the association between baseline white blood cell count and in-hospital mortality of patients presented with Acute Coronary Syndrome? The Greek study of Acute Coronary Syndromes (GREECS)

OBJECTIVES

In this work, we sought to investigate whether smoking status modifies the effect of white blood cell count (WBC) on in-hospital mortality of patients presented with acute coronary syndrome (ACS).

METHODS

A sample of 6 hospitals located in Greek urban and rural regions was selected. We recorded almost all consecutive patients due to ACS, from October 2003 to September 2004 (2172 patients).

RESULTS

The mean (standard deviation) WBC count was 9.14 (3.16) cells/dL. The in-hospital mortality rate was higher in patients of upper tertile compared to those of lower tertile of WBC (p<0.05). The interaction between smoking status and WBC count revealed that smoking status modifies the effect of WBC count on mortality (p for interaction=0.004). Thus, stratified analysis showed that the WBC count is an independent predictor of in-hospital mortality only among former and current smokers.

CONCLUSIONS

We demonstrated that the association between WBC count and mortality modified by smoking status and that WBC count is a predictor of mortality only among former and current smokers.

C-reactive protein: a marker or a player?

It has been suggested that Type 2 diabetes may, in part, be precipitated or accelerated by an acute-phase reaction as part of the innate immune response, in which large amounts of cytokines are released from adipose tissue, creating a low-grade inflammatory milieu. There is also firm evidence that atherosclerosis is an immune-mediated inflammatory disease. Therefore it is reasonable to imply that low-grade inflammation is an important pathogenetic factor in atherosclerosis and cardiovascular events in patients with Type 2 diabetes. Over the last few years, there have been a lot of promising clinical markers proposed to link inflammation and atherosclerosis. Of these markers, hs-CRP (high-sensitivity C-reactive protein) might be a prognostic marker for further cardiovascular events, although this has been refuted recently. In this issue of Clinical Science, Castoldi and co-workers have demonstrated that, in patients with Type 2 diabetes categorized into low (<1.0 mg/l), medium (1.0-3.0 mg/l) and high (>3.0 mg/l) hs-CRP groups, serum levels of hs-CRP correlated with lipopolysaccharide-stimulated release of interleukin-1beta and interleukin-6 in whole blood. This finding may indicate that low-grade inflammatory activity might influence cytokine production in these patients.

Relation of plasma lipoprotein levels with low-grade inflammation in white men without clinical evidence of myocardial ischemia

There is a growing body of evidence indicating that high triglyceride levels are an independent risk factor for cardiovascular disease (CVD) events. In this study we compared the association of fasting levels of non-high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, HDL cholesterol, and triglycerides with white blood cell (WBC) count, an inflammatory marker associated with an adverse CVD prognosis. We studied 458 asymptomatic men (46.0 +/- 7.0 years old) who presented for CVD risk stratification. WBC count (x10(9) cells/L) increased significantly across increasing tertiles of triglyceride level (tertile 1, 6.04 +/- 1.49; tertile 2 6.21 +/- 1.44; tertile 3 6.78 +/- 1.73, p <0.0001), whereas a trend of lower WBC counts was observed across increasing tertiles of HDL cholesterol (tertile 1, 6.52 +/- 1.62; tertile 2, 6.24 +/- 1.50; tertile 3, 6.21 +/- 1.61, p = 0.08). In models adjusted for age, gender, and CVD risk factor, the odds ratio for a high WBC count (quartile > or =4 vs lower 3 quartiles) was significantly higher with increasing levels of triglyceride (2.4, 95% confidence interval 1.3 to 4.8, p = 0.02). When all lipid variables were introduced in the models in addition to traditional CVD risk factors, the association between plasma triglyceride level and WBC count persisted (p = 0.04), which was not found for other lipid parameters. In conclusion, in our study, only plasma triglyceride level was independently associated with a higher WBC count.

Platelet and White Blood Cell Counts Are Elevated in Patients With the Metabolic Syndrome

Platelet and white blood cell counts are higher among some insulin-resistant patients and may contribute to atherothromboembolic complications. Metabolic syndrome patients are insulin resistant, often hypertensive, and at high cardiovascular disease risk, yet the relationship of platelets to the metabolic syndrome is unknown. Platelet and white blood cell counts were obtained from 135 volunteers who had measurements of blood pressure, fasting triglycerides, high-density lipoprotein cholesterol, and glucose. A body mass index >30 kg/m2 served as a surrogate for increased waist circumference. Subjects were subdivided into three groups by the number of metabolic syndrome criteria, i.e., no metabolic syndrome risk factor (MS-0; n = 40), one or two metabolic syndrome risk factors (MS1-2; n = 61), and three to five metabolic syndrome risk factors (MS3-5; n = 34). Platelet counts were increased significantly from 226+/-8 to 257+/-8 and 276+/-10 (x10(3)/mm3) in the MS-0, MS1-2, and MS3-5 groups, respectively (p < 0.01), after adjustment for age, gender, ethnicity, total cholesterol, and low-density lipoprotein cholesterol. White blood cell counts were also increased across the three groups (5.4+/-0.2, 6.2+/-0.2, and 6.6+/-0.3 [x10(3)/mm3]; p < 0.01) after multivariate adjustment. Compared with patients with zero to two metabolic syndrome risk factors, metabolic syndrome patients have higher platelet and white blood counts, which may serve as markers of a prothrombotic and proinflammatory state and contributors to atherothromboembolic risk.

The association between circulating white blood cell count, triglyceride level and cardiovascular and all-cause mortality: Population-based cohort study

OBJECTIVES

To examine the individual and combined relationship between elevated white blood cell count (WBC), triglyceride level and cardiovascular and all-cause mortality among older Australians.

DESIGN

Prospective population-based cohort study.

SETTING

Community in Blue Mountains region, Australia.

PARTICIPANTS

2904 individuals, aged 49-84 years, free of cardiovascular disease and cancer at the baseline examination.

MAIN OUTCOME MEASURES

Cardiovascular (n=242) and all-cause mortality (n=575).

RESULTS

Elevated WBC count and triglyceride level were found to be associated with cardiovascular and all-cause mortality, independent of several important confounders. Multivariable relative risk [RR] (95% confidence interval [CI]) comparing fourth (6.8 x 10(9) cells/L and above) versus first quartile (4.8 x 10(9) cells/L and below) of WBC count was 2.01 (1.40-2.90) for cardiovascular mortality and 1.68 (1.35-2.09) for all-cause mortality. Multivariable RR (95% CI) comparing fourth (1.98 mmol/L and above) versus first quartile (0.95 mmol/L and below) of triglyceride level was 1.58 (1.08-2.30) for cardiovascular mortality and 1.40 (1.11-1.77) for all-cause mortality. Furthermore, a combined exposure to the fourth quartiles of both WBC count and triglyceride level was found to be related to more than three-fold risk of cardiovascular mortality (RR [95% CI]: 3.15 [2.17-4.57], p-interaction=0.01), independent of traditional risk factors.

CONCLUSIONS

Elevated WBC count and triglyceride level were associated with cardiovascular and all-cause mortality among older Australians. These data provide new epidemiological evidence regarding cardiovascular risk stratification using simple, inexpensive, and routinely available measures, suggesting that a combined exposure to both high WBC count and triglyceride level is related to more than three-fold risk of cardiovascular mortality, independent of traditional risk factors.

Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans

BACKGROUND

Conjugated linoleic acid (CLA) has been shown to be an effective supplement for reducing fat mass in animals, whereas results in humans have been inconsistent.

OBJECTIVE

This is a meta-analysis of human studies in which CLA was provided as a dietary supplement to test its efficacy in reducing fat mass.

DESIGN

We searched the PubMed database (National Library of Medicine, Bethesda, MD) and references from the resulting search to identify studies in which CLA was provided to humans in randomized, double-blinded, placebo-controlled trials and in which body composition was assessed by using a validated technique.

RESULTS

We identified 18 eligible studies. Of these, 3 were single-isomer studies, and results comparing CLA isomers were inconclusive. We compared the length of treatment by using studies in which a mixture of purified isomers were used and those in which purified trans-10,cis-12 isomers were used. This comparison indicated that the effect of CLA was linear for up to 6 mo and then slowly approached an asymptote at 2 y. An analysis of the dose effect indicated that fat loss compared with placebo was -0.024 kg x g CLA(-1) x wk(-1) (P=0.03). After adjustment to the median dose of 3.2 g CLA/d, CLA was effective and produced a reduction in fat mass for the CLA group alone (0.05 +/- 0.05 kg/wk; P<0.001) and for the CLA group compared with placebo (0.09 +/- 0.08 kg/wk; P<0.001)

CONCLUSION

Given at a dose of 3.2 g/d, CLA produces a modest loss in body fat in humans.

Relationship between white blood cell count and Framingham Risk Score in asymptomatic men

BACKGROUND

There is an independent association between white blood cell (WBC) and coronary heart disease (CHD) risk. However, the relationship between WBC and Framingham Risk Score (FRS) remains unclear.

METHODS

This is a cross-sectional study on a consecutive sample of 520 white asymptomatic men (mean age 46 +/- 7 years) without CHD. The study population was divided into WBC quartiles (x10(9) cells/L): 1(st) quartile: 3.1-5.3 (n = 139), 2(nd) quartile: 5.4-6.1 (n = 129), 3(rd) quartile: 6.2-7.1 (n = 131), 4(th) quartile: >/=7.2 (n = 121), and into tertiles according to the 10-year FRS: 1(st) tertile (low risk <5%, n = 180, 35%), 2(nd) tertile (intermediate risk 5-12%, n = 210, 40%), 3(rd) tertile (high risk: >/=13%, n = 130, 25%).

RESULTS

WBC correlated only weakly with FRS (r = 0.18, p = 0.001). Among individual components of FRS, WBC correlated minimally with smoking (r = 0.12, p = 0.003), systolic blood pressure (r = 0.07, p = 0.1), and high-density lipoprotein cholesterol (r = -0.06, p = 0.1). However, no correlation was observed with age (p = 0.3) and total cholesterol (p = 0.5). Nearly one third (31%) of men in the low-risk (FRS <5%) had WBC count in the 1(st) quartile compared to 20% of those classified as high risk (FRS >/=13%). The prevalence of WBC in the 4(th) quartile increased across FRS tertiles (18, 22, 32%) (p = 0.09).

CONCLUSIONS

WBC correlates weakly with FRS or its individual components. Since WBC count is strongly related to CHD, WBC may reflect different components of cardiovascular risk, which might not be captured by traditional cardiovascular risk factors used in calculating FRS. Inflammatory biomarkers afford adjunctive value to FRS and may be used to improve CHD risk stratification.

White Blood Cell Count and Risk of All-Cause and Cardiovascular Mortality in Nationwide Sample of Japanese Results From the NIPPON DATA90

BACKGROUND

The association of white blood cell (WBC) count with all-cause and cardiovascular disease (CVD) mortality were examined in the National Integrated Project for Prospective Observation of Non-communicable Disease and Its Trends in the Aged (NIPPON DATA) 90.

METHODS AND RESULTS

A total of 6,756 Japanese residents (2,773 men and 3,983 women) throughout Japan without a history of CVD were followed for 9.6 years. A Cox proportional hazards regression model was used to estimate the relative risk (RR) and 95% confidence interval (CI). We documented 576 deaths with 161 deaths from CVD. Overall, after adjusting for several confounders including age, sex, body mass index at baseline, smoking status, alcohol consumption, regular exercise, diastlic blood pressure, total cholesterol, high-density lipoprotein-cholesterol and hemoglobin A1c, a graded association between WBC count and higher risk of all-cause mortality was observed (WBC of 9,000-10,000 cells/mm(3) vs WBC of 4,000-4,900: RR =1.61, 95% CI: 1.07-2.40, p for trend =0.02). Elevated WBC count was almost significantly associated with high risk of CVD mortality (WBC of 9,000-10,000 vs WBC of 4,000-4,900: RR =1.79, 95% CI: 0.97-3.71). These associations strengthened among women. Stratified by smoking status, never-smokers with WBC counts of 9,000-10,000 had a 3.2 fold elevated risk for CVD death compared with those with WBC counts of 4,000-4,900.

CONCLUSIONS

The WBC count may have potential as a predictor for all-cause mortality, particularly CVD mortality.

Total and differential leukocytes counts, but not hsCRP, ESR, and five fractioned serum proteins have significant potency to predict stable coronary artery disease

BACKGROUND

The role and diagnostic value of markers of inflammation is well recognized in acute coronary syndromes but it is uncertain in patients with stable coronary artery disease (CAD). This study was done to investigate the association of markers of inflammation with the occurrence and severity of CAD and to evaluate their predictive values.

METHODS

Markers of inflammation, electrophoresis serum protein fractions, serum (apo)lipoproteins and classical risk factors were determined in 270 angiographically documented subjects. The subjects were classified as CAD cases and controls according to angiography. The severity of CAD was scored on the basis of the number and extent of lesions.

RESULTS

The counts of total leukocytes (7.14+/-1.86 cell/nl vs. 6.58+/-1.62, p<or=0.02), neutrophils (3.95+/-1.42 vs. 3.59+/-1.07, p<or=0.05) and eosinophils (0.25+/-0.28 vs. 0.19+/-0.24, p<or=0.03) were increased significantly, whereas the concentrations of high-sensitivity C-reactive protein (hsCRP, 2.03 (0.0-32.0) mg/l vs.1.72 (0.09-11.36), p<or=0.07) changed modestly in CAD patients relative to controls. There were no significant differences in the counts of monocytes and lymphocytes and the concentrations of erythrocyte sedimentation rate (ESR) and any five fractions of serum proteins between two groups. The counts of total leukocytes, neutrophils and eosinophils, but not hsCRP and ESR exhibited significant associations with the severity of CAD. In univariate logistic regression analysis, leukocytes count associated significantly (OR=1.97, p<or=0.01) whereas hsCRP modestly (OR=1.76, p<or=0.06) with the occurrence of CAD. The association was lessened by diabetes mellitus in multivariable adjustment. Receiver operating characteristic (ROC) analysis showed that, only total leukocyte and differential counts had significant potency to predict CAD (area under curve, AUC=0.60+/-0.04, p<or=0.02).

CONCLUSIONS

The total leukocytes count and its subgroups are associated with the presence and severity of CAD, but the associations were not independent. The efficiency was questioned for hsCRP, ESR and five fractioned serum proteins to identify stable CAD.

Relationship between white cell count, neuropsychologic outcome, and microemboli in 161 patients undergoing coronary artery bypass surgery

OBJECTIVE

Neuropsychologic impairment remains a problem after coronary artery bypass grafting. Relatively few studies have examined the potential role of the perioperative inflammatory response. This study aimed to determine whether there was any association between perioperative white cell count, microemboli, and cognitive performance after surgical intervention.

METHODS

White cell count and differential were prospectively measured perioperatively in 161 patients undergoing coronary artery bypass grafting. A neuropsychologic test battery (9 tests) was administered preoperatively and 6 to 8 weeks postoperatively in all 161 patients. Cerebral microemboli during cardiopulmonary bypass were also recorded by means of a transcranial Doppler scan of the right middle cerebral artery.

RESULTS

There was no correlation between microemboli and white cell counts at any time point. There were weak but significant inverse correlations between both preoperative (r = -0.19, P = .02) and postoperative (r = -0.21, P < .01) white cell count and a measure of overall neuropsychologic test performance (total z change score). There was a weak but significant positive correlation between the neutrophil count 10 minutes after bypass and the intraoperative microemboli count (r = 0.23, P = .01).

CONCLUSIONS

The correlation between white cell count and neuropsychologic outcome suggests that an inflammatory response might have a role in determining cognitive outcome after coronary artery surgery with cardiopulmonary bypass. The positive correlation between the microemboli during cardiopulmonary bypass and the neutrophil count 10 minutes after bypass is compatible with microemboli contributing to the inflammatory response. The patients' preoperative inflammatory status might also be predictive of the response to surgical intervention.

Risk factors for renal dysfunction in type 2 diabetes: U.K. Prospective Diabetes Study 74

Not all patients with type 2 diabetes develop renal dysfunction. Identifying those at risk is problematic because even microalbuminuria, often used clinically as an indicator of future renal dysfunction, does not always precede worsening renal function. We sought to identify clinical risk factors at diagnosis of type 2 diabetes associated with later development of renal dysfunction. Of 5,102 U.K. Prospective Diabetes Study (UKPDS) participants, prospective analyses were undertaken in those without albuminuria (n = 4,031) or with normal plasma creatinine (n=5,032) at diagnosis. Stepwise proportional hazards multivariate regression was used to assess association of putative baseline risk factors with subsequent development of albuminuria (microalbuminuria or macroalbuminuria) or renal impairment (Cockcroft-Gault estimated creatinine clearance <60 ml/min or doubling of plasma creatinine). Over a median of 15 years of follow-up 1,544 (38%) of 4,031 patients developed albuminuria and 1,449 (29%) of 5,032 developed renal impairment. Of 4,006 patients with the requisite data for both outcomes, 1,534 (38%) developed albuminuria and 1,132 (28%) developed renal impairment. Of the latter, 575 (51%) did not have preceding albuminuria. Development of albuminuria or renal impairment was independently associated with increased baseline systolic blood pressure, urinary albumin, plasma creatinine, and Indian-Asian ethnicity. Additional independent risk factors for albuminuria were male sex, increased waist circumference, plasma triglycerides, LDL cholesterol, HbA(1c) (A1C), increased white cell count, ever having smoked, and previous retinopathy. Additional independent risk factors for renal impairment were female sex, decreased waist circumference, age, increased insulin sensitivity, and previous sensory neuropathy. Over a median of 15 years from diagnosis of type 2 diabetes, nearly 40% of UKPDS patients developed albuminuria and nearly 30% developed renal impairment. Distinct sets of risk factors are associated with the development of these two outcomes, consistent with the concept that they are not linked inexorably in type 2 diabetes.

Self-rated health showed a graded association with frequently used biomarkers in a large population sample

BACKGROUND AND OBJECTIVES

Self-rated health is a widely used measure of health status, but its biologic foundations are poorly understood. We investigated the association of frequently used biomarkers with self-rated health, and the role of these biomarkers in the association of self-rated health with mortality.

METHODS

The relation of self-rated health to blood levels of albumin, white blood cell count, hemoglobin, HDL cholesterol, and creatinine was examined in a population-based sample of 4,065 men and women aged 71 years or older. A Cox proportional hazards model was used to determine the association of self-rated health with mortality during 4.9 years. Sociodemographic factors, diagnosed chronic conditions, and activities of daily living disability were controlled for in these analyses.

RESULTS

All the biomarkers showed a graded relationship with self-rated health. After adjusting for other indicators, hemoglobin and white cell count were significantly associated with fair or poor self-rated health. When biomarkers and other indicators were adjusted for, self-rated health still was a significant predictor of mortality.

CONCLUSION

Self-rated health has a biologic basis, and it can be a sensitive barometer of physiologic states. Self-rated health is likely to predict mortality because it covers the spectrum of health conditions better than the variables measured in the study.

Fibrinolysis and cardiovascular risk factors: association with fibrinogen, lipids, and monocyte count

BACKGROUND

Numerous risk factors for cardiovascular disease (CVD) have been determined by clinical epidemiological observations. The missing link could be related to endothelial dysfunction and the resulting hypofibrinolysis.

METHODS

In this cross-sectional study, we evaluated 160 subjects (134 in primary prevention) characterized by their clinical cardiovascular risk factors (CVRF), i.e., age, gender, diabetes, hypertension, smoking habit, and history of coronary event or stroke, and by their blood parameters, i.e., C-reactive protein (CRP), fibrinogen, leukocyte count (WBC), monocyte count (MC), total cholesterol, HDL cholesterol (HDL-c), LDL cholesterol (LDL-c), and triglycerides. We assessed their fibrinolytic capacity with a new method, Euglobulin Clot Lysis Time (ECLT). The effects of these clinical and biological parameters were evaluated in multivariate analysis (backward stepwise regression).

RESULTS

ECLT was correlated with the Framingham risk score and was significantly influenced by the number of clinical CVRF. MC was confirmed to be an important predictive factor influencing ECLT. In subjects without clinical CVRF (n=46), 67% of the variability of ECLT was explained by a combination of MC, LDL-c, and fibrinogen.

CONCLUSION

ECLT is related to the number of epidemiologically defined clinical CVRF and to MC. Because it integrates many risk factors, we suggest that fibrinolytic function could be a biological test useful for physicians in the cardiovascular risk assessment of their patients.

Conjugated linoleic acid supplementation for 1 y does not prevent weight or body fat regain

BACKGROUND

Conjugated linoleic acid (CLA) is marketed as a safe, simple, and effective dietary supplement to promote the loss of body fat and weight. However, most previous studies have been of short duration and inconclusive, and some recent studies have questioned the safety of long-term supplementation with CLA.

OBJECTIVE

Our aim was to assess the effect of 1-y supplementation with CLA (3.4 g/d) on body weight and body fat regain in moderately obese people.

DESIGN

One hundred twenty-two obese healthy subjects with a body mass index (in kg/m2) > 28 underwent an 8-wk dietary run-in with energy restriction (3300-4200 kJ/d). One hundred one subjects who lost >8% of their initial body weight were subsequently randomly assigned to a 1-y double-blind CLA (3.4 g/d; n = 51) or placebo (olive oil; n = 50) supplementation regime in combination with a modest hypocaloric diet of -1250 kJ/d. The effects of treatment on body composition and safety were assessed with the use of dual-energy X-ray absorptiometry and with blood samples and the incidence of adverse events, respectively.

RESULTS

After 1 y, no significant difference in body weight or body fat regain was observed between the treatments. The CLA group (n = 40) regained a mean (+/-SD) 4.0 +/- 5.6 kg body weight and 2.1 +/- 5.0 kg fat mass compared with a regain of 4.0 +/- 5.0 kg body weight and 2.7 +/- 4.9 kg fat mass in the placebo group (n = 43). No significant differences in reported adverse effects or indexes of insulin resistance were observed, but a significant increase in the number of leukocytes was observed with CLA supplementation.

CONCLUSION

A 3.4-g daily CLA supplementation for 1 y does not prevent weight or fat mass regain in a healthy obese population.

Antiplatelet Therapy after Percutaneous Coronary Intervention

There is intense interest in the relationship between inflammation, thrombosis, platelet aggregation, and hyperlipidemia in patients with coronary artery disease. The specific role of inflammation with its linkage to the coagulation cascade has been well studied. A number of inflammatory markers have been identified which can be used for risk stratification in patients with acute coronary syndromes. Patients with acute coronary syndromes at the time of presentation often have an underlying inflammatory state which needs therapy with antiplatelet regimens including now increasingly frequently clopidogrel in addition to the standard of aspirin. In those patients who are treated medically for their acute coronary syndromes, long-term treatment with dual antiplatelet therapy has been documented to be associated with improved outcome. In patients who undergo an invasive approach with placement of intracoronary stents, the importance of dual antiplatelet therapy is increased. Drug-eluting stents are now used in approximately 90% of all interventional procedures. There is evidence to suggest that while these patients have improved outcome in terms of a decreased need for subsequent procedures to treat restenosis, there is the potential for late subacute stent thrombosis. When late subacute stent thrombosis occurs, it results in mortality or infarction in 40-60% of patients. Dual antiplatelet therapy is therefore recommended for an increasingly longer time in this patient group. At the present time, protocols indicate 3 months for one of the drug-eluting stents and 6 months for the other. However, increasingly longer antiplatelet therapy is being used clinically. Assessment of platelet function during follow-up is as yet early. There are issues about which specific test to use and the definition of platelet hyperreactivity. In the future, more individually targeted therapy may be possible if we can more adequately assess the degree of hyperreactivity and underlying inflammation.

The metabolic syndrome and cardiovascular disease

The metabolic syndrome, which is very common in the general population, is defined by the clustering of several classic cardiovascular risk factors, such as type 2 diabetes, hypertension, high triglycerides and low high-density lipoprotein cholesterol (HDL). Central obesity and insulin resistance, which are the two underlying disorders of the syndrome, are further risk factors for cardiovascular disease. Moreover, a panel of novel (non-traditional) risk factors are ancillary features of the metabolic syndrome. They include biomarkers of chronic mild inflammation (e.g. C-reactive protein, CRP), increased oxidant stress (e.g. oxidized low density lipoprotein, LDL), thrombophilia (e.g. plasminogen activator inhibitor-1, PAI-1) and endothelial dysfunction (e.g. E-selectin). Therefore, subjects with the metabolic syndrome are potentially at high risk of developing atherosclerosis and clinical cardiovascular events.In recent years several longitudinal studies have confirmed that subjects with the metabolic syndrome present with atherosclerosis and suffer from myocardial infarction and stroke at rates higher than subjects without the syndrome. The risk of cardiovascular disease (CVD) is particularly high in women with the syndrome and in subjects with pre-existing diabetes, CVD and/or high CRP. However, an increased risk is already present in subjects with a cluster of multiple mild abnormalities. The risk related to the metabolic syndrome is definitely higher when subjects affected are compared to subjects free of any metabolic abnormality.

Blood leukocyte count is a risk factor for intima-media thickening and subclinical carotid atherosclerosis in middle-aged men

Leukocytosis is known to predict future cardiovascular events even in subjects without coronary heart disease (CHD), but its association with early atherosclerotic changes has remained less certain. The aim of the present study was to investigate how the blood leukocyte count compares with several other risk factors for CHD in determining carotid artery intima-media thickness (IMT) and subclinical carotid atherosclerosis in a population sample. Both carotid arteries were investigated with high-resolution B-mode ultrasound in a community-based sample of 219 randomly selected men aged 50-59 years to calculate the mean maximum IMT (MMax IMT) of 12 standard sites. Risk factor assessment included several traditional biochemical risk factors, blood pressure, maximal oxygen consumption and work load on ergometry, life-style habits and hematologic parameters. As genetic determinants, apolipoprotein E and A-IV polymorphisms were studied. According to multivariate regression analysis, age (P<0.0001), blood leukocyte count (P<0.0001) and systolic blood pressure (P<0.042) were the only significant predictors of MMax IMT. MMax IMT increased linearly from the lowest tertile of blood leukocyte count (1.14+/-0.20mm) to the second (1.18+/-0.25 mm) and to the highest tertile (1.25+/-0.27 mm, P=0.019). This difference remained significant after adjustment with age, systolic blood pressure and smoking (P=0.032). Leukocytes seem to have an independent role in the early arterial damage and they may reflect subclinical disease. This implies that leukocyte count is undervalued in the diagnostics and prognostics of carotid atherosclerosis.

White blood cell count and risk for all-cause, cardiovascular, and cancer mortality in a cohort of Koreans

The authors conducted a 10-year prospective cohort study of mortality in relation to white blood cell counts of 437,454 Koreans, aged 40-95 years, who received health insurance from the National Health Insurance Corporation and were medically evaluated in 1993 or 1995, with white blood cell measurement. The main outcome measures were mortality from all causes, all cancers, and all atherosclerotic cardiovascular diseases (ASCVD). Hazard ratios and 95% confidence intervals were calculated using Cox proportional hazards models with adjustment for age and potential confounders. During follow-up, 48,757 deaths occurred, with 15,507 deaths from cancer and 11,676 from ASCVD. For men and women, white blood cell count was associated with all-cause mortality and ASCVD mortality but not with cancer mortality. In healthy nonsmokers, a graded association between a higher white blood cell count and a higher risk of ASCVD was observed in men (highest vs. lowest quintile: hazard ratio = 2.10, 95% confidence interval: 1.50, 2.94) and in women (hazard ratio = 1.35, 95% confidence interval: 1.17, 1.56). In healthy smokers, a graded association between a higher white blood cell count and a higher risk of ASCVD was also observed in men (highest vs. lowest quintile: hazard ratio = 1.46, 95% confidence interval: 1.25, 1.72). These findings indicate that the white blood cell count is an independent risk factor for all-cause mortality and for ASCVD mortality.

A white blood cell count in the normal concentration range is independently related to cardiorespiratory fitness in apparently healthy Korean men

Despite the documented health benefits of physical activity, the mechanism whereby physical activity prevents cardiovascular disease is incompletely understood. In the present study, we investigated the relationship between white blood cell (WBC) count and cardiorespiratory fitness (V o(2)max) after adjusting for several well-known cardiovascular risk factors. Subjects who visited our health promotion center for a medical checkup and treadmill test (n=8241; age: median, 48 years; range, 16-79 years) were classified into 3 groups based on their WBC counts (group 1, 2200-5300 microL, n=2823; group 2, 5301-6500 microL, n=2709; group 3, 6501-10000 microL, n=2709). After adjusting for age, body mass index, body fat percentage, smoking history, systolic blood pressure, diastolic blood pressure, serum lipid profile, and fasting plasma glucose, V o(2)max still showed a significant association with WBC count (partial r=-0.11, P<.001). In logistic regression analyses, subjects in the highest WBC tertile showed lower V o(2)max compared with those in the lowest WBC tertile after adjusting for age and cardiovascular risk factors (odds ratio, 0.42; 95% confidence interval, 0.36-0.49 for the highest V o(2)max tertile). These results suggest that a WBC count in the normal concentration range is independently related to cardiorespiratory fitness in Korean men.

White blood cell count and the incidence of ischemic stroke in coronary heart disease patients

PURPOSE

White blood cell (WBC) count is a marker of inflammation and has been associated with the development of cardiovascular disease. We investigated the relationship between WBC counts and the incidence of ischemic cerebrovascular disease in a large cohort of patients with pre-existing atherothrombotic disease and defined blood lipid boundaries.

SUBJECTS AND METHODS

We followed up patients with documented coronary heart disease for 4.8 to 8.1 years. An extensive medical evaluation, conducted at baseline, included assessment of vascular risk factors and measures of blood lipids. Among 5435 patients with WBC counts, free of stroke, 295 developed an ischemic cerebrovascular disease (fatal and nonfatal). After review of available medical records, 186 of these cases had ischemic stroke or TIA.

RESULTS

Higher WBC counts were associated with increased risk for ischemic cerebrovascular disease. Age-adjusted hazard ratio (HR) was 1.55 with 95% confidence interval (CI) 1.16-2.07, upper WBC tertile compared with the lowest. Adjusting for clinical covariates, WBC count remained an independent predictor for ischemic cerebrovascular disease (HR = 1.39; 95% CI 1.03-1.87, upper WBC tertile compared with the lowest). A similar trend appeared for the endpoint of ischemic stroke/transient ischemic attack (TIA). Further adjustment for plasma fibrinogen did not change the association materially (HR = 1.32; 95% CI 1.01-1.80; upper tertile of WBC compared with lowest).

CONCLUSIONS

These findings support the role of WBC count as a simple inexpensive and readily available marker for risk stratification of ischemic cerebrovascular disease among patients with pre-existing atherothrombotic disease and defined blood lipid boundaries.

Effects of biochemically confirmed smoking cessation on white blood cell count

OBJECTIVES

To determine the relationship between white blood cell (WBC) Indices and several baseline variables In a large cohort of healthy smokers and to assess whether these changed after biochemically confirmed smoking cessation.

SUBJECTS AND METHODS

The study consisted of 784 healthy smokers enrolled in a trial of sustained-release bupropion, 300 mg/d, for relapse prevention after smoking cessation from 1995 to 1998. Both WBC counts and absolute neutrophil counts (ANCs) were measured at baseline, week 7, and week 52. Smoking status was assessed at weeks 7 and 52 by self-report and biochemically confirmed with expired air carbon monoxide levels. Multivariate analyses compared changes in WBC count and ANC between smokers who did and did not stop smoking, adjusting for treatment group, age, sex, and body mass index.

RESULTS

Of 784 smokers enrolled, 461 had biochemically confirmed tobacco abstinence after 7 weeks of bupropion; 429 were randomly assigned to receive continued bupropion therapy or placebo until week 52. Between baseline and week 7, there was a significantly larger decrease in WBC count in continuously abstinent subjects compared with continuing smokers (adjusted P = .03). At 52 weeks, continuously abstinent subjects, compared with continuing smokers, had a greater decline from baseline in WBC count (1.2 +/- 1.9 x 10(9)/L vs 0.1 +/- 1.9 x 10(9)/L; P < .001) and ANC (1.0 +/- 1.6 x 10(9)/L vs 0.2 +/- 1.5 x 10(9)/L; P < .001).

CONCLUSION

Biochemically confirmed tobacco abstinence leads to a rapid and sustained decrease in WBC and ANC, possibly reflecting a decrease In an underlying state of tobacco-induced inflammation.

The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial

BACKGROUND

There is growing evidence that oxidative stress contributes to the pathogenesis of hypertension and endothelial dysfunction. Thus, dietary antioxidants may beneficially influence blood pressure (BP) and endothelial function by reducing oxidative stress.

OBJECTIVE

To determine if vitamin C and polyphenols, alone or in combination, can lower BP, improve endothelial function and reduce oxidative stress in hypertensive individuals.

DESIGN

A total of 69 treated hypertensive individuals with a mean 24-h ambulatory systolic blood pressure > or = 125 mmHg participated in a randomized, double-blind, placebo-controlled, factorial trial. Following a 3-week washout, participants received 500 mg/day vitamin C, 1000 mg/day grape-seed polyphenols, both vitamin C and polyphenols, or neither for 6 weeks. At baseline and post-intervention, 24-h ambulatory BP, ultrasound-assessed endothelium-dependent and -independent vasodilation of the brachial artery, and markers of oxidative damage, (plasma and urinary F2-isoprostanes, oxidized low-density lipoproteins and plasma tocopherols), were measured.

RESULTS

A significant interaction between grape-seed and vitamin C treatments for effects on BP was observed. Vitamin C alone reduced systolic BP versus placebo (-1.8 +/- 0.8 mmHg, P = 0.03), while polyphenols did not (-1.3 +/- 0.8 mmHg, P = 0.12). However, treatment with the combination of vitamin C and polyphenols increased systolic BP (4.8 +/- 0.9 mmHg versus placebo; 6.6 +/- 0.8 mmHg versus vitamin C; 6.1 +/- 0.9 mmHg versus polyphenols mmHg, each P < 0.0001) and diastolic BP (2.7 +/- 0.6 mmHg, P < 0.0001 versus placebo; 1.5 +/- 0.6 mmHg, P = 0.016 versus vitamin C; 3.2 +/- 0.7 mmHg, P < 0.0001 versus polyphenols). Endothelium-dependent and -independent vasodilation, and markers of oxidative damage were not significantly altered.

CONCLUSION

Although the mechanism remains to be elucidated, these results suggest caution for hypertensive subjects taking supplements containing combinations of vitamin C and polyphenols.

Relationship of monocyte count and peripheral arterial disease: results from the National Health and Nutrition Examination Survey 1999-2002

BACKGROUND

Although white blood cell (WBC) count has been consistently associated with cardiovascular end points, little information is available on the independent contribution of specific white blood cell types. The objective of this study is to assess the independent association of WBC types and other inflammatory markers with the presence of reduced ankle-brachial blood pressure index (ABI), a marker of subclinical peripheral arterial disease (PAD).

METHODS & RESULTS

Cross-sectional study in 3949 individuals > or =40 years of age without known cardiovascular disease who participated in the 1999 to 2002 National Health and Nutrition Examination Survey (NHANES). PAD was defined as an ABI <0.9 in at least 1 leg. After adjustment for traditional cardiovascular risk factors, the odds ratios of PAD comparing the highest to the lowest quartiles were 2.24 (95% confidence interval 1.24 to 4.04) for monocytes, 1.74 (0.87 to 3.45) for neutrophils, 2.53 (1.62 to 3.96) for C-reactive protein, and 2.68 (1.03 to 6.94) for fibrinogen. When WBC types and inflammatory markers were simultaneously included in the full model, the corresponding odds ratios were 1.91 (95% confidence interval 1.06 to 3.42) for monocytes, 1.15 (0.49 to 2.69) for neutrophils, 1.37 (0.75 to 2.49) for C-reactive protein, and 2.21 (0.88 to 5.57) for fibrinogen.

CONCLUSIONS

Monocytes were the only WBC type significantly and independently associated with PAD in a representative sample of the U.S. population after adjustment for other inflammatory markers. These findings reflect the potential role of circulating monocyte counts as markers of atherosclerosis.

Prognostic value of erythrocyte sedimentation rate in ST segment elevation myocardial infarction: interaction with hyperglycaemia

OBJECTIVES

Many inflammatory markers are associated with an adverse prognosis after ST segment elevation myocardial infarction (STEMI). Hyperglycaemia may exacerbate this inflammatory response. We investigated whether the erythrocyte sedimentation rate (ESR) was associated with an adverse prognosis and whether this was mediated by glucose levels.

RESEARCH DESIGN AND METHODS

It concerns a post hoc analysis of a prospective randomised trial. In 346 patients with STEMI treated with reperfusion therapy, we investigated long-term outcome. Patients with ESR in the upper quartile (>14 mm h(-1)) were compared to patients with a normal ESR. Hyperglycaemia was defined as admission glucose >or=7.8 mmol L(-1). Median follow up was 7.4 years (range: 5.7-8.3).

MAIN OUTCOME MEASURES

All cause mortality, cardiovascular mortality, sudden death, death as a result of heart failure.

RESULTS

Both elevated ESR and hyperglycaemia were associated with a worse prognosis and increased mortality. Elevated ESR was particularly associated with an increased risk of sudden death (OR: 3.3, 17% vs. 6%, P < 0.01) whereas hyperglycaemia was especially associated with an increased risk of death because of heart failure (OR: 6.5, 8% vs. 1%, P < 0.01). There was no association between increased ESR and elevated glucose levels. Multivariate analysis did reveal that both elevated ESR and admission glucose were independent predictors of long-term mortality.

CONCLUSIONS

Elevated ESR and admission glucose are independent predictors of mortality in STEMI patients treated with reperfusion therapy. There is no association or interaction between glucose levels and the inflammatory response as reflected by ESR.

Which white blood cell subtypes predict increased cardiovascular risk?

OBJECTIVES

We sought to determine the predictive ability of total white blood cell (WBC) count and its subtypes for risk of death or myocardial infarction (MI).

BACKGROUND

An elevated WBC count has been associated with cardiovascular risk, but which leukocyte subtypes carry this risk is uncertain.

METHODS

Consecutive patients without acute MI who were assessed angiographically for coronary artery disease (CAD) and were followed up long-term were studied. The predictive ability for death/MI of quartile (Q) 4 versus Q1 total WBC, neutrophil (N), lymphocyte (L), and monocyte (M) counts and N/L ratio were assessed using Cox regressions.

RESULTS

A total of 3,227 patients was studied. Mean age was 63 years; 63% of patients were male, and 65% had CAD. In multivariable modeling entering standard risk factors, presentation, and CAD severity, the total WBC (hazard ratio [HR] 1.4, p = 0.01) and M (HR 1.3, p < 0.02) were weaker and N (HR 1.8, p < 0.001), L (HR 0.51, p < 0.001), and N/L ratio (HR 2.2, p < 0.001) were independent predictors of death/MI. When WBC variables were entered together, N/L ratio and M were retained as independent predictors. Risk associations persisted in analyses restricted to CAD patients or including acute MI patients.

CONCLUSIONS

Total WBC count is confirmed to be an independent predictor of death/MI in patients with or at high risk for CAD, but greater predictive ability is provided by high N (Q4 >6.6 x 10(3)/microl) or low L counts. The greatest risk prediction is given by the N/L ratio, with Q4 versus Q1 (>4.71 versus <1.96) increasing the hazard 2.2-fold. These findings have important implications for CAD risk assessment.

Exposure to welding fumes is associated with acute systemic inflammatory responses

AIMS

To investigate the acute systemic inflammatory response to welding fume exposure.

METHODS

Twenty four welders (42% smokers) and 13 non-exposed controls (23% smokers) were monitored at a welding school. Exposure to fine particulate matter (PM2.5) was assessed using cyclone samplers. Markers of systemic inflammation, including C-reactive protein (CRP), fibrinogen, and white blood cell (WBC) levels, were determined in peripheral blood samples collected at baseline and after 5.3 (SD 1.0) hours of exposure.

RESULTS

The median PM2.5 concentration for welders was 1.66 mg/m3, which was significantly greater than that for controls (0.04 mg/m3). Compared to non-smokers, smokers had a significantly higher baseline WBC count, but comparable levels of CRP and fibrinogen. In non-smokers, welding fume exposure was associated with a significant increase in WBC and neutrophil counts immediately following exposure (+0.8x10(3)/mul, 95% CI 0.1 to 1.6, and +1.0x10(3)/mul, 95% CI 0.4 to 1.7, respectively). A significant decrease in fibrinogen levels was observed in non-smokers (-32 mg/dl, 95% CI -63 to -1). No significant changes in WBC, neutrophil, and fibrinogen levels were found in smokers. Sixteen hours after welding exposure, CRP levels were found to be significantly increased in both non-smokers and smokers (0.90 mg/l, 95% CI 0.17 to 1.64). PM2.5 concentrations were found to be significantly associated with absolute neutrophil counts in non-smokers, and CRP levels in both non-smokers and smokers.

CONCLUSIONS

High levels of welding fume exposure induce acute systemic inflammation in a relatively young, healthy working population. These results also suggest that smoking may modify the effect of welding fume exposure on specific inflammatory markers.

A taurine-supplemented vegan diet may blunt the contribution of neutrophil activation to acute coronary events

Neutrophils are activated in the coronary circulation during acute coronary events (unstable angina and myocardial infarction), often prior to the onset of ischemic damage. Moreover, neutrophils infiltrate coronary plaque in these circumstances, and may contribute to the rupture or erosion of this plaque, triggering thrombosis. Activated neutrophils secrete proteolytic enzymes in latent forms which are activated by the hypochlorous acid (HOCl) generated by myeloperoxidase. These phenomena may help to explain why an elevated white cell count has been found to be an independent coronary risk factor. Low-fat vegan diets can decrease circulating leukocytes--neutrophils and monocytes--possibly owing to down-regulation of systemic IGF-I activity. Thus, a relative neutropenia may contribute to the coronary protection afforded by such diets. However, vegetarian diets are devoid of taurine - the physiological antagonist of HOCl--and tissue levels of this nutrient are relatively low in vegetarians. Taurine has anti-atherosclerotic activity in animal models, possibly reflecting a role for macrophage-derived myeloperoxidase in the atherogenic process. Taurine also has platelet-stabilizing and anti-hypertensive effects that presumably could reduce coronary risk. Thus, it is proposed that a taurine-supplemented low-fat vegan diet represents a rational strategy for diminishing the contribution of activated neutrophils to acute coronary events; moreover, such a regimen would work in a number of other complementary ways to promote cardiovascular health. Moderate alcohol consumption, the well-tolerated drug pentoxifylline, and 5-lipoxygenase inhibitors--zileuton, boswellic acids, fish oil--may also have potential in this regard.

Leukocytosis and ischemic vascular disease morbidity and mortality: is it time to intervene?

The association between leukocytosis and increased morbidity and mortality of ischemic vascular disease has been observed for more than half a century, and recent studies in >350,000 patients confirm the robustness of the association and the dramatically higher relative and absolute acute and chronic mortality rates in patients with high versus low leukocyte counts. Although there is reason to believe that the association is not causal (that is, that leukocytosis is simply a marker of inflammation), there is also reason to believe that the leukocytosis directly enhances acute thrombosis and chronic atherosclerosis. Leukocytosis also is associated with poor prognosis and vaso-occlusive events in patients with sickle cell disease, and experimental data suggest a direct role for leukocytes in microvascular obstruction. The only way to test whether leukocytes contribute directly to poor outcome in ischemic cardiovascular disease is to assess the effect of modifying leukocyte function or number. Because selective blockade of leukocyte integrin alphaMbeta2 and P-selectin have thus far been disappointing as therapeutic strategies in human cardiovascular and cerebrovascular disease, I discuss the potential risks and benefits of short-term treatment with hydroxyurea to decrease the leukocyte count in select populations of patients at the highest risk of short-term death.

Macrophage migration inhibitory factor and the risk of myocardial infarction or death due to coronary artery disease in adults without prior myocardial infarction or stroke: the EPIC-Norfolk Prospective Population study

PURPOSE

To determine whether plasma levels of macrophage migration inhibitory factor, a proinflammatory cytokine involved in atherogenesis, are predictive of myocardial infarction or death from coronary artery disease.

METHODS

We performed a prospective case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort. We selected men and women who did not report a history of myocardial infarction or stroke at baseline. Baseline concentrations of macrophage migration inhibitory factor were measured among 777 patients who had a myocardial infarction or died of coronary artery disease during follow-up, and 1554 matched controls who remained free of coronary artery disease.

RESULTS

Baseline macrophage migration inhibitory factor concentrations were higher in cases than controls (median, 107.4 microg/L vs. 90.7 microg/L, P = 0.001). The risk of myocardial infarction or death from coronary artery disease increased with increasing quartiles of macrophage migration inhibitory factor (P for linearity <0.0001). Patients in the highest quartile had the greatest likelihood of myocardial infarction or death due to coronary artery disease (unadjusted odds ratio [OR] = 1.6; 95% confidence interval [CI]: 1.2 to 2.0). After adjustment for traditional risk factors and C-reactive protein level, the odds ratio decreased slightly (OR = 1.3; 95% CI: 1.0 to 1.7). Upon additional adjustment for white cell count, this association was no longer statistically significant.

CONCLUSION

Prospective data suggest that the relation between macrophage migration inhibitory factor and the risk of myocardial infarction or death due to coronary artery disease in adults without a history of myocardial infarction or stroke is not very strong. However, the data support a regulatory role for macrophage migration inhibitory factor in the process of atherosclerosis.

Association of single nucleotide polymorphisms in the thrombopoietin-receptor gene, but not the thrombopoietin gene, with differences in platelet count

Little is known about the mechanisms explaining the wide variation in platelet counts (PLT) and other hematologic parameters in humans. We previously showed that the sex-based difference in hematocrit was associated with nucleotide variation in the erythropoietin receptor gene (EPOR). We sought to identify new polymorphisms of the human thrombopoietin (TPO) and thrombopoietin receptor (TPOR) genes to determine any associations with blood PLT counts. We screened TPO and TPOR for polymorphisms using single-strand conformation polymorphism (SSCP) and DNA sequencing. Association of polymorphisms was studied in 304 normal subjects with low or high PLT counts. Distribution of allelic frequency was analyzed by the Chi-square statistic. Single nucleotide polymorphisms (SNPs) with two alleles were found in TPO and TPOR. The TPO SNP was a G to A transition at nucleotide 5753, and the TPOR SNP was a C to A transversion at position 550 in the 5'-promoter area. The allelic frequencies were 0.54 for G and 0.46 for A of TPO, and 0.62 for C and 0.38 for A of TPOR in a Caucasian population. The frequency of the TPOR allele "C" was significantly higher in subjects with high PLT count (>258 k/mm3) versus low PLT count (<224 k/mm3) and in males with high PLT count (>258 k/mm3) versus males with low PLT count (<212 k/mm3). In contrast, the frequency of the TPO alleles was not related to blood PLT counts. An association of TPO and TPOR allele distribution to red and white blood cell parameters was seen. These new SNPs found for the human TPO and TPOR genes help explain variations in blood PLT counts and may be useful in patient studies related to the roles of TPO and/or TPOR in disease.

Relation of an elevated white blood cell count after percutaneous coronary intervention to long-term mortality

Increased inflammatory markers are associated with a poor prognosis after percutaneous coronary intervention. Leukocytes play a key role in inflammation, and an increase in white blood cell (WBC) counts is a nonspecific marker of inflammation. In patients undergoing percutaneous coronary intervention, baseline WBC counts independently predict long-term mortality. In a pooled cohort of patients from the Evaluation of c7E3 for the Prevention of Ischemic Complications (EPIC), the Evaluation in PTCA to Improve Long-term Outcome with abciximab Glycoprotein IIb/IIIa blockade (EPILOG), and Evaluation of Platelet IIb/IIIa inhibitor for STENTing (EPISTENT) trials, postprocedural WBC counts were also found to be an independent predictor of long-term mortality.

Associations between White Blood Cell Count and Risk for Cerebrovascular Disease Mortality: NHANES II Mortality Study, 1976–1992

PURPOSE

To examine associations between elevated white blood cell count (WBC) and cerebrovascular disease (CeVD) mortality independent of cigarette smoking and by gender.

METHODS

We used Cox regression analyses of data from 8459 adults (3982 men; 4477 women) aged 30 to 75 years in the NHANES II Mortality Study (1976-1992) to estimate the relative risk of death from CeVD across quartiles of WBC.

RESULTS

During 17 years of follow-up, there were 192 deaths from CeVD (93 men; 99 women). Compared with those with WBC (cells/mm(3))<5700, adults with WBC>8200 were at increased risk of CeVD mortality (relative risk [RR], 2.1; 95% confidence interval [CI], 1.2-3.7) after adjustment for smoking and other cardiovascular disease risk factors. Similar results were observed among never smokers (RR, 2.0; 95% CI, 1.0-3.8). The adjusted relative risk of CeVD mortality comparing those with WBC>8200 to those with WBC<5700 was 1.5 (95% CI, 0.7-3.5) among men and 2.7 (95% CI, 1.4-5.0) among women.

CONCLUSIONS

Elevated WBC may predict CeVD mortality even after considering the effects of smoking and other cardiovascular disease risk factors.

IL-8 plasma concentrations and the risk of future coronary artery disease in apparently healthy men and women: the EPIC-Norfolk prospective population study

OBJECTIVE

To study the role of IL-8 in predicting future coronary artery disease (CAD) in apparently healthy men and women.

METHODS AND RESULTS

A nested case-control study was performed in the prospective EPIC-Norfolk population study. We measured baseline IL-8 concentrations among 785 apparently healthy individuals in whom fatal or nonfatal CAD developed during follow-up and 1570 matched controls. Baseline IL-8 concentrations were higher in cases than in matched controls (3.5 pg/mL versus 3.1 pg/mL, P=0.001). The risk of future CAD increased with increasing quartiles of IL-8 (P linearity <0.0001). Among individuals in the highest IL-8 quartile, the unadjusted odds ratio for future CAD was 1.72 (95% CI, 1.34 to 2.21; P<0.0001). The odds ratio for future CAD was still significant after adjustment for traditional risk factors (OR, 1.58; 95%CI, 1.19 to 2.09; P=0.002) and after additional adjustment for C-reactive protein and white cell count (OR, 1.77; 95% CI, 1.21 to 2.60; P=0.001).

CONCLUSIONS

We conclude that among apparently healthy men and women, elevated levels of IL-8 are associated with an increased risk of future CAD. These prospective data support a role for IL-8 in the development of CAD events.

Relationship between peripheral leukocyte count and the severity of stable angina determined by coronary angiography

BACKGROUND

Inflammation has been demonstrated to be an important risk factor for the development of cardiovascular disease (CVD). The relationship of the peripheral leukocyte count to the severity of stable angina remains to be clarified. The present study analyzed the relationship of the peripheral leukocyte count to the severity of stable angina determined by coronary angiography.

METHODS

The data from 108 patients with stable angina, and 92 subjects with normal coronary angiograms were reviewed, and the role of the peripheral leukocyte count as a risk factor for stable angina evaluated. In addition, the correlation of the peripheral leukocyte count and the severity of stable angina, as assessed by the Gensini's score in the stable angina group, were analyzed.

RESULTS

Age, the prevalence of hypertension and diabetes, and the fasting blood sugar were significantly higher, and the HDL was lower in the stable angina than the control group. A multivariate analysis showed that a peripheral leukocyte count over 6,800/mm3 was an independent variable, but with no statistical significance (p=0.067), and diabetes (OR=3.02, 95% CI: 1.29-7.02) and old age (OR=3.62, 95% CI: 1.3-9.87) were independent risk factors for stable angina. A positive correlation between peripheral leukocyte count and Gensini's score was noted in the stable angina group even after adjusting for age, fasting blood sugar, blood pressure and lipid profiles (R2=0.198, p=0.015).

CONCLUSION

An increased peripheral leukocyte count is considered not so much an indicator of the pathogenesis of stable angina, but as a predictor for disease progression. Furthermore, it is considered that the above correlation will be helpful in screening high-risk groups that require relatively active interventional therapy.