Elsevier

Atherosclerosis

Volume 192, Issue 1, May 2007, Pages 177-183
Atherosclerosis

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

https://doi.org/10.1016/j.atherosclerosis.2006.04.029Get rights and content

Abstract

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 × 109 cells/L and above) versus first quartile (4.8 × 109 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.

Introduction

The pathogenesis of cardiovascular disease is multifactorial and involves interactions between genetic and various traditional and non-traditional environmental factors [1], [2]. Increasing evidence supports a role for inflammation in the atherosclerotic process [3]. Several prospective studies have shown that elevated circulating white blood cell (WBC) count, a widely available marker of systemic inflammation, is related to cardiovascular disease (CVD) and mortality, independent of the traditional risk factors [4], [5], [6], [7], [8], [9], [10], [11], [12]. To our knowledge, the relationship between WBC count and cardiovascular mortality has not been examined in a population-based study from Australia.

Triglyceride levels are related to markers of inflammation [13], [14]. Elevated triglyceride levels are found to be independently predictive of CVD in some [15], [16], [17], but not all studies [18], [19], [20]. The relationship between elevated WBC count, triglyceride levels and their relationship to CVD has not been compared simultaneously in a population-based study before.

We examined the relationship between WBC count, triglyceride levels and cardiovascular and all-cause mortality in an older Australian population, after adjusting for several main confounding variables.

Section snippets

Study population

The Blue Mountains Eye Study (BMES) is a population-based cohort study of age-related eye diseases and other health outcomes in an urban Australian population. Study details were described previously [21]. After a door-to-door census of residents living in two postcodes in the Blue Mountains region, west of Sydney, Australia, persons born before 1 January 1943, were invited to attend a detailed examination at a local hospital. Baseline examination was performed on 3654 of 4433 (82.4%) eligible

Results

Baseline characteristics of the cohort according to WBC count quartiles are shown in Table 1. Individuals with higher WBC count were more likely to be male, current smokers, physically inactive, have higher hematocrit, BMI, more likely to have diabetes, higher systolic blood pressure, total cholesterol and triglyceride level, lower HDL-C level, and less likely to have self-rated health as “excellent”.

There were 242 cardiovascular (n = 179 ischemic heart disease, n = 63 stroke) deaths and 575

Discussion

In the Blue Mountains cohort of older Australians, we found that elevated WBC count was associated with cardiovascular and all-cause mortality, independent of smoking, diabetes, hypertension, lipid levels and other related factors. Compared to individuals in the first quartile (4.8 × 109 cells/L and below), individuals in the fourth quartile (6.8 × 109 cells/L and above) of WBC count had over two-fold risk of cardiovascular mortality. Plasma triglyceride levels were also found to be independently

References (32)

  • D.J. Rader

    Inflammatory markers of coronary risk

    N Engl J Med

    (2000)
  • K.L. Margolis et al.

    Leukocyte count as a predictor of cardiovascular events and mortality in postmenopausal women: the Women's Health Initiative Observational Study

    Arch Intern Med

    (2005)
  • A.R. Folsom et al.

    Prospective study of hemostatic factors and incidence of coronary heart disease: the Atherosclerosis Risk in Communities (ARIC) Study

    Circulation

    (1997)
  • R.H. Grimm et al.

    Prognostic importance of the white blood cell count for coronary, cancer, and all-cause mortality

    JAMA

    (1985)
  • C.D. Lee et al.

    White blood cell count and incidence of coronary heart disease and ischemic stroke and mortality from cardiovascular disease in African-American and White men and women: atherosclerosis risk in communities study

    Am J Epidemiol

    (2001)
  • P.M. Sweetnam et al.

    Total and differential leukocyte counts as predictors of ischemic heart disease: the Caerphilly and Speedwell studies

    Am J Epidemiol

    (1997)
  • Cited by (0)

    View full text