White blood cell count and the risk of coronary heart disease and all-cause mortality in elderly men

Abstract

Because the importance of established risk factors for coronary heart disease (CHD) is unclear in older people, the associations of white blood cell (WBC) count with the risk for CHD and all-cause mortality were investigated in an elderly cohort that was followed up for 5 years. In 1985, complete information on the risk factors of interest was available for 884 randomly selected men, aged 64 to 84 years, from the Dutch town of Zutphen (participation rate, 74%). Relative risks (RRs) for each 10(9)/L increase in WBC count were obtained for the 5-year incidence of and mortality from CHD and all causes. RRs were adjusted for age, body mass index, systolic blood pressure, total and high density lipoprotein cholesterol levels, and cigarette smoking habit. The WBC count was 6.7 +/- 1.8 X 10(9)/L (means +/- SD) at baseline. An increased WBC count was independently associated with mortality due to CHD, and the RR amounted to 1.32 (95% confidence interval [95% CI], 1.15 to 1.51). For the incidence of CHD the RR was 1.14 (95% CI, 0.98 to 1.32). These associations were observed regardless of cigarette smoking habit. Regarding all-cause mortality, the RR amounted to 1.25 (95% CI, 1.17 to 1.35). This association was especially noticeable among former smokers and those who had never smoked. In conclusion, during 5 years of follow-up WBC count predicted CHD and all-cause mortality in elderly men, independent of the conventional risk factors for CHD.