Differential white blood cell count and incident heart failure in men and women in the EPIC-Norfolk study.

AIMS Markers of inflammation are associated with increased risk of heart failure, but data on differential white blood cell (WBC) count are lacking. We examined the prospective association between differential WBC count and incident heart failure events. METHODS AND RESULTS Hazard ratios (HRs) (per increase of 1000 cells/μL, 95% confidence interval) of total WBC count and individual components on heart failure were calculated in apparently healthy 7195 men and 8816 women aged 39-79 participating in the 'European Prospective Investigation into Cancer and Nutrition' (EPIC) study in Norfolk. During a mean follow-up of 12.4 years, 935 incident cases of heart failure occurred. In women, neither total WBC count (1.02, 0.96-1.09) nor individual components were associated with HR of heart failure after accounting for known risk factors. In men, HR of heart failure increased with increasing levels of total WBC count (1.09, 1.04-1.15) after accounting for established risk factors; analysis of WBC components showed increased hazard with increasing levels of granulocyte count (1.16, 1.09-1.24) and, independently of this, decreased hazard with increasing levels of monocyte count (0.71, 0.53-0.93); lymphocyte count was not significantly associated with heart failure (0.97, 0.83-1.13). Results did not change materially after excluding smokers, adjusting for intermediate myocardial infarction and coronary heart disease and C-reactive protein. CONCLUSION Inflammation as measured by WBC count was independently associated with incident heart failure in apparently healthy men but not women. The association observed in men was driven by granulocyte count, but there was an independent inverse association between monocyte count and incident heart failure.