Associations between differential leucocyte count and incident coronary heart disease: 1764 incident cases from seven prospective studies of 30 374 individuals

Aims We aimed to assess potential associations between different leucocyte components and coronary heart disease (CHD) in a prospective cohort study, and to put these findings in context of other relevant prospective studies in a meta-analysis. Methods and results We report data on differential leucocyte count and CHD derived from the first National Health and Nutrition Examination Survey (NHANES 1) and the NHANES 1 Epidemiologic Follow-up Study (NHEFS) involving 4625 individuals followed, on average, for 18 years. The NHEFS involved 914 incident CHD cases and yielded an adjusted risk ratio of 1.09 (0.93-1.29) comparing individuals with neutrophil counts in the top third versus those in the bottom third of the population. In a meta-analysis involving the NHEFS and four other studies comprising a total of 1764 incident CHD cases, the association of CHD with neutrophil counts was somewhat stronger than those with other specific leucocyte components (combined risk ratio = 1.33 [1.17-1.50]) but there was substantial heterogeneity between the separate studies (chi(2) = 18.0, p < 0.001). Conclusions Although the present synthesis provides the most comprehensive assessment so far of specific leucocyte components in CHD, additional prospective data will be needed to resolve whether neutrophil. counts are much stronger predictors of CHD risk than other components. (C) 2004 The European Society of Cardiology. Published by Elsevier Ltd. All rights reserved.