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

The authors examined the association between white blood cell (WBC) count a nd incidence of coronary heart disease and ischemic stroke and mortality fr om cardiovascular disease in 13,555 African-American and White men and wome n from the Atherosclerosis Risk in Communities (ARIC) Study. Blood was draw n at the ARIC baseline examination, beginning in 1987-1989. During an avera ge of 8 years of follow-up (through December 1996), there were 488 incident coronary heart disease events, 220 incident strokes, and 258 deaths from c ardiovascular disease. After adjustment for age, sex, ARIC field center, an d multiple risk factors, there was a direct association between WBC count a nd incidence of coronary heart disease (p < 0.001 for trend) and stroke (p for trend < 0.001) and mortality from cardiovascular disease (p for trend < 0.001) in African Americans. The African Americans in the highest quartile of WBC count (greater than or equal to7,000 cellS/mm(3)) had 1.9 times the risk of incident coronary heart disease (95% confidence interval (CI): 1.1 9, 3.09), 1.9 times the risk of incident ischemic stroke (95% CI: 1.03, 3.3 4), and 2.3 times the risk of cardiovascular disease mortality (95% CI: 1.3 8, 3.72) as their counterparts in the lowest quartile of WBC count (<4,800 cells/mm(3)). These associations were similar in Whites and in never smoker s. An elevated WBC count is directly associated with increased incidence of coronary heart disease and ischemic stroke and mortality from cardiovascul ar disease in African-American and White men and women.