The multiplicative interactions of leukocyte counts with some other risk factors enhance the prognostic value for coronary artery disease

Background: The markers of inflammation and (apo)lipoproteins are associated with coronary artery disease (CAD). Simultaneous assessment of the risk factors has been proposed to improve the diagnosis of CAD. The aim of this study was to examine the potential interactions between leukocyte counts and other risk factors. Methods: The markers of inflammation, (apo)(lipo)proteins, (non)electrolytes, hematological parameters and classical risk factors, were determined in 264 clinically stable angiographically documented subjects. The subjects were classified as CAD cases or controls according to the results of coronary angiography. Results: The frequency and severity of CAD, Framingham CAD scores, relative and absolute risk for CAD and the prevalence of diabetes mellitus and smoking were significantly higher in the third relative to the first tertile of leukocyte counts. Subjects with leukocyte counts in the upper tertile had significant higher levels of serum glucose, triglyceride, hsC-reactive protein, potassium, phosphorus and measured osmolality, and lower levels of apoAI, total protein, albumin and the ratio of albumin/globulins. Analyses by bivariate correlation on differential leukocyte counts showed that these associations are carried mostly by neutrophil, except for diabetes, glucose and triglyceride which were due to lymphocyte counts. By constructing dummy combined variables, high leukocyte counts accompanied by smoking, hypertension, diabetes, and high levels of serum glucose, cholesterol, apoB and apoB/apoAI ratio, exhibited amplified high risk for CAD. Conclusions: The results show that leukocyte count does interact multiplicatively with smoking, hypertension, diabetes, glucose, cholesterol, apoB and apoB/AI ratio. The simultaneous assessment of leukocyte counts and interactive risk factors enhances the diagnosis of CAD. (Cardiol J 2011; 18, 3: 246–253