White blood cell count predicts all-cause, cardiovascular disease-cause and infection-cause one-year mortality of maintenance hemodialysis patients

Abstract

Elevated white blood cell (WBC) counts predict coronary heart disease and all-cause mortality in the general population. Chronic inflammation and malnutrition are associated with increased risk of cardiovascular death in individuals with chronic kidney disease. In this study, we investigated the association between WBC count with inflammation, malnutrition, and mortality in maintenance hemodialysis (MHD) patients. A total of 959 MHD patients were stratified into four equal sized groups based on WBC count. Demographic, hematological, nutritional and inflammatory markers, and biochemical and dialysis-related data were obtained for cross-sectional analysis. All patients were followed for one year to investigate the risks for mortality. The mean WBC count was 6.4 ± 1.8 × 10(3)/µL (range: 2.3-16.3 × 10(3)/µL). Stepwise multiple linear regression analysis indicated a positive correlation between WBC count and inflammation (high-sensitivity C-reactive protein > 3 mg/L). Forty-five patients (4.7%) died within the 1-year study period. Cox multivariate regression analysis demonstrated that total WBC count significantly predicts 1-year mortality due to all-cause (hazard ratio (HR): 1.228, 95% confidence interval (CI): 1.095-1.378; P < 0.001), due to cardiovascular disease (HR: 1.242, 95% CI: 1.046-1.475; P = 0.013) and due to infection (HR: 1.252, 95% CI: 1.066-1.470; P = 0.006). These findings suggest that total WBC count should be measured in future studies that evaluate the clinical outcome of MHD patients and that dialysis patients with elevated WBC counts require further medical attention to reduce risks of mortality.