Red Blood Cell Distribution Width and the Risk of Death in Middle-aged and Older Adults

Abstract

Red blood cell distribution width (RDW) is routinely assessed as part of the complete blood count (CBC) to gather information on the heterogeneity in the size of circulating erythrocytes. Computationally, RDW is the coefficient of variation of red blood cell (RBC) volume, and therefore higher RDW values reflect greater heterogeneity in RBC size (anisocytosis), which is usually caused by perturbation in erythrocyte maturation or degradation. The RDW is used as an auxiliary index to help diagnose different types of anemia but has also been evaluated as a potential screening marker for colon cancer and celiac disease because of its responsiveness to subtle nutrient deficiency.^1,2 Recently, researchers have reported higher mortality risk associated with higher RDW in patient populations with cardiovascular disease (CVD).^3-5 However, none of these prospective studies was able to account for nutritional status or levels of inflammation.