A routine but overlooked parameter for impaired glucose control: red cell distribution width

Red cell distribution width (RDW), an index of erythrocyte size, is recently found to be associated with inflammation and a high risk for cardiovascular disease. Hyperglycemia, the hallmark of prediabetes (PDM) and diabetes mellitus (DM), causes endothelial dysfunction and a proinflammatory state. We investigated the relationship between RDW and hs-CRP in patients with prediabetes and overt DM.

A total of 155 patients were categorized into 3 groups according to the 2007 guideline for American Diabetes Association: "Type 2 DM" group (n = 45), "PDM" group (n = 60) and "Control" group (n = 50). RDW and hs-CRP levels were measured.

PDM group had higher hs-CRP and RDW levels than the control group (14.3 ± 0.84 vs. 12.7 ± 0.8, p < 0.001 for RDW; (0.91 ± 0.49 vs. 0.55 ± 0.37, p < 0.001 for hs-CRP). Similarly, when compared with the PDM, RDW and hs-CRP levels were higher in the DM group (14.8 ± 0.87 vs. 14.3 ± 0.84, p = 0.002 for RDW; 1.15 ± 0.59 vs. 0.91 ± 0.49, p = 0.03 for hs-CRP).

Prediabetes and diabetes were associated with elevated RDW levels which may be attributed to a subclinical inflammatory background.