Elevated red blood cell distribution width in healthy smokers

Objectives: Red blood cell distribution width (RDW) has been reported to be a marker of morbidity and mortality for some cardiovascular and pulmonary diseases. We aimed to evaluate RDW values in otherwise healthy smokers. Study design: Two hundred and twenty consecutive subjects with current smoking and 230 age-and gender-matched healthy subjects without smoking history were enrolled. Number of cigarettes smoked per day and duration of smoking, evaluated as pack years, were recorded. Complete blood count, high-sensitivity C-reactive protein (hs-CRP) levels and lipid profile were analyzed in all study participants. Results: The mean RDW values were higher in smokers than in nonsmokers (13.9+/-1.2 vs. 13.1+/-0.8, p<0.0001). The mean leukocyte count, mean platelet volume and hs-CRP levels were also significantly greater in smokers when compared to nonsmokers (8440+/-1.750 vs. 7090+/-1550, p<0.0001; 8.7+/-0.8 fL vs. 8.3+/-0.6 fL, p<0.0001; 2.42+/-0.53 mg/L vs. 1.46+/-0.52 mg/L, p<0.0001, respectively). Significant positive correlations between RDW and number of cigarettes smoked per day and between RDW and duration of smoking were identified (r=0.565 and r=0.305, respectively). Conclusion: Elevated RDW is associated with cigarette smoking and may be a useful indicator of inflammatory activity in smokers.