Red blood cell distribution width in patients with chronic obstructive pulmonary disease and healthy subjects

Background Chronic obstructive pulmonary disease (COPD) increases the risk of cardiovascular disease (CVD). Red blood cell distribution width (RDW) is accepted as a powerful predictor of outcomes in patients with CVD. Aims To study RDW in patients with COPD, and to compare the value of this measurement with clinical, echocardiographic, nutritional and laboratory status. Secondly, we aimed to determine the effect of smoking on RDW values in healthy subjects. Methods One hundred and seventy-five patients with stable COPD and 210 healthy controls were enrolled in the study. Demographic, clinical, nutritional status, echocardiographic, and laboratory characteristics, RDW values were recorded and compared. Results RDW values were higher in the COPD group than in controls (15±2.3% vs 13.8±2.5%, p<0.001). In COPD patients, RDW levels positively correlated with CRP levels (r=0.27, p<.001), albumin levels (r=0.23, P=.04), right ventricular dysfunction (RVD) (r=0.24, P=.001), pulmonary hypertension (PAH) (r=0.1, P=.02), and presence of CVD (r=0.24, P=.02). In multivariable logistic regression suggested that presence of CVD (4.3; 95% CI: 1.3–11; P=.01), and presence of RVD (3.1; 95% CI: 1.7–8.3; P=.02) were independently related to elevated RDW levels in COPD patients. In the healthy population, correlations analysis showed only a significant correlation between RDW and cigarette smoking years (r=0.57, p<.001). Conclusion RDW is independently associated with CVD and RVD in patients with COPD. In the healthy population, RDW is also associated with smoking status.