Influence of inflammatory and lipidic parameters on red blood cell distribution width in a healthy population

Red blood cell distribution width (RDW) is a routine red blood cell count parameter which has been shown to be associated with inflammatory parameters. Recently, some authors proposed that RDW seems to be a marker of an adverse lipidic profile. In order to clarify whether RDW is related to inflammation, plasma lipids, or both, we determined anthropometric, hematimetric, inflammatory and lipidic parameters in 1111 healthy subjects. RDW correlated directly with age, body mass index (BMI), inflammatory parameters (plasma viscosity, erythrocyte sedimentation rate (ESR), fibrinogen, leukocyte and neutrophil count), and inversely with iron and hematimetric parameters (P < 0.05). When subjects were divided according to gender, RDW correlated inversely with triglycerides only in women (P < 0.05). When subjects were classified into RDW-quartiles, increased RDW values were accompanied by decreased serum iron levels and hematimetric indices (P < 0.01), whereas age and inflammatory markers increased according to RDW-quartiles (P < 0.001 and P < 0.05, respectively). However, plasma lipids did not change with increasing RDW-quartiles (P > 0.05). In the linear regression analysis, age, hemoglobin, MCV (beta coefficient: 0.202, -0.234, -0.316, P < 0.001) and fibrinogen (beta coefficient: 0.059, P = 0.048) were the only independent predictors of RDW. The present study indicates that RDW is associated with inflammatory markers and hematimetric indices, but not with plasma lipid levels in a healthy population.