Red cell distribution width and cerebral white matter hyperintensity

Red cell distribution width (RDW) is an indicator of red blood cell size heterogeneity and may reflect underlying chronic hypoxemia or inflammation. While RDW has been associated with the prognosis of various pulmonary and cardiovascular diseases, its relevance in cerebrovascular disease remains underexplored. In this study, we evaluated the association between RDW and cerebral small vessel disease (cSVD). We evaluated consecutive health check-up participants who underwent brain MRI between January 2006 and December 2013. As subtypes of cSVD, white matter hyperintensity (WMH) was quantitatively assessed, while lacunes and cerebral microbleeds (CMBs) were evaluated qualitatively. RDW was measured from blood samples as part of the complete blood cell count. A total of 3,040 health check-up participants were evaluated (mean age: 56.3 years, male sex: 53.6%, mean body mass index: 24.16 kg/m2). In multivariable linear regression analysis, RDW was significantly associated with WMH volume after adjusting for confounders [β = 1.789, 95% confidence interval (CI): 0.115 to 3.463]. Age, systolic blood pressure, white blood cell and red blood cell counts were also associated with WMH volume, independent of RDW. On the other hand, lacunes and CMBs were not significantly associated with RDW after adjusting for confounders. RDW was associated with cSVD in health check-up participants. This association was observed exclusively with the WMH, while no significant relationship was found with lacunes or CMBs.