Anemia is associated with the progression of white matter disease in older adults with high blood pressure: The Cardiovascular Health Study

OBJECTIVES: To investigate whether anemia predicts worsening white matter hyperintensities (WMHs) in older community-dwellers. DESIGN: Prospective cohort Study. SETTING: Older community-dwellers. PARTICIPANTS: One thousand eight hundred forty-six Cardiovascular Health Study (CHS) participants (mean age 73.7 +/- 4.4, 41% male, 15.6% African American). MEASUREMENTS: Participants had hemoglobin measured and brain magnetic resonance imaging (MRI) in 1992/93 and a second brain MRI in 1997/98. Anemia was defined according to World Health Organization criteria (hemoglobin < 12 g/dL in women and < 13 g/dL in men). Worsening WMHs were determined according to standardized side-by-side readings. RESULTS: After 5 years, WMHs worsened in 517 participants (28%). Progression was not associated with anemia in the whole sample, in sex or race strata, or in other pre-specified subgroups (participants with renal dysfunction or diabetes mellitus), except in participants with high blood pressure (>= 140/90 mm Hg). Of the 678 participants with high blood pressure, those with anemia (10.5%) had a 1.79 times greater risk of WMHs worsening (95% confidence interval = 1.06-2.98; P for interaction between anemia and high blood pressure = .01) independent of demographics, baseline WMHs, cardiovascular risk factors and comorbidities, medications, renal function, inflammation, and incident stroke (logistic regression models). There was no greater risk in participants with anemia with normal blood pressure. CONCLUSION: Anemia may contribute to worsening of WMHs in older adults with high blood pressure.