Cerebral Microbleeds: Prevalence and Associations With Cardiovascular Risk Factors in the Framingham Study

Background and Purpose— Cerebral microbleeds (CMBs) are areas of low signal intensity on gradient echo T2*-weighted magnetic resonance imaging (T2*MRI) corresponding to hemosiderin deposits in the perivascular space. Microangiopathy from atherosclerosis or amyloid angiopathy might lead to the formation of these lesions; therefore, there may be associations between CMBs and cardiovascular risk factors, APOE allele status, and brain morphology. We examined these relationships in the Framingham Study (FHS). Methods— In 472 subjects from the FHS Offspring and Cohort, we related CMB status to age, sex, systolic blood pressure, total cholesterol and high-density lipoprotein cholesterol (HDL-C) levels, smoking, diabetes, total hemispheric brain volume, white matter hyperintensity volume (WMHV), and APOE allele status. Results— Overall prevalence of CMBs was 4.7%, but CMBs were more prevalent with advanced age and male sex. Blood pressure, brain volume, and WMHV were related to CMBs in crude analysis but not after adjustment for age and sex. There were no significant relationships demonstrated between CMBs and APOE allele status, cholesterol, smoking, or diabetes. Conclusions— There is a low prevalence of CMBs in the community and a strong relationship with increasing age and male sex. We found no independent relationships with cardiovascular risk factors, APOE status, brain volumes, or WMH.