Clinical correlating factors and cognitive function in community-dwelling healthy subjects with cerebral microbleeds

We performed brain gradient-echo T2(∗)-weighted magnetic resonance imaging (GE-MRI) in community-dwelling healthy people to investigate the clinical correlates (i.e., possible risk factors) and cognitive function in subjects with cerebral microbleeds (MBs). We examined 368 healthy subjects age 39 years or older living in a Japanese rural community, performing baseline and clinical assessments and brain MRI (T2(∗)-weighted, T1-weighted, T2-weighted, and FLAIR). We assessed global cognitive function in subjects age 60 years or older using the Mini-Mental State Examination (MMSE). An MMSE score >1.5 standard deviations (SD) below the mean score for a particular age group was considered subnormal. MBs were present in 14 of 368 subjects overall (3.8%; 11 males and 3 females) and in 14 of 225 subjects age≥60 years (6.2%). In a logistic regression analysis, older age (odds ratio [OR]=2.649/10 years; 95% confidence interval [CI]=1.465-4.788) and male sex (OR=6.876; 95% CI=1.801-26.248) were significantly related to the presence of MBs. The presence of silent brain infarction and white matter lesions was correlated with MBs, suggesting that MBs were the consequence of small-vessel diseases. There was a significant association between the presence of MBs and subnormal cognition defined by MMSE (OR=5.226; 95% CI=1.463-18.662). Our data suggest that in healthy community-dwelling subjects, MBs may be a consequence of small-vessel disease, which is correlated with aging, male sex, and subnormal cognition.