Incident Risk and Progression of Cerebral Microbleeds in Healthy Adults: A Multi-Occasion Longitudinal Study

摘要

Decline in cerebrovascular health complicates brain aging and development of cerebral microbleeds (CMBs) is one of its prominent indicators. In a large sample of healthy adults (N = 251, age 18–78 years at baseline, 70% women), the contributions of chronological age and vascular health indicators to risk of developing a CMB was examined in a prospective eight-year longitudinal study, as well as change in CMB size and iron content from susceptibility weighted imaging. Twenty-six persons (10.4%), most of whom were 40 years of age or older, had at least one CMB during the study. Older age was associated with greater risk for developing a CMB (odds ratio 1.03), and elevation of combined metabolic syndrome indicators (b = 0.15, p =0.001) that conferred additional risk (odds ratio 1.02). High body mass index worsened risk associated with poor vascular health (b = 0.75, p < 0.001) and frequent exercise mitigated it (b = −0.46, p = 0.03). CMBs persisted over time, yet their volume decreased (mean change = −0.32, p<0.05), while their relative iron content remained stable (mean change = −0.14, p = 0.05). We conclude that although developing a CMB is unlikely during normal aging, risk increases with declining vascular health, which is modifiable via behavioral and pharmaceutical intervention.