Stroke Incidence and Risk Factors in a Tri-ethnic Region

Study Summary

Enrollment of a population-based, prospective cohort of 3298 stroke-free adults was completed in 2001 and annual follow-up has continued since then. This collaborative study is the first prospective cohort study among whites, blacks and Caribbean Hispanics living in the same community. This grant supports continued follow-up and outcome detection and expansion of data collection in this cohort. The aims are to evaluate the relationship between vascular outcomes (stroke, myocardial infarction (MI), and vascular death) and insulin resistance, carotid intima-media thickness, carotid distensibility, and quantitative magnetic resonance imaging (MRI) measures of vascular subclinical brain disease and to determine if MRI subclinical disease accounts for race/ethnic differences in cognitive impairment. To accomplish these aims further data collection using the population-based, prospective cohort study is proposed. Stored baseline serum will be used to measure fasting insulin levels to evaluate insulin resistance. High-resolution carotid imaging data will be collected at subsequent visits to expand the measurements of subclinical carotid disease to 1300 subjects. MRIs and a neuropsychological battery emphasizing frontal executive domains will be done on 1300 subjects and quantitative analyses performed to measure white matter hyperintensities, silent infarcts, and silent cerebral microbleeds. Starting in 2005, subjects enrolled in the MRI substudy began to have echocardiograms and 24hour ambulatory blood pressure monitoring. Subjects will be followed by annual telephone interviews to ascertain stroke, MI, death, and changes in cognitive state. In-person assessment will be done for all subjects who screen positive. Community stroke surveillance will be maintained to insure stroke detection among the cohort. Specific diagnostic committees classify stroke, MI and vascular death.