A follow-up study of blood pressure and cerebral white matter lesions

White matter lesions are often observed on cerebral magnetic resonance imag ing scans of elderly people and may play a role in the pathogenesis of deme ntia. Cross-sectional studies have shown an association between elevated bl ood pressure and white matter lesions. We prospectively studied the relatio n between blood pressure and white matter lesions in 1,077 subjects aged 60 to 90 years who were randomly sampled from two prospective population-base d studies. One study had blood pressure measurements 20 years before, the o ther 5 years before. Overall response for the magnetic resonance imaging st udy was 63%, and declined from 73% among 60- to 70-year-olds to 48% for 80- to 90-year-olds. Diastolic and systolic blood pressure levels assessed 20 years before were significantly associated with subcortical and periventric ular white matter lesions. The association between 20-year change in diasto lic blood pressure and subcortical white matter lesions was J-shaped (relat ive risk, 2.2; 95% confidence interval, 1.0-5.2; and relative risk, 3.2; 95 % confidence interval, 1.4-7.4, for decrease or increase of more than 10 mm Hg, respectively). The association between concurrent diastolic blood pres sure level and white matter lesions was linear in subjects without, and J-s haped in subjects with, a history of myocardial infarction. Our results ind icate that the J-shape relationship of diastolic blood pressure is not rest ricted to cardiovascular disease, but is also manifest in cerebrovascular d isease.