Baseline and longitudinal increases in diastolic blood pressure are associated with greater white matter hyperintensity volume: the northern Manhattan study.

BACKGROUND AND PURPOSE Elevated blood pressure (BP) is a risk factor for stroke and dementia, but the effect of BP, and change in BP over time, on white matter hyperintensity volume (WMHV) is not fully understood. Few studies have included Hispanics, who are at greater risk of stroke and dementia than non-Hispanic whites. We examined BP in relation to WMHV in a stroke-free cohort. METHODS The Northern Manhattan Study includes 1290 stroke-free participants who had brain MRI. We examined baseline systolic and diastolic (DBP) BP, and changes in BP from baseline to MRI, and WMHV. RESULTS There were 1281 participants with brain MRI and 2 BP measurements (mean age, 64 years; SD=8; range, 40 to 94 years). Baseline DBP was associated with greater WMHV (P<0.0001) independent of sociodemographic and vascular risk factors. Each 10 mm Hg above the mean baseline DBP (83±11 mm Hg) was associated with a 1.17% greater WMHV. Over 7 years average follow-up, participants with an increase >5 mm Hg DBP from baseline to MRI had 1.21% greater WMHV relative to those whose BP did not increase (P=0.02). The association between baseline DBP and WMHV was strongest for blacks compared with Hispanics and whites (interaction P=0.04). CONCLUSIONS Baseline DBP and longitudinal increases in DBP were independently associated with a greater WMHV, and the association between DBP and WMHV was greatest among blacks.