Low Blood Pressure and Incidence of Dementia in a Very Old Sample: Dependent on Initial Cognition

OBJECTIVE: To examine whether initially low blood pressure is related to the incidence of dementia. DESIGN: A population-based prospective study. SETTING: The Kungsholmen district of Stockholm, Sweden PARTICIPANTS: Three hundred four nondemented subjects aged 75 to 96 years at baseline. MEASUREMENTS AND MAIN RESULTS: After an average of 3 years, 81 dementia cases were identified (67 with Alzheimer's disease cases). Compared with individuals with baseline systolic pressure of 141 to 179 mm Hg, those with systolic pressure or = 24). Baseline MMSE < 24 significantly predicted the occurrence of dementia (RR = 6.9; 95% CI, 4.3-11.1). Systolic pressure < or = 140 mm Hg was significantly related to MMSE score < 24 at baseline. CONCLUSIONS: These data suggest that low blood pressure may be an early correlate of a dementing process although a causative effect cannot be definitely ruled out.