Midlife blood pressure and the risk of hippocampal atrophy: The Honolulu Asia aging study

Hippocampal atrophy (HA) is usually attributed to the neurofibrillary tangles and neuritic plaques of Alzheimer disease. However, the hippocampus is vulnerable to global ischemia, which may lead to atrophy. We investigated the association of midlife blood pressure (BP) and late-life HA in a sample of Japanese-American men born between 1900 and 1919. BP was measured on 3 occasions between 1965 and 1971. In 1994 to 1996 a subsample underwent magnetic resonance imaging (MRI) of the brain. Hippocampal volume was estimated by manually drawing regions of interest on relevant scan slices; HA was defined as the lowest quartile of hippocampal volume. Also assessed on the MRI were cortical and subcortical infarcts, lacunes, and white matter hyperintensities. The risk (OR, 95% CI) was estimated for HA associated with systolic (<140 versus ≥140 mm Hg) and diastolic (