Low BP may lead to dementia

A fall in systolic blood pressure (the higher number in a BP reading) appears to predict the development of Alzheimer's disease or dementia in elderly subjects with low blood pressure.Researchers from the Karolinska Institute in Stockholm, found that poor blood flow in the brain, resulting from an extensive decline in blood pressure, may promote the dementia process. The study involved 947 elderly adults who did not have dementia when the study began in 1987. Blood pressure and mental status were assessed at follow-up visits that occurred about every 3 years. From 3 years before dementia diagnosis and subsequently, a marked drop in blood pressure was observed. In contrast, no substantial decline was seen in the previous visit, 6 years before diagnosis. Among subjects with low blood pressure or with blood vessel disease, a 15-point or greater drop in systolic blood pressure during this period raised the risk of both Alzheimer's disease and dementia by about threefold. In patients with blood vessel disease, the dementia risk increased steadily, as the blood pressure fell.

Medical treatment of hypertension is important but it is necessary to monitor the drugs treatment in the very old to avoid a probable dangerous drop of blood pressure under a certain threshold, to prevent the development of dementia.