BP and Alzheimer's

A significant drop in systolic blood pressure may forewarn of Alzheimer's disease & dementia.

A new research conducted at the Karolinska Institutet in Stockholm, suggests that a significant drop in systolic blood pressure may forewarn of Alzheimer's disease and dementia in some elderly people.

The researchers led by professor Laura Fratiglioni found that a substantial drop in systolic blood pressure predicted the onset of dementia in people with a systolic pressure of less than 160 millimeters of mercury (mm Hg).

A drop of 15 mm Hg or more was linked to a three-fold increase in the risk of getting Alzheimer's. In patients who already had vascular disorders such as stroke and diabetes mellitus, this drop increased their risk of Alzheimer's 2.4 times, and 2.5 times for all types of dementia.

According to lead author Chengxuan Qiu, "Our findings imply that poor blood flow in the brain, resulting from an extensive decline in blood pressure, may promote the dementia process."

The study aimed to verify blood pressure variations before and after dementia diagnosis, and to investigate whether blood pressure decline was predictive of Alzheimer's disease and dementia.

The researchers examined 947 people aged 75 or older who had no evidence of dementia. Their blood pressure measurements were taken and physical examination done when they began the study and again three and six years later.

Of these, 147 were diagnosed with Alzheimer's disease and 39 with other dementia after the three-year follow-up examination. While after six years, another 91 were diagnosed with Alzheimer's and an additional 27 with other types of dementia.

According to co-author Bengt Winblad, "Our data show no substantial differences in blood pressure levels at enrollment between non-demented persons and those that were demented three to six years later. However, some elderly people who experience a significant decline in systolic blood pressure three to six years before diagnosis do have an increased risk of dementia and Alzheimer's disease."