Study: Low Blood Pressure May Cause More Severe Dementia in Alzheimer's Patients

Low blood pressure appears to cause dementia and memory problems to be more severe in Alzheimer's disease patients, according to a study reported in January's Archives of Clinical Neuropsychology.

Previous studies have found blood pressure to be lower among patients with Alzheimer's disease than those without the disease, but the effects were uncertain. This lower blood pressure is believed to be related to reduced cerebral blood flow and cortical atrophy.

University of Houston researchers assessed the effects of blood pressure in Alzheimer's patients by testing them on the severity of dementia, attention, memory, language, verbal and nonverbal reasoning, function and impact on activities of daily living among 609 patients with probable Alzheimer's disease.

The researchers found that Alzheimer's patients with lower systolic blood pressure had reduced attention and memory levels and performed fewer daily living activities. The researchers expected this based on past studies.

Unexpectedly, the researchers also found that lower pulse pressure, which is calculated by substracting the diastolic reading from the systolic reading, predicted greater dementia severity, attention and memory leveles and a decline in daily living activities.

"These findings may reflect a tendency for less severely demented patients to exhibit normal age-related changes in blood pressure, whereas abnormal patterns may develop with increased dementia severity," concluded the researchers.

Other sources: Archives of Clinical Neuropsychology. 2003 Jan;18(1):19-32