High blood pressure (hypertension) from mid-life to later life, as well as high mid-life blood pressure followed by low blood pressure (hypotension) later in life has been associated with an increased risk of dementia in a study from the US.
This observational study included nearly 4,800 participants who had blood pressure measurements taken over 24 years at five visits plus a detailed neurocognitive evaluation during the fifth and a sixth visits, where dementia was assessed.
Data has shown patterns of high blood pressure in midlife that extend to late life or high blood pressure in midlife followed by low blood pressure later in life were associated with increased risk for dementia compared to having normal blood pressure.
There were 516 new cases of dementia diagnosed between the fifth and sixth visits.
Study authors report that compared with maintaining normal blood pressure, an increased risk of dementia was associated with hypertension (greater than 140/90 mm Hg or use of antihypertensive medication) in midlife (age 54 to 63) that was sustained to later life. The same was found with a pattern of hypertension in midlife and low blood pressure (less than 90/60 mm Hg) in later life.
Midlife hypertension followed by late-life low blood pressure also was associated with increased risk of mild cognitive impairment.
Limitations of the study include that the findings may have been biased because of the increased likelihood that participants with higher blood pressure and poorer cognition during midlife dropped out of the study.