With hypertension affecting 2/3 of North Americans, much of it goes undiagnosed and under treated. Hypertension is a significant risk factor for heart disease and stroke. Given the fact that vascular risk for heart disease are also risks for dementia, we are not sure if controlling BP can prevent cognitive decline.
As many as 8 per cent of Alzheimer cases may be because of blood pressure.
The trends toward declining dementia may in part be because of better awareness and control of hypertension.
The present study ARIC -the Atherosclerosis Risk in Communities study-looked at this very question.
After 19 years of follow up ( ages 45-64, 4000 participants) those with hypertension died sooner, were more likely to have diabetes and stroke and had a steeper 20 year global cognitive decline. Even those with prehypertension had a greater decline although it was less than those with true hypertension. The good news is those with treated hypertension had intermediate decline of cognition compared to those with prehypertension and untreated hypertension.
So what can we take away? The summary of what the authors suggest is:
- For anyone with a history of stroke-BP rx is effective for reducing post stroke dementia
- Anyone middle aged or young elderly requires BP lowering for prevention of late life dementia
- It is not clear if BP rx is useful for anyone older than 80 in terms of prevention
