Hypertension and Risk for Dementia and Alzheimer Disease: The Evidence
Hypertension and Risk for Dementia and Alzheimer Disease: The Evidence
Hi. I'm Dr. Henry Black. I'm a Clinical Professor of Internal Medicine at the New York University School of Medicine, a member of the Center for the Prevention of Cardiovascular Disease, and Immediate Past President of the American Society of Hypertension. We have had innumerable studies and evidence that hypertension leads to kidney disease, strokes, heart attacks, peripheral vascular disease, and problems with ocular function. One of the things that seemed to make sense was that hypertension would cause dementia. It causes strokes, so why not dementia? However, it has been very difficult to prove.
A nicely done study from Japan, which has been following individuals since the 1960s, has shed some light on this problem. The authors looked at approximately 550 individuals in that population, recruited from about 90% of the population, and followed them over time to see what their blood pressures were at baseline and what they were after the 17-year or longer follow-up. The results are pretty interesting in many different ways. One finding that was not surprising is that if you had an elevated blood pressure as a younger person in your 50s and as an older person in your 60s and 70s, the likelihood of having vascular dementia (ie, dementia that you can attribute to elevated blood pressure) was higher.
It was not so clear for Alzheimer disease. How did they tell the difference? Almost everybody who developed dementia (about 200 individuals out of the 550) had either imaging studies or autopsies performed to try to nail down what type of dementia it was. It is very difficult to clinically distinguish between the two. Of particular interest was that individuals who had a higher blood pressure at midlife, even if their blood pressure was reduced over time, had an increased incidence of vascular dementia. There was a clear relationship between midlife blood pressure and increased likelihood of vascular dementia later. Individuals who got hypertension later in life had a much less reduced risk and no increase in Alzheimer risk.
As we are beginning to focus on things that we have not been able to show that we can prevent, one of the lessons from this very interesting and well-done study is that we need to start paying more attention to elevated blood pressures in people who are in their 40s and early 50s. This is a group that we tend to ignore. This is a group for whom we have recommended lifestyle modifications, delayed drug treatment, and we haven't been able to show that we prevented this. If you start treating them later, which is what these investigators found, you don't necessarily prevent vascular dementia from happening. Let's get out there and start paying attention right now to blood pressure in younger people. This is something that I think we have ignored. Thank you very much.
Hi. I'm Dr. Henry Black. I'm a Clinical Professor of Internal Medicine at the New York University School of Medicine, a member of the Center for the Prevention of Cardiovascular Disease, and Immediate Past President of the American Society of Hypertension. We have had innumerable studies and evidence that hypertension leads to kidney disease, strokes, heart attacks, peripheral vascular disease, and problems with ocular function. One of the things that seemed to make sense was that hypertension would cause dementia. It causes strokes, so why not dementia? However, it has been very difficult to prove.
A nicely done study from Japan, which has been following individuals since the 1960s, has shed some light on this problem. The authors looked at approximately 550 individuals in that population, recruited from about 90% of the population, and followed them over time to see what their blood pressures were at baseline and what they were after the 17-year or longer follow-up. The results are pretty interesting in many different ways. One finding that was not surprising is that if you had an elevated blood pressure as a younger person in your 50s and as an older person in your 60s and 70s, the likelihood of having vascular dementia (ie, dementia that you can attribute to elevated blood pressure) was higher.
It was not so clear for Alzheimer disease. How did they tell the difference? Almost everybody who developed dementia (about 200 individuals out of the 550) had either imaging studies or autopsies performed to try to nail down what type of dementia it was. It is very difficult to clinically distinguish between the two. Of particular interest was that individuals who had a higher blood pressure at midlife, even if their blood pressure was reduced over time, had an increased incidence of vascular dementia. There was a clear relationship between midlife blood pressure and increased likelihood of vascular dementia later. Individuals who got hypertension later in life had a much less reduced risk and no increase in Alzheimer risk.
As we are beginning to focus on things that we have not been able to show that we can prevent, one of the lessons from this very interesting and well-done study is that we need to start paying more attention to elevated blood pressures in people who are in their 40s and early 50s. This is a group that we tend to ignore. This is a group for whom we have recommended lifestyle modifications, delayed drug treatment, and we haven't been able to show that we prevented this. If you start treating them later, which is what these investigators found, you don't necessarily prevent vascular dementia from happening. Let's get out there and start paying attention right now to blood pressure in younger people. This is something that I think we have ignored. Thank you very much.
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