The findings suggest that intensive lowering of blood pressure may reduce the risk of mild cognitive impairment and the combined risk of mild cognitive impairment and dementia, but not dementia alone.
Jeff D. Williamson, MD, MHS
Jeff Williamson, MD, MHS, professor of internal medicine and epidemiology, chief of geriatric medicine at Wake Forest School of Medicine and co-director of Wake Forest Alzheimer's Disease Core Center, sat down with NeurologyLive at the 2018 Alzheimer’s Association International Conference in Chicago, Illinois, to discuss the preliminary results related to the risk of dementia and cognitive decline from the Systolic Blood Pressure Intervention Trial (SPRINT) Memory and Cognition IN Decreased Hypertension (MIND) trial. The results suggest that intensive lowering of blood pressure may reduce the risk of mild cognitive impairment and the combined risk of mild cognitive impairment and dementia, but not dementia alone.
SPRINT is a randomized clinical trial that compared 2 strategies for managing high blood pressure in adults, an intensive strategy with a systolic blood pressure goal of <120 mm Hg versus a standard care strategy targeting a systolic blood pressure goal of <140 mm Hg. SPRINT MIND examined whether the lower blood pressure target reduces the risk of developing dementia and/or mild cognitive impairment, reducing the total volume of white matter lesions in the brain detected by MRI.
Jeff Williamson, MD, MHS: The main message from SPRINT MIND is that for the first time, we've shown that what is good for the heart is also good for the brain, so I think that's the top-line message for all practitioners as well as the public. In a more detailed fashion, SPRINT MIND showed that the blood pressure target of 120 systolic is more effective at reducing the risk for developing mild cognitive impairment than a blood pressure target of 140. This is the first time, really in history, that any treatment has shown to reduce mild cognitive impairment. SPRINT MIND did not show a reduction in dementia that was significant, it showed a 15% non-significant reduction in the occurrence of dementia in again the
intensively treated group.
JW: Since this is the first trial showing blood pressure reduction or anything for that matter is effective for reducing mild cognitive impairment, they’ll be more trials I’m sure to verify this result. This opens up additional frontiers on other cardiovascular interventions that may reduce the risk for mild cognitive impairment, which is for all purposes ‘the gateway’ to dementia, whether that be Alzheimer dementia or vascular dementia. This also opens up more opportunity for basic science like understanding the mechanisms that blood pressure lowering encouraged so that the risk for mild cognitive impairment could be reduced.
JW: One of the main questions that was outstanding, still, was “is blood pressure lowering safe for the brain?” And so SPRINT MIND clearly shows that it's not only safe for the brain, it's actually beneficial to the brain, this is a very important point for clinicians and their patients. I think the other important thing to note is that there are many biologic phenomenons that show a lower blood pressure or a lower weight without the context of being treated, may be harmful, so people whose weight is falling or low without trying to lose weight, that's a sign of poor health, but the same for blood pressure, people whose blood pressure is low without any treatment, that's perhaps a sign of poor health, especially in older people, but in the context of treatment, lowering blood pressure can be very beneficial and so this is something that physicians and their patients will need to discuss.
JW: One of the first things to show is that the first couple of decades of research in this area have provided a foundation, a biologic basis for how interventions may work, it’s also shown that interventions that don’t have a carefully worked out biologic foundation often will not work. So, to me this meeting is a turning point that we’re showing that the brain and the body are connected, but also that interventions that help the heart are good for the brain. We’re showing other forms of interventions that may help with prevention, which is the key to almost all diseases, is preventing them to start with.
JW: One of the important things to note about SPRINT is that although we did not see a significant reduction in dementia, one of the reasons we believe for this is first of all that we were unable to follow the participants for a long enough period of time—it was just short of 5 years that we were able to follow the participants. The other important thing to note is that this intervention was stopped about halfway between the second and the third year and so if we'd been able to continue that, perhaps we would have seen a significant effect. There's a silver lining to this, however, that only 2 and a half years of blood pressure lowering produced the first ever intervention that could reduce the risk of someone developing mild cognitive impairment, so that's a bit of a 2-edged sword but I think very exciting.
Transcript edited for clarity.