3/11/2019 4:10:05 PM

Does Intensive Blood Pressure Control Reduce the Risk for Dementia?

A large randomized, controlled trial suggests that intensive blood pressure control can reduce the risk of mild cognitive impairment, though not dementia. Independent experts debated the clinical implications of the findings.

A debate among neurologists over the findings of a huge, multi-site, randomized clinical trial testing the effects of intensive control of systolic blood pressure on cognitive outcomes seemed to come down to the age-old question: Is the glass half empty or half full?

On the half-empty side, the so-called SPRINT MIND—for Systolic Blood Pressure Intervention Trial-Memory and Cognition in Decreased Hypertension—failed to reach statistical significance on its primary cognitive outcome of a reduction in the occurrence of dementia. Moreover, the trial did not explicitly screen out mild cognitive impairment (MCI) at baseline, and did not include the sort of very old, frail or medically complex patients for whom the risks of intensive blood pressure control may be highest.

On the half-full side, however, the trial did significantly reduce the risk of MCI (14.6 versus 18.3 cases per 1,000 person-years) and the combined rate of MCI or probable dementia (20.2 versus 24.1 cases per 1,000 person-years). What's more, the trend for dementia alone was in the right direction and only just missed statistical significance: (7.2 versus 8.6 cases per 1,000 person-years).

For all the uncertainty, neurologists praised the study for providing what appears to be the first evidence ever from a randomized controlled trial that an intervention can reduce the risk of cognitive decline, even as they emphasized that the results need to be interpreted with caution.

An editorial accompanying the paper in the Journal of the American Medical Association (JAMA) stated: “The SPRINT MIND study may not be the final approach for prevention of AD or other cognitive impairment, but it represents a major leap forward in what has emerged as a marathon journey.”

In hopes of clarifying the results, the Alzheimer's Association announced that it is providing 0,000 in “seed” money for the investigators to add two additional years of follow-up to the original study. The goal, the organization stated in a released statement, is “to allow for a more definitive statement on reducing dementia risk.”