Intensive control of blood pressure in older people strongly reduced the risk of developing mild cognitive impairment (MCI), a precursor of early dementia, according to a new study.
The clinical study was led by scientists at Wake Forest School of Medicine, part of Wake Forest Baptist Health.
However, the National Institutes of Health-supported SPRINT MIND study did not prove that treating blood pressure to a goal of 120 mm Hg or less statistically reduced the risk of dementia.
This result may have been due to too few new cases of dementia occurring in the study, the authors noted.
MCI is defined as a decline in memory and thinking skills that is greater than expected with normal aging and is a risk factor for dementia.
Dementia is defined as a group of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person’s ability to perform everyday activities.
The objective of SPRINT MIND was to evaluate the effect of intensive blood pressure control on risk of dementia.
Hypertension, which affects more than half of people over age 50 and more than 75 percent of those older than 65, has been identified as a potentially modifiable risk factor for MCI and dementia in previous observational studies.
The clinical trial, which enrolled 9361 volunteers, was conducted at 102 sites in the United States and Puerto Rico among adults 50 and older with hypertension but without diabetes or history of stroke.
The participating group was 35.6 percent female, 30 percent black and 10.5 percent Hispanic and thus representative of the broader U.S. population.
Participants were randomly assigned to a systolic blood pressure goal of either less than 120 mm HG (intensive treatment) or less than 140 mm HG (standard treatment).
They were then classified after five years as having no cognitive impairment, MCI or probable dementia.
The study showed a 15 percent reduction in dementia in the intensively controlled group, but the results did not achieve statistical significance for this outcome.
SPRINT was stopped early due to the success of the trial in reducing cardiovascular disease.
As a result, participants were on intensive blood pressure lowering treatment for a shorter period than originally planned.
The authors concluded that the shorter time may have made it difficult to accurately determine the role of intensive blood pressure control on dementia cases.
The team said MCI was not the primary cognitive focus of the trial and because it is not clear what intensive blood pressure control may mean for the longer-term incidence of dementia.
Although MCI considerably increases the risk of dementia, this progression is not inevitable and reversion to normal cognition is possible.
The study’s principal investigator is Jeff Williamson at Wake Forest School of Medicine.
The study is published in the Journal of the American Medical Association.
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Source: Journal of the American Medical Association.
