Intensive BP lowering may help delay mental decline
Intensive systolic blood pressure (SBP) lowering to <120 mm Hg significantly reduced the risk of mental decline that can lead to Alzheimer’s disease, reveals the SPRINT* MIND study presented at the Alzheimer's Association International Conference (AAIC) 2018.
Compared with participants who received standard BP lowering to a target of <140 mm Hg, those who were aggressively treated to <120 mm Hg had a 19 percent significantly lower risk of incident mild cognitive impairment (MCI) after a median 3.26 years of follow-up (hazard ratio [HR], 0.81; p=0.01). [AAIC 2018, abstract 27525]
Similarly, the composite outcome of MCI plus probable dementia was significantly reduced by 15 percent with intensive treatment vs standard treatment (HR, 0.85; p=0.02).
There was also a trend towards reduction in the risk of probable dementia in the intensive treatment arm (HR, 0.83; p=0.10), although the difference was not significantly different between groups.
“This study shows more conclusively than ever before that there are things you can do — especially regarding cardiovascular disease risk factors — to reduce your risk of MCI and dementia,” said Dr Maria Carrillo, Alzheimer’s Association Chief Science Officer.
In the study, 9,361 SPRINT participants were randomized to intensive BP control (to an SBP target of <120 mm Hg) or standard BP lowering (to a target of <140 mm Hg). Study subjects were older adults with hypertension and elevated cardiovascular risk but without diabetes. Ninety-two percent of the participants (mean age 67.9 years, 35.6 percent women) completed ≥1 cognitive assessment during follow-up and were included in the analysis.
This is the first randomized controlled trial to demonstrate the reduction of MCI risk through BP lowering, according to lead author Professor Jeff Williamson of Wake Forest School of Medicine in Winston-Salem, North Carolina, US.
The findings were further supported by another related subgroup analysis of 673 participants in SPRINT MIND who underwent MRI at a median of 3.98 years after randomization. [AAIC 2018, abstract 27526]
Volume of white matter lesion (WML), which has been associated with an increased risk of vascular dementia and presents a potential risk factor for Alzheimer’s disease, increased in both the intensive treatment and the standard treatment groups, but the increase was significantly less with intensive treatment (0.28 cm3 vs 0.92 cm3; p=0.004).
Meanwhile, no significant difference between groups was observed in total brain volume (-27.3 cm3 vs -24.8 cm3; p=0.16).
“These results support the need to maintain well-controlled BP, especially for persons over the age of 50,” said Williamson. “This is something doctors and the majority of their community-dwelling patients with elevated BP should be doing now to keep their hearts — and brains — healthier. These new results for maintaining cognitive health provide another strong rationale for starting and maintaining healthy lifestyle changes in midlife.”
“The future of reducing MCI and dementia could be in treating the whole person with a combination of drugs and modifiable risk factor interventions — as we do now in heart disease,” Carrillo suggested.