Dementia may be more likely to develop in individuals who have sustained hypertension in midlife to late life, according to a new study.
An analysis of 4761 participants in the Atherosclerosis Risk in Communities (ARIC) prospective population-based cohort study showed that individuals who had sustained midlife and late-life hypertension had a significant 49% increased risk of subsequent dementia compared with those who remained normotensive, Keenan A. Walker, PhD, of Johns Hopkins Hospital in Baltimore, and colleagues reported in JAMA. Individuals who had a pattern of midlife hypertension and late-life hypotension had a significant 62% increased risk.
In ARIC, investigators examined blood pressure over 24 years at 5 in-person visits. During visits 5 and 6, participants underwent detailed neurocognitive evaluations. The primary outcome was dementia onset after visit 5 based on responses to Ascertain Dementia-8 informant questionnaires, Six-Item Screener telephone assessments, hospital discharge and death certificate codes, and the visit 6 neurocognitive evaluation, the authors noted.
The dementia incidence rate for participants with midlife and late-life normotension was 1.31 per 100 person-years. For participants with midlife normotension and late-life hypertension, the rate was 1.99 per 100 person-years. The rate for those with midlife and late-life hypertension was 2.83 per 100 person-years. The rate for individuals with midlife normotension and late-life hypotension was 2.07 per 100 person-years. The rate for participants with midlife hypertension and late-life hypotension was 4.26 per 100 person-years.
In a separate JAMA paper in the same issue, a team led by R. Nick Bryan, MD, PhD, of the University of Texas at Austin, reported on evidence suggesting that intensive systolic BP (SBP) control is associated with a smaller increase in cerebral white matter lesion volume, a measure of small vessel ischemic disease (SVID) progression, compared with conventional BP targets. The investigators cited previous research suggesting that SVID is associated with cognitive decline and pathogenesis of Alzheimer’s disease and related dementias. In addition, previous research has identified hypertension as a primary risk factor for SVID, particularly development of white matter lesions, they noted.
Dr Bryan and his collaborators conducted a substudy of 449 participants in the Systolic Blood Pressure Intervention Trial (SPRINT), in which investigators randomly assigned hypertensive patients to receive intensive SBP control (to a target of less than 120 mm Hg) or standard SBP control (to a target below than 140 mm Hg). All patients underwent longitudinal brain magnetic resonance imaging. Results showed that the intensive-treatment group experienced a smaller increase in white matter lesion volume than the standard-treatment arm (0.92 vs 1.45 cm3 ).
In an accompanying editorial, Shyam Prabhakaran, MD, MS, of the University of Chicago, commented: “While an opportunity exists for blood pressure modification in the prevention of dementia, earlier, midlife management may be optimal, and later blood pressure–lowering interventions require careful monitoring for the potential cognitive harm associated with late-life hypotension. It is imperative that these nuanced effects of blood pressure on brain health inform future therapeutic approaches to prevent dementia.”
Walker KA, Sharrett AR, Wu A, et al. Association of midlife to late-life blood pressure patterns with incidence dementia. JAMA. 2019;322:535-545. doi:10.1001/jama.2019.10575
The SPRINT MIND investigators for the SPRINT Research Group. Association of intensive vs standard blood pressure control with cerebral white matter lesions. JAMA. 2019;322:524-534. doi:10.1001/jama.2019.10551
Prabhakaran S. Blood pressure, brain volume, and white matter hyperintensities, and dementia risk. JAMA. 2019;322:512-513. doi:10.1001/jama.2019.10849