Optimal measures of cardiovascular health are associated with brain health in adults, according to two studies published in the August 21 issue of JAMA.
In a French population-based cohort study, adults ages 65 and older with more cardiovascular health measures at ideal levels had a lower risk of dementia and lower rates of cognitive decline than did those with fewer optimal cardiovascular measures, such as blood pressure and physical activity.
In addition, a preliminary, cross-sectional study of younger adults found that the number of modifiable cardiovascular risk factors at recommended levels was associated with brain vessel structure and function and the number of white matter hyperintensities.
“These two studies convey an immediately actionable message to clinicians, policy makers, and patients,” said Jeffrey L. Saver, MD, and Mary Cushman, MD, in an accompanying editorial. “Available evidence indicates that to achieve a lifetime of robust brain health free of dementia, it is never too early or too late to strive for attainment of ideal cardiovascular health.” Dr. Saver is a Professor of Neurology and Director of the Stroke Center at the University of California, Los Angeles. Dr. Cushman is a Professor of Medicine and Pathology at Larner College of Medicine at the University of Vermont in Burlington.
Cardiovascular Health in Older Age
Vascular dementia is the second most common neuropathologic basis of dementia, after Alzheimer’s disease, and “most cases of dementia arise from a combination of [Alzheimer’s disease] and cerebrovascular pathology,” the editorialists noted. Studies have suggested a connection between cardiovascular health and dementia, but the evidence is limited.
Cécilia Samieri, PhD, a Senior Researcher at the Bordeaux Population Health Research Center at the Université de Bordeaux in France, and colleagues studied people age 65 and older from Bordeaux, Dijon, and Montpellier, France, to examine the association between cardiovascular health level and risk of dementia and cognitive decline in older adults.
The study included 6,626 people without a history of cardiovascular disease or dementia at baseline. Participants underwent in-person neuropsychologic testing between January 1999 and July 2016 and systematic detection of incident dementia. Participants had a mean age of 73.7, and 63.4% were women.
The investigators defined cardiovascular health using a seven-item tool from the American Heart Association (AHA). They determined the number of the AHA’s Life’s Simple Seven metrics that were at recommended levels (ie, nonsmoking, BMI < 25, regular physical activity, eating fish at least twice per week and fruits and vegetables at least three times per day, cholesterol < 200 mg/dL [untreated], fasting glucose < 100 mg/dL [untreated], and blood pressure < 120/80 mm Hg [untreated]).
Approximately 36.5% of the cohort had zero, one, or two optimal health metrics, 57.1% had three or four optimal health metrics, and 6.5% had five, six, or seven optimal health metrics.
During an average follow-up of 8.5 years, 745 participants developed dementia. Among participants with zero or one health metrics at optimal levels at baseline, the incidence rate of dementia was 1.76 per 100 person-years. Compared with this rate, the incidence rate per 100 person-years was 0.26 lower for participants with two optimal health metrics, 0.59 lower for participants with three optimal health metrics, 0.43 lower for participants with four optimal health metrics, 0.93 lower for participants with five optimal health metrics, and 0.96 lower for participants with six or seven optimal health metrics.
“In multivariable models, the hazard ratios for dementia were 0.90 per additional optimal metric,” the investigators said. “The study results support the recent recommendations of the AHA and the American Stroke Association for the promotion of the Life’s Simple Seven tool.”