The closer that older adults come to meeting the American Heart Association’s “ideal” targets for seven factors that determine cardiovascular health, the lower their risk for cognitive decline, according to a report published online March 16 in Journal of the American Heart Association.
A secondary analysis of data from a prospective population-based cohort study of stroke risk demonstrated that better alignment with the AHA’s “Life’s Simple 7” cardiovascular health metrics correlated with less decline in mental processing speed, and, to a lesser extent, in executive function and episodic memory. “The results of this study suggest that achievement of the AHA’s ideal cardiovascular health metrics may have benefits for brain health, in addition to preventing strokes and myocardial infarctions ... underscoring the importance of public health initiatives aimed to better control these seven factors,” said Hannah Gardener, Sc.D., of the department of neurology, University of Miami, and her associates.
Hannah Gardener, Sc.D.
The AHA recently defined ideal target levels for seven modifiable cardiovascular (CV) risk factors: smoking status, body mass index, physical activity level, diet, blood pressure, total cholesterol level, and fasting glucose level. Meeting or closely approaching these ideals has already been linked to a decreased risk of stroke and MI. To examine a possible association with brain health, Dr. Gardener and her colleagues assessed these seven metrics in an ethnically diverse cohort of 722 participants aged 50 years and older in the Northern Manhattan Study who underwent serial comprehensive neuropsychological testing including brain MRI.
Of the total cohort, 3% had zero ideal factors, 15% had one factor, 33% had two factors, 30% had three factors, 14% had four factors, 14% had five factors, 1% had six factors, and none had all seven factors.
“An increasing number of ideal cardiovascular health factors was positively associated with processing speed,” and the association was particularly strong for three of the factors: ideal body mass index, lack of smoking, and ideal fasting glucose level. This association persisted when the data were adjusted to account for MRI markers of subclinical vascular damage, such as abnormalities in white matter volume, brain atrophy, and previous infarctions. A similar but less strong association was seen between an increasing number of ideal cardiovascular health factors and performance on measures of episodic memory and executive function.
These seven CV factors also were associated with less decline over time in these three areas of cognitive function. In contrast, the CV factors showed no association with measures of semantic memory, the investigators said (J Am Heart Assoc. 2016 Mar 16).
The associations remained unchanged in sensitivity analyses that controlled for the presence and severity of depression.
“The results of our study add to a growing body of literature suggesting the effects of smoking and blood glucose levels on cognitive health in particular,” and support the role of vascular damage and metabolic processes in the etiology of cognitive aging and dementia, they added.