The Link Between Cardiovascular Health and Brain Function – Commentary from Thomas Dayspring, MD, FACP, FNLA

The CDC recently released sobering statistics regarding cognitive impairment showing that the burden of Alzheimer’s Disease and Related Dementia (ADRD) in 2014 was an estimated 5 million adults aged ≥65 years or 1.6% of the population. ADRD burden will double to 3.3% by 2060 when 13.9 million Americans are projected to have the disease1.

The societal burden of financial costs and emotional suffering are intimidating to comprehend and may ultimately affect all citizens in one way or another. Once symptoms of the disease occurs, the availability of current treatments is extremely limited. Many studies have related midlife cardiovascular risk factors with cognitive impairment and ADRD2. Two new studies and an accompanying editorial in the August 21st issue of JAMA provides some insight on how to improve the outlook.

The first study followed >6600 adults, ~ 73 years old, over an average of 8.5 (some up to 16) years, and correlated the absence or presence of modifiable risk metrics to psychological evaluation for cognitive function and dementia. A total cardiovascular (CV) health score was formulated at baseline using readily available measures: BMI, smoking, physical activity, fish intake twice a week, fruits/vegetables three times daily, cholesterol intake < 200 mg/day, fasting glucose < 100 mg/dL, and BP < 120/80 mm Hg.

The study used Global Cognition Scores to follow brain health over time; results demonstrated that more optimal CV scores were unambiguously associated with lower risk for developing cognitive decline and dementia, even when controlling for education level and those who carried the apoE4 gene. Trajectories of global cognition and memory related to an increase in the number of optimal CV metrics, and the presence of even a single additional optimal measure was beneficially impactful3. Although the data is observational, a reasonable if not obvious conclusion is that promotion of cardiovascular health would lessen the nightmare of cognitive decline that too frequently afflicts the elderly.

The second study evaluated 125 younger healthy persons, aged 18-40, by correlating a CV risk score derived from: BMI, CV fitness, alcohol use, smoking, blood pressure, diastolic response to exercise, cholesterol, and glucose, to the presence of MRI indices of cerebral vessel density, caliber, tortuosity, and brain white matter hyperintensity. The analysis made it clear that compromise of brain function begins earlier than previously appreciated and better CV risk scores are associated with increased cerebral vessel density and caliber, higher cerebral blood flow, and fewer white matter intensities4.

The recent editorial by Saver and Cushman nicely wraps up the studies and the epidemiology and makes the case that reducing the incidence of age-specific dementia will likely be facilitated by continued advocacy for strong preventive measures which lessen and improve CV-risk metrics5. The lipidology community has recognized chronic diseases like atherosclerosis related to early and persistent exposure of the vasculature to metabolic pathologies including lipoproteins, inflammation, insulin resistance, hypertension, smoking, etc., all of which, once recognized, are immediately amenable to adherence of healthy lifestyles and other therapeutics.

Thomas Dayspring, MD, FACP, FNLA, is True Health’s Chief Academic Officer and an expert on cardiovascular health. He has authored or co-authored numerous manuscripts published across leading journals such as the American Journal of Cardiology and the Journal of Clinical Lipidology.

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References

[1] Matthews KA, Xub W, Gagliotic AH et al. Racial and ethnic estimates of Alzheimer’s disease and related dementias in the United States (2015–2060) in adults aged > 65 years. Alzheimer’s & Dementia 2018;1-8.

[2]Langa KM. Is the risk of Alzheimer’s disease and dementia declining? Alzheimer’s Research & Therapy 2015;7:34

[3]Samieri C, Perier MC, Gaye B, et al. Association of cardiovascular health level in older age with cognitive decline and incident dementia. JAMA 2018;320(7):657-664.

[4]Williamson W, Lewandowski AJ, Forkert ND, et al Association of cardiovascular risk factors with MRI indices of cerebrovascular structure and function and white matter hyperintensities in young adults. JAMA 2018;320(7):665-673

[5]Saver JL, Cushmam M. Striving for ideal cardiovascular and brain health. JAMA 2018;320(7):645-647