neurodegeneration

Cardiovascular diseases such as diabetes and hypertension are established risk factors for mild cognitive impairment (MCI) and vascular dementia (VD). Vascular pathology occurs alongside neurodegenerative disease pathology, and both are associated with interactive effects on the clinical presentation of VD¹. Several cardiovascular risk factors of VD could be modified during the preclinical course of the disease during midlife rather than later in life or closer to VD onset^2,3.

In this year at ISC19, Angela L. Jefferson reported results supporting that age-related aortic stiffness contributes to transmission of damaging pulsatility and reduction in blood flow. This contributes to blood brain barrier compromise, resulting in reduced cerebral perfusion and subsequent tissue damage⁴. Brain MRI results suggest that vascular dysregulation may drive neurodegeneration over time, possibly due to neurofibrillary tangle formation or synaptic degradation⁴.

Looking from another angle, Lawrence J. Fine presented on the interplay between CVD and VD in epidemiological studies. According to data from the American Heart Association, loss of a perfect cardiovascular health during midlife is concurrently associated with steep increase in risk of MCI and vascular dementia. A recent report from the Women Health Initiative Memory Study (WHIMS) assessed MCI and Parkinson’s disease (PD) in women with myocardial infarction (MI). The data suggests modest absolute numbers, but higher rates of MCI and Parkinson’s disease (PD) cases in women with myocardial infarction (MI) (adjusted HR for PD or MCI was 2.23, 95% CI 1.51 to 3.30)⁵.

Investigators of the SprintMind trial examined the effect of one or more intensive high blood pressure treatment than is currently recommended. SprintMind was a randomized controlled trial that compared intensive treatment (goal SBP < 120 mm hg) to standard treatment (goal SBP < 140 mm Hg). Patients with major CVD as strokes, diabetes and congestive heart failure were excluded. The results suggest that intensive blood pressure control causes no harm on cognition with actual reduction in MCI risk compared to standard treatment⁶.

Overall, these observations add novel insights on the association between CVD and VD. More data is needed to assess the extent to which CVD contributes to the occurrence of MCI and dementia in more diverse populations and over longer follow-up periods.

REFERENCES

1. Yaffe, Kristine. “Prevention of cognitive impairment with intensive systolic blood pressure control.” Jama (2019).
2. Gottesman, Rebecca F., et al. “Associations between midlife vascular risk factors and 25-year incident dementia in the Atherosclerosis Risk in Communities (ARIC) cohort.” Jama neurology 74.10 (2017): 1246-1254.
3. Gottesman, Rebecca F., et al. “Association between midlife vascular risk factors and estimated brain amyloid deposition.” Jama 317.14 (2017): 1443-1450.
4. Jefferson, Angela L., et al. “Higher Aortic Stiffness Is Related to Lower Cerebral Blood Flow and Preserved Cerebrovascular Reactivity in Older Adults.” Circulation 138.18 (2018): 1951-1962.
5. Haring, Bernhard, et al. “Cardiovascular Disease and Cognitive Decline in Postmenopausal Women: Results from the Women’s Health Initiative Memory Study.” Journal of the American Heart Association 2.6 (2013): e000369.
6. Williamson, Jeff D. “A randomized trial of intensive versus standard systolic blood pressure control and the risk of mild cognitive impairment and dementia: results from SPRINT MIND.” Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association 14.7 (2018): P1665-P1666.