Arterial stiffness and medial temporal lobe atrophy in elders with memory disorders

Hypertension is a risk factor for cognitive impairment and dementia. Arterial stiffness could be involved in the mechanisms of vascular cognitive impairment and in Alzheimer's disease. We examined the association between arterial stiffness, assessed by carotid-femoral pulse wave velocity (PWV), and medial temporal lobe (MTL) atrophy, a biomarker of Alzheimer's disease.

Elderly community-dwelling study participants (n = 149) with memory complaints were diagnosed with Alzheimer's disease (n = 62) or mild cognitive impairment (n = 87) at a memory clinic. PWV, peripheral and central blood pressure (SBP), and pulse pressure (PP) were measured. MTL was graded on MRI according to the Scheltens' scale.

Mean age was 79.5 (SD = 5) years old, 36% of study participants were men. MTL was absent or discrete in 23.5%, moderate in 53.0% and severe in 23.5% of study participants. PWV was 9.3 (2.2) m/s in none or discrete, 11.1 (2.8) in moderate and 13.5 (4.0) in severe MTL atrophy (P < 0.0001). PWV, central SBP, and central PP were overall associated with MTL atrophy after adjustment for age, sex, antihypertensive treatments and white matter lesions, and further adjusted for mean BP for PWV, whereas peripheral SBP and PP were not associated with MTL atrophy. PWV was significantly associated with severe MTL atrophy [odds ratio = 3.69 (95% confidence interval = 1.69-8.05), P = 0.001] and marginally associated with moderate MTL atrophy [1.80 (0.92-3.53), P = 0.09]. Furthermore PWV was significantly associated with severe MTL atrophy in Alzheimer's disease and mild cognitive impairment study participants separately.

The result of this study suggests a role of arterial stiffness in the pathogenesis of Alzheimer's disease.