Aortic elastic properties and cognitive function in elderly individuals: the Ikaria Study

Abstract

Background: The aim of this work was to evaluate the association between aortic elastic properties and cognitive function in elderly individuals, permanent inhabitants of Ikaria Island.

Methods: In 535 individuals (75 ± 6 years, 53% males) aortic distensibility (AoD) was non-invasively calculated from the aortic diameters measured with echocardiography and brachial artery pressure using the formula by Stefanadis et al.; cognitive status was evaluated using the Mini Mental State Examination (MMSE).

Results: 88% of the elders had normal values of MMSE score (i.e., ≥ 24). Elders who achieved MMSE score ≥ 24 had higher values of AoD (1.90 ± 2.06 vs. 1.08 ± 1.42, p < 0.001), as well as were more physically active (85% vs. 69%, p = 0.05), had higher educational status (8.5 ± 2.8 years vs. 6 ± 2 years, p = 0.001), higher creatinine clearance levels (70 ± 21 vs. 63 ± 23, p = 0.05) and lower pulse pressure (PP) values (63 ± 16 vs. 68 ± 18, p = 0.06), as compared with those individuals with MMSE < 24. Logistic regression analysis showed that for every unit increase in AoD there was a 25% higher likelihood of having MMSE ≥ 24 (OR per 1000 × mmHg(-1) = 1.25, 95%CI 0.99-1.58), after adjustments for age, gender, current smoking, cardiovascular disease, creatinine clearance, hypertension, diabetes mellitus, obesity, physical activity status and education status. Furthermore having PP levels in the upper tertile (> 70 mmHg), increases by 55% the likelihood of having MMSE < 24 (OR for above 70 mmHg = 0.45, 95%CI 0.22, 0.92), after the same adjustments were made.

Conclusion: Arterial aging seems to affect cognitive function; a finding that states a novel research hypothesis about the pathophysiological mechanisms of mental functioning.

Keywords: Aortic stiffness; Cognitive function; Elderly.