A Linear Relationship of Ankle-Brachial Systolic Blood Pressure Index for Cognitive Function Decline Among Older Adults Without Peripheral Artery Disease: The Halst Study

Objective: Peripheral artery disease is associated with higher cognitive impairment. However, the association between ankle-brachial index (ABI) and cognitive function decline remains unclear. We aimed to investigate the association of ABI with cognitive function decline among older adults. Design and method: A total of 3662 people aged more than 55 years old (Men: 1702 and Women: 1960) without peripheral artery disease (0.9 < ABI < 1.4) from the Healthy Aging Longitudinal Study in Taiwan was evaluated for cognitive function using MMSE in baseline (2009∼2013) and 2nd wave (2014∼2019). Ankle-brachial index was measured by the ratio of supine ankle and brachial systolic blood pressure. Cognitive function decline was calculated by MMSE at baseline mines MMSE at 2nd wave. Linear regression was used to investigate the associations of baseline ABI with future cognitive function and cognitive function decline. Results: The average of MMSE at baseline, at 2nd wave and the change during the follow-period were 26.9 (standard deviation[s.d.]=3.17), 25.5 (s.d.=4.28) and -1.42 (s.d.=2.94), respectively. Baseline left-ABI (beta = 1.50, p=0.0060) was positively associated with future MMSE, independent of age, gender, education and baseline MMSE, but right-ABI (Beta=0.80, p=0.1517) was not. Furthermore, the MMSE score change (from baseline to 2nd wave) was -0.36 (p=0.0084) for the 1st (Lowest), -0.25 (p=0.00736) for the 2nd, and -0.211 (p=0.1296) for the 3rd Left-ABI, compared to the referent group (highest) of Left-ABI, respectively, in the multivariable model. Conclusions: Baseline higher ankle-brachial index was positively associated with future cognitive performance and with a lower decline rate of cognitive function among older adults.