A decade of aging in healthy older adults: longitudinal findings on cerebrovascular and cognitive health

Abstract

Research suggests an association between cerebrovascular health and cognitive decline, but previous work is limited by its cross-sectional nature or short (< 1-2 years) follow-up. Our aim was to examine, across 10 years of follow-up in healthy older adults, changes in cerebrovascular health and their relationship with subjective memory complaints as an early marker of cognitive decline. Between 2008 and 2010, twenty-eight healthy older adults (69 ± 4 years) underwent baseline blood pressure and transcranial Doppler measurements to assess middle cerebral artery blood velocity (MCAv), cerebrovascular resistance index (CVRi), and measures of cerebral autoregulation (CA). After 9-12 years of follow-up, these measurements were repeated, and presence of memory complaints was evaluated. Linear mixed-model analyses explored effects of aging on cerebrovascular parameters and whether memory complaints were associated with cerebrovascular changes. Across a median follow-up of 10.9 years, no changes in MCAv, CVRi, or CA were found. At baseline, these parameters were not different between subjects with (n = 15) versus without (n = 13) memory complaints. During follow-up, subjects with memory complaints showed larger decreases in MCAv (- 10% versus + 9%, P = 0.041) and increases in CVRi (+ 26% versus - 9%, P = 0.029) compared to other peers without memory complaints, but no distinct changes in CA parameters (P > 0.05). Although a decade of aging does not lead to deterioration in cerebral blood flow or autoregulation, our findings suggest that reductions in cerebral blood flow and increases in cerebrovascular resistance are associated with early subjective cognitive decline.

Keywords: Aged; Brain blood flow; Cognition; Dementia; Longevity; Longitudinal studies.

Fig. 1

CONSORT-style flowchart diagram. Flowchart diagram showing the flow of participants from the original study population at baseline to inclusion in the present follow-up study, together with numbers of successful assessments for each type of measurement at both baseline and follow-up. Abbreviations: 30CST 30-s chair stand test, BRP Dutch Personal Records Database, HG maximal handgrip strength, LAPAQ Longitudinal Ageing study Amsterdam Physical Activity Questionnaire, MMSE Mini-Mental State Examination, MoCA Montreal Cognitive Assessment, TCD transcranial Doppler, TOPICS-SF The Older Persons and Informal Caregivers Survey - Short Form, TUG Timed Up & Go. Adobe Illustrator (2021) was used to create Fig. 1

Fig. 2

Longitudinal changes in cerebrovascular parameters in participants with and without subjective memory complaints. Graphs show estimated marginal means with 95% CI for MAP, MCAv, and CVRi at baseline (black circles) and after follow-up (black triangles) in participants with and without subjective memory complaints. Small gray data points show individual values available at each timepoint, with connecting lines indicating changes within participants. P values represent significance levels for the time-by-memory complaints interaction effect derived from the linear mixed-model analyses. Abbreviations: CVRi cerebrovascular resistance index, MAP mean arterial pressure, MCAv mean bilateral middle cerebral artery blood velocity. GraphPad Prism (version 9.3.1) was used to create Fig. 2