Yoneda, in progress. Blood Pressure Variability and Cognitive Functioning: A Systematic Review and Meta-Analysis

Status: 
in progress
Abstract: 

Introduction: Several studies indicate that blood pressure variability (BPV) is negatively related to cognitive functioning at the interindividual level, as well as cognitive decline at the intraindividual level. However, a small number of studies report a positive relationship between BPV and cognitive functioning in individuals at high risk of cardiovascular disease. Study features in this field vary considerably, including differences in the health of the participants that are targeted, the number of assessments that are included to calculate variability, the timing between assessments, the way in which variability is calculated, the position of participants during measurement, and the assessment of cognition. The objective of this project is to critically analyze the outcome of research reporting the association between blood pressure variability and cognitive functioning or cognitive status in order to understand which (if any) study characteristics may be contributing to inconsistencies in the field. Data Sources: PsycInfo and Web of Science without language restrictions, including papers published in any year, as well as forward and backward searches of reference lists of included articles and relevant reviews for additional reports.

Methods: Study justification, search strategy, and methodological approach for this research synthesis are documented and pre-registered through the Open Science Framework (OSF), which is publically available for readers (https://osf.io/vmnuq/). PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses; Moher et al., 2009) was used to create the protocol for this systematic review and meta-analysis. Multi-level meta-analysis with random effects and maximum likelihood variance estimation will be applied to examine the cumulative evidence for the association between BPV and cognitive functioning.

Results: In Progress

Discussion: In Progress

Thorvaldsson et al., 2012. Nonlinear blood pressure effects on cognition in old age: Separating between-person and within-person associations

Thorvaldsson, V., Skoog, I., Hofer, S. M., Börjesson-Hanson, A., Östling, S., Sacuiu, S., & Johansson, B. (2012). Non-linear blood pressure effects on cognition in old age: Separating between-person and within-person associations. Psychology & Aging, 27, 375-383.

Year: 
2012
Status: 
complete
Abstract: 

Midlife hypertension is associated with increased risk of cognitive impairment in later life. The association between blood pressure (BP) in older ages and cognition is less clear. In this study we provide estimates of between-person and within-person associations of BP and cognition in a population-based sample (N = 382) followed from age 70 across 12 occasions over 30 years. Between-person associations refer to how individual differences in BP relates to individual differences in cognition. Within-person associations refer to how individual and time specific changes in BP relate to variation in cognition. Hierarchical linear models were fitted to data from three cognitive measurements (verbal ability, spatial ability, and perceptual speed) while accounting for demographic and health-related covariates. We found consistent nonlinear between-person associations between diastolic BP (DBP) and cognition, such that both low (<75 mmHg) and high (>95 mmHg) pressure were associated with poorer cognition. Within-person decreases in systolic BP (SBP) and DBP were associated with decreases in perceptual speed. Notably, between-person and within-person estimates did not reveal similar associations, suggesting the need to separate the two effects in the analysis of associations between BP and cognition in old age.

Der et al., 2010. Age-related changes in memory and fluid reasoning in a sample of healthy old people.

Der, G., Allerhand, M., Starr, J. M., Hofer, S. M., Deary, I. J. (2010). Age-related changes in memory and fluid reasoning in a sample of healthy old people. Aging, Neuropsychology, & Cognition, 17(1), 55-70.

Year: 
2010
Status: 
complete
Abstract: 

Participants in the Healthy Old People in Edinburgh (HOPE) study (N = 398) were assessed on Raven's Progressive Matrices and Logical Memory on up to three occasions. Covariates included education, social class, disease and medication status, blood pressure and study outcome. Raven's score declined linearly with age, whereas decline in Logical Memory was accelerating. There was significant variation in individuals' rates of decline for Ravens but not Logical Memory. Slope–intercept covariances were not significant. Those who later developed dementia already exhibited lower scores, more so for Logical Memory than Raven's. Death and study attrition were related to performance, again greater for Logical Memory. Conclusions: The HOPE approach of progressive screening is a feasible and practical method for studying healthy cognitive ageing. As predicted for an initially healthy sample, rates of decline were relatively homogeneous. The hypothesis of differential decline was not supported, nor was a strict interpretation of the hypothesis that cognitive ageing is entirely pathology driven.