Brain health correlates of mobility-related confidence

Abstract

Background: Mobility is important for independence in older age. While brain health correlates of objectively measured mobility-related features like gait and balance have been reported, we aimed to test neuroimaging and cognitive correlates of subjective measures of mobility-related confidence.

Methods: We carried out a cross-sectional observational study comprised of N = 29 cognitively unimpaired older adult participants, mean age 75.8 ± 5.8, 52% female, 24% non-white. We measured cognition, hippocampal volume, white matter hyperintensities, cerebral amyloid-β (Aβ), and gait and balance confidence. We tested associations using unadjusted Spearman correlations and correlations partialling out covariates of interest one at a time.

Results: Greater gait confidence was associated with better attention (unadjusted ρ = 0.37, p = 0.05; partially attenuated by adjustment for age, APOE4, anxiety, motivation, gait speed, or Aβ); executive performance (unadjusted ρ = 0.35, p = 0.06; partially attenuated by adjustment for age, APOE4, gait speed, or Aβ); and lower Aβ levels (unadjusted ρ = -0.40, p = 0.04; partially attenuated by adjustment for age, depressive symptoms, motivation, or gait speed). Greater balance confidence was associated with better global cognition (unadjusted ρ = 0.41, p = 0.03; partially attenuated by adjustment for APOE4, gait speed, or Aβ); attention (unadjusted ρ = 0.46, p = 0.01; robust to adjustment); and lower Aβ levels (unadjusted ρ = -0.35, p = 0.07; partially attenuated by adjustment for age, education, APOE4, depressive symptoms, anxiety, motivation, or gait speed).

Conclusions: Self-reported mobility-related confidence is associated with neuroimaging and cognitive measures and would be easy for providers to use in clinical evaluations. These associations should be further evaluated in larger samples, and longitudinal studies can help determine temporality of declines.

Keywords: Amyloid-β; Cognition; Hippocampal volume; Mobility; White matter hyperintensities.

Figure 1.. Scatterplots of mobility-related confidence measures by cognition for significant correlations.

Correlation of balance confidence with global cognition (top left) and attention (top right) and of gait confidence with attention (bottom left) and executive function (bottom right). Note: Regression lines are to aid visualization only. For Spearman correlation coefficients, refer to text and Table 4.

Figure 2.. Scatterplots of mobility-related confidence measures by PiB SUVR.

Correlation of gait confidence with amyloid-β burden in all participants (top left) and those who are PiB negative (top right) and of balance confidence with amyloid-β burden in all participants (bottom left) and those who are PiB negative (bottom right). Note: Regression lines are to aid visualization only. For Spearman correlation coefficients, refer to text and Table 4. SUVR=standardized uptake value ratio.