Multiscale motor activity regulation and cognitive performance in middle‐aged adults: A cross‐sectional study using baseline data of UK Biobank Cohort

Abstract

AbstractBackgroundMotor activity fluctuations in healthy young humans display robust temporal correlations across a wide range of time scales. The multiscale correlations are altered in elderly adults, and their changes are associated with cognitive decline and risk for Alzheimer’s disease. We sought to examine whether the multiscale regulation is associated with cognitive performance in middle age using a population‐based cohort.MethodWe analyzed motor activity recordings that were collected from 97,284 non‐demented participants [aged 39‐70 (mean±SD: 56.1±7.8) years old; female: 54,776 (56.3%)] in the UK Biobank. The detrended fluctuation analysis was performed to quantify temporal correlations at time scales ≤90 min (α1) and ≥2 h (α2; up to 10 h) according to previous studies. Participants also completed four neurocognitive tests, and poorer cognitive performance was characterized by longer reaction time (RT; for information processing speed), more errors made in the pairs matching test (for visual episodic memory), lower fluid intelligence (FI) score (for reasoning), or making incorrect first choice during the prospective memory (PM) test. Linear regression models (or logistic regression for PM) were used to examine the associations of each cognitive outcome with α1 and, separately α2, adjusted for ethnicity, college, social‐economic status, mental and behavioral disorders, diseases of the nervous system, and number of treatments/medications. The 95% confidence intervals (CI) were derived non‐parametrically based on 1,000 bootstrapped samples with replacement.ResultBoth α1 and α2 showed normal distributions: α1=0.99±0.05 (SD) and α2=0.91±0.11. There was a positive association between α1 and FI with 1‐SD decrease of α1 corresponding to a decrease of 0.03 in FI (95% CI 0.01—0.05) that was about the effect of being 2 years older. α2 was negatively associated with RT and positively associated with FI; for 1‐SD decrease in α2, participants took ln(1 ms) longer during RT, and FI decreased by 0.04 (95% CI 0.02—0.06), both equivalent to being ∼2.5‐3 years older.ConclusionMultiscale motor activity regulation is linked to cognitive performance of specific domains in the middle‐aged population. Further studies are required to establish the relevance of these domain‐specific associations to incident dementia in later life and to understand their underlying neurobiology.