A population-based prospective study on rest-activity rhythm and mild cognitive impairment among Hong Kong healthy community-dwelling older adults

Abstract

Background Relatively few studies investigated the association between rest-activity circadian rhythm and cognitive impairment in population-based study, and the evidence from Asian populations is sparse. We aimed to examine the relationship of actigraphy measured rest-activity circadian rhythm with mild cognitive impairment (MCI) or cognitive impairment in Hong Kong healthy community-dwelling older adults. Methods We recruited 174 Hong Kong healthy adults aged ≥65 years (36 male vs. 138 female) during April–September 2018, and followed up them for 12 months. Participants were invited to wear wrist actigraphy for 7 days in both baseline and follow-up study. We used the actigraph data to calculate their midline statistic of rhythm (MESOR), amplitude, acrophase and percent rhythm. Montreal Cognitive Assessment (MoCA) was used to assess their cognitive scores at baseline and follow-up. Multivariate logistic regression model was performed to estimate the association of rest-activity circadian rhythm parameters with MCI; whilst multinomial logistic regression model was used to examine the association between rhythm parameters and changes of cognitive scores (i.e., worsen: <-1, stable: -1 to 1, better cognition: ≥2) after 12-months follow-up respectively. Results There was no association between rest-activity circadian rhythm parameters and MCI or cognitive impairment at baseline. Compared to those with an averaged value of acrophase (1:24pm-3:00pm), results of multinominal logistic regression showed that participants with a delayed acrophase (after 3:00pm) were less likely to have better cognition (adjusted odds ratio (AOR) = 0.32, 95% confidence interval (CI) = 0.11–0.88). Upon one year of follow-up, participants who delayed their acrophase for 24 min than their baseline measurements were also less likely to have better cognitive functions (AOR = 0.26, 95%CI = 0.08–0.79). Conclusions Results from both the baseline survey and follow-up study consistently confirmed that older adults, especially in light of the majority of participants being the females, with delayed acrophase were less likely to have better cognition in the Asian population.

Circadian Rhythm Changes in Healthy Aging and Mild Cognitive Impairment

“…with patients with MCI. [58] Several recent studies have also confirmed that advanced acrophase (representing the rest-activity phase and timing of peak activity) and increased activity fragmentation, as reflected by increased intra-daily variability, are the most consistent alterations in MCI relative to age-matched healthy comparison groups. [23,35,59]…”

“…[ 56 ] Patients with MCI have also greater nighttime activity and less activity in the morning compared to aged matched controls (Figure 1b); [ 57 ] although, one study found no differences in circadian phase or rest‐activity patterns in cognitively intact older adults compared with patients with MCI. [ 58 ] Several recent studies have also confirmed that advanced acrophase (representing the rest‐activity phase and timing of peak activity) and increased activity fragmentation, as reflected by increased intra‐daily variability, are the most consistent alterations in MCI relative to age‐matched healthy comparison groups. [ 23,35,59 ]…”

“…[57] Another study suggested that very subtle changes in circadian rhythm are detected in older adults (e.g., amplitude change, mean activity level around which the rhythm oscillates (MESOR), or percentage of variance in activity explained by the 24 h cosine wave) that are related to pre-clinical changes in cognitive performance, [141] while a prospective study confirmed significant changes between delayed acrophase were associated with worse cognition in Hong Kong healthy community-dwelling older adults. [58] Furthermore, a couple of recent studies showed that the reduced amplitude and overall rhythmicity of RAR were associated with adverse cognitive outcomes and that individuals with RAR alterations exhibited a faster cognitive decline during follow-up assessments compared with subjects with intact RAR. [34,142]…”

Associations of circadian rest/activity rhythms with cognition in middle-aged and older adults: Demographic and genetic interactions

“… Oosterman et al (2009) and Yang et al (2022) also found that weaker CRARs (i.e., lower amplitude and relative amplitude) were associated with poorer performance on tests of memory, executive function, auditory attention, and global cognition. Yi Lee et al (2021) , however, found no association of rhythm strength metrics (i.e., mesor, amplitude) or circadian timing (i.e., acrophase) with dementia or MCI status at baseline. Longitudinal studies examining CRARs with subsequent change in cognitive performance have found that metrics indicative of lower rhythm strength (i.e., mesor, amplitude) and delayed rhythm timing (i.e., later acrophase) were associated with greater declines in global cognition and executive function ( Walsh et al, 2014 ; Rogers-Soeder et al, 2018 ; Yi Lee et al, 2021 ; Xiao et al, 2022a , b ), and increased risk for MCI and dementia ( Xiao et al, 2022b ).…”

“… Yi Lee et al (2021) , however, found no association of rhythm strength metrics (i.e., mesor, amplitude) or circadian timing (i.e., acrophase) with dementia or MCI status at baseline. Longitudinal studies examining CRARs with subsequent change in cognitive performance have found that metrics indicative of lower rhythm strength (i.e., mesor, amplitude) and delayed rhythm timing (i.e., later acrophase) were associated with greater declines in global cognition and executive function ( Walsh et al, 2014 ; Rogers-Soeder et al, 2018 ; Yi Lee et al, 2021 ; Xiao et al, 2022a , b ), and increased risk for MCI and dementia ( Xiao et al, 2022b ). Other work has shown that greater IV at baseline and greater increases in IV were associated with greater declines in global cognition, and that lower RA and IS, and higher IV at baseline was associated with greater risk for developing incident cognitive impairments among older adult men ( Xiao et al, 2022a ).…”