Association Between Mild Cognitive Impairment and Seasonal Rest-Activity Patterns of Older Adults.

Christina Reynolds,Miranda M Lim,Jeffrey Kaye,Nora Mattek,Zachary Beattie,Hiroko H Dodge

doi:10.3389/fdgth.2022.809370

Abstract

Seasonal variation in rest-activity patterns has been observed in healthy adult populations. This study examined seasonal variation in total time spent overnight in the bedroom by cognitively intact older adults and older adults with mild cognitive impairment (MCI). We hypothesize that seasonal variation in rest-activity patterns is observed in the cognitively intact group and that this variation is disturbed in those with MCI. Study participants were 128 older adults; mean age 85.2 years. Ninety-eight were cognitively intact, and 30 had been diagnosed with MCI. All were enrolled in an ongoing longitudinal study using in-home passive monitoring technology. Infrared presence sensors were placed throughout each participant's home to monitor movement and presence in each room of the home. Activity data was collected from the sensors over a period of up to 527 days. Overnight time in bedroom was found to vary seasonally for the cognitively intact group, with longer times spent overnight in the bedroom during the winter months. This seasonal variation was not observed for those with non-amnestic MCI. MCI is associated with an attenuation of seasonal variation in total time spent in the bedroom at night. Detection of changes in infradian sleep patterns may be an early marker of cognitive decline. Which key determinants are driving these disturbed rhythms, such as features intrinsic to changes in the brain or to environmental factors or external cues, remains an important question for ongoing and future studies.

Highlights

Normal aging is associated with many changes in sleep patterns such as increasing sleep fragmentation, insomnia, and difficulty falling asleep [1]
Mild cognitive impairment (MCI), a clinical precursor to Alzheimer’s disease is associated with altered sleep patterns, including increased wake after sleep onset and sleep latency [5, 6]. These sleep changes may provide a way of identifying older adults who are experiencing early changes leading to dementia
The cosinor fit for the mild cognitive impairment (MCI) group shows a much weaker relationship between total time in bedroom and day of year compared to the fit for the cognitively intact group

Summary

Introduction

Normal aging is associated with many changes in sleep patterns such as increasing sleep fragmentation, insomnia, and difficulty falling asleep [1]. Sleep quality is closely linked to cognitive function with poor sleep quality affecting cognitive performance even in healthy aging adults [2] This is of further concern because poor sleep quality is associated with a variety of health concerns, ranging from an increase in falls to cognitive changes and depression [3]. Mild cognitive impairment (MCI), a clinical precursor to Alzheimer’s disease is associated with altered sleep patterns, including increased wake after sleep onset and sleep latency [5, 6]. These sleep changes may provide a way of identifying older adults who are experiencing early changes leading to dementia. Monitoring sleep offers a valuable window into the ongoing cognitive status of the older population

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