<p>Fragmentation of Rest/Activity Patterns in Community-Based Elderly Individuals Predicts Incident Heart Failure</p>

Abstract

Study Objectives: Heart failure has previously been linked to sleep disorders that are often associated with frequent disturbances to human rest/activity patterns. We tested whether fragmentation of sustained rest/activity patterns derived from actigraphic recordings at baseline predicts incident heart failure in community-based elderly individuals. Methods: We studied 1099 community-based elderly adults participating in the Rush Memory and Aging Project who had baseline motor activity monitoring up to 11 days and were followed annually for up to 14 years. Fragmentation was assessed using previously validated indexes, derived from the probability of transitions once sustained rest or activity has been established. Heart failure was recorded via a clinical interview during the annual follow-up. Cox proportional hazards models were constructed to examine the relationship between rest fragmentation index and incident heart failure. Covariates grouped in terms of demographics, lifestyle factors and co-morbidities and cardiovascular risk factors/diseases were included. Results: Increased rest fragmentation (but not activity fragmentation) was associated with higher risk for incident heart failure. Specifically, a subject with a rest fragmentation at the 90th percentile showed a 57% increased risk of developing incident heart failure compared to a subject at the 10th percentile in this cohort. This effect was equivalent to that of being over a decade older. These observations were consistent after adjusting for all covariates. Conclusion: Increased rest fragmentation, a potential surrogate for sleep fragmentation, is independently associated with a higher risk of developing heart failure in community-based elderly adults during up to 14 years of follow-up. Further work is required to examine the specific contributions from daytime napping versus nighttime sleep periods in the elderly, as well as the underlying autonomic and cardio-dynamic pathways that may explain the effects on heart function.

Daytime napping and Alzheimer's dementia: A potential bidirectional relationship

“…We grouped covariates in terms of (1) demographics (age, sex, and education), (2) nighttime sleep and circadian daily activity rhythm (total nighttime sleep duration, sleep fragmentation, 24 wake after sleep onset [WASO], interdaily stability, and intradaily variability), 25 (3) comorbidities and medications (depression, thyroid disease, vascular diseases, vascular disease risk factors, and medications that may affect sleep [anxiety and insomnia treatments, analgesics, anticonvulsants, or beta blockers]), and (4) apolipoprotein E ( APOE ) ε4 allele (carriers or not). Detailed methods for assessing each covariate were summarized in supporting information Methods.…”

Fractal motor activity regulation and sex differences in preclinical Alzheimer's disease pathology

“…Motor activity was continuously monitored for 14 days using an actigraph monitor (Actiwatch2; Phillips-Respironics) worn on the non-(B) 15,25,26 and quality issues such as (1) isolated spikes with amplitude beyond 10 SD away from the individual global mean levels; and (2) sequences of zeros with duration > 60 minutes during the daytime (likely representing off-wrist periods) were identified and marked as gaps. 27,28 Finally, each recording was manually inspected to confirm quality control prior to FMAR assessment.…”

Circadian Rest–Activity Rhythms, Delirium Risk, and Progression to Dementia

“…An accepted hallmark of healthy physiology and resistance to stressors is a robust circadian system 27 . For example, circadian dysregulation has been associated with cardiometabolic disease 26,28 and brain disorders 3 . Thus, both RAR disturbances and delirium are suspected to be indicators of physiological frailty, as well as possible precipitating and accelerating factors in cognitive and physical decline 29–31 …”