Rest-Activity Rhythm Fragmentation and Weaker Circadian Strength Are Associated With Cognitive Impairment in Survivors of Acute Respiratory Failure

Sleep and Circadian-Related Outcomes after Critical Illness

Sleep and circadian disruptions are frequently reported in studies of critically ill patients. Less is known about sleep and circadian disruptions after an intensive care unit (ICU) admission. It is recognized now that survivors of critical illness may develop what is termed post-intensive care syndrome (PICS) which is a constellation of symptoms of which two of the most prominent features are fatigue and sleep complaints. Clinicians and researchers are now recognizing the importance of examining symptoms in survivors which impact their quality of life. Although current data are limited this review addresses what is now known about sleep and circadian disruptions post-ICU. Current ongoing research and future studies should continue to inform our understanding of how critical illness and the ICU environment both influence long-term outcomes in critically ill patients.

Association between Acute Respiratory Distress Syndrome Due to COVID-19 and Long-Term Sleep and Circadian Sleep-Wake Disorders

Current studies agree on the impact of sleep and circadian rest-activity rhythm alterations in acute respiratory distress syndrome (ARDS) survivors. However, research on the duration of this impact is scarce. In this study, we evaluate the impact of ARDS on the sleep and circadian rest-activity rhythm of COVID-19 survivors twelve months after hospital discharge. This is a prospective study including COVID-19 survivors with and without ARDS during hospitalization. Data was collected four and twelve months after hospital discharge. The interventions included one-week wrist actigraphy and a home sleep apnea test (HSAT), and evaluations were conducted according to the Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale (ESS), and insomnia severity index (ISI). Fifty-two patients were evaluated (ARDS = 31 and non-ARDS = 21); they had a median age of 49.0 [39.0;57.2] years and 53.8% were male. After twelve months, 91.3% presented poor sleep quality, 58.7% presented insomnia, 50% presented daytime somnolence, and 37% presented comorbid insomnia and obstructive sleep apnea (COMISA). No significant improvement was observed in relation to sleep or the circadian rest-activity rhythm between four and twelve months. A tendency of poor sleep quality, insomnia, daytime somnolence, and COMISA was observed. Finally, there was no significant impact on the circadian rest-activity rhythm between four and twelve months or between the groups.

Sleep-related predictors of cognition among adults with chronic insomnia and heart failure enrolled in a randomized controlled trial of cognitive behavioral therapy for insomnia

STUDY OBJECTIVES

Cognitive impairment and insomnia are common in chronic heart failure (HF). We examined the effects of cognitive behavioral therapy for insomnia (CBT-I) and the extent to which demographic, clinical, symptom, and functional characteristics predicted cognition among people with chronic HF and insomnia who participated in a randomized controlled trial of CBT-I.

METHODS

Participants with HF were randomized to group-based CBT-I or an attention control (HF self-management education). Outcomes were measured over 1 year. We measured psychomotor vigilance and self-reported cognitive ability (PROMIS Cognitive Abilities Scale), clinical and demographic characteristics, history of sleep apnea, fatigue, pain, insomnia (Insomnia Severity Index), sleepiness (Epworth Sleepiness Scale), Six Minute Walk, EuroQoL Quality of Life, and wrist actigraphy (sleep characteristics and rest-activity rhythms). We used cosinor analysis to compute rest-activity rhythms and general linear models and general estimating equations to test the effects of predictors over 1 year.

RESULTS

The sample included 175 participants (mean age = 63 SD = 12.9 Years; 43% women). There was a statistically significant group-time effect on self-reported cognitive function and increases in the proportion of participants, with < 3 psychomotor vigilance lapses in the CBT-I group. Controlling for group-time effects and baseline cognition, decreased sleepiness, improved rest-activity rhythms, and 6-minute walk distance predicted a composite measure of cognition (psychomotor vigilance lapses and self-reported cognition).

CONCLUSIONS

CBT-I may improve cognition in adults with chronic HF. A future fully powered randomized controlled trial is needed to confirm the extent to which CBT-I improves multiple dimensions of cognition.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Cognitive Behavioral Therapy for Insomnia: A Self-Management Strategy for Chronic Illness in Heart Failure; URL: https://clinicaltrials.gov/ct2/show/NCT02660385; Identifier: NCT02660385.

CITATION

Redeker NS, Conley S, O'Connell M, Geer JH, Yaggi H, Jeon S. Sleep-related predictors of cognition among adults with chronic insomnia and heart failure enrolled in a randomized controlled trial of cognitive behavioral therapy for insomnia. J Clin Sleep Med. 2023;19(6):1073-1081.

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

Objectives

Wrist actigraphs (accelerometers) can record motor activity over multiple days and nights. The resulting data can be used to quantify 24-h activity profiles, known as circadian rest-activity rhythms (CRARs). Actigraphic CRARs have been tied to cognitive performance and decline in older adults; however, little is known about links between CRARs and performance or change in specific cognitive domains, or how individual differences may influence these associations. We investigated associations of actigraphic CRARs with cognitive performance and change in middle-aged and older adults, and explored whether age, sex/gender, race, and apolipoprotein E (APOE) e4 carrier status moderated these associations.

Materials and methods

Participants (N = 422; 47% male) were cognitively healthy adults (i.e., without mild cognitive impairment or dementia) at baseline aged ≥ 50 years from the Baltimore Longitudinal Study of Aging who completed 5.6 ± 0.89 nights of wrist actigraphy and tests of memory, executive function, attention, language, and visuospatial ability at the same visit the actigraph was issued; 292 participants had repeat cognitive testing 3.12 (1.58) years later. Predictors included indices of rhythm strength [i.e., amplitude; relative amplitude (RA); interdaily stability (IS); mesor], delayed timing of the rhythm peak [i.e., later acrophase; midpoint of an individual's least active 5 h (L5 time); midpoint of an individual's most active 10 h (M10 time)], and fragmentation [i.e., intradaily variability (IV)].

Results

In main effects, later L5 time was cross sectionally associated with poorer memory, and greater IS predicted slower longitudinal memory decline. Associations of CRARs with cognition differed as a function of age, sex/gender, race, and APOE e4 carrier status.

Conclusion

Among middle-aged and older adults, delayed circadian phase is associated with poorer memory performance, and greater day-to-day rhythm stability is associated with slower declines in memory. Significant interactions suggest that CRARs are generally more strongly associated with cognitive performance and rate of cognitive decline among women, Black adults, older individuals, and APOE e4 carriers. Replication in independent samples is needed.