What a difference a year makes: Objective rest/activity patterns, circadian phase markers, and sleep quality before and during the COVID-19 pandemic.

OBJECTIVES: The COVID-19 pandemic led to numerous changes in sleep duration, quality, and timing. The goal of this study was to examine objective and self-reported changes in sleep and circadian timing before and during the pandemic. METHODS: Data were utilized from an ongoing longitudinal study of sleep and circadian timing with assessments at baseline and 1-year follow-up. Participants had baseline assessment between 2019 and March 2020 (before pandemic) and 12-month follow-up between September 2020 and March 2021 (during pandemic). Participants completed 7 days of wrist actigraphy, self-report questionnaires, and laboratory-collected circadian phase assessment (dim light melatonin onset). RESULTS: Actigraphy and questionnaire data were available for 18 participants (11 women and 7 men, Mean = 38.8 years, SD = 11.8). Dim light melatonin onset was available for 11 participants. Participants demonstrated statistically significant decreases in sleep efficiency (Mean = -4.11%, SD = 3.22, P = .001), worse scores on Patient-Reported Outcome Measurement Information System sleep disturbance scale (Mean increase = 4.48, SD = 6.87, P = .017), and sleep end time delay (Mean = 22.4 mins, SD = 44.4 mins, P = .046). Chronotype was significantly correlated with change in dim light melatonin onset (r = 0.649, P = .031). This suggests that a later chronotype is associated with a greater delay in dim light melatonin onset. There were also non-significant increases in total sleep time (Mean = 12.4 mins, SD = 44.4 mins, P = .255), later dim light melatonin onset (Mean = 25.2 mins, SD = 1.15 hrs, P = .295), and earlier sleep start time (Mean = 11.4 mins, SD = 48 mins, P = .322). CONCLUSION: Our data demonstrate objective and self-reported changes to sleep during the COVID-19 pandemic. Future studies should look at whether some individuals will require intervention to phase advance sleep when returning to previous routines such as returning to office and school settings.

Circadian Timing, Information processing and Metabolism (TIME) study: protocol of a longitudinal study of sleep duration, circadian alignment and cardiometabolic health among overweight adults.

BACKGROUND: Both short sleep duration and circadian rhythm misalignment are risk factors for metabolic dysfunction, but the underlying mechanisms are unknown. The goal of this study is to examine how sleep duration and circadian alignment predict changes in cardiometabolic risk factors over a 12-month period, and test cognitive function and hedonic eating tendencies as potential mechanisms. METHODS: We will recruit a sample of 120 working aged adults with BMI 25-35 kg/m2 (overweight to class I obesity). The protocol includes 5 visits over a 12-month period. Study visits include wrist actigraphy to measure sleep behaviors, 24-h diet recalls, dim light melatonin collection, a computerized neurobehavioral assessment, eating in the absence of hunger task, and frequently sampled IV glucose tolerance test. DISCUSSION: The results of the TIME study will advance the understanding of how both short sleep duration and circadian misalignment contribute to behavioral aspects of obesity and metabolic dysfunction. TRIAL REGISTRATION: ClinicalTrials.Gov, NCT04759755 , registered retrospectively February 13, 2021.

The prevalence and impact of pre-existing sleep disorder diagnoses and objective sleep parameters in patients hospitalized for COVID-19.

STUDY OBJECTIVES: Obstructive sleep apnea and other sleep disorders overlap with comorbidities associated with poor outcomes related to severe acute respiratory syndrome coronavirus 2 infection. However, the prevalence of obstructive sleep apnea among patients hospitalized for COVID-19 and relationship to outcomes is poorly characterized, and the relevance of other sleep disorders remains unknown. The objective of this study was to identify the prevalence of pre-existing sleep disorders and association with outcomes related to severe COVID-19 illness. METHODS: Patients with severe acute respiratory syndrome coronavirus 2 infection admitted to the University of Michigan Hospital System were included. Electronic medical records were queried for sleep disorders diagnostic codes. Data were extracted from polysomnography and home sleep testing in a subgroup with previous diagnostic testing at our center. Logistic regression was used to examine the association of sleep disorders with mechanical ventilation requirement, treatment with vasopressors, and death and Cox proportional hazards regression for time to discharge. RESULTS: Among n = 572 adult patients hospitalized for COVID-19, 113 (19.8%) patients had obstructive sleep apnea, 4 patients had central sleep apnea (0.7%), 5 had hypoventilation (0.9%), 63 had insomnia (11.0%), and 22 had restless legs syndrome or periodic limb movements disorder (3.9%). After adjusting for age, sex, body mass index, and race, no significant relationship was apparent between sleep disorders diagnoses or indices of sleep-disordered breathing severity and outcomes. CONCLUSIONS: This is the first study to determine the prevalence of obstructive sleep apnea and other sleep disorders in a well-characterized cohort of patients hospitalized for COVID-19. Once hospitalized, a significant contribution of sleep disorders to outcomes was not identified. Therefore, future evaluations should focus on earlier outcomes, such as infection or clinical manifestations after exposure to severe acute respiratory syndrome coronavirus 2.

The effects of COVID-19 stay-at-home order on sleep, health, and working patterns: a survey study of US health care workers.

STUDY OBJECTIVES: By March 2020, COVID-19 forced much of the world to stay at home to reduce the spread of the disease. Whereas some health care workers transitioned to working from home, many continued to report to work in person as essential employees. We sought to explore changes in sleep, health, work, and mood in health care workers during the stay-at-home orders. METHODS: We developed a cross-sectional online survey administered to health care workers. The survey assessed changes in sleep, work, screen time, media exposure, diet, exercise, substance use, and mood. The survey data were collected between March 28, 2020, and April 29, 2020. RESULTS: A total of 834 of 936 individuals completed the entire survey. Respondents were from 41 US states. Mood after the stay-at-home orders worsened, and screen time and substance use increased. Total sleep time shortened in those continuing to work in person (P < .001), whereas it was unchanged in those working from home (P = .73). Those working from home went to bed later, woke up later, and worked fewer hours. Reduced total sleep time and increased screen time before bed were associated with worse mood and screen time. Longer sleep time was associated with better mood. CONCLUSIONS: Health care workers' mood worsened regardless of whether work was in person or remote, although total sleep time was shorter for those working in person. Those working from home may have shifted their sleep time to be more in line with their endogenous circadian phase. Peer or other support services may be indicated to address sleep, mood, and health behaviors among health care workers during these unprecedented times.