Sleep and cardiorespiratory function assessed by a smart bed over 10 weeks post COVID-19 infection

Abstract

Inadequate information exists regarding physiological changes post-COVID-19 infection. We used smart beds to record biometric data following COVID-19 infection in nonhospitalized patients. Recordings of daily biometric signals over 14 weeks in 59 COVID-positive participants' homes in 2020 were compared with the same participants' data from 2019. Participants completed a survey of demographic information, health conditions, COVID exposure and testing, and symptom prevalence/subjective severity. Mean age was 47.5 years (standard deviation [SD] 9.5), mean body mass index was 30.1 kg/m² (SD 7.1), and 46% were men. During acute infection, 64% exhibited 5-6 h increased sleep duration, 51% had increased movement, and 64% had increased breathing rate (BR). Nearly 34% had paradoxical bradycardia (decreased heart rate by ~ 10 BPM concomitant with elevated BR and/or fever), with more-severe symptoms. Smart beds can detect physiological changes during COVID-19. A subtype of acute response (paradoxical bradycardia) may predict delay recovery from COVID-19.

Fig. 1

CONSORT diagram: Participants with a positive COVID-19 test between March 2020 and November 2020 were included in the analysis. Of the survey participants, 190 reported a valid symptom onset date, 81 were excluded because of a gap of 3 or more days of missing data during the critical period, and 49 were excluded because of 9 or more days of missing data in the reference period. In total, 59 participants were included in this study. ^aCritical period (2020): starting 3 days before and ending 10 days after reported date of symptom onset. ^bReference period (2019): a 14-day period 1 year prior to the critical period in 2020, at the same time of year in 2019. CONSORT, Consolidated Standards of Reporting Trials.

Fig. 2

Parts a–d: differences in mean profiles of (a) sleep duration, (b) movement, (c) BR and (d) HR in response to COVID-19 infection in 2020 versus 2019. For all 59 participants, the mean profiles for (a) sleep duration, (b) movement, (c) BR and (d) HR over the 14-week period surrounding COVID-19 infection in 2020 as compared to habitual conditions in 2019 are illustrated. Mean (solid lines) values for each metric in 2020 (red) and the corresponding period in 2019 (blue) for the 59 participants are shown. For both 2019 and 2020, the mean ± SEM is represented by dashed lines below and above the mean. All data are referenced relative to time 0 (shown as a vertical black dashed line), the date of onset of symptoms in 2020, and the corresponding date in 2019. The baseline period was − 4 to − 1 weeks (indicated by the gray horizontal bar), the acute phase of infection was time 0 to + 4 weeks (indicated by the orange horizontal bar), and the postacute phase was weeks + 5 to + 10 (indicated by the green horizontal bar) as represented on the abscissa. The vertical red dashed line indicates the end of the acute phase and beginning of the postacute phase. bpm, beats per minute; BR, breathing rate; brpm, breaths per minute; h, hour; HR, heart rate; Pa, Pascal; SEM, standard error of the mean.

Fig. 3

Parts a–d: subtypes of mean profiles of (a) sleep duration, (b) movement, (c) BR, and (d) HR. Participants that did not experience significant changes after time zero of COVID-19 infection were separated from participants with robust changes in each physiological variable. Mean profiles for participants with significant changes or no significant changes in (a) sleep duration, (b) movement, (c) BR, and (d) HR are illustrated. Mean (solid lines) and ± SEM (dotted lines) values for each metric in 2020 (red) and the corresponding period in 2019 (blue) for subgroups of participants are shown. The baseline period was − 4 to − 1 weeks (indicated by the gray horizontal bar), the acute phase of infection was time 0 to + 4 weeks (indicated by the orange horizontal bar) and the postacute phase was weeks + 5 to + 10 (indicated by the green horizontal bar). The vertical black dashed line indicates subjective symptom onset date. The vertical red dashed line indicates the end of the acute phase and beginning of the postacute phase. All data are referenced relative to time 0, the date of onset of symptoms in 2020 and the corresponding date in 2019. bpm, beats per minute; BR, breathing rate; brpm, breaths per minute; h, hour; HR, heart rate; Pa, Pascal; SEM, standard error of the mean.

Fig. 4

Parts a–c: postacute phase mean profiles from 3 subtypes of HR for (a) HR, (b) sleep duration, and (c) BR. The profiles of HR, sleep duration, and BR during the 6-week postacute phase are illustrated for each subtype (no change, decrease, or increase) of acute HR response to infection. Mean (solid lines) and ± SEM (dotted lines) values for HR, sleep duration, and BR in 2020 (red) and the corresponding period in 2019 (blue) for subgroups of participants are shown. The postacute phase was weeks + 5 to + 10 (indicated by the green horizontal bar). All data are referenced relative to time 0, the date of onset of symptoms in 2020 and the corresponding date in 2019. bpm, beats per minute; BR, breathing rate; brpm, breaths per minute; h, hour; HR, heart rate; SEM, standard error of the mean.