Impact on health outcomes associated with changing the clock one hour during fall and spring transitions in the Southern American Hemisphere.

STUDY OBJECTIVES: Changing the clocks seasonally is potentially harmful because it interferes with normal daytime activities. Studies aimed at quantifying this association are scant. The objective of this study was to determine the effects of one year's worth of changing the clocks (fall and spring transitions) on healthy young men located in the Southern American Hemisphere. METHODS: We performed an observational prospective study. Thirty healthy male university students were evaluated from two weeks before to two weeks after both the fall and spring transitions. We administered an overall sleep questionnaire, assessed quality of life, recorded 7-day wrist actigraphy, and had participants perform a Psychomotor Vigilance Task (PVT). We defined the one-hour clock change as the primary exposure and the change in PVT lapses of 500 ms or more in response time as our primary outcome. Changes were evaluated by the Wilcoxon rank test (significance: P<0.05). RESULTS: After the fall transition, we found a significant worsening in PVT performance (median [IQR] 9.9 [6.0-14.3] lapses of ≥ 500 ms in response time at baseline vs 16.8 [8.2-28.0] after transition; P<0.002). Additionally, we found a median loss of about one hour of total sleep time and time in bed after the fall transition. Furthermore, participants presented with insomnia. PVT performance was also affected after the spring transition (16.7 [10-23] vs 23 [12.2-32.2]; P<0.001). CONCLUSIONS: A decrease in performance in neurocognitive tests was found after both time transitions. The transition led to insomnia and a significant worsening of sleep variables.

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.