Prospective changes in sleep problems in response to the daily rest period among Japanese daytime workers: A longitudinal web survey

Association between sleep regularity and arterial stiffness among middle-age adults in Southwestern China

BACKGROUND

Sleep regularity has been linked to a risk of arterial stiffness (AS). However, the association between sleep regularity indicators, which reflect 24-hour sleep variability, and AS has not yet been examined.

METHODS

We analyzed data from 516 adults, aged 40-65 years (the median age of 51 years), from the 'Follow-up Study of Sleep Characteristics and Chronic Diseases in the Middle-aged and Elderly Population in Guizhou Province'. Participants underwent assessments of AS (OMRON HBP-8000, baPWV ≥ 1400 cm/s) and sleep (wrist smart band (Honor band 5i) for ≥ 7 days). Logistic regression was utilized to evaluate the odds ratio (OR) and 95% confidence interval (CI) of the association between sleep regularity and AS.

RESULTS

A total of 516 people were included in this study, of which 279 (54.07%) were in the AS group. The univariate results showed that the AS group (Median 71.18) had lower SRI compared to the No-AS group (Median 75.00) (p < 0.001). The multifactorial results showed participants with higher SRI scores were more likely to have a lower risk of AS compared to those with lower SRI scores (ORQ4 VS. Q1=0.46, 95%CI: 0.25-0.85, p = 0.013). The SRI effect was more pronounced in male (ORQ4 VS. Q1=0.28, 95%CI: 0.12-0.69, p = 0.005), snoring populations (ORQ4 VS. Q1=0.13, 95%CI: 0.04-0.48, p = 0.002), and non-retired populations (ORQ4 VS. Q1=0.45, 95%CI: 0.22-0.92, p = 0.028).

CONCLUSIONS

The present findings indicated that the effect between SRI and AS may be more sensitive than the standard deviation of sleep duration as well as the standard deviation of sleep onset.

Protocol for a web-based study on the work environment and daily lifestyle of Japanese employees

Mental health problems are prevalent among the working population and must be resolved. We conducted a web-based large-scale study of workers, including a baseline survey and two follow-up surveys, to investigate the associations between self-care behaviors in daily life (e.g., stress coping, sleep, diet, and exercise), work environment improvements, and mental health among Japanese employees from various industries. In this protocol, we demonstrate the study design and demographic data of the participants in the baseline survey. Invitations to participate in this study were sent to 421,825 internet monitor registrants in February 2022. Overall, 20,000 registrants who met the inclusion criteria participated in the survey. There were large variations in occupations and working styles (e.g., physical work, night work, and teleworking) among the participants, and we also found significant differences between male and female participants in the demographic data. An overview of the survey data suggests that the demographic characteristics of the participants in this study are comparable to those reported in previous studies on Japanese employees. We plan to use these survey data in the future to examine the associations of daily lifestyles and work environments with the mental health of Japanese employees.

The association between work interval regularity and sleep regularity: a 2-week observational study in daytime employees

OBJECTIVES

Several health issues are associated with irregular sleep patterns. However, it is unclear what causes workers to sleep irregularly. The work interval (WI) between the end of one day's working hours and the start of the next day's working hours contains sleep opportunities, and an irregular WI may result in irregular sleep. This study investigated this association among Japanese daytime workers.

METHODS

This study recruited 141 daytime workers without shiftwork for a 14-day observational study. Participants reported the WI duration, WI timing, time in bed (TIB: difference between bedtime and wake-up time), and bedtime timing every day before bedtime. The SD over 14 days was used to calculate the regularity scores. Logistic regression analysis was performed. The dependent variables were ≥60 minutes of TIB SD and bedtime timing SD, whereas the independent variables were WI duration and timing SD.

RESULTS

The odds ratios (ORs) (95% CIs) for ≥60 minutes of TIB SD across categories of WI duration SD were 1.000 (reference) for <30 minutes, 1.344 (0.337-5.360) for 30-60 minutes, and 4.743 (1.441-15.607) for ≥60 minutes. The ORs (95% CIs) for ≥60 min of bedtime timing SD across categories of WI timing SD were 1.000 for <30 minutes, 4.154 (1.574-10.965) for 30-60 minutes, and 7.714 (2.124-28.015) for ≥60 minutes.

CONCLUSIONS

Regularity of WI was associated with regularity of sleep. To ensure worker health, workers should have regular WI, and if they are exposed to irregular WI, they should make every effort to maintain regular sleep.

Sleep Debt Mediates the Relationship between Work-Related Social Factors, Presenteeism, and Well-Being in Japanese Workers

Sleep debt is associated with presenteeism and mental health; however, the association of sleep debt with presenteeism and well-being in the context of work-related social factors (commuting time, workdays, and working hours) has not been fully elucidated. This study aimed to examine whether work-related social factors are associated with presenteeism and well-being via sleep debt. The participant group comprised 872 full-time and 526 part-time workers (mean age: 44.65 ± 12.37 and 48.47 ± 12.93 years, respectively). For both the full-time and part-time workers, increased sleep debt was significantly associated with presenteeism (β = -0.171; β = -0.160) and low well-being (β = -0.135; β = -0.153). Notably, commuting time was significantly associated with increased sleep debt in full-time workers (β = 0.09). In contrast, the number of workdays was significantly associated with increased sleep debt in part-time workers (β = -0.102). Working hours were not significantly associated with sleep debt for both full- and part-time workers. These results reveal that sleep debt might lead to various risks among workers, elucidating the work-related social factors related to sleep debt. They also highlight the importance of considering work-related social factors when addressing sleep debt.

The Joint Association of Daily Rest Periods and Sleep Duration with Worker Health and Productivity: A Cross-Sectional Web Survey of Japanese Daytime Workers

A daily rest period (DRP) is a daily inter-work interval that contains sleep opportunity. This study investigates the joint association of DRP and sleep duration with worker health and productivity. A total of 13,306 Japanese daytime workers participated in this web-based cross-sectional survey. Participants reported on their DRPs and sleep duration; moreover, sleep difficulties, mental health, and presenteeism were assessed by the standardized questionnaires. The participants were divided into 10 groups based on their DRPs and sleep duration. Logistic regression analyses showed that the combination of quick return (QR: DRP of <11 h) and short sleep duration (<6 h) was found to be significantly associated with sleep difficulties (odds ratio [OR] = 4.45, 95% confidence interval [CI] = 2.83-7.01), poor mental health (OR = 3.04, 95% CI = 1.79-5.15), and presenteeism (OR = 2.35, 95% CI = 1.47-3.77) compared with the reference group (the combination of adequate DRP [15 h] and a normal sleep duration [≥6 h]). The combination of QR and normal sleep duration or adequate DRP and short sleep duration was significantly associated with high ORs for the outcomes. QR, short sleep duration, or both negatively affect worker health and productivity.