Irregular sleep and all-cause mortality: A large prospective cohort study.

Area of Science:

• Epidemiology
• Sleep Science
• Public Health

Background:

• Previous research indicates objective sleep irregularity is linked to disease and mortality.
• Subjective sleep parameters are less understood in relation to mortality risk.

Purpose of the Study:

• To investigate the association between subjective sleep duration and sleep regularity with all-cause mortality.
• To analyze mortality risk across different sleep patterns in a large population.

Main Methods:

• Utilized data from the Japan Multi-Institutional Collaborative Cohort study (n=81,382).
• Assessed sleep duration and regularity via self-administered questionnaires.
• Employed Cox proportional hazards models to calculate hazard ratios for mortality.

Main Results:

• Irregular sleep significantly elevated all-cause mortality risk (HR 1.30) compared to regular sleep.
• All sleep durations (<6h, 6-<8h, ≥8h) were associated with increased mortality when sleep was irregular.
• Compared to regular sleep with 6-<8h duration, irregular sleep patterns showed 1.2-1.5 fold increases in mortality.

Conclusions:

• Sleep irregularity is associated with increased all-cause mortality in a large Japanese population.
• Sleep regularity is an important factor for mortality risk, alongside sleep duration.