Sleep regularity is a stronger predictor of mortality than sleep duration (2023)
Irregular sleep patterns may shorten lifespan more than simply getting too little sleep, according to a large UK accelerometer study that links inconsistent bed and wake times to higher all‑cause mortality. Commenters weigh this finding against issues of correlation vs causation, pointing to confounders like stress, chronic illness, socioeconomic status, parenting, and mental health that both disrupt sleep and raise health risks. Many share practical experiences with shift work, freelancing, circadian rhythm disorders, alcohol and screen use, and fixed wake times, debating how much to prioritize regular sleep given that the measured effect, while statistically real, appears modest.
Genetic and individual variability in sleep need
- Several participants report naturally short sleep (e.g., 4–6 hours) with good daytime functioning, sometimes linked to known mutations like DEC2.
- Others need 8–10+ hours and feel awful below that; some can easily sleep 12 hours on days off.
- Many stress that population-level recommendations don’t always apply to individuals.
Anxiety, sleep, and mindset
- Some readers feel the study adds to health anxiety and makes sleep harder.
- Others argue stressing about sleep is counterproductive; focusing on living well, social connection, activity, and not catastrophizing helped their sleep more than chasing studies or gadgets.
Correlation, causation, and confounders
- Multiple comments highlight that sleep regularity may be a marker, not a cause, of poor health.
- Proposed confounders: stress, low income, shift work, caregiving for children or grandchildren, chronic disease, substance use, mental health, and neuroticism/ACEs.
- There’s debate over whether adjustments for sociodemographic and lifestyle factors are sufficient; some see such skepticism as essential scientific critique.
Study design limitations
- Main concern: only ~1 week of accelerometer data used to predict mortality 10–15 years later.
- People question whether that week captures chronic sleep patterns vs late-life illness.
- The paper itself notes this snapshot as a limitation and calls for longer tracking.
Irregular schedules, circadian rhythm, and real-life constraints
- Many describe non-24/“drifting” cycles (25–28h), night-owl tendencies, or extreme patterns (e.g., 32h awake / 12h asleep).
- Parenting, shift work, on-call duty, and DST are cited as major disruptors; some say regularity is practically impossible.
- A few suggest sleep irregularity may just reflect life difficulties and structural pressures.
Practical strategies people report
- Fixed wake time (or wake window), even on weekends, is often cited as key; others say this failed them.
- Tactics mentioned: reducing evening light/screens, exercise, avoiding alcohol, naps, power naps during extreme events, sleep apps, wearables, vibrating alarms, smart bulbs, and even pets as “natural alarm clocks.”
- Some favor “sleep when tired” and reject rigid schedules if they chronically fail.
Magnitude of effect and tradeoffs
- One reader reads the survival curves as only a small absolute difference over ~8 years.
- Others argue even a few percent change in mortality from a single modifiable factor is meaningful, among many contributors to longevity.