Long Sleep Durations May Substantially Increase Risk of Mortality and Morbidity

Sarfaroj Khan 


April 09, 2021


  • Long and short sleep durations were associated with a modest but statistically significant increased risk of a composite of incident cardiovascular disease (CVD), cancer and mortality.

  • Snoring, insomnia and narcolepsy were independently associated with increased risk of incident CVD.

Why this matters

  • Authors encourage people to keep their sleep durations to 7-8 hours per day.

  • Findings may support sleep medicine research to develop and promote sleep education to more people and contribute to a larger proportion of the population receiving knowledge on sleep hygiene to reduce the incidences of mortality and morbidity.   

Study design

  • A prospective cohort study of 407,500 participants from the UK Biobank.

  • Associations of sleep duration and quality with incident CVD, cancer and mortality were evaluated.

  • Funding: National Natural Science Foundation of China.

Key results

  • Compared with a sleep duration of 7 hours, sleep durations of ≤5 hours and ≥9 hours were both associated with a significantly higher risk of :

    • all-cause mortality (adjusted HR [aHR], 1.25; 95% CI, 1.16-1.34 and 1.30; 95% CI, 1.22-1.38, respectively);

    • CVD mortality (aHR, 1.27; 95% CI, 1.09-1.49 and 1.32; 95% CI, 1.16-1.50, respectively); and

    • CVD incidence (aHR, 1.23; 95% CI, 1.16-1.31 and 1.08; 95% CI, 1.02-1.15, respectively).

  • Long sleep duration (≥9 hours) was associated with a higher risk of cancer mortality (aHR, 1.19; 95% CI, 1.10-1.30) and cancer incidence (aHR, 1.08; 95% CI, 1.04-1.12).

  • CVD incidence was significantly associated with:

    • snoring (aHR, 1.07; 95% CI, 1.04-1.11);

    • insomnia (aHR, 1.26; 95% CI, 1.21-1.32); and

    • narcolepsy (aHR, 1.20; 95% CI, 1.11-1.31).


  • The validity of self-reported snoring, insomnia and narcolepsy was not fully evaluated.


Tao F, Cao Z, Jiang Y, Fan N, Xu F, Yang H, Li S, Zhang Y, Zhang X, Sun L, Wang Y. Associations of sleep duration and quality with incident cardiovascular disease, cancer, and mortality: a prospective cohort study of 407,500 UK biobank participants. Sleep Med. 2021 Mar 15 [Epub ahead of print];81:401-409. doi: 10.1016/j.sleep.2021.03.015. PMID: 33819843.  View abstract 

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.


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