Sleep duration linked to increased risk of cancer and related mortality

Sleep duration is emerging as an important modifiable risk factor for morbidity and mortality.

The researchers conducted a study to assess the association between sleep duration and cancer incidence and mortality among Japanese adults using data from six population-based cohorts with 271 694 participants. During a total follow-up period of about 5.9 million person-years, we identified 40 751 incident cancer cases and 18 323 cancer deaths.

The results of the study:

• They computed study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression models and pooled the estimates using a random-effects meta-analysis.
• Sleep duration of ≥10 hours (vs 7 hours) was associated with increased risk of cancer incidence among women, but not men, and increased risk of cancer mortality among men and women
• Sleep duration of ≤5 hours (vs 7 hours) was not associated with cancer incidence and mortality.
• However, among postmenopausal women, sleep durations of both ≤5 and ≥10 hours (vs 7 hours) were associated with an increased risk of cancer mortality.

The researchers concluded that among Japanese adults, sleep duration of ≥10 hours is associated with an increased risk of cancer incidence and mortality among women and cancer mortality among men.One of the limitations of the study are that Sleep duration was self-reported. Also the data on sleep quality were missing.

Reference:

Wilunda, C, Abe, SK, Svensson, T, et al. Sleep duration and risk of cancer incidence and mortality: A pooled analysis of six population-based cohorts in Japan. Int J Cancer. 2022; 1- 13. doi:10.1002/ijc.34133