Sleep traits implicated in lung cancer

Long sleep duration, frequent insomnia symptoms, and delayed sleep period or eveningness appear to contribute to an increased risk of developing lung cancer, a study has found.

Researchers recruited 382,966 participants between 2006 and 2010 and followed through 2020. They used Cox proportional hazards models to analyse the relationships between sleep duration, chronotype, and insomnia symptoms and lung cancer risk.

Furthermore, joint effects analyses were conducted between sleep duration and three sleep traits (chronotype, insomnia, and daytime napping).

A total of 3,664 participants had incident lung cancer. The risk was 22-percent higher among participants with longer sleep (>8 hours) than among those with normal sleep duration (7–8 hours; hazard ratio [HR], 1.22, 95 percent confidence interval [CI], 1.10–1.36). Frequent insomnia symptoms also conferred a 16-percent risk increase (HR, 1.16, 95 percent CI, 1.05–1.28).

Of note, there were joint effects observed between sleep duration and chronotype, as well as between sleep duration and insomnia symptoms.

In an analysis excluding participants reporting shift work at baseline, evening chronotypes (those who were most active and alert in the evening) had a 17-to-37-percent greater risk of incident lung cancer compared with definite morning chronotype (slight evening chronotype: HR, 1.17, 95 percent CI, 1.06–1.28; definite evening chronotype: HR, 1.37, 95 percent CI, 1.21–1.54).

More studies are needed to confirm the findings and further investigate the joint effects of sleep traits on lung cancer risk.