Proper Sleep Duration, Ease of Getting Up Protective Against CRC

The risk of colorectal cancer (CRC) was found to be tied to different sleep factors, according to a study published in Journal of Gastrointestinal Oncology.¹ Proper sleep duration and ease of getting up in the morning were found to be protective against CRC compared with snoring, which was found to have a link to CRC.

The risk of cardiovascular diseases has been shown to increase in patients with sleep disorders, as proper sleep is a factor of a healthy lifestyle. Sleep disorders also have been linked to other forms of cancer, including breast, liver, and prostate cancers.² Previous studies have found a link between sleep disorders and CRC, but these links have been from observational studies. This study aimed to use a mendelian randomization (MR) analysis to assess the association between sleep and CRC by using data from previous genetic studies.

A multivariable MR analysis was used for this study, and 7 traits were used as exposure factors. These included daytime napping, ease of getting up in the morning, morning chronotype, daytime dozing, insomnia symptoms, snoring, and sleep duration. The open genome-wide association study (GWAS) from Independent Education Union was used alongside the UK Biobank to collect data between 2006 and 2010, primarily from 337,000 patients aged 40 to 69 years. Statistically significant thresholds were calculated by identifying single nucleotide polymorphisms.

Sleep factors, such as sleep duration and insomnia, can affect the risk of CRC in patients | Image credit: terovesalainen - stock.adobe.com

Seven sleep traits and 3 outcomes for CRC were used to conduct the bidirectional MR. The analysis found that ease of getting up in the morning (OR, 0.992; 95% CI, 0.984-0.999) and sleep duration (OR, 0.989; 95% CI, 0.980-0.998) were both protective factors for patients with CRC. Insomnia symptoms were also found to be protective against CRC (OR, 0.988; 95% CI, 0.978-0.997), but this wasn’t significant. Incidence of CRC was not significantly affected by snoring (OR, 1.010; 95% CI, 0.994-1.027) in the 2-sample MR group but the multivariable MR results found that snoring had a negative effect on CRC (OR, 1.021; 95% CI, 1.002-1.041).

When evaluating the relationship between sleep traits and colon cancer, ease of getting up in the morning (OR, 0.995; 95% CI, 0.989-1.000) and appropriate sleep duration (OR, 0.993; 95% CI, 0.986-1.000) had protective effects, although the multivariate MR analysis found these effects were not statistically significant. The multivariate MR analysis also found that morning chronotype had a negative effect on colon cancer (OR, 1.004; 95% CI, 1.000-1.007), and that insomnia symptoms acted as a protective factor for rectal cancer (OR, 0.995; 95% CI, 0.990-0.999).

There were some limitations associated with this study. The data were primarily from the UK Biobank, which would prevent generalizability to all populations. Individual-level statistics were not included in this study in favor of the pooled database of GWAS data, and a dose-response relationship could not be evaluated between sleep and CRC. Also, the OR values included were small despite the significant associations.

The researchers concluded that adequate sleep duration and the ease of waking up in the morning were positively associated with CRC, acting as protective factors. Preventing the risk of CRC can be done through more consistent and healthy sleep patterns in patients.

“Future studies should further investigate the causal relationships between sleep traits and CRC across diverse populations and explore potential dose-response relationships,” the authors concluded.

References

1. He F, Yang F, Tang C, et al. Association between sleep traits and risk of colorectal cancer: a bidirectional Mendelian randomization study. J Gastrointest Oncol. 2024;15(4):1556-1567. doi:10.21037/jgo-24-11

2. Suni E, Singh A. Cancer and sleep. Sleep Foundation. Updated February 23, 2023. Accessed September 23, 2024. https://www.sleepfoundation.org/physical-health/cancer-and-sleep