Sleep is an essential biological process known to contribute to both mental and physical health. In addition to supporting memory processes and learning, boosting concentration, facilitating the body's recovery, and promoting cardiovascular health, good quality sleep for approximately 7–8 hours a day has been found to strengthen the body's immune system.

Some studies have found that a lack of sleep could potentially contribute to the development of infectious diseases. As these diseases are estimated to be responsible for 18.4% of deaths worldwide, identifying factors that increase the risk of contracting infections, particularly if these factors can be modified, could thus be highly valuable for global health.

Researchers at the Southern Medical University in China recently carried out a study aimed at further exploring the connection between sleep and infections by analysing data from a well-known health database, the UK Biobank. Their findings, published in Translational Psychiatry, suggest that healthy sleep patterns decrease the risk of being hospitalised for infections.

"Sleep behaviours are potentially modifiable risk factors for infectious disease," wrote Hong-Min Li, Xi-Ru Zhang and their colleagues in their paper. "However, little is known about the combined effects of multiple sleep factors on the risk of infections."

To explore the link between sleep and infections, Li, Zhang and their colleagues analysed data from the UK Biobank database, which pertained to the sleep patterns and hospitalisations of 397,523 people. Their findings showed that an average of 7–8 hours of good quality sleep per night was linked to fewer hospitalisations for infections.

"Healthy sleep patterns were defined by healthy sleep scores according to a combination of adequate sleep duration (7–8 h/day), early chronotype, no insomnia, and no excessive daytime sleepiness," wrote Li, Zhang and their colleagues.

During a median follow-up of 13.5 (interquartile range: 12.4–14.2) years, 60,377 cases of hospitalisation for any infection were documented. A healthy sleep score was inversely associated with the risk of hospitalisation for any infection and various infection subtypes in a dose-dependent manner."

Essentially, the researchers found that the individuals included in the sample they analysed were more likely to be hospitalized due to infections if they did not sleep well or enough, while they were less likely to visit the hospital due to infections if they reported sleeping well for an average of 7–8 hours per night. This hints at the potential value of improving sleep patterns to improve health and reduce the risk of contracting serious infections.

"The associations between a one-point increment of healthy sleep score and hospitalization for infections ranged from a 9% lower risk for sepsis (HR = 0.91; 95% CI, 0.89–0.93) to a 20% lower risk for liver infection (HR = 0.80; 95% CI, 0.74–0.87)," wrote Li, Zhang and their colleagues.

"More than 10% of hospitalisations for any infection could have been prevented if all participants adhered to the four low-risk sleep behaviours. Adherence to a healthy sleep pattern was associated with a decreased risk of hospitalisation for infections, especially for individuals <65 years of age and females."

The findings of this recent study by Li, Zhang and their colleagues could inform the development of new health programs aimed at preventing serious and life-threatening infectious diseases by improving people's sleep patterns. Concurrently, it could inspire other research groups to examine the link between sleep and infection, which might also shed new light on the biological processes underpinning their relationship.

--Ingrid Fadelli