Sleep and genetics play individual roles in increasing a person’s risk for asthma, but their combination also heightens that risk.
Poor sleep quality was associated with increased risk of asthma, especially among individuals with high genetic risk, according to a new study. This potential suggests how a healthy sleep pattern may be beneficial in preventing and managing asthma, regardless of genetic predispositions.
“The negative impact of sleep disorders on asthma, which is generally considered a chronic inflammatory disease, might be mediated by sleep-induced chronic inflammation,” wrote the study researchers. “Previous studies have demonstrated that sleep disorders, such as unfavorable sleep duration and insomnia, are associated with chronic inflammation.”
The results of this prospective cohort study were published in BMJ Open Respiratory Research.
Comorbid sleep disturbances are common among individuals with asthma; however, it remains unclear if sleep quality independently increases asthma risk. In response, the researchers of this study aimed to examine the relationship between poor sleep patterns and increased asthma risk and if improved sleep could relieve the impact of genetic disposition.
The study was conducted using a UK Biobank cohort of 455,405 participants aged 38 to 73 years who were selected based on the number of their genetic variants associated with asthma in. Using polygenic risk scores (PRS), the researchers grouped participants as being at high (n = 150,429), intermediate (n = 284,267), or low risk (151,970) for asthma. Additionally, the researchers were able to construct comprehensive sleep scores ranging from 0 to 5, with higher scores representing healthier sleep patterns.
Sleep patterns included traits, chronotype, sleep duration, insomnia, snoring, and excessive daytime sleepiness. Therefore, healthy sleep patterns were defined as early chronotype, sleeping 7 to 9 hours per day, never or rare insomnia, no snoring, and no frequent daytime sleepiness.
Lastly, the researchers created a regression model to evaluate the independent and combined association between sleep pattern and genetics on asthma, which included sex and sensitivity analysis over a 5-year lag. As a result, 17,836 individuals received an asthma diagnosis over a 10-year follow-up.
Individuals grouped with the highest PRS (HR, 1.47; 95% CI, 1.41-1.52 P < .001) and poor sleep patterns (HR, 1.55; 95% CI, 1.45-1.65; P < .001), were most at risk for asthma. Furthermore, the combination of poor sleep and genetic susceptibility produced a 122% greater risk compared with the low-risk combination (HR, 2.22; 95% CI, 1.97-2.49; P < .001).
On the other hand, a healthy sleep pattern was associated with lower risk of asthma across all 3 genetic groups:
Finally, the risk analysis showed that 19% of asthma cases could be prevented by improvement of sleep traits.
Although this was a prospective study, and cannot conclude a causal relationship, the researchers of this study believe the results suggest how better sleep management may reduce asthma among individuals, regardless of their genetic predisposition for asthma.
“In theory, the immune response to inflammation could generate pro-inflammatory cytokines that result in cellular infiltration and airway inflammation, further increasing the risk of asthma,” wrote the researchers.
Xiang B, Hu M, Yu H, et al. Highlighting the importance of healthy sleep patterns in the risk of adult asthma under the combined effects of genetic susceptibility: a large-scale prospective cohort study of 455 405 participants. BMJ Open Respiratory Research 2023;10:e001535. doi:10.1136/bmjresp-2022-001535