A UK Biobank research published in the open-access journal BMJ Open Respiratory Research reveals that poor sleep might increase a person’s genetic predisposition to asthma and potentially doubles the chances of them being diagnosed with the illness.
However, it seems that a healthy sleep pattern is linked to a lower risk of asthma which has prompted researchers to suggest that diagnosing and treating sleep disorders early might lessen the risks, irrespective of genetic predisposition. It is pertinent to note that people with asthma often report sleep disturbances, including broken/short sleep or insomnia.
However, it is not clear if sleep quality influences the risk of asthma or whether healthy sleep patterns reduce the risk, according to the researchers. The researchers drew on 455, 405 UK Biobank participants who were between 38 and 73 years old when enrolled between 2006 and 2010.
The researchers ask the participants about their sleep patterns based on five specific traits: early or late chronotype (‘morning lark’ or ‘night owl’); sleep duration; insomnia; snoring; and excessive daytime sleepiness. A healthy sleep pattern was defined as early chronotype, clocking up 7-9 hours of sleep every night, never or rare insomnia, no snoring, and no frequent daytime sleepiness.
Based on the responses received, 73,223 people met the criteria for a healthy sleep pattern, 284,267 for an intermediate sleep pattern, and 97,915 for a poor sleep pattern. The genetic makeup of all UK Biobank participants is routinely mapped. A genetic asthma risk score for each of the 455,405 people in this study was drawn up according to the number of genetic variants associated with asthma in their genome.
About 1 out of 3 participants were classified as ‘high’ genetic risk (150,429) and another third (151,970) as ‘intermediate’ risk. The remainder were classified as ‘low’ risk. The participants’ respiratory health was tracked up to the date of an asthma diagnosis or death, or until March 31, 2017, whichever came first.
17,836 people were diagnosed with asthma during the nine years of monitoring. These people were more likely to have potentially influential risk factors than others who were not diagnosed with the condition, such as lower levels of education, a greater likelihood of unhealthy sleep traits and patterns; obesity; higher genetic asthma risk scores; higher levels of smoking and drinking; high blood pressure, diabetes, depression, and acid reflux; and greater exposure to air pollution.
Some 7,105 people at high genetic risk of asthma and 5,748 at intermediate genetic risk were diagnosed with the condition during the monitoring period. Compared with those at low genetic risk, those with the highest risk were 47% more likely to be diagnosed with asthma, while those with a poor sleep pattern were 55% more likely.
However, the people at high genetic risk who also reported poor sleep patterns were 122% more likely to be diagnosed with asthma than those with both a healthy sleep pattern and a low genetic risk–in other words, they were more than twice as likely to be diagnosed with asthma.
All five sleep traits were independently associated with lower risks for asthma, with never/rare insomnia and sleep duration of 7-9 hours a night seemingly the most influential, with 25% and 20% risk reductions, respectively.
Further in-depth analysis on a smaller group of people indicated that a healthy sleep pattern might reduce the risk of asthma in those at high genetic risk by 37%, suggesting that a healthy sleep pattern might help offset asthma risk, regardless of genetic susceptibility, say the researchers.
In theory, at the population level, a low genetic risk combined with a healthy sleep pattern might translate into 19% fewer cases of asthma, suggest the researchers. The association between sleep and asthma may be two-way, they suggest, offering some possible explanations for their findings.
“The negative impact of sleep disorders on asthma, which is generally considered a chronic inflammatory disease, might be mediated by sleep-induced chronic inflammation. Previous studies have demonstrated that sleep disorders, such as unfavourable sleep duration and insomnia, are associated with chronic inflammation.
“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,” they write.
This is an observational study; as such, it can’t establish cause, and the researchers acknowledge several limitations to their findings. As the UK Biobank only provided information on 38-73-year-olds, the effect on children and younger adults is still unclear, added to which the findings apply only to people of European ancestry.
Lastly, the UK Biobank may be subject to a ‘healthy volunteer’ selection bias. Nevertheless, the researchers conclude: “Considering that poor sleep combined with high genetic susceptibility yielded a greater than twofold asthma risk, sleep patterns could be recommended as an effective lifestyle intervention to prevent future asthma, especially for individuals with high-risk genetics.”
[with inputs from ANI]
