Reversing the Question: Does Sleep Affect Asthma?
While it makes sense that asthma can have a negative effect on sleep quality, I recently wondered about the effects of sleep on asthma.
Can getting adequate sleep--that is, enough hours of high-quality sleep, not just time we spend in bed staring at the wall--impact our asthma? In the process of figuring out how to build the appropriate search term (one that didn't simply render results on nocturnal asthma!), I also questioned the impact of other things (exercise, mealtimes, etc.) on both sleep quality and quantity, and asthma. Okay… First question first, right?
Can sleep affect asthma? The National Sleep Foundation suggests it can, noting that not only can asthma impact sleep, sleep can have an impact on asthma.1 Both asthma symptoms and pulmonary function are suggested in a variety of sources to be impacted by inadequate sleep2, but few studies using objective data (such as lung function test results) exist to make any significant conclusions on the relationship of sleep on asthma, versus of asthma on sleep 2.
One study of a small sample of adolescent boys in Vancouver, British Columbia, which used a daily self-report on sleep hours (or, more accurately, amount of time spent in bed) and perceived sleep quality, multiple daily peak flow readings and analysis of saliva samples to check cortisol levels (samples were collected on two consecutive days, at four specific points throughout the day) 2, as cortisol in lower levels is indicative of lower levels of asthma control (or, higher incidence of asthma symptoms), and higher levels suggest greater asthma control (and thus, fewer symptoms). 3
The results of this study conclude that poor quality sleep and high quantity of sleep may be risk factors for more frequent or severe asthma symptoms, lower pulmonary function test results, and lower cortisol levels 2.
It is noted that there may be limitations in this study due a lack of a comparison (control) group, the small sample size, as well as the imprecise nature of measuring the time that was spent in bed versus actual time asleep2—given the study was published in 2008, it’s not unreasonable to consider that much time spent in bed could have also been spent online or texting! The study also focused on adolescents, however, the researchers note that as the group studied had variable asthma severities, they believe the results would be able to be generalized to other populations with asthma 2.
On the opposing side, Dr. Sande O. Okelo a pediatrician from University of California - Los Angeles, believes that sleep quality or quantity in itself has no impact on asthma symptoms in children—only that asthma, if uncontrolled or symptomatic, can cause sleep deprivation. 4This is not at all difficult to believe for those of us who live with asthma—children or adults!—it is clear that sometimes, or for some of us, more often than we’d care to admit, our asthma prevents us from getting the sleep that we need.
While I realize there is nothing definitive to consider whether or not our sleep quality or quantity affects our asthma, I believe that the steps suggested in the article for physicians of teens with asthma are worthwhile to consider—for all of us. We should be aware that sleep may indeed affect our asthma, and use that as a motivator to improve our sleep habits if necessary. Going to bed at a routine time each day, minimizing lights in our bedrooms 2, establishing a bedtime routine to prepare our bodies and minds for sleep, minimizing our exposure to the “blue light” emitted from our phones and electronic devices (hello, Night Shift on iOS!) and generally just unwinding ourselves from the hype of the day, are all steps that can be taken to improve what’s been coined our ‘sleep hygiene’.
Taking a look at how my asthma and sleep are connected is a step I’m going to take in the near future—to see what my own personal results are. How about you? Is what you’ve learned reading this going to change how you approach sleep, with hopes of improving your asthma control? Let me know in the comments.
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