If you think your snoring gets worse in the winter, you might very well be right. It’s also more likely that you develop sleep apnea in the winter, and that your breathing is worse. At least, that’s the result of two recent studies looking at the seasonal effect of sleep apnea.
Two Ways to Come to the Same Answer
These two studies used very different approaches to determine the seasonal effects of sleep apnea.
The more recent study, just published online in Sleep Breathing, took an Internet age approach. It used search traffic as a stand-in for people’s interest, something that Google and marketers do very regularly in trying to determine developing trends. Researchers used data from both the US and Australia to eliminate calendar effects, and analyzed search traffic for a variety of terms related to snoring and sleep apnea. They found that many terms had some degree of variation, perhaps as little as 5% and as much as 50%, and that in both the US and Australia these searches peaked in the late winter and early spring.
A 2012 study published in the journal Chest, also showed a strong variation in sleep apnea during the winter. This study looked at the records of more than 7500 patients who had visited a sleep clinic over the past 10 years. Their records showed that the apnea-hypopnea index (AHI) was much higher for patients that came in for sleep studies during winter months. The AHI is a measure of how disrupted your breathing is and how much it affects oxygen levels in your body. The median value during the winter was 17.8, compared to only 15.0 during the summer. In addition, more patients had severe sleep apnea in the winter (34% vs. 28%).
What Makes Sleep Apnea Worse in Winter?
Researchers in the earlier study note that sleep apnea may seem to be worse during the winter because people have the time or incentive (such as a flex account) to visit the doctor more in the winter.
However, sleep apnea may actually be worsened by many factors in the winter, including:
Weather conditions like high pressure
Increased carbon monoxide levels
More frequent colds
Allergens spread by forced air heating
Dry air leading to irritation of the airway
People may also experience more incidental effects that make them aware of their sleep apnea. For example, short days in which people leave and arrive home in the dark may make people more prone to daytime sleepiness, and then they begin investigating potential causes.
Whether sleep apnea gets worse in the winter, it remains a year-round condition that requires year-round treatment.