People living in areas of elevated air pollution may be at risk of more serious sleep apnea events, according to a large new study that spans multiple countries. However, being aware of your air quality means you can mitigate that risk to improve your sleep and health.
Led by Martino Pengo, an associate professor at the University of Milano-Bicocca in Madrid, the research analyzed data from 19,325 obstructive sleep apnea (OSA) patients across 25 cities in 14 European countries. Information about their age, sex, BMI and smoking habits was matched with detailed sleep study data, then measured against long-term air-quality records from the Copernicus Atmosphere Monitoring Service (CAMS).
"We know that OSA is more common in people who are older or overweight, but there’s growing concern that air pollution also might make the condition worse," said Pengo, who presented the new research at the European Respiratory Society (ERS) conference. "However, previous studies, mostly focused on just one country, have produced mixed results. We wanted to look at this on a larger scale, across several European cities, to better understand if and how air pollution affects OSA."
The air-quality data featured longitudinal records of PM10 concentration specific to where each patient resided. PM10 concentration is the amount of tiny particles, 10 micrometers or smaller, released into the air by modern pollutants such as vehicle exhausts and industry.
The team found that for every one-unit rise in PM10 levels, there was an average increase of 0.41 breathing disruptions per hour of sleep. While this is small on an individual scale, it's significant at a population level. On average, people in low-pollution areas had milder sleep apnoea scores, while those in higher-pollution regions fared considerably worse.
"We confirmed a statistically significant positive association between average long-term exposure to air pollution, specifically fine particles known as PM10, and the severity of obstructive sleep apnea," said Pengo. "Even after we took account for other factors that we know have an effect on OSA, we still found an average increase in the number of respiratory events per hour of sleep of 0.41 for every one unit increase in PM10. This effect may seem small for an individual, but across entire populations it can shift many people into higher-severity categories, making it meaningful from a public health perspective."
The study adds to the body of evidence suggesting that environmental factors such as air quality, seasonal shifts and temperature play a more important role in the severity of OSA than previously thought.
"One of the most interesting findings was that the link between air pollution and OSA severity wasn’t the same in every European location," said Pengo. "In some cities, the impact was stronger; in others, it was weaker or even absent. These regional differences might be due to things like local climate, the type of pollution or even how healthcare systems detect OSA."
While the research is observational, the team found significant associations with pollution and OSA prevalence in many cities, and suggests this data – and more regional air-quality studies of this kind – can help improve the day-to-day lives and lower the risk of more severe outcomes from the condition.
"For doctors caring for people with OSA, this research highlights the need to consider environmental factors like air quality alongside other risk factors," said Professor Sophia Schiza, who is Head of the ESR's expert group on sleep disordered breathing, based at the University of Crete. "This study strengthens the connection between environmental health and sleep medicine. It reminds us that tackling air pollution isn't just good for the planet, it's also vital for our lungs and our sleep quality too."
OSA is not just snoring and disturbed sleep; it has serious health consequences including an elevated risk of high blood pressure, heart attack, stroke and heart failure. If left untreated, it can lead to type 2 diabetes, depression, cognitive deficits and daytime accidents from sleepiness. Intervening with indoors air purifiers could help reduce the risk of severe OSA triggered by pollution.
The researchers now plan to investigate why some populations appear more vulnerable, and whether cutting air-pollution levels could help alleviate OSA symptoms.
The research was presented at the ERS Congress in Amsterdam.
Source: European Respiratory Society via Scimex
