New Delhi: Higher levels of air pollution may not only harm your lungs but also worsen health for people with obstructive sleep apnea (OSA), according to a multi-national study, that strengthened the connection between environmental health and sleep medicine. 

While OSA is a common condition, many people do not realise they have it. People with OSA often snore loudly, their breathing starts and stops during the night, and they may wake up several times.

The study, presented at the European Respiratory Society (ERS) Congress in Amsterdam, the Netherlands, revealed that, overall, for every one unit increase in PM10 -- tiny particles, 10 micrometers or smaller, released into the air by vehicle exhausts and industrial processes -- there was a modest but measurable increase in the patients' apnoea hypopnea index (AHI).

AHI is the number of apnoeas (when breathing stops) and hypopnoeas (when breathing is reduced) per hour during sleep.

For example, among patients with low AHI (less than five), the average PM10 in the area where they live was relatively low (around 16 micrograms per cubic meter of air).

In contrast, in patients with high AHI (five or more), the average PM10 was also higher (around 19 micrograms per cubic meter of air).

"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 Martino Pengo, Associate Professor from the University of Milano-Bicocca and clinician at Istituto Auxologico Italiano IRCCS, Milan, Italy.

The study included data on 19,325 patients with OSA from 25 different cities in 14 countries.

The study found differences between the strength of the link between air pollution and OSA in different cities.

"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 apnoea," Pengo said.

"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," Pengo added.

The research highlights the need to consider environmental factors like air quality alongside other risk factors when treating people with OSA.

(IANS)