Snoring linked to chronic bronchitis – more so if you smoke as well.

Chronic bronchitis occurs when there is inflammation and obstruction of the air passages and symptoms include a cough that produces phlegm and shortness of breath.

People who snore a few times a week are at a greater risk of developing chronic bronchitis and the media, including The Daily Telegraph and GMTV have really covered the subject for once – instead of the whole subject of snoring being ignored – despite all the proof of its serious impact on health.

The Daily Telegraph Telegraph reported on 9th March 2013 that “people who snore five times or less have a 25 per cent higher chance of developing bronchitis.”.

In addition GMTV added that a study has found that “those who snore six or seven times per week are 68% more likely to develop the condition than those who never snore”.

The reports are based on a four-year study following over 4,000 people, to see if they developed chronic bronchitis.

Where did the story come from?

Several Universities in the Far East, plus Shiga University of Medical Science in Japan, and the University Of Virginia School Of Medicine in the US, carried out this research and Ii was published in the peer-reviewed medical journal: Archives of Internal Medicine.

What kind of scientific study was this?

This was a study that looked at whether people who snored were more likely to develop bronchitis.

The researchers enrolled 5,015 people aged 40 to 69 between June 2001 and January 2003. The volunteers had a medical examination and were questioned about themselves, their health, lifestyle and their family disease history. The interview also included questions about whether they snored and how often (infrequently, once to three times a week, four to five times a week, or six to seven times a week). Those who reported that they coughed and produced phlegm on most days for three or more months of the year, or that they had been diagnosed with chronic obstructive pulmonary disease, cancer, tuberculosis, cardiovascular disease, or asthma, were excluded from the study. This left 4,270 people for analysis.

Researchers followed these participants for up to four years, and asked them to fill in questionnaires about their health every year, to see if they developed chronic bronchitis. The researchers defined chronic bronchitis as coughing and production of phlegm on most days for three or more months of the year, for at least two successive years. Those who still met inclusion criteria after the first two years of the study were included in the second two years.

The researchers then looked at whether the proportion of people who developed chronic bronchitis differed between snorers and non-snorers. Snoring was classified as: never, five times a week or less, or almost every night (six to seven times a week). The researchers took into account factors that might affect risk of developing bronchitis, including age and smoking. They also looked at the joint effects of snoring and other risk factors for chronic bronchitis, including smoking, occupation, and body mass index (BMI).

What were the results of the study?

There were 314 new cases of chronic bronchitis during the four years of the study. People who snored six to seven nights a week were more likely to develop chronic bronchitis than people who did not snore. Although those who snored five times a week or less were at increased risk of chronic bronchitis, this increase did not reach statistical significance. People who smoked and snored were almost three times more likely to develop chronic bronchitis than people who did not smoke or snore.

What interpretations did the researchers draw from these results?

The researchers concluded that their results “support…the hypothesis that snoring influences the development of chronic bronchitis”. They suggest that more research should be done to confirm these findings and to understand in more depth exactly how it happens.

By John Redfern