Snoring may significantly increase the risk of a person to develop chronic bronchitis, a persistent cough that can last for weeks and reappear for years, a new study revealed.

According to the U.S. National Institutes of Health, bronchitis is an inflammation of air passages to the lungs, which causes chest tightness, shortness of breath and coughing.

A team led by Inkyung Baik of Korea University Ansan Hospital in South Korea discovered that regular snoring was associated with a 25 percent to 68 percent increased frequency of new-onset chronic bronchitis compared with those who never snore.

“Our findings may provide novel information that snores are at greater risk of developing chronic bronchitis than persons who do not snore during sleep,” the authors concluded.

The researchers studied 4,270 Korean individuals (52 percent men and 48 percent women) who participated in a prospective health examination. The participants enrolled from June 25, 2001 to January 29, 2003 and were followed through November 17, 2006. They provided information on demographics, health conditions, family disease history and lifestyle, as well as details about how often they snored.

People suffering from asthma were excluded from the analysis. During follow-up, there were 314 participants who developed chronic bronchitis, meaning 27.1 cases per 1,000 persons in a year, the researchers found.

Those who snored five times a week or less were 25 percent more likely to develop bronchitis. Those who snored six to seven times a week were 68 percent more likely to develop bronchitis than those who never snored, the analysis found.

A surprising discovery of the study was that stratification by chronic bronchitis risk factors that included smoking, occupation and body mass index showed stronger associations among never-smokers, house workers and overweight people.

“It has been suggested that structural or functional changes in the airway due to inflammation may cause snoring and obstructive sleep apnea syndrome. Conversely, repeated snoring vibrations may act as mechanical stresses, leading to increased inflammatory response in the upper airway,” the authors wrote.

Dr. Robert Keeton, a researcher at the University of Michigan Sleep Disorders Center, called the findings an interesting association, but he added that more study is needed. “It can’t be something you can cite to tell patients in the clinic that they have chronic bronchitis because they snore,” he said.

The study supported by the Korea Centers for Disease Control and Prevention and the Japan Society for the Promotion of Science was published in the January 28 issue of the Journal of the American Medical Association’s Archives of Internal Medicine.