Snorers Appear More Likely To Develop Chronic Bronchitis

Chronic bronchitis involves inflammation of the lower airways accompanied by a persistent cough and the production of mucus or phlegm, according to background information and the article. Snoring appears more common among individuals with bronchitis.

Inkyung Baik, Ph.D., of the Korea University Ansan Hospital, Ansan, Republic of Korea, and colleagues studied 4,270 individuals (52 percent men and 48 percent women) starting in 2001 to 2003. At the beginning of the study, participants provided information on demographics, health conditions, family disease history and lifestyle, as well as details about how often they snored.

Every two years through 2006, participants were re-interviewed and were classified as developing chronic bronchitis if they reported having a cough and sputum (phlegm produced during cough) on most days for at least three months per year for at least two years but did not have an asthma diagnosis.

During four years of follow-up, 314 individuals developed chronic bronchitis. After adjusting for age, smoking and other bronchitis risk factors, individuals who snored regularly were more likely to develop bronchitis than those who did not. Compared with those who never snored, individuals who snored six five times per week or less were 25 percent more likely and those who snored six to seven times per week were 68 percent more likely to develop bronchitis. The association was strongest in individuals who had never smoked, who worked in the home or who were overweight.

"The mechanisms underlying the association between snoring and chronic bronchitis are largely unknown," the authors write. "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."

"Further investigations are needed to confirm the association between snoring and chronic bronchitis and to explore the mechanisms underlying the association," they conclude.

Journal reference: Arch Intern Med. 2008;168[2]:167-173.

This study was supported by a grant from the Korea Centers for Disease Control and Prevention and by the Japan Society for the Promotion of Science.