The role of the nose in the pathogenesis of obstructive sleep apnoea and snoring.

Data from observational studies suggest that nasal obstruction contributes to the pathogenesis of snoring and obstructive sleep apnoea (OSA). To define more accurately the relationship between snoring, OSA and nasal obstruction, the current authors have summarised the literature on epidemiological and physiological studies, and performed a systematic review of randomised controlled trials in which the effects of treating nasal obstruction on snoring and OSA were investigated. Searches of bibliographical databases revealed nine trials with randomised controlled design. External nasal dilators were used in five studies, topically applied steroids in one, nasal decongestants in two, and surgical treatment in one study. Data from studies using nasal dilators, intranasal steroids and decongestants to relieve nasal congestion showed beneficial effects on sleep architecture, but only minor improvement of OSA symptoms or severity. Snoring seemed to be reduced by nasal dilators. Nasal surgery also had minimal impact on OSA symptoms. In conclusion, chronic nasal obstruction seems to play a minor role in the pathogenesis of obstructive sleep apnoea, and seems to be of some relevance in the origin of snoring. The impact of treating nasal obstruction in patients with snoring and obstructive sleep apnoea on long-term outcome remains to be defined through randomised controlled trials of medical and surgical therapies.