[Occupational exposure to low concentrations of carbon monoxide and sleep disordered breathing. A negative result]

This study explored the possibility that occupational exposure to low concentrations of carbon monoxide (CO) could influence the synchronisation of upper airway and lower respiratory muscles and thus induce sleep disordered breathing.

Two hundred and thirty subjects exposed to between 1 and 5 ppm (peaks up to 25 ppm) at work and one hundred and sixteen unexposed controls were studied with a protocol comprising anthropomorphic measurements and a self-completed French translation of the Wisconsin Sleep Questionnaire.

The two groups had similar anthropomorphic and lifestyle data with the exception that the exposed group were slightly younger (2.5 years). No differences were found in personal or family history, sleep related breathing disorder (snoring, breathing pauses etc) and disturbed sleep.

Occupational exposure to low concentrations of CO do not seem to affect ventilatory drive and the synchronisation of upper airway and respiratory muscles during sleep. It should be recognised that these results were obtained by a relatively insensitive technique (questionnaire); a protocol including polysomnography applied to subjects exposed to higher concentrations of CO could lead to other conclusions.