To determine the prevalence of sleep disordered breathing (SDB) in a Canadian population of industrial workers (grainworkers). To determine the clinical features that are predictive of SDB and the validity of self-reported snoring.
Cross-sectional, interviewer-administered questionnaire with selective recruitment of subjects for home sleep monitoring.
Community setting, Vancouver, British Columbia.
All male grainworkers at grain elevators in Vancouver were approached for completion of a questionnaire. Eighty-three per cent of 524 subjects completed the questionnaire and were divided by presumed risk for SDB into four groups. All subjects in the highest risk group (group 1- frequent snoring and witnessed apneas) and a random sample of 40 subjects in the other three groups (group 2 - frequent snoring without witnessed apneas; group 3 - infrequent snoring rare; group 4 - nonsnoring) were approached for home sleep monitoring and 42% consented.
Interviewer-administered questionnaire and home sleep monitoring.
The overall prevalence of SDB in this relatively overweight group was estimated to be 25%, with a stepwise increase from group 4 to group 1 (7%, 29%, 40%, 60%). Presence of snoring and witnessed apneas, a greater body-mass index and a larger neck circumference were associated with SDB. Self-reported snoring was not found to be predictive.
This first study of the prevalence of SDB in Canada suggests that SDB is at least as prevalent in Canada as in other industrialized nations and may actually be more common than previously thought. Further studies are required to determine the morbidity, mortality and economic loss associated with SDB in industrial workers.