Exercise, Occupational Activity, and Risk of Sleep Apnea: A Cross-Sectional Study

Study Objectives: To investigate whether structured exercise and occupational activity are associated with obstructive sleep apnea (OSA) severity. Methods: The International Physical Activity Questionnaire was answered by 5,453 individuals who underwent full-night polysomnography. Participants were classified as exercisers or non-exercisers and also as occupationally active or non-active. The apnea-hypopnea index (AHI), minimum oxygen saturation (SaO(2)min), and time with saturation below 90% (TB90%) during polysomnography were used as indicators of OSA severity. Results: The sample included mostly men (59%), non-exercisers (56%), and occupationally non-active individuals (75%). Mean age (+/- standard deviation) was 44 +/- 14 years, and mean body mass index was 29.9 +/- 7.3 kg/m(2). Non-exercisers had higher AHI (median 14, 25-75% interquartile range 4-34) than exercisers (8 [2-24]), lower SaO(2)min (83 +/- 9 vs. 86 +/- 8%), and longer TB90% (2 [0-18] vs. 0 [0-7] minutes), with p < 0.001 for all comparisons. AHI was higher in active (16 [6-34]) vs. non-active occupations (10 [3-27]; p < 0.001). Multinomial logistic regression with control for age, sex, overweight, obesity, and occupational activity showed that structured exercise was significantly associated with a 23% lower odds ratio for moderate OSA and 34% lower odds ratio for severe OSA. Active occupation was not associated with OSA. Conclusions: Structured physical exercise is associated with lower odds for OSA, independently of confounders. Occupational activity does not seem to replace the effects of regular exercise. Compensatory behaviors may be involved in these diverging outcomes. Our results warrant further research about the effect of occupational activity on OSA severity.