Abstract
Background: Several studies have investigated associations between OSAS and asthma, with inconsistent results.
Aim: To determine if asthma and bronchodilator reactivity (BDR) are independent risk factors for OSA in the Norwegian population.
Methods: An age and sex stratified random sample of all adults aged 47-48 and 71-73 living in Bergen, Norway, were invited to a cross-sectional survey. The 3506 attendants (69%) completed a questionnaire including symptoms of OSAS. Subjects were classified as having OSAS if they reported snoring, breathing cessations, and daytime sleepiness using the Karolinska Sleep Questionnaire, previously validated against polysomnography. Subjects were classified as asthmatics if they had ever received a doctor's diagnosis of asthma and currently were on antiobstructive medication. Spirometry including bronchodilator test inhaling 400 μg Salbutamol was performed by all subjects. Two logistic regression models were fitted with OSAS as the outcome variable; one with current asthma and one with BDR as main explanatory variable. Both models included age, sex, body mass index (BMI), waist-hip ratio and smoking.
Results: The prevalence of OSAS was 4,5% (147/3289) in subjects without asthma, and 9,7% (21/217) in subjects with asthma [P=0.001]. Subjects with current asthma had an increased risk for OSA with an OR of 2.2 (1.3, 3.7), after adjustment for all confounders. BDR, measured by difference in ml between pre- and post-bronchodilator spirometry, did not seem to confer increased risk for OSAS; OR 1.0 (0.3, 3.8).
Conclusions: Our study confirms asthma as an independent risk factor for OSAS. We were not able to demonstrate a relationship between bronchodilator reactivity and OSAS.
- © 2011 ERS