Objectives: This study aimed to investigate the association of asthma-related symptoms with snoring and apnea, and to assess their effects on health-related quality of life (HRQL).
Design: Population-based cross-sectional study.
Subjects and methods: A total of 10,224 parents and grandparents of students from 14 randomly selected primary schools in city center were asked to answer questionnaires sent by their children. All subjects were questioned for asthma-related symptoms, sleep-related disorders (snoring and apnea), and for HRQL using the Respiratory Questionnaire, Sleep and Health Questionnaire, and Short Form-12 (SF-12) Health Survey, respectively.
Results: The overall response rate to questionnaires was 97.7%, and all analysis was performed on 7,469 subjects (3,920 women and 3,549 men) who provided sufficient responses to questions. There were 2,713 subjects who reported asthma-related symptoms. The snoring and the observed apnea were more prevalent in subjects with asthma-related symptoms (54.0% vs 41.4%; odds ratio [OR], 1.7; 95% confidence interval [CI], 1.5 to 1.8; p < 0.001) than those without asthma-related symptoms (16.7% vs 7.0%; OR, 2.7; 95% CI, 2.3 to 3.1; p < 0.001), respectively. Asthma-related symptoms were found to be associated with snoring (OR, 1.5; 95% CI, 1.3 to 1.6; p < 0.001) and observed apnea (OR, 2.2; 95% CI, 1.8 to 2.5; p < 0.001) after adjusting for gender, age, body mass index, income, education, and smoking. Also, HRQL was found to be adversely affected by asthma-related symptoms, snoring, and observed apnea (β = − 0.26, p < 0.001; β = − 0.07, p < 0.001; and β = − 0.08, p < 0.001, respectively, for SF-12 overall score) after adjusting for other confounding factors.
Conclusion: Present data suggest that there is a link between the sleep-related breathing disorders and asthma-related symptoms. Moreover, the presence of snoring and observed apnea in individuals with asthma-related symptoms causes further impairment in HRQL. The effects on HRQL of coexistence of these three disorders should be supported by clinical studies.