Insomnia symptoms and asthma control—Interrelations and importance of comorbidities

BACKGROUND: Insomnia symptoms are common with asthma. The aim of the study was to analyse the associations between insomnia symptoms and asthma control, asthma severity, and asthma-related comorbidity in a community-based population. METHODS: Adults (n = 23 875, ages 18-45) from the community-based LifeGene study answered a questionnaire on insomnia symptoms, airway symptoms, asthma diagnosis, asthma medication, and asthma-related comorbidities (chronic rhinosinusitis, gastro-oesophageal reflux, anxiety, depression, or obesity). RESULTS: Of the participants, 1272 (5.3%) had asthma. The prevalence of any insomnia symptom was higher in participants with uncontrolled asthma (n = 201) than with controlled or partially controlled asthma (32.2% vs 19.9% and 20.1%, respectively, P < .01). There was no significant difference in the prevalence of insomnia symptoms between subjects with controlled asthma and subjects without asthma. Subjects with asthma and any asthma-related comorbidity reported more insomnia symptoms (29.0% vs 22.4%, P < .01) compared to asthmatics without comorbidity. Moreover, the prevalence was highest among subjects reporting both uncontrolled asthma and any asthma-related comorbidity (45.1%, P < .01). Uncontrolled asthma remained significantly associated with insomnia symptoms (OR 1.72 (1.15-2.56)) after adjusting for age, sex, BMI, smoking history, comorbidities, physical activity, and educational level, while medication level was not. Among asthma-related comorbidities, chronic rhinosinusitis (OR 1.62 (1.20-2.19)), obesity (1.87 (1.07-3.25)), and depression (OR 1.85 (1.34-2.55)) were independently associated with insomnia symptoms. CONCLUSION: Uncontrolled asthma was significantly associated with insomnia symptoms, while controlled or partially controlled asthma was not. Asthma-related comorbidity is of great importance, and asthma control seems to be more important than asthma severity for insomnia symptoms.