Sleep disorders and asthma incidence in adults: the CONSTANCES cohort

Sleep disorders have been suggested to play a role in asthma development, but epidemiological studies are scarce. We explored this hypothesis in 21,775 adults without any asthma symptoms, diagnosis or treatment at baseline, from the French population-based CONSTANCES cohort. Four sleep binary characteristics were considered: short sleep duration (<7h per night), sleep onset difficulties (≥8 nights in the last month), night-awakenings (≥8 nights in the last month), and insomnia (short sleep duration and sleep onset difficulties and night-awakenings). Asthma symptom incidence was assessed using a continuous asthma score based on reports of ever asthma, asthma attacks, symptoms or treatment (range: 0-8, expressed as 0, 1, ≥2). Associations between sleep and asthma symptom incidence were assessed using multinomial logistic regressions adjusted for age, sex, socioeconomic status and smoking status. At baseline, 5% of the participants (50±12 yrs. old, 50% men, 11% smokers, 38% overweight/obese) reported insomnia, 30% short sleep duration, 11% sleep onset difficulties, 29% night-awakenings. Asthma symptom score of 0, 1 and ≥2 after 4 to 8 years of follow-up was reported by 84%, 12% and 4%, respectively. Significant positive associations were found for all sleep disorders: ORs [95% CI] for an incidence of 1 and ≥2 asthma symptoms respectively = 1.18 [1.07-1.29] and 1.47 [1.26-1.71] for short sleep duration, 1.35 [1.19-1.54] and 1.86 [1.53-2.26] for sleep onset difficulties, 1.34 [1.22-1.47] and 1.52 [1.30-1.78] for night-awakenings, and 1.30 [1.08-1.56] and 1.70 [1.28-2.25] for insomnia. Results from this longitudinal study suggest that sleep disorders may increase the risk of asthma development during adulthood.