Sleep-related symptoms among asthmatics in the RHINESSA study

Introduction: Sleep disorders are common in asthmatics. However, the prevalence of sleep-related symptoms is not well described. Method: Data were available from 8754 participants in the community-based Respiratory Health in Northern Europe, Spain, and Australia (RHINESSA) study. Information on difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, snoring, nocturnal sweating, nocturnal gastroesophageal reflux, sleep time, and excessive daytime sleepiness was assessed using standard questionnaires. Asthma was defined as self-reported asthma attack in the last 12 months, current use of asthma medication or the presence of more than three asthma-like symptoms. Multivariable logistic regression and multinominal logistic regression were used to study associations between asthma and sleep-related symptoms. Results: The prevalence of asthma was 14%. Participants (58% female, mean age 30 years) with asthma had 1.61 (1.20-2.17) times higher odds of reporting ≤6 hours vs 8 hours of sleep compared to the non-asthmatics. Those with asthma had higher odds of difficulty initiating sleep 1.92 (1.65-2.23), maintaining sleep 1.79 (1.56-2.07), and early morning awakening 2.36 (1.96-2.84). A significant interaction was found between sex and asthma for obstructive sleep apnea, nocturnal gastroesophageal reflux, and snoring symptoms (p <0.05). The odds of reporting obstructive sleep apnea, nocturnal gastroesophageal reflux, and snoring symptoms were 3.75, 2.53, and 2.00 and 1.36,2.78 and 1.34 for male respectively adjusted for age, BMI and smoking. Conclusion: Our findings suggest an interaction between gender and sleep symptoms in asthma patients. Follow-up studies are warranted to understand the association.