Purpose of review: To examine recent advancements of the epidemiology, pathophysiology, and treatment of nocturnal asthma.
Recent findings: In a large cross-sectional survey, the prevalence of nocturnal symptoms was 60%. Forty-two percent of patients who completed the study did not declare nocturnal symptoms that were detected by physicians. A recent study including 47 individuals with nocturnal and nonnocturnal asthma showed that allele genotype Gly16 was significantly higher in the nocturnal asthma group (72%) compared with the nonnocturnal asthma group (54%). A randomized double-blind study of nocturnal asthma with esomeprazole improved the peak expiratory flow rate in individuals with both nocturnal asthma and gastroesophageal reflux disease. Of patients with nocturnal asthma and snoring, 48% had obstructive sleep apnea. After continuous positive airway pressure treatment, there was significant improvement of asthma nighttime symptom scores; however, no significant difference in lung functions was observed.
Summary: Nocturnal symptoms in asthma are frequently underdiagnosed. Obstructive sleep apnea may be prevalent in nocturnal asthma. The Gly16 polymorphism of the beta2-receptor is common in nocturnal asthma. Gastric suppression treatment in patients with both gastroesophageal reflux disease and nocturnal asthma improved the peak expiratory flow rate. Continuous positive airway pressure improves nocturnal symptoms but not lung function tests.