Nocturnal Worsening of Asthma and Sleep-Disordered Breathing

Abstract

Asthma has a tendency to destabilize and get worse at night, probably due to a nocturnal increase in airway inflammation and bronchial responsiveness. Nocturnal airway narrowing in asthma is often associated with sleep disorders, such as episodes of nocturnal and early morning awakening, difficulty in maintaining sleep, and daytime sleepiness. On the other hand, an association has been documented between nocturnal sleep-disordered breathing and asthma. This review highlights the causes of nocturnal worsening of asthma and examines the evidence pointing toward a causal relationship between nocturnal asthma and sleep-disordered breathing.

• Nocturnal asthma
• Sleep-disordered breathing
• Circadian rhythm
• Airway inflammation
• Bronchial hyperresponsiveness