Circadian changes in the sputum of asthmatic subjects and healthy controls.

Background: : Asthma is exhibiting classical circadian fluctuations of clinical symptoms and airflow measurements, presumably influenced by the underlying airway inflammation and the endogenous cortisol secretion. The aim of our study was to examine the cellular and eosinophilic cationic protein (ECP) contents of sputum, collected andfrozen at 2 opposite time points of the day-and-night cycle, and tocorrelate them to blood cortisol levels.

Methods: : Thirteen subjects with uncontrolled asthma (8 men, aged 25-54 years) and 10 healthy subjects (6 men, aged 25-50 years) volunteered for the study.