Current Respiratory Medicine Reviews

Joseph Varon  
The University of Texas Health Science Center
Houston, TX
USA

Back

Mechanisms and Therapeutic Implications of Asthma Circadian Rhythm

Author(s): Elcio O. Vianna.

Abstract:

Nocturnal worsening of asthma is very common and employed in clinical practice as a marker of asthma severity. The fall in overnight lung function can reach 50%. Several mechanisms contribute to this circadian (24 h) variation. Cortisol, steroid responsiveness, vagal tone, leukotriene, airway inflammation and airway hyperresponsiveness vary in a circadian fashion and have been described as potential mechanisms. Studies on the ability of corticosteroids to block circadian recruitment of inflammatory cells show that a single corticosteroid systemic dose in the afternoon results in a significant pancellular reduction in bronchoalveolar lavage cytology at 4: 00 h and a reduction in the overnight fall in FEV1. The same single dose in the morning or night does not lead to significant improvement. Further studies on chronotherapy of asthma have revealed a rapid and time-dependent effect of inhaled steroids. A single dose of inhaled steroid in the afternoon has a protective effect against asthma worsening in the same night. Chronotherapeutic principles are also applied with other than corticosteroid drugs in the regular asthma treatment.

Keywords: asthma, circadian rhythm, chronotherapy, airway hyperresponsiveness, bronchial inflammation

Order Reprints Order Eprints Rights & PermissionsPrintExport

Article Details

VOLUME: 1
ISSUE: 2
Year: 2005
Page: [171 - 183]
Pages: 13
DOI: 10.2174/1573398054023019
Price: $58