SELECTED ARTICLES FROM THE RECENT LITERATURE 2003

12/16/03

Increased serum melatonin levels in nocturnal worsening of asthma

Summary
Nocturnal worsening in asthma (NA) occurs commonly with adverse effects on the quality of life. More frequent NA in an individual patient is also considered to be a marker of worsening asthma. There is some debate about the role of disordered sleep in NA. However, some evidence suggests a greater bronchial inflammatory reaction during the night as a possible cause of NA. Other factors such as changes in endogenous catecholamine and/or corticosteroid levels at night may also play a role.

Melatonin (Mel) has several major effects in human physiology including modulation of circadian rhythms and sleep. Exogenous Mel administration may be pro-inflammatory. However, it is unknown whether endogenous Mel levels affect airway inflammation in NA. Sutherland et al of the National Jewish Medical and Research Center in Denver, CO compared serum Mel levels and airflow rates throughout a 24 hour period in those with/without NA. They found that peak serum Mel levels were significantly higher in patients with NA than in healthy controls (p=0.03) correlating inversely with decreases in FEV-1 in the NA group (r= 0.79; p=0.04). These findings were not seen in asthmatics who did not manifest NA.

Reference
J Allergy Clin Immu;nol 2003;112:513-7

Editor's Comments
Mel has been found to exert diverse effects on human biologic responses particularly related to sleep (reviewed recently in J Neuroendocrinol 2003;15:432-7). Because of its soporific effects, exogenous Mel has been used extensively in some sleep disorders, particularly in older individuals. Sleep is frequently disordered in some asthmatics. There may be a tendency to try exogenous Mel treatment to correct insomnia in an asthmatic. These findings suggest that increasing serum Mel levels by such treatment may actually predispose to NA. However, this thesis must be validated by a controlled trial.

<-- BACK