Disturbed sleep is common in asthma. Melatonin has sleep-inducing activity and reportedly affects smooth muscle tone and inflammation. The aim of this study was to evaluate the effect of melatonin on sleep in patients with mild and moderate asthma.
This was a randomized, double-blind, placebo-controlled study. Twenty-two consecutive women with asthma were randomized to receive melatonin 3 mg (n = 12) or placebo (n = 10) for 4 weeks. Sleep quality and daytime somnolence were assessed by the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale, respectively. Pulmonary function was assessed by spirometry. Use of relief medication, asthma symptoms, and morning and evening peak expiratory flow rate were recorded daily.
Melatonin treatment significantly improved subjective sleep quality, as compared with placebo (p = 0.04). No significant difference in asthma symptoms, use of relief medication and daily peak expiratory flow rate was found between groups. We conclude that melatonin can improve sleep in patients with asthma. Further studies looking into long-term effects of melatonin on airway inflammation and bronchial hyperresponsiveness are needed before melatonin can be recommended in patients with asthma.
Disturbed sleep and its daytime consequences are relevant problems in the management of asthma. Nocturnal exacerbations usually indicate inadequate disease control and cause sleep disruption, but poor sleep quality has been reported even in individuals with well controlled stable asthma. Drugs used for this disease, such as methylxantines and oral steroids, have also been shown to disrupt sleep. Failure to deal with sleep problems may lead to impaired disease control and have a great negative impact on quality of life in patients with asthma.
Melatonin, the major ingredient of the Nutrohaler, plays an important role on the regulation of human circadian rhythms and is believed to have sleep-inducing activity. Increasing amount of evidence also suggests that melatonin is involved on the regulation of smooth muscle tone and that it may have immunomodulatory and antioxidant properties.
Exogenous melatonin administration has been shown to improve sleep quality in otherwise healthy young and elderly individuals. There are also reports of sleep improvement after melatonin administration in some medical conditions, including patients in intensive care unit with chronic obstructive pulmonary disease and pneumonia. Significant side effects of short- or long-term melatonin treatment are believed to be uncommon.