Nov. 1, 2004 — Melatonin therapy significantly improves subjective sleep quality in patients with mild and moderate asthma without improvements in lung function or asthma symptoms, according to the results of a randomized, double-blind, placebo-controlled study published in the November issue of the American Journal of Respiratory and Critical Care Medicine.
"Disturbed sleep and its daytime consequences are relevant problems in the management of asthma," write Francineide L. Campos, MPharm, and colleagues, from the Universidade Federal do Ceará in Fortaleza, Brazil. "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."
According to the authors, melatonin has sleep-inducing activity and reportedly affects smooth muscle tone and inflammation. "There are...reports of sleep improvement after melatonin administration in some medical conditions, including patients in intensive care unit[s] with chronic obstructive pulmonary disease and pneumonia," they write.
The investigators explored the effect of exogenous melatonin on sleep quality in 22 consecutive women with mild or moderate asthma (mean age, 29.7 ± 7.7 years) randomized to receive 3 mg of melatonin (n = 12) or placebo (n = 10) in a single dose two hours prior to bedtime for 28 days. Women were selected for the study on the basis of reports showing melatonin bioavailability to be nearly threefold greater in women than in men.
Results at four weeks showed that melatonin therapy significantly improved Pittsburgh Sleep Quality Index (PSQI) scores compared with baseline (P < .001), including parameters of subjective quality of sleep (P = .02), reduced sleep latency (P = .02), increased sleep duration (P = .034), and decreased daytime and sleep disturbances (P = .025; P = .02). A trend toward improving Epworth Sleepiness Scale (ESS) scores compared with baseline was also observed (P = .05). No changes from baseline were noted in the placebo group.
Compared with placebo, melatonin therapy significantly improved global sleep quality (P = .04) but did not decrease daytime somnolence (P > .05).
Lung function parameters remained unchanged by administration of melatonin or placebo, with the exception of significantly increased peak expiratory flow rates in both groups (PEFR: melatonin, P = .014; placebo, P = .016). PEFR, PEFR morning to evening variation, diurnal and nocturnal symptoms of asthma, and number of inhalations of a ß2-agonist were similar between groups during the four-week study period (P > .05).
"Improved subjective sleep quality associated with melatonin administration could not be correlated to any improvement in lung function or in asthma symptoms," the authors point out.
"[M]elatonin as used in this study can improve subjective sleep quality in patients with mild and moderate asthma in the absence of any significant change in pulmonary function," the authors conclude, suggesting that the long-term effects of melatonin on airway inflammation and bronchial hyperresponsiveness be evaluated prior to its use in the management of sleep disturbances in asthmatics.
The study was funded in part by the Brazilian National Research Council.
Am J Resp Crit Care Med. 2004;170:947-951
Reviewed by Gary D. Vogin, MD
Medscape Medical News © 2004
Cite this: Yael Waknine. Melatonin May Improve Sleep Quality in Patients With Asthma - Medscape - Nov 01, 2004.