Aggressive control of gastro-esophageal reflux does not appear to improve asthma symptoms, a study has shown.
The findings challenge the theory that people with poorly controlled asthma frequently have reflux, and that treatment would lead to better asthma control.
The multicenter, double-blind, randomized controlled trial involved 412 adults whose symptoms of asthma were inadequately controlled despite the use of moderate to high doses of inhaled corticosteroids. Participants were assigned to receive either a placebo or 40 mg of esomeprazole, a prescription proton pump inhibitor, twice daily for 24 weeks. This dose was higher than that typically used to treat symptomatic gastroesophageal reflux (N. Engl. J. Med. 2009;360:1487–99).
The study was conducted by the research group of the American Lung Association Asthma Clinical Research Centers, and the article was prepared by a writing committee led by Dr. John G. Mastronarde of Ohio State University Medical College, Columbus.
Although only 15% of the participants reported a history of gastroesophageal reflux, ambulatory pH monitoring revealed that 41% of patients in the placebo group and 40% in the esomeprazole group had evidence of reflux. This is a common finding among patients with asthma—for many, their reflux is asymptomatic.
Patients kept daily diaries of their asthma symptoms, and they were assessed by spirometry every 4 weeks. Depending on the definition of poor asthma control, between 42% and 61% of all participants experienced at least one episode, and 18% required an urgent-care visit or a course of prednisone. There were no significant differences in any of those measures between patients taking placebo and those taking esomeprazole.
About half of the participants reported night awakening caused by asthma symptoms, and that rate also did not differ significantly between the two groups.
The study was powered to detect a difference of 33% in the proportion of participants having one or more episodes of poor asthma control.
The study was supported by grants from the National Heart, Lung, and Blood Institute and the American Lung Association. Esomeprazole and placebo were supplied by AstraZeneca, which manufactures esomeprazole. Several members of the writing committee disclosed receiving consulting or lecture fees from AstraZeneca, and they also reported relationships with several other pharmaceutical companies.