In addition, researchers found that severe asthma is more common than previously thought. The study is published in the online scientific journal Respiratory Research.
In conducting the study, Jan Lötvall, one of the study's authors and professor at the Sahlgrenska Academy's Krefting Research Center, and colleagues interviewed 30,000 randomly selected participants from western Sweden. The participants were asked questions about various aspects of health.
Says Lötvall, "This is the first time that the prevalence of severe asthma has been estimated in a population study, documenting that approximately 2 percent of the population in West Sweden is showing signs of severe asthma. This argues that more severe forms of asthma are far more common than previously believed, and that healthcare professionals should pay extra attention to patients with such symptoms."
Drawing from the study's results, Lötvall advises that patients reporting certain nasal and respiratory symptoms - such as chronic rhinosinusitis, wheezing, shortness of breath during physical effort, and night-time awakenings due to breathing problems - should be examined for asthma.
"These findings suggest that some parts of the immune system that are activated in connection with chronic nasal problems might be linked to severe asthma, and this insight could lead to new forms of treatment in the long run," says Lötvall. "Effective treatment for troublesome nasal and sinus complaints could, in theory, reduce the risk of severe asthma, though this is something that needs further research."