People with severe asthma are less likely to respond to their medication than people with mild asthma, new research indicates.

Asthma is a very common inflammatory lung disease affecting millions of people worldwide, including some 470,000 people in Ireland.

Despite this, experts still do not understand why some people develop a more severe form of the disease than others.

An EU-funded project - U-BIOPRED - is examining this very issue. Scientists are looking at how severe asthma affects different people in the hope of categorising the condition into sub-groups. By doing this, it is hoped that more personalised medicine can be developed, treating each individual for the specific type of asthma they have.

The first analysis from this project has found that those with severe forms of the condition - sometimes referred to as ‘steroid dependent' - are less likely to respond to their treatment.

The analysis was based on over three million samples from 700 adults and 300 children. These participants included people with no asthma, mild asthma and severe asthma.

The scientists found a number of similar characteristics among those with severe asthma. For example, over half of adults with severe asthma regularly took oral corticosteroids, but still had greater airway obstruction compared to people with mild asthma.

Furthermore, those with severe asthma still experienced severe symptoms and exacerbations even though they were taking higher amounts of corticosteroids.

According to the study's lead author, David Gideon of Imperial College London, the scientists want to find out why people with severe asthma ‘are less responsive to the effects of corticosteroids'.

"Our parallel work on the ways in which patients with asthma respond to corticosteroid treatment show that asthmatics may become less responsive to this treatment in many different molecular ways. This initial analysis will provide an overview of the groups which exist within asthma, which will help us develop a more personalised approach to treating the individual patient with asthma," he explained.

Details of these findings were presented at the 2013 Annual Congress of the European Respiratory Society in Barcelona.

For more information on asthma, see our Asthma Clinic here