PhD ceremony Mr. E.D. Telenga: On phenotyping in asthma and COPD

PhD ceremony: Mr. E.D. Telenga, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: On phenotyping in asthma and COPD

Promotor(s): prof. D.S. Postma

Faculty: Medical Sciences

Inhaled corticosteroids (ICS) are frequently used medications in obstructive pulmonary diseases. ICS are the cornerstone of treatment in asthma. The role of ICS is less clear in COPD. COPD patients respond less to ICS treatment than asthma patients. There are also asthma patients who respond less or not at all to ICS. Since smoking is the main risk factor for COPD, we investigated if smoking influences corticosteroid sensitivity in asthma patients. We showed that current- and ex-smoking asthma patients have a lower short-term response to ICS treatment than never-smoking asthma patients. However, the long-term response of current- and ex-smoking asthma patients appears similar to that of never-smokers. Additionally, we investigated the ICS response in obese asthma patients. After a short-term treatment with ICS, obese asthma patients (BMI >30) showed significantly less improvement in lung function than patients with normal weight (BMI < 25).

We also investigated the association between small airways and bronchial hyper responsiveness with impulse oscillometrie. We showed that in healthy subjects the airway wall thickness, measured with high resolution CT-scans, decreases with increasing age, but increases in smokers. Finally, we investigated the lipid profile in sputum of COPD patients and healthy subjects. We showed that multiple lipids are differentially regulated in COPD patients than in healthy smokers. This suggests a role for changes in the lipid profile in the development of COPD.