In 1965 one of the first large epidemiological studies started in the Netherlands: the population study in Vlagtwedde and Vlaardingen. Over 8000 people took part. The cohort study was concluded in 1990, but the data from the databank still provide useful information in the research into the origin of lung diseases. For instance, follow-up research into mortality in this cohort has resulted in the discovery that people with a higher airway sensitivity have a greater chance of dying from COPD. Research is currently being conducted into genetic causes of reduced lung function in the Vlagtwedde/Vlaardingen cohort. Reduced lung function is a normal phenomenon of ageing, but in some people it is accelerated. This can result in bronchial problems and diseases like COPD. UMCG researchers have found that the ADAM33 gene is responsible for an accelerated reduction in lung function in the population as a whole and in patients with asthma and (severe) COPD. This gene can therefore be considered a general lung-ageing gene.