According to recent study in Chest, people with asthma are 12.5 times more likely to develop chronic obstructive pulmonary disease (COPD) later in life. Researchers had previously made a firm distinction between asthma and COPD but they are now finding a common basis. More than 3000 Tucson residents were followed for up to 20 years where they periodically completed questionnaires regarding their respiratory health, as well as a lung function test known as spirometry. Of the 3000 residents, 2751 reported no asthma, 156 had previously had asthma, and 192 had active asthma. Results showed those with active asthma were 12.5 times more likely to develop COPD, while the risk for emphysema was 17 times greater and the risk for bronchitis was 10 times greater. Smoking status was also a risk factor for developing COPD. Researchers are quick to point out that this association between asthma and COPD does not prove a cause and effect. The most important preventive measure against COPD is to not smoke or stop smoking, particularly if there is a history of allergies or asthma.