ABSTRACT
Chronic obstructive pulmonary disease (COPD) is a very common disease around the world, especially in the aged and in the industrialized countries (1), afflicting as many as 600 million people (2). In 1996 COPD was the fifth leading cause of death, and current trends suggest that it will become the third leading cause of death (3) by the year 2020 (4). The primary trigger for COPD is cigarette smoking (5); other potential risk factors for developing COPD including childhood asthma, occupational exposure, and air pollution. The vast majority of patients with COPD are current or former smokers, and it is estimated that 80-90% of all COPD cases are caused by smoking. The likelihood of dying as a result of COPD is 10 times higher for a smoker than for a nonsmoker (6).
