ABSTRACT
A number of risk factors for chronic obstructive pulmonary disease (COPD) have been identified. The single most important cause of COPD is cigarette smoking, but other risk factors include the effect of diet, early childhood diseases and genetic factors. Individual susceptibility to developing COPD in relation to cigarette smoking varies. Fletcher C. and colleagues showed that although chronic bronchitis and progressive airway obstruction were both related to cigarette smoke, some conditions were distinct with regard to prognosis. Cannabis is often mixed with tobacco, and cannabis smokers often inhale more deeply than cigarette smokers. A dietary deficiency of antioxidants has also been postulated to increase the risk of COPD. Pre-existing bronchial hyper-responsiveness is another risk factor. Although there are many reports of a genetic association with COPD, few of these findings have been replicated in different populations. COPD is common among low socio-economic groups, due to high levels of smoking and poor nutrition.
