Table 1– Summary of adverse effects of active cigarette smoking and asthma
Adverse effects of active smoking and asthmaDetails of adverse effects
Increased prevalence of asthmaHigher prevalence of asthma particularly among female smokers compared to female nonsmokers; the interaction between smoking and sex is particularly evident among heavier smokers compared to lighter smokers or nonsmokers [6–14]
Incident asthmaSmoking is highly predictive of the development of new onset asthma in allergic adults with a clear dose–response effect of smoking exposure [15]
Increased asthma morbidity and mortalityAsthmatic smokers are at risk of developing more severe symptoms, higher frequency of exacerbations, and worse asthma-specific quality of life [16–21]; cigarette smoking in asthma is also associated with increased numbers of life threatening asthma attacks and greater asthma mortality [22, 23]
Greater asthma severitySmoking status and smoking duration are strongly related in a dose-dependent fashion to the level of asthma severity [24]
The strongest association with disease severity was observed in those who smoked >20 pack-yrs
Uncontrolled asthmaA relationship between smoking and poor asthma control has been reported in population-based surveys [25–29] and in controlled studies [24, 25]
Smoking status and smoking duration are also related to poor asthma control in a dose-dependent fashion [24]
Accelerated decline in lung functionThe rate of decline in lung function is accelerated in smokers with asthma compared with nonsmokers with asthma [30–34], although there are also a few negative studies [36, 37]
Persistent airflow obstructionA proportion of smokers with asthma develop persistent airflow obstruction [31, 32]
Corticosteroid insensitivityAsthma patients who smoke appear to be less sensitive to the beneficial effects of corticosteroids with regard to respiratory symptoms and lung function, irrespective of the route of administration of treatment [37–43]