Other known risk factors

Infections (viral and bacterial): May contribute to the pathogenesis and progression of COPD, they may also play a significant role in exacerbations.¹

Genetics: As only 50% of long-term smokers will actually develop COPD, certain people must have a genetic predisposition to the disease. In support of this is the finding that COPD occurs more frequently amongst relatives of COPD patients who smoke than unrelated smokers.²

Asthma: Asthma may be a risk factor for the development of COPD, although the evidence is not conclusive.¹

Gender: Some studies have indicated that women are more susceptible to the effects of tobacco smoke than men.^3,4 This is of concern given the increasing rate of smoking among women. Women with severe COPD exhibit smaller airway lumens and disproportionately thicker airway walls relative to men with the same disease severity, illustrating the different impact of the disease on each sex.⁵

Socio-economic status: There is evidence that the risk of developing COPD is inversely related to socio-economic status.¹ However this pattern may reflect the elevated exposure to indoor and outdoor pollutants, crowding and poor nutrition that are associated with poverty.

References

1. Global Initiative for chronic obstructive lung disease: Global strategy for the diagnosis, management, and prevention of COPD. 2010. www.goldcopd.org
2. Silverman EK, Chapman HA, Drazen JM, et al. Genetic epidemiology of severe, early-onset COPD. Risk to relatives for airflow obstruction and chronic bronchitis. Am J Respir Crit Care Med 1998;157:1770-1778.
3. Anthonisen NR, Connett JE, Kiley JP, et al. Effects of smoking intervention and the use of an inhaled anticholinergic bronchodilator on the rate of decline of FEV₁. The Lung Health Study. JAMA 1994;272(19):1497-1505. 
4. Silverman EK, Weiss ST, Drazen JM, et al. Gender-related differences in severe, early-onset chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2000;162(6):2152-2158.
5. Martinez FJ, Curtis JL, Sciurba F, et al. National Emphysema Treatment Trial Research Group. Sex differences in severe pulmonary emphysema. Am J Respir Crit Care Med 2007;176(3):243-252.