The association of active and passive smoking with peripheral arterial disease: results from NHANES 1999-2004.

We aim to quantify the association between different forms of tobacco use and peripheral arterial disease (PAD) and to characterize the association between secondhand smoke exposure and PAD in a large nationally representative sample of the US population. We observed significant associations between current and former cigarette smoking and PAD. The association between noncigarette forms of tobacco and PAD was not significant even after adjustment for clinical and demographic variables. Secondhand smoke was not significantly associated with PAD. Interestingly, a ;;threshold phenomenon'' for tobacco exposure was demonstrated for PAD occurrence. Individuals with serum cotinine >155 ng/ mL were at significantly higher risk of having PAD as compared with a nonexistent or a minimal risk below this threshold value. Lack of association between PAD and secondhand smoke exposure in conjunction with the threshold phenomenon described above leads us to speculate existence of striking differences between the systemic circulation and lower extremity vasculature in terms of pathogenesis of atherosclerosis.