Association between level of exposure to secondhand smoke and peripheral arterial disease: cross-sectional study of 5,686 never smokers.

OBJECTIVE Active smoking is a recognised risk factor for peripheral arterial disease (PAD). Many studies have demonstrated an association between exposure to secondhand smoke (SHS) and both coronary heart disease and stroke. In contrast, there is a paucity of studies on PAD. The goal of this study was to examine the association between level of exposure to SHS and risk of PAD among adults who have never smoked. METHODS AND RESULTS We undertook a cross-sectional study of the association between self-reported level of SHS exposure and PAD (defined as an ankle brachial pressure index <0.9) using baseline data, from the Scottish Family Health Study, on adult (≥ 18 years), never smokers. Multivariate logistic regression analyses were used to adjust for potential confounders. Of the 5686 never smokers, 134 (2.4%) had PAD. Three percent of individuals with PAD reported being exposed to SHS for ≥ 40 h per week, compared with only 0.6% of those without PAD (χ(2) test, p = 0.010). After adjusting for potential confounders, exposure to ≥ 40 h per week was associated with significantly increased risk of PAD (adjusted OR 5.56, 95% CI 1.82-17.06, p = 0.003), with suggestion of a log-linear dose relationship among those exposed. CONCLUSIONS In common with coronary heart disease and stroke, SHS exposure is an independent risk factor for PAD. Our findings lend support to tobacco control efforts aiming at protecting the public from SHS exposure.