Passive smoking and risk of peripheral arterial disease and ischemic stroke in Chinese women who never smoked

Background-The association between secondhand smoke (SHS) and risk of peripheral arterial disease (PAD) and stroke remains uncertain. Methods and Results-We examined the relationship between SHS and cardiovascular diseases, particularly PAD and stroke, in Chinese women who never smoked from a population-based cross-sectional study in Beijing, China. SHS exposure was defined as exposure to another person's tobacco smoke at home or in the workplace. Cardiovascular disease events included coronary heart disease, stroke, and PAD. PAD was defined by signs of intermittent claudication as measured by the World Health Organization Rose questionnaire and an ankle-brachial index of <0.90. Among 1209 women who never smoked, 39.5% were exposed to SHS at home or in workplaces. Those individuals who were exposed to SHS had a significantly higher risk of coronary heart disease (adjusted odds ratio [OR], 1.69; 95% CI, 1.31 to 2.18) and ischemic stroke (OR, 1.56; 95% CI, 1.03 to 2.35) than those never exposed to SHS after adjustment for 13 potential risk factors. The adjusted ORs of PAD defined by intermittent claudication, by ankle-brachial index <0.90, and by either intermittent claudication or ankle-brachial index <0.90 were 1.87 (95% CI, 1.30 to 2.68), 1.47 (95% CI, 1.07 to 2.03), and 1.67 (95% CI, 1.23 to 2.16), respectively. Dose-response relationships were found between SHS exposure amount (cigarettes per day) and duration (minutes per day) and increasing prevalence of coronary heart disease, ischemic stroke, and PAD. Conclusions-In China, SHS exposure in women is highly prevalent. In addition to being a risk factor for coronary heart disease, SHS should be considered an important risk factor for ischemic stroke and PAD in nonsmoking women.