Associations of Smoke‐Free Policies in Restaurants, Bars, and Workplaces With Blood Pressure Changes in the CARDIA Study

BACKGROUND: Smoke‐free legislation has been associated with reductions in secondhand smoke exposure and cardiovascular disease. However, it remains unknown whether smoke‐free policies are associated with reductions in blood pressure (BP). METHODS AND RESULTS: Longitudinal data from 2606 nonsmoking adult participants of the CARDIA (Coronary Artery Risk Development in Young Adults) Study (1995–2011) were linked to state, county, and local‐level 100% smoke‐free policies in bars, restaurants, and/or nonhospitality workplaces based on participants’ census tract of residence. Mixed‐effects models estimated associations of policies with BP and hypertension trajectories over 15 years of follow‐up. Fixed‐effects regression estimated associations of smoke‐free policies with within‐person changes in systolic and diastolic BP and hypertension. Models were adjusted for sociodemographic, health‐related, and policy/geographic covariates. Smoke‐free policies were associated with between‐person differences and within‐person changes in systolic BP. Participants living in areas with smoke‐free policies had lower systolic BP on average at the end of follow‐up compared with those in areas without policies (adjusted predicted mean differences [in mm Hg]: restaurant: −1.14 [95% confidence interval: −2.15, −0.12]; bar: −1.52 [−2.48, −0.57]; workplace: −1.41 [−2.32, −0.50]). Smoke‐free policies in restaurants and bars were associated with mean within‐person reductions in systolic BP of −0.85 (−1.61, −0.09) and −1.08 (−1.82, −0.34), respectively. Only restaurant policies were associated with a significant within‐person reduction in diastolic BP, of −0.58 (−1.15, −0.01). CONCLUSIONS: While the magnitude of associations was small at the individual level, results suggest a potential mechanism through which reductions in secondhand smoke because of smoke‐free policies may improve population‐level cardiovascular health.