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.