Smoke-free policies in public places like bars and restaurants were linked to lower systolic blood pressures (SBPs) among participants from the longitudinal CARDIA study, according to new research published in the Journal of the American Heart Association.
These policies have previously been tied to reduced rates of hospitalization for heart disease, but this is the first study to evaluate the relationship between smoking bans and blood pressure changes, noted lead author Stephanie Mayne, PhD, a research scientist at Policy Lab and the Center for Pediatric Clinical Effectiveness at Children’s Hospital of Philadelphia, and colleagues.
“While no prior studies have examined associations of smoke‐free policies with changes to BP, our results are consistent in the context of prior findings for SHS (second-hand smoke) and CVD,” the authors wrote. “High BP significantly increases the risk of coronary heart disease and SHS exposure has been linked to hypertension, likely because of adverse effects of harmful components of SHS (nicotine, carbon monoxide, methane, formaldehyde, and others) on vasoconstriction or vasodilation, as well as vascular dysfunction.”
Mayne et al.’s study followed 2,606 nonsmoking adults enrolled from four U.S. cities from 1995 to 2011. Over that timeframe, the proportion of participants living in areas with smoke-free policies in restaurants (1.5 percent to 88 percent), bars (0.8 percent to 75 percent) and workplaces (7.3 percent to 73 percent) all increased dramatically.
Compared to individuals residing in areas without those policies, participants with those policies averaged SBPs 1.14 mm Hg to 1.52 mm Hg lower at the end of follow-up, after adjusting for covariates. Only smoke-free policies in restaurants were associated with a significant drop in diastolic blood pressure (-0.58 mm Hg).
“Smoke‐free policies were associated with small but significant between‐person differences and within‐person reductions in systolic blood pressure,” Mayne and coauthors wrote. “While the magnitude of associations was small on an individual level, systolic blood pressure reduction is a potential mechanism through which smoke‐free policies may reduce cardiovascular risk at the population level.”
Mayne et al. pointed to another study which estimated a population-wide intervention that achieved a 1 mm Hg reduction in SBP would equate to 10 fewer coronary heart disease events per 100,000 people each year.
“Thus, changes to SBP of the magnitude seen in our study have important implications for cardiovascular public health,” they wrote.
The CARDIA study enrolled black and white adults aged 18 to 30 in 1985-86 in Birmingham, Alabama, Chicago, Minneapolis and Oakland, California. This analysis evaluated blood pressure changes and smoke-free policies from years 10 to 25 of the study, meaning participants were between the ages of 43 and 55 at the end of follow-up.