Smoke-free policies linked to lower BP among non-smokers

A recent study as observed that smoke-free policies in public spaces are associated with lower blood pressure readings among non-smokers.

While smoke-free policies and laws that prohibit smoking in public places like bars and restaurants have been associated with reduced rates of hospitalisation for heart disease, previous studies have not examined changes in blood pressure.

"We found that nonsmoking adults in the study who lived in areas with smoke-free laws in restaurants, bars or workplaces had lower systolic blood pressure by the end of the follow-up period compared to those who lived in areas without smoke-free laws," said Stephanie Mayne, Ph.D., lead author of the study, which was published in the Journal of the American Heart Association/American Stroke Association.

 

Smoke-free laws were associated with reduced systolic blood pressure, but surprisingly not with reductions in diastolic blood pressure or high blood pressure. It's not entirely certain why this was the case, but it's possible that we are detecting effects on systolic blood pressure that are below the threshold for hypertension, Mayne added.

Higher systolic blood pressure increases the risk of cardiovascular disease even when they are below the hypertension threshold, so the reductions in systolic blood pressure seen in this study suggest a potentially meaningful effect on population-level risk, she said.

"Also, when we looked at differences in blood pressure over time within individuals, comparing years when they lived in an area with a smoke-free law to years when they didn't, systolic blood pressure was lower on average when they lived in an area with smoke-free laws, after accounting for overall trends in blood pressure and for how people's levels of risk factors like diet and physical activity changed over the study period," Mayne explained.

While the magnitude of associations was small at the individual level, researchers said the results point to a potential mechanism through which reductions in secondhand smoke, due to smoke-free policies, may improve population-level heart health.