Childhood tobacco smoke exposure ups risk of atrial fibrillation in adulthood

Exposure to secondhand smoke during childhood is associated with an increased risk for atrial fibrillation (AF) during adulthood, a recent study has shown. Moreover, this association may be mediated by a greater tendency among offspring of smoking parents to smoke themselves.

The authors analysed participants from the offspring cohort of the Framingham Heart Study with parents in the original cohort who were known to smoke during the offspring’s childhood. Participants were assessed every 2 to 8 years and were under routine surveillance for incident AF. Assessment of AF incidence among participants exposed to parental smoking was performed through age 18 years.

The authors also determined the extent to which offspring smoking might explain the observed associations by conducting a mediation analysis.

A total of 2,816 offspring participants with at least one parent in the Original cohort were included, of whom 82 percent were exposed to parental smoking.

An 18-percent increase was noted in offspring AF incidence (adjusted hazard ratio, 1.18, 95 percent CI, 1.00–1.39; p=0.04) for every pack/day increase in parental smoking. In addition, parental smoking was a predictor of offspring smoking (adjusted odds ratio, 1.34, 1.17–1.54; p<0.001). The association between parental smoking and offspring AF was partly mediated by offspring smoking (17 percent, 1.5–103.3 percent).

“These findings highlight potential new pathways for AF risk that begin during childhood, offering new evidence to motivate smoking avoidance and cessation,” the authors said.

“Cigarette smoking is known to increase the risk of AF, and a recent cross-sectional analysis suggested that parental smoking may be an AF risk factor,” they added.