Secondhand smoke exposure ups atrial fibrillation risk in women

Women exposed to secondhand smoke (SHS) suffer from an elevated risk of atrial fibrillation (AF), a recent study has found.

Researchers conducted a population-based case-control study of 102 women never-smokers (aged 30–80 years) who had been diagnosed with AF. Questionnaire-based interviews were administered for the assessment of SHS exposure, along with the collection of sociodemographic variables. Another 109 population-based controls were also included.

Univariate logistic regression analysis found that those with AF were nearly four times more likely to have been exposed to SHS (odds ratio [OR], 3.81, 95 percent confidence interval [CI], 2.02–7.18). Taking exposure as a continuous variable yielded the same effect: exposure to each additional pack per day almost tripled the risk of AF relative to no exposure (OR, 2.89, 95 percent CI, 2.05–4.09).

The trend remained significant even after disaggregation according to different life stages. Exposure to SHS during childhood (OR, 3.39, 95 percent CI, 1.92–5.97), adolescence (OR, 4.07, 95 percent CI, 2.29–7.22) and adulthood (OR, 4.61, 95 percent CI, 2.58–8.25) all increased the risk of AF.

Multivariable adjustment did not meaningfully alter these findings. SHS exposure remained significantly associated with an increased risk of AF in the study participants (OR, 6.29, 95 percent CI, 2.76–14.33; p<0.001), even when it was taken as a continuous variable (packs per day: OR, 3.40, 95 percent CI, 2.24–5.18; p<0.000).

Notably, SHS exposure across two or more life periods was predictive of AF risk, as compared with no exposure. No such effect was reported when exposure was documented in only one life period.